Cataract, its treatment and the role of Optometry in Nigeria 2

Optom
We discussed the crystalline lens extensively in a previous blog. It is important to discuss how cataract is developed in this avascular structure.
As I said earlier, Cataract is a clouding of the crystalline lens with a resultant reduction in subjective visual output! This clouding phenomenon undermines the transparent mechanism of the crystalline lens. Such factors ensure lens transparency and they include a) Avascularity of the lens materials, b) Tightly packed lens cell fibres, 3) The structural arrengements of lens cell proteins, 4) Semi-permeable nature of the lens cell capsule, 5) Active transport mechanism of the lens cell fibres, 5)Auto-oxidation and high concentration of reduced gluthatione in lens cells and, 6) coluration of the crystalline lens including other factors.
To fully understand pathogenesis of cataract formation, it becomes important to shed light on some factors that disrupts lens transparency.
For instance the primary reson the crystalline lens is avascular is to enable the structure transmit light without shadows or haloes that vascularity of structures often promote. Again, it is histologically documented that lens cell fibres are arrenged in a lattice three-dimensional way to reduce any interferance with light refraction though this medium. Also it should be noted that the tightly packed lens cell fibres especially as we approach the lens nucleus is apparently meant to reduce hydration of the lens cell fibres. Any disruption in this state of homeostasis triggers an apparent denaturing of lens protein, consequent upon which lens clouding ensues. What could disrupt this homeostasis relationship? Injury could. Aging is another factor. Let us not forget diseases like Diabetes, also the effect of radiation like the infra-red ray wich is absorbed in the crystalline lens (this is a protective function of the crystalline lens which in turn filters the kind of light reaching the very sensitive retina!) etc.
Metabolism of the lens fibre uses osmotic differentials to keep hydration in check, while using active transport to maintain sodium, potassium and calcium levels in the crystalline lens. Gluthatione, in its reduced form. Active transport mechanism helps allow selected materials into the crystalline lens and push out others into the surrounding areas while maintaining a threshood 'tension' that regulates dehydration of the lens fibre cells. Diseases, trauma, age and genetic disruptions have reportedly altered the metabolic activities of the crystalline lens hence the formation of cataract.
It should be noted that as the lens grow old it does not shed its old materials, it rather pushes them to the middle and associated wear and tear phenomenon of the lens makes the lens change from transparent to a graying shift. The later, including disruption in protein synthesis with age in some persons, is generally responsible for geriatric kind of cataract!
Commonly among the children is congenitial or genetic-induced cataract. Diseases among the parents prior to delivery could cause this. It could also be a result of food habit amongs the pregnant women. Exposure harmful rays in pregnant women or the use of drugs among these group has been implicated in the formation of congenital cataract!
There are about 17 million persons living with cataract all over the world and 75% are in Asia and Africa!
The most common type of cataract is geriatric cataract. Other types of cataract are not uncommon. In the youths and children the most common cause of cataract is genetic disruptions and trauma. Among a large swath of outdoor workers, radiation cataract is very common either through synthetic toxic materials or as a result of unhindered absorption of infra-red rich light common in hot regions.
Thanks... To be continued!

 A catactous eye as seen under biomicroscope view courtesy of Karl

(http://lasereyesurger-y.com/cataract-eye)   

Dr Okwudiri Ezebuiroh.

This blog does not draw any financial interest anywhere. Thanks.

Cataract, its treatment and the role of Optometry in Nigeria 1

Optom
Cataract is a condition of the crystalline lens which leads to its (crystaline len's) opacification. The crystalline lense is an avascular and transparent structure which consists of the lens capsule, the lens epithelium, the lens fibre- the nucleus and the peripheral cortex. The crystalline lens is situated behind the iris but lies anterior to the vitreous chamber and the retina.
The lens capsule is the thin, transparent hyaline membrane that surrounds the crystalline lens. It is rich in elastins and collagen. It also contains phospholipids in the form of glycosaminoglycans, a substance the provides connective tissue-like reinforcement to the lens capsule. The cilliary body attaches zonules projecting from the lens capsule known as suspensory ligaments.
 The lens epithelium is a basal membrane that is situated in the anterior portion of the lens. It is made up of single layer of cubiodal cells with active mitosis taking place throughout life. The older lens fibre produced are pushed to the middle where it forms the nucleus and the outer surface forms the peripheral cortex. The lens fibre, it should be noted, consists of the main mass of the lens material. The fibres are formed by the multiplication and differentiation of the lens epithelial cells. The posterior portion of the lens has no epithelium.
The crystalline lens is composed of chiefly of crystallins. Crystallins are transparent proteins that gives the crystallines its transparency including the parallel arrengement of lens cell materials. Crystallins commonly found in the human is alpha-, beta- & gamma-crystallins and it composes of about 90% of the total lens protein. The crystalline lens is bathed anteriorly by the more active aqueous humor, while the less active vitreous humor bathes posterior aspect of the crystalline lens. Any loss of transperency of the lens results to cataract.
Cataract causes functional blindness to the individual.
To be continued...

                                          Fig 1. An African Woman with OD mature cataract.
Dr Ezebuiroh Victor Okwudiri.

Allergic conjunctivities in Clinical Optometry!

Optom
Wow its been  long time folks and friends. Sorry for the long absense. Thanks goodness, the world is a little bit better with such persons like Ghaddaffi, Sadam Hussain, Osama bin Laden etc gone... It is also heart warming to know that the referendum for South Sudan became a reality! The Arab spring is still spewing out more loosers e.g. in Yemen but life still goes on.
Without dwelling much on frivolities lets get blogging...
As the name implies, Allergic conjunctivities is a group of allergic conditions of the conjunctiva that is triggered when mast cells laden with IgE comes in contact with an allergen (antigen) and an antibody/antigen complex reaction is formed. Mast cell contains unreleased histmine. When a mast cell laden with IgE cross-links an antigen after been primed  by Beta-chemokines (a type of cytokines that actively involves in chemotaxis!) they (the mast cells) release histamine and a host other active intermediaries. These intermediaries are prostalglandin-G, Serotonin, leukotrienes, platlet activating factor and cytokines that further lead to priminig of more mast cells to repeat the circle. The T cells too play a role in the activation and degranulation process of mast cells. T cells contributes the specific IgE for a given mast cell. The release of these substances results in ocular itching, conjunctval and lid edema, formation of mucus (the string-like type of mucus common in allergic conjunctivitis).
In situations where the allergen becomes perennial, the cytokines in the viscious circle of mast cell degranulations will also attract Basophils and recruit tissue damaging body immune substances like T cells, macrophages, neutrophils & eosinopils. These immune substances form a complex pathway to the resulting tissue damage and deeper allergic reactions like papillae formations on the conjunctiva,sinusitis, rhinitis, tinitus etc
Apart from an allergen or injury causing degranulation of mast cells, it has been reported that a particular amount of stress can activate the mast cells even in the absense of IgE , especially those in the cerebrum! The complex mechanism, it is said, leads to mast cell reactions even in the absense of an allergen! (Theoharis C.T., David E.C. [2003]). Hypothetically it could explain why some refractive or binocular difficulties in the eye can trigger ocular itching!
From the foregoing discussion, it can be understood that allergic conjunctivitis is an immuno- sensitization degenerative condition of the outer 1/6 of the eye. It is very difficult to manage and usually it is self-limiting after a period of time. Lets discuss some ways to manage this condition.
First this condition causes vasodilation of conjunctival blood vessels. Histamine is responsible for this dilation of conjuntival blood vessels. One method to arrest this sign is by using steroids as vasoconstrictors. It is used as a short-term remedy. In the long run, it is important to combine it with an anti-histamine like gutt: spercellerg and/or tablets like tab: chlorophetamine while tappering the steroids. Anti-histamines tend to influence the effect of the elaborated histamines from the degranulated mast cells. Other class of drugs that could play an active role in combating this allergy includes Sodium cromoglycates, lodoxamide, nedocromil are known as mast cell stabilizers. They function by inhibiting the calcium ions that triggers the elaboration of histamine onto the tissue. They are the most effective therapy for this allergic condition. Other non medical mesures includes using cold compresses, wearing shades when outdoors and proper ventillation.
The main objective of treatment is the removal of the allergen which could be dust, smoke,pollen grains from flower, chemicals, paints, lots of exogenous substances that might come in contact with the eye. It should be put in mind to remove any form of refractive stress or binocular stress that might accompany the eye. Please ensure you discuss ocular hygiene with your patient.
Different types of allergic conjunctivitis will be discussed subsequently and specific measures to contain them will be enumerated. Thanks
Dr Ezebuiroh Victor Okwudiri.

Vitamin A Deficiency & Childhood blindness

Optom
Vitamin A Deficiency in children is the lack of Vitamin A in their body to a point of creating functional changes & creating disease conditions in their human system.
Vitamin A deficiency, though it can affect adults, results in horrific ocular & immunologic consequences especially in children. It is both a precursor to measles & aggrevated by measles! It causes corneal blindness in children, especially those in developing countries like Africa & Asia.
Other ocular implications include Xerophthalmia (secondary to reduced presence & influence of meibomian gland & other secretory apparatus in the eyes), then chronic corneal ulceration followed by Keratomalasia & subsequent anterior Staphyloma. Night blindness, or Nyctalopia is usually the first implication of this condition. In Vitamin A deficiency, it involves the inability of the Rhodopsin to be ibe formed because Vitamin A which is the primary source of retinal (a Vitamin A precursor for Rhodopsin formation with the contributions of light sensitive opsin proteins! Nyctalopia can also be caused by a genetic condition known as Retinitis Pigmentosa, or could be attributed to genetic deficiency of the rods to function beyond threshhold but does not progress like the Retinitis Pigmentosa. This later condition is known as X-link congenital Stationary Night blindness.
  Vitamin A deficiency (VAD) in children and pregnant women causes a weakness of the human immune system and has hence become implicated in low body defence response to diseases like measles & also to other bacterial infections, not common in healthy individuals! VAD affects 1 in every 3 children as at 2008! It is reported that between 250,000-500,000 children become blind annually as a result of VAD and half of these children die within 1 year of becoming blind. With the combined help of World Health Organization, United States Agency for International Development, Canadian International Developmental Agency and Micronutrient initiative under the umbrella of Vitamin A Global Initiative has been able to avert about 1.25 million deaths in about 40 countries since 1998! The year 2010 was put forward as the year VAD should be eliminated in the general population, but we are yet to see the end of this child-killer disease!
 In Nigeria, Xerophthalmia was estimated to be 1.1 % prevalent in the children population and 7% have VAD (Ajayeoba A.I., 2001). Xerophthalmia describes the ocular manifestations of VAD. It is estimated, by projection, that about 1 million children are affected by VAD and about 100,000 could have an eye involvement (Xerophthalmia) and 50,000 may go blind while 25,000 children are estimated to die annually (Sommers, 1995). This condition is more prevalent in the northwest but least prevalent in the southeast! I think dietary differences play a role here and such findings should be varified by Optometric study nationally!
Treating VAD is done using Vitamin A supplementation therapy and managing the systemic effect like Diarrhea, Measles etc. If there is any ocular effect, it is most appropiate to manage the Xerophthalmia in its early stages when the cornea is not affected! It is best treated with Ocular lubricants, while such conditions like corneal ulceration is best managed with non steroidal anti inflamatory agents like Diclofenac Sodium, others includes topical antibiotic agents like Ciprofloxacin and chloramphenicol ointment! Look out for any corneal involvement in any reported case VAD! It could save that child's sight! It is very appropiate to educate pregnant women and lactating mothers on the need to avoid getting VAD. In these group of people, bilateral blindness could result! Treat them in conjunction with their Gynacologists/Obestricians. Their kind of blindness is retinal in nature!
VAD is a public health issue and Optometrists are adviced to contribute to eliminating this condition! Lets make the future of our children stress free because they are the leaders of tommorrow! Lets make vision 2020 a reality. I know we can. Happy December and Christmas in advance!

Ophthalmia Neonatorum and childhood blindness!

Optom
In our quest to fight against childhood blindness, I decided to start discussing some common causes of childhood blindness. Ophthalmia Neonatorum refers to any bilateral infection of the eyes of a child of less than one month old! Inshort, if your kid/ward of less than one week tears profusely, suspect ophthalmia neonatorum! Also suspect it when the child's eyeslids are swollen, shut and often smeared with mucous discharge especially produced by Neisseria Gonorrhoae as the infecting agent.
Other organisms too can cause Ophthalmia neonatorum. They include other bacterias like Staphylococcus aureus, streptococcus Pneumonia, Streptococcus haemolyticus; Serotypes D & K of Chlamydia Trachomatis; Chemicals used as prophylasis, Herpes Simplex virus etc But the Gonorraoeae type is the most complicating!
The eventual complication of Ophthalmia neonatorum is a form of corneal blindness that starts with corneal ulcer which then progresses to anterior staphyloma secondary to the opacification that the corneal ulcer precipitated.

This condition is often arrested by using a prophylasis like Silver Nitrate 1% in Crede's Method or the use of antibiotics like Erythromycin 0.5% or Tetracycline 1% drops one or two hours after birth of especially @ risk children. It should be noted that a pregnant woman an STD infection stands a very high chance of giving birth to a child with Ophthalmia neonatorum. Again, if there was injury to the child in the his or her eyes during delivery. The child could be infected in the womb or during delivery or after delivery! The most common infection comes during delivery. While Gonorrrhoeae type of the infection is reducing drastically globally, its a very common cause of Ophthalmia neonatorum in African children; while the Chlamydia type is the most common cause of this disease in children in developed economies! The onset of infection varies from infecting organisms from a matter of hours to days! But the end result, if not treated on time, is corneal blindness in these children. So beware.
While the best way to manage this disease is by either prevention, where the @risk mother is treated of any STDs and/or the child is treated prophylactically; some situations where the infection has become clinical requires a vigorous use of anti-biotics to manage after a microbial swab test has isolated the infecting organism (it should be noted that cemical induced Ophthalmia neonatorum is a self limiting condition, but do not relent to seek medical advice. It could save the eye of that child!).
An intensive use of broad spectrum antibiotic ophthalmic solution and ointment is very important. Check for any keratitis and manage it immediatly (The corneal involvement is usually very dangerous, blindness could occur in a matter of days!). Ocassionally systemic injections or tablets of broad spectrum antibiotics has proven to help in management of this condition!
In Vision 2020-right to sight, Ophthalmia neonatorum is a major issue in childhood blindness which has recieved an international attention. We ask Optometrists to be in the fore-front of tackling this menancing condition especially in Africa. We ask for a program that'll involve us educating mid-wives and gynacologists on the need for prophylasis in the new born child. We should also remind traditional mid-wives on the need for this eye-saving prophylasis! Vitamin A deficiency, Ophthalmia neonatorum and Measles in children are the main cause of corneal blindness and especially in developing countries like ours. This type of blindness in irreversible, but could be tackled after going through this article! We can give this children a sense of belonging by saving them from a live time of blindness and poverty! I will discuss Vitamin A deficiency as a cause of corneal blindness in my next article!
Great Optometry!
Great!
To be continued...
Dr Ezebuiroh Victor Okwudiri.

The month of May, Childhood blindness and the role of the Optometrist!

OptomWow! Its just like yesterday, the month of May, the month just gone by filled with intrigues, drama, war, stagnated 'peace processes', the Arab spring, increased Taliban insurgency, the killing of Osama bin Laden, the Memorial day in the United States of America and our own Children's Day (May 27th!); the pomp that accompanied that day all over the country, the joy on the faces of the children who matched, the pride of seeing our children march, salute and the stone-like expression on the faces of our executives who mounted the podium to observe the gallant leaders of tomorrow doing what they know best! In these children I saw our future. In these kids I saw the hope of continuity. They're the best stage of humanity. I thank God for these children. God bless Nigeria.But who is a child?UNICEF defined a child as anyone who is 16 years or less. These children are the most precious resource of families. They represent the family's future and their hopes. It should be noted that a blind child is a tragedy for his family and the society @ large. A child whose blindness could have been prevented or cured is even a great disaster.Childhood blindness is a collections of diseases or other factors like genetics and environmental influence that can definitively lead to blindness of the child. On its own, blindness is a visual acuity of  less than 3/60 on the better seeing eye.While we watched our children march on May 27th, Children's Day, it might interest you to know that there are estimated 500,000 new cases of childhood blindness per year and approximately 50% of these children die between 1-2 years of life! Definitely childhood blindness increases the mortality rates of children of under 5 years. This is worth giving serious attention because, 57% of all childhood blindness is unavoidable (i.e. cannot be cured!). 47% of childhood blindness could either be preventable (about 28%) through improved primary health care services, especially prenatal care for women. While the remaining 15% could be treated through improved Primary eye care services (the Primary eye care Optometrists etc) and specialized surgical eye care and low vision services.
Curiously, childhood blindness is reportedly the second largest cause of blind person years after cataract! It contributes approximately 70 million blind person years globally! This means that a child who is either born blind or someone who becomes blind @ childhood is expected to live 50 years approximately blind and hence contributing a very huge burden to the family, the society and to the individual too! I believe this calls for urgency in tackling childhood blindness by the Optometrists and other eye health professionals!
Economically, blindness in general has been documented to cost communities billionns of dollars in lost productivity, in caring for the blind person, in rehabilitation of the blind person & for special education. Childhood blindness is believed to gulp 1/3 of the total economic cost! For instance, in Africa & Asia that accommodates about 75 percent of blindness & approximately same percentage of blind children, 0.5 percent GDP is lost to blindness in general population with childhood blindness taking 0.16 percent of GDP approximately! This is very baffling & calls for serious looking into!
1.4 million children are said to be blind globally, Africa & Asia accommodates about 75 percent of these children! The prevalence of blindness in developed economies (childhood blindness is said to correlate with economic status of any given region!) is 0.3/1000 persons, while in under-developed economies is as high as 1.5/1000 persons! It should interest us to know that for every blind child, three children have serious vision impairments and 13 children needs glasses!
Finally, the following have been pencilled down as the most common causes of childhood blindness & will require more elaboration in subsequent blogs-
1) Corneal scarring secondary to measles & Vit A deficiencies
2) Ophthalmia neonatorum
3) Retinal diseases
4) Central nervous system lesions
5)Hereditory & Genetic diseases etc
I will be discussing each conditions in details subsequently! Thanks for your readership! Your comments will be highly appreciated! Sorry ones again for the delay in releasing this piece, I found myself in an unusual tarrain but thank goodness that I was able to meander through it!
To be continued...
Dr Victor Okwudiri Ezebuiroh.

Why do I have photophobia?

Optom
Photophobia is an involuntary reaction of the eyes when it comes in contact with light, either the natural sunlight or the artificial light from either our bulb or car light; and it is often accompanied with discomforts such as deep piercing ocular pains in the eyeball, associated eyebrow headaches, hyperemia of the conjunctiva, mild to severe blespherospasm etc or sometimes it might present with much milder like slight sandy sensation, but nonetheless ones visual acuity (the extent one sees in open space) is often compromised as a result.
Photophobia could be as a result of active pathology of the eye, it could be as a result of Physiological state of the pupils and the iris pigment or it could affect the individual as a result of error of refraction.
In any active inflammation of the eyes, the iris, which is the most vascularised part of the anterior eye, often responds to postalglandins and other immuno-inflammatory substances present in these area of the eyes. The resultant effect is a breakdown of the blood barrier provided by the iris epithelium with a consequent movement of fluid into the iris spaces and the fluid-logged iris responds to light very sluggishly, rubbing each other in the process, and with am effort too. The pain receptor of the eyes are activated in this situation. Hence, the photophobia experienced in that condition.
When the pupil of the eyes is very large, the extent of contraction under a very bright illumination and/or in an unfavorable glare situation, the pupils often fail to contract enough to allow 'optimum' illumination get into the retina. The individual involuntarily keeps his/her face frowned to cut off the 'excess' light entering the eye and the result is ocular discomfort, pseudo-spasm of the eyebrow and consequently a physiological photophobia ensues. Again, iris with little or no pigment, as seen in light-skinned or Albinos, often exhibits photophobia secondary to light scatter into the eyes. The iris pigments absorbs light from outside the eyes and inside hence reducing total internal reflection of light in the eyes. In absence of these pigments or when these pigments are minimal, total internal reflections, light scatter, enhanced glare sensation results in photophobia.
Photophobia can manifest when an individual is either myopic, hyperopic, astigmatic or anisometropic.  Apart from Myopia, the other cases are a consequence of an impaired relationship between accommodation-convergence mechanism of the eyes. The Myopes often have larger than normal pupils and this is an important reason why individuals with myopia exhibit photophobia! It should be remembered that myopes don't accommodate and the induced Amplitude of accommodation they acquire, seldom induces photophobia....
Pupillary sizes change with different levels accommodative changes. Somehow the involuntary 'spasm' that accompanies illumination and the associated change in the accommodative amplitude triggers a form of 'pain' especially if the induced accommodation is beyond the accommodative reserve of the subject, which is always the case in hyperopia, Astigmatism and Anisometropia.
Photophobia as a result of pathology can be relieved when the source of such pathology, e.g. when a patient with anterior uveitis and an associated photophobia has his/her uveitis treated with medications. Physiological Photophobia can only be managed with wearing dark sunshades, especially when outdoors or when exposed to bright light. While the later can be managed by restoring emmetropia with optical lenses that could either be tinted or that could possess be photochromic properties.
Finally, I will advice you with a symptom of photophobia to go and receive an Optometric eye care. This essential step can help you cope and manage with photophobia and the general use of dark sunshades is highly recommended! Don't let any form of photophobia disturb your visual comfort...its your right to enjoy comfortable vision... The Optometrist is your friend. Take care.
Dr Victor Ezebuiroh Okwudiri.

Routine Eye examination, Vision screening and saving the eye sight!

Optom
Most eye conditions are not emergency conditions and are often neglected, often times this becomes our worst undoing!
When Mr X walked into my eye clinic just to do a routine eye examination (he has never been to an eye clinic before and he has no observable symptom) unknown to him, he was going about with 0.6 excavated Optic nerve head bilaterally with his centralvision intact!
In another instance, as I was doing vision screening exercise for a group of volunteers, I saw one Mrs Y who has bilateral degeneration encroaching her macular and on further questioning it became known that she was a chronic diabetic patient (she has been diabetic for almost 12 years!).
A young fellow, A who's just 19 years and wants to be a pilot or a marine engineer did not know that the measles he had when he was 7 years has formed macular scar and drusen in both his eyes. The unfortunate thing is that he wont be able to achieve his dreams since he the condition is a progressive condition.
These are a few persons who do not have any unusual symptom related to vision handicap or any form of visual challenge prior to the eye test. In fact our meeting was out chance and not necessity! They might have been missed in the general population and the ensuring consequence relegated to superstition.
It is a national concern, or should be, that could help save people from unnecessary embarrassment if inculcated into our sub-consciousness- to have time @least ones in a year to visit an eye clinic! It is also welcoming if people would volunteer for eye tests whenever a vision screening program comes to your area, it does not matter if you have an eye problem or not! You could just save your sight by that singular act!
Your eyes are one of the most important organ in the human body. It cannot be replaced ones anything destroys it or makes it become blind! It becomes imperative to pay serious attention to it...We ask you to visit any Optometric or Ophthalmologist clinic in your area for a routine eye examination. Cos a stitch in time always saves nine!
Your eye no get duplicate! Protect it with a passion! You will be doing yourself, your family and the society great service by not becoming blind.

Blindness no dey show for face...it starts with your eyes and ends up affecting the whole society around you. Someone must stop school or work to look after you, your contributions to making the society a better place will be lost and instead you become a burden to yourself and to everyone! We have a role to play here. Do it wisely! Have a lovely week...
Dr Ezebuiroh Victor Okwudiri.

Routine Eye examination, Vision screening and saving the eye sight! Part 2

Optom
Most eye conditions are not emergency conditions and are often neglected, often times this becomes our worst undoing!Unlike conditions like hypertension, diabetes, Cardiovascular diseases, Accidents etc which often require an urgent need for medical attention; eye conditions that could lead to blindness don't often present with dramatically serious symptoms and hence it is not given much attention in relation to other health cases. But unfortunately, conditions that can cause blindness, eye diseases that are chronic and that has ability to reduce the patient to  visually challenged or visual handicap statue are capable of evading early dictation! Take for instance open angle Glaucoma or senile cataract! Do not forget too that conditions like Retinitis Pigmentosa etc are painless but sight threatening!
Routine eye examination involves  voluntary eye tests to ensure that there is no deviation in ocular anatomy and doing functional tests for the eyes to rule out any deviation in ocular physiology. Such tests like Visual Acuity, penlight examination of the pupils etc qualifies for functonal tests! In Routine eye examination, patient is not necessarily symptomatic. individuals are often enlightened and/or motivated to take care of his/her eyes! In routine examination, the following procedure of test batteries are performed! Patient is first required to complete a personal demographic data followed by question and answer session with the eye care specialist. In this process a case history file on the patient is developed and likely chief complaint (if there is any) is identified. The next step involves taking visual acuity @far and @ near followed by doing external examination either with a penlight, ophthalmoscope or with a slit lamp biomicroscope. The eyelid, the conjunctiva, the iris, the conjunctiva and pupillary reaction to light etc are checked and any loss of anatomic and/or physiologic integrity is noted. It is followed by doing an objective refraction either with a retinoscope or auto-refractors. There is need to do a subjective refraction, with or without significant change in visual acuity! The next step involves using the ophthalmoscope to view the posterior fundus of the eye. The aqueous humor, Optic nerve head, the retinal walls and vessels, the vitreous gel, the maculae area and the fovea centralis should be viewed and changes documented. I advocate for dilated fundus examination of atleast one eye except in situation where it could be contra-indicative, say, in closed angle glaucoma or patients with very narrow angle! In most cases, the batteries of tests could reveal subtle changes in the eyes that could be sight threatening! If needs be, I will also encourage further tests for differential diagnosis and confirmation of a particular pathology or defect! Such tests like Tangent screen tests, central visual field tests, intra ocular pressure checks, color vision tests, flouresin tests etc could come in handy to rule out disease conditions!
 On the other hand, Vision screening involves gross routine tests to rule out any visual anomaly. It is less complex than routine eye test and even much simpler than a thorough eye examination as performed in a clinic! You can screen for glaucoma in the adult population; you can screen for refractive error among school children; you can screen for hypertensive and/or diabetic retinopathy in patients having this chronic diseases! You can screen for cataract in the adult populations etc! It involves tests like visual acuity tests far and near. Confrontational tests. Shadow tests. Broad H tests etc It is usually carried out in public places but it is not unusual to have it in a clinic! Vision screening is very handy when parents are registering their children in school! it is very important when security men are conscripted or when a company is trying to employ new workers! Though some subtle changes in the eye might be missed, it is nontheless very necessary to identify sight threatening conditions in a group of people! In situation whereby the eyes are suspicious referal to appropiate eye care experts becomes important! A thorough eye examination would be carried out by the expert!
In Optometry practice both here in Nigeria and the world @ large, we are involved continously with patients and the public to nip eye disease condition in the bud! Being primary eye care providers, our practice requires us to encourage the general population to participate fully to screen, examine and/or thoroughly do eye tests to identify and manage eye conditions that might not necessarily be symptomatic but could be sight threatenig! I am encouraging colleagues and other eye care specialists to develop vision screening models, routine eye examination models and other specific examinations to alleviate the consequences of blindness! It is our ethical and moral responsibilities to ensure that blindness is avoided! Thank you.
Dr Ezebuiroh Victor Okwudiri.

optometry.naija: The Challenges militating against Optometry practi...

optometry.naija: The Challenges militating against Optometry practi...: "OptomNigerian Optometric practice is essential to effective eye care in Nigeria and no doubt about that...The challenges of eye care in Nige..."

Optom

The Challenges militating against Optometry practice in Nigeria and effective participation in Vision2020 :Right to Sight. (An Updated version of the origina blog!)

Optom
Nigerian Optometric practice is essential to effective eye care in Nigeria and no doubt about that...
The challenges of eye care in Nigeria with a population of about 150 million with just about 2130 registered Optometrists and I think with a fewer Ophthalmologists who draw strength from their parent body, The Nigerian Medical and Dental Association etc etc, are very enormous. The politico-academic position of the Optometrists is neither helping the matter nor is it alleviating the burden of blindness and visual handicap as envisioned by Vision 2020: Right to Sight!
As I have been saying all along, we need to position our practice, professionalize a Nigerian version of Optometry by empowering members to do researches and hence develop a statistical effect of blindness, causes of such blinding conditions, develop a model of practice, browbeat our professional heads (ODOBN & NOA) into growing some teeth, ensuring our state chapters of Nigerian Optometric Association is fully represented in state ministries of Health... I will advice that another professional body, primarily for Professional Optometrists, be formed. This body should oversee professional Practice among Optometrists in Practice, we can call it Nigerian Optometrist Society (N.O.S.). Unlike ODOBN & NOA, this professional body would require a written exam to become a member! The examination should discuss the scope of practice and developments in visual health and general eye care. Also the body should be conducting an online examination annually for professional Optometrists.
We need to develop our school curriculum to embrace contemporary realities... We are not opticians, need is rife to prove that we are Optometrists, that we are truly Primary eye care Practitioners. There is need to equip our Schools with newer technological advanced instruments and employ fully motivated professionals relating to the general scope of our practice. We should advocate for residency programs and ensure that fellowship courses are institutionalized. N.O.S. school chapters should be involved in eye researches for students and intern Optometrists and it should be funded by the school and the body @ the national level. There is also a serious need to enforce a gold standard both in education and practice of Optometry in Nigeria. We need to specialize and hence become consultants in a particular aspect of eye care, if we aim @ becoming heads of Departments. The later is a prerequisite to forming a Department of Optometry in Health care setting!
We need a stronger representation in Ministry of Health than mere having an office there alone. Optometry can generate more money than most Professional bodies under Federal Ministry of Health in Nigeria if properly packaged. All Optical services and resources should be supervised by Optometrists and dispensing Optician Board of Nigeria (O.D.O.B.N) and a fee should be charged for such services and payable to the coffers of the Ministry of Health! Including the funds generated from renewal of registrations, fees generated by N.O.S/ N.O.S.A (Nigerian Optometrists Society/ Nigerian Optometrist Students Association, if started!), fees generated by dispensing of lenses and other eye care services rendered by Optometrists in both federal and state owned hospitals (If more Optometrists are employed in Public health sector. Currently, they under-employed and under utilized in that sector!), funds generated from manufacturing of lenses both @ home and supervision of those imported into the country.
Finally, we should become fully independent of Ophthalmologists, especially in the area of competence development, professional growth and in practice...we should rather develop a complementary relationship in eye health care services with them. We need the Ministry of Health to wade into this chronic 'warfare' that has left eye care in the mercy of charlatans. The imbroglio between these two bodies is the most important factor that has reduced whatever the dreams of Vision 2020 both @ home and internationally...especially here in Nigeria. We are oppressed by them through that rebellious Decree 34 of 1989 which is very anti-Optometrist and should be totally over hauled and new clauses incorporated into it. Our academic chasm is so obvious that the Nigerian Optometrist is often academically intimidated into whatever name or role they wish us to play (they are the architectural design of O.D.O.B.N, like virus they replicate WHO we should be in practice & the last time I might remember, they don't bloody care about us, "@least the Ophthalmic nurse is there!". To achieve what 'Vision 2020 :Right to Sight' stands for, the current trend of Optometry practice should be updated by us, the constitution reviewed to change outdated clauses, develop a 'Nigerian Optometrist Society' to reposition Optometry professionally through research while ODOBN should supervise Optometry practice including resources and personel. NOA should be responsible both to the dispensing Opticians, Optometrists, Optometric technicians and other members in the eye health sector.
 I am not making any political nor sentimental contribution to the obvious discuss; am only stating the fact!
Take for instance the way unlicensed and even some licensed opticians invade people in their homes to make glasses for them, while @ the same time claiming to be healers of sight problems! They end up forcing many optometrists into the foray! What results? A desperate attempt to foist glasses and drugs on people without ethically considering our actions! We need to live up to our doctors status, most are self employed and cannot meet up financially with our peers employed by the state or federal government! There is no regulatory over sight mechanism in place by neither ODORBN nor NOA! They are two toothless bulldogs that cannot even bark...@ least not now; not yet! If am being biased in my opinion, why did Optometry in Nigeria not include its own clause in the recently passed National Health Bill? Why are state branches of NOA/ODORBN not fully assimilated into state ministry of healths just like NMA, Pharmasists, Lab scientists etc?
 Look @ this other scenario, an Ophthalmologist who seems to question our credibility in the field! Its always a thing of pride for them to undermine our efforts making it very easy for ophthalmic nurses and even cleaners in eye centres to atimes question our profession! I do not always blame them. Lets call a spade a spade, how many functional slit lamp biomicroscope do we have in Abia State university, school of Optometry now? Because as at 2006 there was no fully functional one in our clinic! How is Optometry learned in Madonna University? Is the school fully accredited to practice Optometry? Has the board visited the institution's school of Optometry for inspection? Credibility of some of our lecturers should be noted here too! In some instance, we often witness some of our lecturers who are not practicing! Optometry is a practical application of theoretical knowledge, I find it very improper for a lecturer not to have a practical knowedge of Optometry and still be allowed to lecture us! And many other sharp practices in our citadels of learning that go unhindered because no serious oversight by our regulatory bodies and absolute lack of "standards"!
It is a fact that a deep chasm exits between us and the Ophthalmologists, but the prejudice against the Optometrists by the Nigerian Medical Association and other allied health assoiations is frustrating!Yet it should not deter us from contributing our quota towards eliminating avoidable causes of blindness by 2020 and beyond.
We should remember that we just have about 9 years to get to year 2020...its rather absurd that we cannot claim any meaningful headway in halting the embarrassment blindness and visual handicap is wreaking on us! We have been busy boxing shadows...Posterity needs more than these from US! Great Optometry in Nigeria!
concluded!

optometry.naija: Vision 2020 & the Practise of Optometry in Nigeria...

optometry.naija: Vision 2020 & the Practise of Optometry in Nigeria...: "Optom Prevention of Blindness group in partnership with World Health Organization (WHO) under the umbrella of vision 2020 came up with- Cat..."

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Vision 2020 & the Practise of Optometry in Nigeria- episode 8

Optom
Prevention of Blindness group in partnership with World Health Organization (WHO) under the umbrella of vision 2020 came up with- Cataract, Trachoma, Onchoceriacis, Childhood blindness, Refractive error/Low Vision, Glaucoma & Diabetes induced blindness- as the most common causes of avoidable causes of blindness that contributes about 80 percent of blindness. It could be avoided or managed effectively when identified early.
Cataract is any opacification of the crystalline lens with a consequent reduction of vision to the point of functional blindness in the affected eye(s). it could be monocular or bilateral depending on the triggering factor(s). such factors as senescense, metabolic, disease, trauma etc can induce cataract formation.
The best treatment of Cataract is surgical extraction of the opacification when the cataract has matured! Though newer technological development has led to earlier (Intumescent stage) removal of the opacification of the crystalline lens. Baring that, Optometrists do manage it @ the intumescent stage, after identifying it with an ophthalmoscope. We use glasses & medications @ this stage, while we ensure that such pre-surgical complications like secondary Glaucoma, itching, tearing, photophobia, pains etc are reduced or even avoided pending cataract surgery.
We refer patients for surgery when the patient's vision is so compromised that either medication or other aids cannot help their vision. Post surgically, the Optometrist ensures that anisometropia is removed, fusion & stereopsis is restored, eye heals properly etc with medications & possibly lenses!
Trachoma & Onchicerciasis ectactically compromises the integrity of the cornea & could ultimately results corneal blindness. Hygiene, therapy & patient education has ultimately proven to effectively check the menace of these oculo-systemic infections. Opthalmologists in conjuntion with Ophthalmic nurses & assistance have used the above method to reduce the incidence & prevalence of these diseases in the Northern & Southern part of Nigeria where Trachoma & Onchocerciasis respectively reigns supreme. But the measure is not complete, especially with the marginal involvement of Optometrists. We could manage corneal complications of these diseases using slit lamps, diagnostic drugs, therapeutic drugs & refering advanced cases for surgery (especially in Trachoma). Post surgically we ensure the lashes maintain aponeurosis & we remove corneal complications as much as medications can.
On Glaucoma and Diabetes induced blindness, the patients are left with retinal blindness in a gradual but steadily chronic fashion. Optometrists are experts in identification of glaucoma, especially during vision screening or routine eye testing. We use medications & glasses to manage Glaucoma; we also encourage patients to go for surgery , when possible. People with Glaucoma frequently show changes in refractive status, just like in ocular manifestations of diabetes.
Ocular manifestation of Diabetes could be in form of glycemic fluctuations of vision in the crystalline lens, cataract, glaucoma (neovascular type, especially), retinopathies & macular degenerations. Maintaining of 'optimum' blood sugar in diabetics can delay these ocular implications & it has proved to have reduced the more serious sequelaes of ocular manifestations of diabetes, especially when accompanied by frequent visit (say ones in a year!) to an eye clinic. Optometrists often use vision check, medications, patient educations & glasses in some cases to help patients with ocular manifestation of diabetes. In cases that require surgery, we prepare the patients & refer them to the specialist Ophthalmologist for surgery. We subsequently co-manage these patients with a resultant 'optimum' vision.
Childhood blindness could be as a result of congenital factors or aquired factors. It manifests in corneal blindness, as in Vit A deficiencies, trauma etc, retinal blindness, as in retinoblastomas, congenital glaucoma etc It could also manifest in crystalline lens opacifications, as in viral infections like measles or pox diseases (this could also affect the cornea). Generally paediatric Optometrists works in partnership with paediatric Ophthalmologists to co-manage these conditions in children. We often use medication pre-surgically & medications and glasses post surgically to induce 'optimization' of the young child's vision!
Finally, Refractive error & low vision which could be primary or a secondary consequence of the other common causes of blindness are expertly managed by the optometrists by removing anisometropia & any form of refractive blur with the use of lenses. apart from blur removal, lenses are also used to restorefusion, stereopsis & other forms of binocularity. We use a retinoscope for this purpose. But most patients blinded by refractive error & low vision cannot access the largely private practise Optometrists, primarily as a result of cost.
It is therefore imperative to build an effective channel to reach an Optometrist in the public sector. Currently, we are very few in public health sector & this should be addressed if Nigeria wants to achieve any meaningful goals of Vision 2020: Right to sight.
Long live Nigeria
Viva Nigerian Optometrist... To be continued...
Dr Ezebuiroh Victor Okwudiri.

optometry.naija: Vision 2020 and the role of Optometry Practise in ...

optometry.naija: Vision 2020 and the role of Optometry Practise in ...: "Optom Vision 2020 : Right to sight is all about strategy, about means to an end in itself, though not necessarily an end. Optometry is stra..."

Optom

Vision 2020 and the role of Optometry Practise in Nigeria- episode 7

Optom
Vision 2020 : Right to sight is all about strategy, about means to an end in itself, though not necessarily an end. Optometry is strategically straddled with a huge responsibility aimed @ blindness prevention and promotion  healthy eye sight. Contrary to that believe that our position in the area of Vision 2020 is @ best a fluke, evidence abounds today that the success of Vision 2020 especially in Africa is a function of how effective Optometrists are and their relationship with the Ophthalmologists. In the hierarchy of Vision 2020 development plan the Optometrists, as the Primary eye care practitioner, are positioned in the upper pyramid of blindness prevention cadre. It is obvious to note that the Optometrist, contrary to popular believe, is pivotal in expunging most embarrassing causes of preventable blindness.
Vision 2020 : Right to sight is based on the following objectives:
1) Creating awareness as a viable option for disease prevention and control. (The Optometrist as a Primary Eye care Physician is expected to play a major role in disease control; having in mind the cliche: "Prevention is better than cure", "A stitch in time saves nine", "Early detection of eye anomalies is sine qua non to effective blindness prevention" etc)
2) Capital to facilitate and sustain blindness prevention activities. (Optometrists are largely in private practise in Nigeria. Capital to sustain blindness prevention activities in private eye care practise shouldered by the patients if it should be sustained and this pinches most the vulnerable patients a lot! Unlike in government run health centres where patient's cost of sustaining prevention of blindness activities is highly subsidized by the government. More Optometrists are expected to absorbed by the ministries of healths [Both @ federal and state levels] to compliment the efforts of the Ophthalmologists, who are largely in public practise! It should be noted that Ophthalmic nurses and GPs are not more versed in Eye care than the Optometrist! Again, the government could encourage the rapid development of Private practise in eye care by providing credits and sustainable environment that can develop a sustained prevention of blindness activities.)
3) How to ensure effective planning, development and implementation of Vision 2020 core stategy. These includes-
a) Disease control: It should be noted that Diabetes Mellitus, Onchocerciasis, Chicken Pox, Small pox, HIV, Hypertension, Trachoma, Tuberculosis etc could lead to sight threatening eye conditions. As Primary eye care Practitioner, we are expected to know about these diseases, how they can cause blindness; we need to develop plans aimed @ preventing these diseases, a need to identify the ocular manifestations of these diseases on time and adopting a management approach...
b) Human resource development : I discussed how Optometrists are building on their human resources from the schools of Optometry (3 of those schools are in Nigeria!), doing continuous education aimed @ practise development by Optometrists etc More needs to be done though, like developing residency in Optometry etc.
c) Developing infrastructure and latest technologies: Eye care requires lots of equipment to increase effectiveness. Most of these equipments are concentrated in private practise...consequently, most patients can not access them because of high cost. Unfortunately still, most government hospital Optometrist's section does not have one single modern equipment to facilitate effectiveness in eye care! This seriously needs to be addressed @ length!
To be continued...

Dr Victor Ezebuiroh Okwudiri.

optometry.naija: Vision 2020 and the role of Optometry Practise in ...

optometry.naija: Vision 2020 and the role of Optometry Practise in ...: "Optom Continuing in our bid to throw light on how far, in terms of professionalization of Optometry practise world over; I will like to ex..."

Optom

Vision 2020 and the role of Optometry Practise in Nigeria- episode 6

Optom
 Continuing in our bid to throw light on how far, in terms of professionalization of Optometry practise world over; I will like to explore on the narrative from the academic demands as required by the constitution and regulated by the Optometrists and Dispensing Opticians Board of Nigeria, a body with 2130 registered members as @ date!
There are three universities that educate Optometrists in Nigeria. University of Benin (UNIBEN), Abia state University Uturu (ABSU) and Imo state University Owerri (IMSU).
Historically, University of Benin was the first school that started training Optometrists B.Sc. It is a four year course equivalent to an Optician in the U.S.A. This form of Optometry is more of a dispensing Opticianry and is not trained to identify and manage ocular infections. It is a UK practise system. Optometry started there in January 1974 (Prof Ogbuehi, 1988) or earlier in 1972 (Dr Enechi Gilbert, 2010). It was nurtured under the tutelage of Professor Robert J. Fletcher of the City University, London; and Professor R.W.H. Wright, the then Dean of the faculty of Science University of Benin. In 1993, University of Benin adopted OD program. Prior to the adoption of OD title, the B.Sc Optometry dont go for internship and they were required to bridge to OD, but not many succeeded. In January 2009 it commenced its post graduate program in Optometry, M.Sc in Vision Science and M. Sc in Ocular Health Optometry. They also do PhD in the two areas.
Abia State University Uturu commenced Optometry in 1981 and were the first Nigerian University to produce OD optometrists in 1987.Professor Ogbuehi, Professor Ikonne etc were said to have contributed immensely here.
When Abia State was carved out from the then Imo State, the University known as Imo state University Okigwe became Abia state University Uturu. It was in 1991. It commenced Optometric education in 1993, and like its counterpart in Abia state University it issues OD certificate. Today, the Optometric regulatory body in Nigeria requires and OD which is a six-year program instead of the four-year B.Sc Optometry. The former also involves internship, while the later does not. To remain relevant to the modern trend of Optometric practise, the adoption of the OD can be said to be a welcoming issue and it portrays the evolutionary and revolutionary posturing of this noble profession in Nigeria.
The good news is that plans are on the way to further entrench this profession in the health community of the Nigerian state. Very soon residency in Optometry would soon be adopted, its on the planning stages. But in our watch, continuous education programs have become an entrenched policy in clinical Optometry while colleagues go abroad to acquire fellowship in a sub specialty. In the field of visual science and eye health, Optometry in Nigeria can be said to have bridged the gap despite the gaping challenges occasioned by this great profession. Lets have it in mind that we have a strong role in the area of instituting  'Primary eye Health care' in our health care and this is the secret of our relevance in the prevention of blindness and developing of our 'Vision 2020 : Right to Sight' strategy...
We shall discuss the journey so far tomorrow...
Dr Victor Ezebuiroh Okwudiri.

optometry.naija: Vision 2020 and the role of Optometry Practise in ...

optometry.naija: Vision 2020 and the role of Optometry Practise in ...: "Optom Am sorry esteemed readers for the delay...something came up that changed my activities. Lets go into the day's doing the talk. Talki..."

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Vision 2020 and the role of Optometry Practise in Nigeria- episode 5

Optom
Am sorry esteemed readers for the delay...something came up that changed my activities. Lets go into the day's doing the talk.
Talking of Decree No 34 of 1989 that professionalized Nigerian Optometrists i will like to run a historical view of what led to all these.
We can gain insight of the larger picture in that decree looking into the origin of Optometric science. What is the origin of Optometric science?
a) From Optics, this can be dated back to some thousand years BC. In BC 434, Aristophanes, an ancient Greek author was said to have wrote something on burning glasses probably used for its decorative purposes. Another Greek Scientist, a mathematician named Euclid in above BC 280 wrote about path of light travel, the angle of incidence, angle of reflection and he introduced the concept of the visual cone equivalent to the concept of visual angle. Claudius Ptolemy measured the angle of incidence, angle of reflection but failed to discover the exact mathematical formula. Johannes Kepler (1571-1630) wrote books to describe the mathematics of lenses, prisms and mirrors. Sir Isaac Newton discovered dispersion of white light into component colors as observed in say, rainbow. Snell discovered the law of Refraction in 1621.
In 1872, Monoyer invented the term Diopter.
b) From knowledge of Image formation by the Eye. Back in c.450 BC, Empedocles proposed the extromission theory and visual ray. Leucippus, Democritus, postulated the theory of intromission, eidola. (This theory was proved by Alhazen [965c-1041 AD]). Aristotle, around the 4th century BC used mediumistic theory of image formation in the eye. With the knowledge of how images are formed in the eye came knowledge of enhancing powers of glasses,such led Opticians like Thomas Young measure Astigmatism, he was the first to measure Astigmatism in 1801, and with the aid of his dispensing Optician, Fuller, corrected with a spherocylinder (in 1827). McAllister, another refracting Optician, was the first to make and prescribe a planoconcave (minus cylinders) for Rev. Goodrich in 1828.
c) Sensory Physiology, this area of visual sciences involves interpretation of the sensory visual pathways and how binocularity, stereopsis and fusion in the intact eye. In ancient Greece visual illusion were discussed and given various supernatural versus scientific interpretations. Later, in 1611, Christopher Scheiner described the size of the images reflected from the cornea. He also described  the double aperture principle In 1613, a mathematician known as Aguillon, was the first to publish the first significant analysis of binocular vision. The first optometer, to measure vision, was invented by William Porterfield in mid 1700. It was also used to discover a relationship between accommodation and convergence. Thomas Young propounded trichomatic theory of color vision and discovered that the crystalline lens induces accommodation in the intact eye. Johannes Purkinje, a Czech physiologist, published books on sensory physiology between 1823 and 1826. Such phenomena like Purkinje images, Purkinje tree etc could attest to his works.
In 1838, Charles Wheatstone invented mirror stereoscope and used it to experiment on binocular vision and stereopsis. Between 1821-1894, Hermann von Helmholtz, a Physiologist and Physicist wrote a book on Physiological Optics and better known as the father of Physiological Optics.
One can now understand how Optometry developed from optics and how it has thrived through the medieval  era by the contributions from other sciences.
With such deeper knowledge in the eyes, especially in the relationship with visual health in general, some Optometrists became interested in treating some ocular infections and with that came the use of medicines to ameliorate the ocular conditions. It is also a known fact that that Optometrists are more dispersed and closer to the grassroots, especially in the rural areas. As primary eye care practitioners and the long wait to see the Ophthalmologists, including the well established fact that Optometrists are more knowledgeable in conditions of the eyes than general practitioners (G.P.), it became imperative for our earlier colleagues to venture into treating ocular diseases. Another area could be traced back to the smearing campaign Ophthalmologists carry around about Optometrists claiming that the later is not knowledgeable enough to handle eye cases completely.
Optometrists were first allowed to diagnose pathologies in Rhode Island (DPA law of 1971) and the first place and time when Optometrists were first allowed to treat ocular diseases was West Virginia in 1976 (TPA law of 1976).
I think Optometry has come of age, yes, despite all odds. The normal postulations of the decree, which seriously needs review, enabled us to be practicing on category 3 and category 4 based on world model for Optometric practice. This categories allow us both diagnosing an ocular problem and using medication to treat or manage ocular diseases as well as doing what we know best, i.e.,  using glasses to treat ocular abnormalities... This dexterity led to awarding of doctor titles, even before 1900. In 1889, the Philadelphia Optical College were the first to award Doctor of Optics (O.D.) and was upgraded to Doctor of Optometry (O.D). Around 1968 to 1970, Optometry developed into a six-year old program and hence the title of doctor stuck. In Nigeria, O.D. program was first introduced in Abia State University, Uturu and in 1987 the first set of Doctor of Optometry was graduated, hence the pressing for professionalism in the practise of Optometry in Nigeria and it came true through that decree no 34 of 1989. It should not be forgotten, 2 other Universities study Optometry. They include University of Benin and Evans Ewerem University Imo state...
To be continued...
Dr Ezebuiroh Okwudiri Victor.

optometry.naija: Vision 2020 and Optometry practise in Nigeria- epi...

optometry.naija: Vision 2020 and Optometry practise in Nigeria- epi...: "Optom December 7th, 1989, Decree No 34 was passed, whose sole aim was to professionalise the practise of Optometry as body of health care p..."

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Vision 2020 and Optometry practise in Nigeria- episode 4

Optom
December 7th, 1989, Decree No 34 was passed, whose sole aim was to professionalise the practise of Optometry as body of health care professionals in Nigeria with the duty of being
the 'Primary eye care' professional in the field of visual health. The decree which was passed during the military regime of Ibrahim Badamosi Babangida and under the tutelage the then Minister of health, Late Olikoye Ransome-Kuti and Prince Bola Ajibola as the Attorney General/Minister of Justice. The decree outlined the 'limit of practise' of Optometry in Nigeria:
1) Eye examinations to determine the Refractive errors and other departures from the optimally healthy and visually efficient eye;
2) Correction of Refractive errors using spectacles, contact lenses, low vision aids and other devices.
3) Correction of errors of binocularity by means of vision training (Orthoptics);
4) Diagnosis and management of MINOR ocular infections, WHICH DO NOT POSE A THREAT TO THE INTEGRITY OF THE OCULAR OR VISUAL SYSTEM; and Ocular first aid.
The decree also stipulates the formation of a regulatory body to ensure professionalism in the practise of Optometry in Nigeria. Hence the formation of Optometrists and Dispensing Optician Board Of Nigeria (ODOBN) on 16th October 1992. The inaugurative speech was by the Late Prof Olikoye Ransome-Kuti, who cheered the efforts of Professional Optometrists then for ACTUALIZING the board. The journey of ACTUALIZATION of the board is akin to the stalemated peace process of the Israeli/Palestine axis. But, while this might have been anticipated, we are yet to do enough to evade its consequences supsequently!
Let me say it here, am yet to understand some of the variables and phrases used in part (4) of Decree No 34.  The adjective MINOR  and the phrase in that line should be thrown out of that sentence to read, "Diagnosis and management of ocular infections; and ocular first aid". This better fits in to the contemporary optometrist's practise protocol. Again, it cannot be effectively said that bacterial conjunctivitis caused by Staphylococcus Aureus or Staphycoccus Epidermis cannot invade the intact cornea and cause lots of visual complications, including blindness; even though many see it as a MINOR apollo! Surely that word leaves a sour test in the mouth. See you tomorrow.

Dr Ezebuiroh Okwudiri Ezebuiroh.

optometry.naija: Vision 2020 and the role of Optometry Practice in ...

optometry.naija: Vision 2020 and the role of Optometry Practice in ...: "Optom Optometry is a health care profession concerned with eyes and related structures, as well as vision, visual systems, and vision info..."

Optom

Vision 2020 and the role of Optometry Practice in Nigeria- episode 3

Optom
 Optometry is a health care profession concerned with eyes and related structures, as well as vision, visual systems, and vision information processing in humans. Optometrists are professionals who provide vision care ranging from sight testing and correction to the diagnosis, treatment, and management of vision changes. Optometrists qualify to diagnose and treat eye diseases such as Diabetic Retinopathy, Cataracts, Glaucoma, and Macular Degeneration. Like most professions, Optometry education, certification and practice is regulated by the government. (Wikipedia).
Optometry has come a long way. Let me take you down memory lane from the medieval period. The word "Optometry" is a combination of two Greek words, 'opsis' which means view ad 'metron'; which means measure or something to measure. We were first called optometrist by Edmund Landolt in 1886; which means 'glass fitter'. So any one then who constructs lenses on a spectacle or on a stand was known as an Optometrist.
About more than a thousand years ago, Sir Joseph Needham a historian, stated that ancient China invented the earliest eyeglasses. David A. Goss, O.D., Ph.D., argued that most likely Italy were already making glasses as @ 1305 AD. Benito Daza de Valdes published a book in Optometry in 1623 were he described use and fitting of eyeglasses. In 1692, William Molyneux wrote a book on optics and lenses, Myopia and other ocular problems. Johanes Kepler discovered how the retina creates vision. Thomas Young discovered Astigmatism and George Biddel Airy designed the first spherocylinders to treat it between 1773-1829. Mr Peter Brown was the first man to wear a pair of glasses in the USA. The first man buy a pair of Glasses in the USA is McAllister Sr., from Philadelphia Pennsylvania in 1783. McAllister Jr., started making glasses in USA in 1811 and in 1853 they started refraction which they taught students.
In January 11, 1922 American Optometric Association was formed. Same year saw Optometry choosing to become professional instead of business! The first school of Optometry in America was built in 1872. in 1940 the first contact lens were invented.
In Nigeria, Nigerian Optical and Ophthalmic Co limited in 1964 introduced Optometry in Nigeria. It was changed to Optical association and Nigerian Optometric Association in 1968. The umbrella body was an all comers affairs, since there was no regulatory body. But based on the above evolving Optometric definition and with emphasis on professionalism. Hence, the formation of Optometrists and Dispensing Optician board following Decree No 34 of 1989 on 7th December. It was inaugurated by the then Minister of Health, late Professor Ransome-Kuti on 12th October 1992. Optometry has come a long way indeed. To be continued....

Dr Victor Ezebuiroh Okwudiri.

optometry.naija: Vision 2020 and the role of Optometry Practice in ...

optometry.naija: Vision 2020 and the role of Optometry Practice in ...: "Optom Back in 15-18 January 1999 when Vision 2020 was launched, it was aimed @ reversing the roller-coaster drive of blindness Prevalence w..."

Optom

Vision 2020 and the role of Optometry Practice in Nigeria- episode 2

Optom
Back in 15-18 January 1999 when Vision 2020 was launched, it was aimed @ reversing the roller-coaster drive of blindness Prevalence which was projected to rise up to 58 million in 2010 and 75 million in 2020. But the almighty question staring @ us, the estimated versus prevailing epidemiological data reality, begs for answers. I wish to draw us to events that finally culminated in formation of Vision 2020 Global initiative, also identified as Vision 2020: Right to Sight.
In 1972, the same year the globally accepted minimum definition of blindness as, " VA of <3/60 with a central visual field of <10 degrees" and as incorporated in the international classifications of diseases ninth revision (ICD-9), the estimated prevalence of blindness was between 10-15 million. This projected estimate was said to be an underestimation by epidemiologists and other experts. The need for a more epidemiological sound estimate of blindness and the need to look into causes of blindness and the myth gave birth to International Agency for Prevention of Blindness (IAPB) in 1975. It is an international umbrella body of governmental and non-governmental eye care providers whose aim is to prevent or treat causes of blindness.
 In that same year, 1975, WHO/ Prevention of Blindness/Blinding disease (WHO/PBL later WHO/PBD) was created as a partnership between world health organization (WHO) and IAPB and world donor groups. In 1979, the first epidemiologically sound estimate of Blindness prevalence based on ICD-9, from 60 distinct geographic areas, was 28.1 million blind as @ 1975. In 1987 the prevalence of blindness, based on ICD-9, was 31 million from 90 distinct geographical area @ 1984. In 1994, there was an estimated 37.9 million people blind @1990. As @ 2000 there was an estimated 45 million blind and the story continues... this seem to correlate with a projection made in 1975, that by 1990 the world prevalence of blindness will be 38 million, in 2000, 45 million people will be blind. If nothing is done, prevalence of blindness is expected to rise to 58 million in 2010 and record 75 million in 2020.
This worrying scenario is further aggravated by a lackadaisical approach towards the goals of achieving the mission statement of Vision 2020: Right to Sight, which has prevention, treatment and elimination of the various preventable causes of blindness as a core message. Another factor that keeps pandering the escalating proportion of prevalence of blindness and visual impairments, is the chronic and persistent professional in-fighting among the professional eye care providers. The Ophthalmologists, the Optometrists, Dispensing Opticians and the Orthoptists are eye care professionals whose aim is to provide visual 'soundness' for the visually challenged.
Finally, in a subsequent blog, I am going to discuss the eye care professionals with emphasis on Optometry.
To be continued...
Dr Victor Okwudiri Ezebuiroh.

optometry.naija: Vision 2020 and the role of Optometry Practice in ...

optometry.naija: Vision 2020 and the role of Optometry Practice in ...: "Optom In 1975, during a World Health Assembly organized by World Health Organization (WHO), WHO Program for the Prevention of Blindness was..."

Optom

Vision 2020 and the role of Optometry Practice in Nigeria- episode 1

Optom
In 1975, during a World Health Assembly organized by World Health Organization (WHO), WHO Program for the Prevention of Blindness was formed. An adoption of the resolution forming such body was reached in 1978 through the efforts of International Agency for Prevention of Blindness (IAPB) and other allied stakeholders. This arm of WHO was aimed @ controlling avoidable visual impairments and blindness. But this body was hampered by low political and professional will.
In 1996, world population data on the magnitude of visual disability and low vision was published. This rattled stakeholders to action and Vision 2020 Global initiative and Vision 2020 Right to sight was introduced.

In 2003 it was adopted as Resolution WHA56.26, whose aimed @ Eliminating the main causes of all preventable and treatable blindness as a public health issue by the year 2020.
The initiative aims @ arresting such potential cause of blindness
i) Cataract
ii) Onchocarciasis
iii) Trachoma
iv) Refractive error/ low vision
v) Common causes of childhood blindness.

Vision 2020 Right to Sight has a laid down core strategies aimed @ Eliminationg avoidable blindness include-
a) Disease control
b) Human Resource development
c) Infrastructure and technological development.
 Today we have barely 9 years to year 2020!
To be continued...

Dr Victor Okwudiri Ezebuiroh.

optometry.naija: Glaucoma week Series -episode 11 (finally on Glauc...

optometry.naija: Glaucoma week Series -episode 11 (finally on Glauc...: "Optom Most Angle-closure Glaucoma often fail to respond properly to drugs, as well as most secondary Glaucoma. It becomes imperative to qui..."

Optom

Glaucoma week Series -episode 11 (finally on Glaucoma management)

Optom
Most Angle-closure Glaucoma often fail to respond properly to drugs, as well as most secondary Glaucoma. It becomes imperative to quickly send those patients for surgical intervention. Various kinds of surgical interventions for Glaucoma could be performed to basically alleviate symptoms and promote management of this chronic and blinding syndrome.
They include both laser & non-laser surgical interventions such as- Scleroctomy ( creating a bleb via the anterior chamber to the sclera), Traculoplasty ( using laser to change the integrity of the trabecular meshwork, its especially good for primary open-angle glaucoma), Trabeculectomy (removal of some portions of the trabecular meshwork; other variants like trabeculotomy [incision without removal of some portions of the trabecular meshwork], Goniotomy [Tabeculectomy using a gonioscope, especially in children]); iridotomy (creating surgical holes in the iris using laser], iridectomy (involving the removal of a portion of the iris), others include viscocanaloplasty, different types of tube shunt surgeries etc.
It is well advised to also continue managing that sugically treated glaucoma with drugs and going for frequent checkups to your primary eyecare provider in your area, especially the first professional eye doctor who diagnosed your case and recommended surgery for you. You can assess your community Optometrist or Ophthalmologist today for your eye check. It could just be glaucoma, you never now.
I was to thank http://www.allaboutvision.com & http:glaucomacures.com for providing me with some relevant materials. Vision 2020 is achievable...
concluded.
Dr Victor Ezebuiroh Okwudiri.

optometry.naija: Glaucoma Week Series- episode 10 (Glaucoma Managem...

optometry.naija: Glaucoma Week Series- episode 10 (Glaucoma Managem...: "Optom Managing Glaucoma tends to be a long term thing. The first thing that should always come to mind when faced with Glaucoma prospect i..."

Optom

Glaucoma Week Series- episode 10 (Glaucoma Management)

Optom
Managing Glaucoma tends to be a long term thing. The first thing that should always come to mind when  faced with Glaucoma prospect is to differentiate between the types of Glaucoma, because the various types require quite a different approach in management. The next question is to start treating versus monitoring! Is it necessary to commence treatment if the symptoms are not there while there is a strong cause of suspicion, like a cupped disk without pressure or a high pressure without a cupping etcThe clinician is faced with the option of either comencement of treatment or close monitoring the patient, but I often start a low grade management @ the slight suspicion of Glaucoma! Such as educating the patient very well about the syndrome & in some cases prescribing gutt: Timolol meleate 0.5 percent i bds. The patient should be returning to the clinic monthly for a close follow up which includes checking intra ocular pressure, measuring the size of the disk (is there any excavation? Has the cup gone beyond 0.5 threshold? etc).If patients comes in with an already established Glaucoma, treatment with drugs comences immediatly! I monitor patient's visual acuity, do refraction, use ophthalmoscope to rule out a secondary cause or any other eye disease while establishing glaucomaas the cause of the impairment (most often a very poor vision in one eye that keeps degenerating and tends towards the other eye or recently changed glasses that no longer effective or even diminishing vision towards evening could be the reason of visit!)I then check patient's I.O.P with schiotz tonometer ( its out-dated though, but desperate times always call for desperate measures!). I always puntuate my tests with patient's education, this is one of the most important pearl in managing Open Angle Glaucoma especially in the rural communities. We send patients to the city to do central visual field tests with either the Humphrey analyser, the Octopus visual field analyser or any automated visual field analyser periodically, which is often attached in the patient's report for analysis and education! We have tried severally to inroduce co-management with Ophthalmologists in the city but seem to leave the patient vulnerable.It should be known that various medications are used in the management of Glaucoma, but I always pay attention to the cost burden on the patients! This is to avoid creating a psycholgical backlash which often times discourages the patient & hence mounts this person's handicap!After establishing that systemically, the patient is not @ risk of any pulmonary disease I give him/her a starting therapy of gutt: Timolol 0.5 percent bds x 1/12. (a beta blocker). I add postalglandin analog like, Latanoprost or travatan or xalatan 1 noct. x 1/12 in the course of management. Recently Alphagan (Brimodimine, an Alpha agonist) has attracted my interest while I no longer use miotics like Pilocarpine as it has been widely reported to have very serious side effects like retinal deterchments etc Alphagan could be combined with either a beta blocker or a postalglandin analog to promote efficacy of management. Note, a beta blocker reduces aqueous production, an alpha blocker promotes outflow and has been hypotesised to contain neuro-protectors to maintain the integrity of neuro-retinas which often suffers in Glaucoma process. On the other hand, a postalglandin analog promotes uveo-scleral flow (this contributes 10 percent of outflow). Acetozolamide (diuretics), Slow K (reduces the clearance of potasium in the body) are adjunts in managing Glaucoma. In some cases, the use of surgery is advised especially in the closed angle type of glaucoma! We shall discuss this mode of treatment/management in subsequent blog! Happy Good Friday! Be responsible for your eyes!To be continued...Dr Ezebuiroh Okwudiri Victor.

Glaucoma Week Series -episode 9 (Identifying closed angle Glaucoma in a rural setting)

Optom
Closed angle glaucoma is often an emergency eye challenge. Its always acute and often present with epiphora in the ipsilateral eyes. Another classic outlook of closed Angle Glaucoma is monocularity in pathogenesis but often assumes binocularity @ an unpredicted pace! This type of Glaucoma, which most times is accompanied by a secondary or predisposing factor, can affect individuals of any age group.
The following triads are cornerstone gems for suspecting closed Angle Glaucoma in a rural setting-
In Adults
1)sudden onset of pain in one eye and necessarily much epiphora.
2)Redness with corneo-scleral limbal injection, not related to ocular infections, but the cornea is relatively clearer on early presentation.
3)Mid-dilated ipsilateral pupil with sluggish or unreactive pupil to light.
In children
1) Epiphora
2) corneal edema
3)Exophthalmos.

These classical triads are often accompanied with photophobia. The pressure of the eye is visibly high and on external examination one can reveal engorged vessels. The patient can misinterpret the throbbing in the eyeball for a generalized headache. It often does not lead to blindness because of the highly symptomatic nature of Angle closure Glaucoma. In children it almost always binocular in pathogenesis. It is not common to Africa, but an important eye challenge to Asians. Glaucoma is no respecter of sight...lets not play with it! Go for an eye test today, it can make the difference!
To be continued....
Dr Ezebuiroh Victor Okwudiri.

optometry.naija: Glaucoma Week Series 2011- episode 8 (Identifying ...

optometry.naija: Glaucoma Week Series 2011- episode 8 (Identifying ...: "Optom In continuation with Glaucoma, identifying this silent killer of sight, poses the most tricky challenge to even a well grounded profes..."

Optom

Glaucoma Week Series 2011- episode 8 (Identifying Open angle Glaucoma in a rural setting!)

Optom
In continuation with Glaucoma, identifying this silent killer of sight, poses the most tricky challenge to even a well grounded professional eye care specialist! Glaucoma is a syndrome which basically does not follow a particular pattern.
The following are some of the early signs of glaucoma- excavation of the optic nerve head, such that the integrity of both the lamina cribosa and the nerve fibres start the process of apoptosis and subsequent increased cupping of the disk (initially the central vision is not affected till the later stages); shrinking of the peripheral visual field as a result of programmed cell-death of the ganglion retinal fibres; and in some cases a rise in intraocular pressure of more than 21-23 mmHg!
In later stages, a form of night blindness ensues, especially when the peripheral nerve bundles of the retina have been badly affected, which of course affects the integrity of the retinal rods! A visible loss of peripheral field is also noticed , especially moving objects; reduced visual acuity accompanied by increased glare sensitivity and poor contrast sensitivity is noticed in patients with confirmed mid-stage glaucoma; these patients tend towards myopia and often times develop an Astigmatism skewed towards the superior-inferior cup-disc excavation (its hardly a with-the rule Astigmatism, more common is an against-the-rule Astigmatism and any form of oblique Astigmatism!). The pupil develops a mid-dilated stare with negative Macus Gunn pupillary reflex and sometimes seldom react to light, the two pupils are not always of equal size (it should be noted that the Edinger Welpher Nucleus which sympathetically innervates the pupils is choked in the Glaucoma process, hence those pupillary changes in this stages!). The fact is that open Angle Glaucoma is very subtle to be detected early enough in a rural setting where the prospect of using Slit-Lamp & accessories, OCT scanning system, pachymeters etc are very limited, hence its best to always advice people staying with you in your area to come for vision screening from time to time! Glaucoma is dangerous, dont play with it!
To be continued...

Dr Ezebuiroh Victor Okwudiri.

optometry.naija: Glaucoma Week Series episode 7 ( Types of Glaucoma...

optometry.naija: Glaucoma Week Series episode 7 ( Types of Glaucoma...: "Optom Glaucoma classifications could be based on the size of the angle between the corneal endothelium and anterior portion of the fenestrat..."

Optom

Glaucoma Week Series episode 7 ( Types of Glaucoma)

Optom
Glaucoma classifications could be based on the size of the angle between the corneal endothelium and anterior portion of the fenestrated iris. This angle is a passage way to the trabecular meshwork, which contributes about 90% of total aqueous humor drainage. Hence, it could be, 1)Open angle glaucoma, & 2) Closed angle glaucoma. The former, as the name denotes, has a clear passage way to the trabecular meshwork when viewed through a Gionoscope lens on a slit lamp bi-microscope. Therefore the cause of this type of Glaucoma is not related to resistance to drainage per say, it often times result as a brake down in the physiology of the trabecular meshwork or as a result of some subtle factors that often results to disk excavation and death of ganglion cell fibres of the Retina.
The Open angle type of Glaucoma shows little or no symptom in early stages and its often always bilateral. This type of Glaucoma rarely affects children! It contributes almost 85% or more of the total glaucoma cases. It is common in the black race.
The later, Closed Angle Glaucoma, often blocks or reduces the passage way to the trabecular meshwork. It shows severe symptoms ranging from redness, pains, epiphora (excessive tearing), photophobia, haziness of the cornea etc It often affects one eye @ a time and causes a lot of discomfort to the person.
Glaucoma could classified according to a precursor. If there is a known secondary cause such as the use of topical steroids, ocular trauma, Diabetes, Hyptertension, cataract etc, such Glaucoma is known as secondary Glaucoma. This type of Glaucoma is common in adults above 60 years. While primary Glaucoma often has no known precursor (i.e. the person's eyes do not have any pre-existing ocular problem).
Glaucoma could be classified depending on mode of onset, hence a sudden symptom of Glaucoma denotes acute Glaucoma, while the type of Glaucoma that does not present symptoms in time suggests a chronic Glaucoma. It should be noted that Acute Glaucoma and closed angle glaucoma are similar also some secondary Glaucoma mimic acute onset glaucoma. And chronic glaucoma is similar to open angle Glaucoma.
Glaucoma is very dangerous but very tricky to identify, hence it becomes imperative for you to go for constant eye check to enable one identify the disease in time!
Glaucoma is a killer...be wary of it!
To be continued.....
Dr Ezebuiroh Victor Okwudiri.

optometry.naija: Glaucoma Week Series 2011- episode 6 ( Understandi...

optometry.naija: Glaucoma Week Series 2011- episode 6 ( Understandi...: "Optom The eyeball is a pear-like globe surrounded by the uveal body and reinforced by the sclera and the cornea externally which actua..."

Optom

Glaucoma Week Series 2011- episode 6 ( Understanding Glaucoma)

Optom
The eyeball is a pear-like globe surrounded  by the uveal body and reinforced by the sclera and the cornea externally which actually provides its (the eyeball's) toughness. It is filled with two types of liquid that defer basically,only, in their viscous status. They are the vitreous humor, occupying the posterior eyeball and bound by the retina posteriorly and the posterior crystalline lens, the pars plana and the ciliary process. the vitreous humor, a gel, faces the optic nerve head and the lamina cribosa. it is always almost static & rather behaves like a connective tissue!
The aqueous humor occupies the anterior portion of the eyeball, separated from the vitreous humor by the crystalline lens, pars plicata, anterior cilliary process and bound anteriorly by the endothelium of the cornea. The fluid is in a constant flux by a process known as inflow and outflow mechanisms. This two mechanisms, though poorly understood, provides the basis of intra-ocular pressure (I.O.P)of the eyeball. I.O.P is an important factor in glaucoma though its effect on individual eyeballs suggests an arbitrary relationship, yet it remains the only controllable factor in Glaucoma management.
Inflow mechanism originates from the ciliary body, anterior crystalline lens on  the posterior channels, the pupillary aperture and ends @ the trabecular meshwork. @ the trabecular meshwork, the outflow mechanism commences. the trigger factor of these two mechanisms of flow is poorly understood but undoubtedly contributes hugely in the pathophysiology of glaucoma. Another outflow channel that dont really influence I.O.P is the uveo-sleral flow located around the junction of the pars plicata and the sclera. It contributes about 10% of total outflow while the trabecular meshwork contributes almost 90% of outflow & influences I.O.P & is influenced by I.O.P too.
The outflow mechanism commences from the trabecular meshwork, the Sinus Venosus Sclerae or Canal of Schlemm, into the larger episcleral venous spaces then into the vena cava...etc etc & the process repeats itself again. The indirect outflow @ the uveo-scleral spaces follows through the capillaries of that part of the ciliary body and escapes into the episcleral spaces & straight into the larger veins- the vena cava!
Any process that disrupts these dual mechanisms results in a disrupted equillibruim of flow with subsequent rise in I.O.P with a resultant pressure on the optic nerve head, the most vulnerable part of the sclera the lamina cribosa becomes a culprit, choking the optic nerve fibres and subsequent death of those fibres.
Cell mediated apoptosis especially on the lamina cribosa and/or the optic nerve fibres can also can contribute to glaucoma formation in some case of 'normal' tension glaucoma.
Ishcaemia of blood vessel supplying the optic nerve head can result to Optic nerve fibre deaths. Also neovascularisation on the optic nerve head, as in Diabetic patients for instance has been implicated in optic nerve death. These all contributes to the formation of Glaucoma but the process is poorly understood, though well articulated.
We will treat the different types of Glaucoma subsequently...
To be continued!
Dr Ezebuiroh Victor Okwudiri.

optometry.naija: Glaucoma Week Series 2011- episode 5 ( The Optic n...

optometry.naija: Glaucoma Week Series 2011- episode 5 ( The Optic n...: "Optom The Optic nerve, the cranial nerve II, is the anterior extension of the white matter of the brain. It arises from the ganglion cells o..."

Optom

Glaucoma Week Series 2011- episode 5 ( The Optic nerve head)

Optom
The Optic nerve, the cranial nerve II, is the anterior extension of the white matter of the brain. It arises from the ganglion cells of the neural retina to the lateral geniculate body. It is made up of approximately 1 million axons, mainly myelinated except those of the retina. These axons relay with the visual cortex of the brain via the optic radiation.  The Optic nerve head is covered by a thin strip of flexible sclera known as the lamina cribrosa.It separates the myelinated part of the Optic nerve from the unmyelinated retina. This strip of sclera is susceptible to damage & injury. The optic nerve does not possess Schwann cell and hence do not regenerate when injured or damaged.
The Optic nerve is is covered by three layers of meninges and it is surrounded by an extension of the subarachnoid space. The Optic nerve head is supplied by the arterial branches of the long and short posterior ciliary arteries, the central retinal artery and from the partial arterial circle of Haller-Zinn. The blood supply of Optic nerve drains into the central retinal vein.
To be continued...

Dr Ezebuiroh Okwudiri Victor.

optometry.naija: Glaucoma Week Series 2011- episode 4 ( The Trabecu...

optometry.naija: Glaucoma Week Series 2011- episode 4 ( The Trabecu...: "Optom To fully understand the pathophysiology of glaucoma, it becomes imparative to understand route of inflow as well as outflow of the aqu..."

Optom

Glaucoma Week Series 2011- episode 4 ( The Trabecular meshwork, the canal of Schlem and the Uveoscleral spaces)

Optom
To fully understand the pathophysiology of glaucoma, it becomes imparative to understand route of inflow as well as outflow of the aqueous humor. It should be remembered that the eye is considered a leaking system of aqueous humor.

The Trabecular Meshwork

The trabecular meshwork is a spongy porous tissue lined with trabeculocytes. It is located around the base of the cornea just beyond the line of Schwalbe. It sits just above the anterior fenestrated iris. It runs the course of the entire corneal base of the eye. It is avascular.

The trabecular meshwork is divided into three, they include the following-

1) The inner uveal meshwork: This part is closest to the anterior chamber. It is radially oriented and contains trabeculae.

2) The corneoscleral meshwork: This part consists oflarge amount of elastin and often described as the ciliary muscle tendon.

3) The Juxtacanacular meshwork (Cribiform meshwork): This part is close to the canal of Schlem (Sinus Venosus Sclerae). It consists of a thin strip of tissue covered by mono-layer endothelial cell. It recieves support by the connective tissues ground substances full of glycoaminoglycans and glycoproteins.

Canal Of Schlem (Sinus Venosus Sclerae)

The canal of Schlem is acircular canal lined with endothelium that runs around the eyeball at the corneoscleral junction. It is positioned within the internal scleral sulcus and posteriorly related to the scleral spur. The inner endothelial wall of the sinus is related to the trabecular meshwork and the anterior chamber; but there is no direct passage way between the trabecular meshwork, the anterior chamber cavity and the sinus.
The scleral sinus is drained by 25-30 collector canals via the deep scleral venous plexus, then into the intrascleral plexus & the episcleral plexus which enters the larger circulation via the anterior ciliary veins.
A few of the collector canals bypass the deep scleral venous plexus and pass directly into the sclera via the subchoroidal vessels. These collector channels are known as aqueous veins.
85-95 % of aqueous outflow takes place through the trabecular meshwork via the Sinus Venosus Sclerae.

The Uveoscleral pathway

The junction between the uveal portion of the eye and the sclera is linked by the ciliary body smooth muscles. This area has been noted to play a role in outflow of aqueous humor. This area provides about 5-15 % drainage of the aqueous humor. It is known as the 'Extracanalicular' pathway. The aqueous humor is drained into the orbital blood vessels. Recently, the uveoscleral  pathway has assumed a very important mechanism in the outflow mechanism of the aqueous humor.

To be continued...

Dr Ezebuiroh Victor Okwudiri

optometry.naija: Glaucoma Week Series 2011- episode 3 (The anatomy ...

optometry.naija: Glaucoma Week Series 2011- episode 3 (The anatomy ...: "Optom The Ciliary Body is a complete ring tissue that runs around the inside of the anterior sclera. It measures about 6 mm wide ( sli..."

Optom

Glaucoma Week Series 2011- episode 3 (The anatomy of the ciliary body)

Optom
 The Ciliary Body is a complete ring tissue that runs around the inside of the anterior sclera. It measures about 6 mm wide ( slightly wider temporally than nasally).  Anteriorly, the ciliary body extends to the sleral spur (This acts as an attacchment for the ciliary body ventrally. On the posterior side, the ciliary body continues into the ora serrata of the retina.
The ciliary body is divided into the anterior 'pars plicata' which is ridged  and give rise to the ciliary process on which the crystalline lens zonule suspensory ligament anastomose. And the posterior 'pars plana' is smooth and flat which extends into the ora serrata and the choroid. @ the margin between the ora serrata and the ciliary body, the 'pars plana' is modified into a scalloped edge that fits into and corresponds with the tooth-like edge of the ora serrata of the neural part of the retina.
Structurally speaking, the ciliary body is made up of (1) The ciliary epithelium, (2) The ciliary stroma, and  (3) The ciliary muscle.
The ciliary epithelium is that outermost part of the ciliary body that cover the inner surface of the cilliary body. It is made of two layers of pigmented and non-pigmented epithelial cells with their apices juxtaposing. Their basement membrances lies paralel with each other. These arrengement is unique and unlike in other epithelial cell which justifies the diferences in the content of blood plasma and  aqueous humor! The ciliary epithelium forms the blood-aqueous barrier which plays a significant role in Intra-ocular pressure (IOP) maintainance.
The ciliary stroma is a bundle of loose connective tissue, rich in blood vessels and melanocytes. The loose connective tissue in the stroma forms a connective tissue core with the ciliary process. The stroma also provides attachment for the ciliary muscles which functions in crystaline lens accomodation.
 The ciliary muscle is innervated by the posganglionic parasympathetic fibres derived from the oculo-motor nerves, via the short cilliary nerves. They form the bulk of the ciliary body and consists of smooth muscle fibres.

Finally,the aim of this detailed discription of the ciliary body is to identify the role it plays in production of aqueous humor and the regulation of IOP in the eye. The eye is regarded as a leaking system for aqueous humor, from the ciliary body to the collector channels and aqueous veins of the Sinus venosus sclerae (canal of Schlem); or the episcleral spaces. It is on record that the rate of aqueous humor formation is approximately 2.4+/-0.6 ul/min (Micro-liter per minute).
To be continued...

Dr Ezebuiroh Okwudiri Victor.