Social medicine, universal eye care coverage, primary eye
care, preventive eye care... blindness etc. They evoke a sensation that
provokes anxiety and urgency! Anxiety, because by the year 2020 there is no way
Nigeria would have being able to stop avoidable blindness in the country.
Urgency, because the Vision 2020 target of reducing avoidable causes of
blindness to 25% in 2015 was not feasible! This is already 2018 and it can be
authoritatively stated that we, as a country, cannot meet the vision 2020 target.
What can we do to bridge the gap?
Let's get some historic perspective of the subject matter...
The first global estimate of the extent of visual impairment,
in 1975, indicated that there were 28 million blind people. In 1990, 38 million
people were estimated blind and 110 with moderate to severe visual impairment.
In 1996, 45 million were estimated blind and 135 million with moderate to
severe visual impairment. In 2002, 45 million persons were estimated blind and
314 million with visual impairment. In 2010, visual impairment reduced from 314
million people of 2002 estimates, to 285.3 million and 39.8 million people
estimated to be blind worldwide. The reduction in the number of persons with
visual impairment was a result of different levels of preventive eye care measures
adopted by IAPB and WHO Vision 2020 initiative and other healthcare interventions by WHO since
early 1950s.
It is estimated that as at 2017, an
estimated 253 million people live with vision impairment: 36 million are blind
and 217 million have moderate to severe vision impairment. 81% of the visually
impaired people are aged 50 years and over.
The visual impairment results from chronic eye diseases like glaucoma,
maculopathies, retinopathy etc. It is estimated that the number of people with
vision impairment could triple due to population growth and ageing. For example,
by 2050 there could be 115 million people who are blind, up from 38.5 million
in 2020. Women are 1.5-2.2 times more prone to visual impairment than men (1). The prevalence of infectious eye diseases has reduced significantly
over the last 25 years.
An estimated 19 million children are vision impaired. An
estimated 12 million children have vision impairment due to refractive error.
An estimated 1.4 million have irreversible blindness.
Globally, chronic eye diseases are the main cause of vision
loss contemporarily. Uncorrected refractive errors and un-operated cataract are
the top two causes of vision impairment. Un-operated cataract remains the
leading cause of blindness in low- and middle-income countries.
And down home in Nigeria...
In 2002, 4.2 million
Nigerians of 40years and above were estimated to have visual impairment.(2)
84% blindness and visual impairment in Nigeria is avoidable.
Uncorrected refractive error is responsible for 57.1% of moderate (6/18–6/60)
visual impairment. Cataract (43%) is the commonest cause of blindness (<3/60).
Prevalence of cataract-related blindness is 1.8% and glaucoma-related blindness
is 0.7%. Prevalence of blindness in Nigeria of age ≥40years+ is 4.2%. (3)
Visual impairment is associated with increasing age, being
female, poor literacy, and residence in the North. The South West had the
lowest prevalence while those in the North East had the highest prevalence of
visual impairment and blindness.
DefinitionsVision function is classified in 4 broad categories, according to the International Classification of Diseases -10 (Update and Revision 2006):
- normal vision
- moderate vision impairment
- severe vision impairment (<6/18 to >3/60)
- Blindness. (<3/60 to NLP)
Moderate vision impairment and severe vision impairment are grouped under the term “low vision”. Low vision and blindness represents all vision impairment.
The causes of visual impairment
According to recent estimates, the major global causes of
moderate to severe vision impairment are:
- uncorrected refractive errors, 53%
- un-operated cataract, 25%
- age-related macular degeneration 4%
- glaucoma, 2%
- Diabetic retinopathy 1%.
The major causes of blindness are:
- un-operated cataract 35 %
- uncorrected refractive error 21 %
- Glaucoma 8 %.
Changes over the last twenty years
Overall, the prevalence of vision impairment worldwide has decreased
since early estimates in the 1990s. This decrease is associated with:
- overall socioeconomic development;
- concerted public health action;
- increased availability of eye care services;
- Awareness of the general population about solutions to the problems related to vision impairment (surgery, refraction devices, etc.).
The Right to Sight initiative was launched in 1999 by WHO and
IAPB. It was estimated that at least
two-thirds of all blindness was avoidable (treatable or preventable) and that
extremely cost-effective interventions were available to prevent or cure
blindness.
In short,
In short,
“There was every reason to consider blindness prevention as one of the most worthwhile public health and developmental interventions that could be undertaken”. (4)
What is
prevention of blindness?
The prevention of blindness cannot be fully understood if we
don’t understand the concept of prevention of diseases and apply it contemporarily
to our eye care service provision.
Dr. VESEC, an acronym we shall use throughout our discussion
to represent our primary eye care facility, is in the fore-front of applying
preventive measures in tackling visual impairments and blindness.
Preventive healthcare is a form of medical care that
concentrates on the prevention of diseases or health maintenance of people. Preventive
health care includes all activities aimed at promoting health, preventing
illness, prolonging life, and improving the functioning of individuals. Disease
prevention covers measures not only to prevent the occurrence of disease, such
as risk factor reduction, but also to arrest its progress and reduce its
consequences once established. (5)
Therefore preventive health care can be conceptualized thus:
“Actions aimed at eradicating, eliminating, or minimizing the impact of disease and disability. The concept of prevention is best defined in the context of levels, traditionally called primary, secondary, and tertiary prevention.”
A historic perspective of the concept of preventive care...
The concept of prevention was expressed in 1959 by Herman E.
Hilleboe, M.D and Dr. G. W. Larimore and has found considerable acceptance
among administrators, epidemiologists, and social scientists alike. A
unified concept of prevention to the health worker embodies the application of
knowledge and processes acquired from the medical, social, and environmental
disciplines for the purpose of preventing the occurrence or progression of
disease, defects, disabilities, and injuries.
In preventive medicine it is the individual, sick or well
alike, who is the focus of attention. In public health, or community health, the
focus is on groups of individuals, formed into a community, whose members face
common health problems among whom an organized community effort is essential
for their resolution.
In the early part of the twentieth century prevention meant
mainly vaccination to avoid communicable diseases, the purification of water
supplies, and the protection of food-especially milk -to avoid contamination with
disease causing organisms. But as time went on many communicable diseases were
largely brought under control and nutritional deficiencies were identified and
became preventable. Prevention gradually came to be talked about and studied
epidemiologically to include the degenerative diseases, injuries, defects, and
a variety of disabilities associated with human ailments.
In the 1950s, health workers spoke of primary and secondary
prevention, the latter pertaining largely to chronic illnesses. These terms had
to be defined and were not self-explanatory to the uninitiated. Some
enthusiasts went so far as to subdivide prevention into six or more different
categories that could not easily be remembered or recalled without reference to
the original articles of the writers. The spectrum covered everything in health
from preconceptual counseling of prospective parents to preparing relatives for
the psychological shock of the death of a loved one.(6)
Types of
Prevention
a) Primordial prevention:
Primordial prevention consists of actions and measures that inhibit the emergence of risk factors.
Dr. VESEC always promotes ocular hygiene, use of sunshades by
sea travellers; discourage the use of breast milk and other harmful and
injurious substances in the eyes; we teach our patients and our host community
at large about protecting the eyes from unnecessary trauma that could lead to
blindness resulting from cataract or glaucoma, in fact we promote any measure
that is not harmful to the eyes, any measure that will protect our eyes.
b) Primary prevention:
Primary prevention can be defined as the action taken prior to the onset of disease, which removes the possibility that the disease will ever occur. It signifies intervention in the prepathogenesis phase of a disease or health problem.
Dr. VESEC is a primary eye care provider. We all know that
81% causes of blindness and visual impairment can be avoided, treated or
managed at the primary eye care level! Based on this, our eye care centre provides comprehensive eye care
examination that is effective, efficient and affordable. In Nigeria,
refractive error is a staggering 57.1% of the total visual impairment based on a 2009 international Ophthalmologists and Vision Science report! To
bridge this gap, we provide very affordable consultation from $0 to $2. We also
have taken steps to take our services to the people. Currently, we have an eye centre
in Finima, Akiama and Cable road in Bonny Kingdom. Those areas have large
number of population clusters to enable us reach to them. Our comprehensive eye
care services are available in all the centres. Comprehensive eye care
examination at the primary eye care level is the single most important primary preventive health care service
that can identify avoidable causes of blindness!
c) Secondary prevention:
“Action which halts the progress of a disease at its incipient stage and prevents complications.”
Secondary prevention
attempts to arrest the disease process, restore health by seeking out
unrecognized disease and treating it before irreversible pathological changes
take place, and reverse communicability of infectious diseases. Cataract,
Glaucoma, Retinopathy, Maculopathy and severe refractive errors constitute
severe visual impairments and can lead to irreversible blindness.
Glaucoma, Maculopathy and
retinopathy cause irreversible blindness. Dr. VESEC has prioritized them as the
most dangerous causes of blindness amongst the list of the entire causes of
blindness in Nigeria. We have incentivized the eye care screening and comprehensive eye examination for these
conditions by making them free for all. We have severally collaborated with
stakeholders to provide free Fasting blood sugar testing and free blood pressure
measurements. We also provide free reading glasses for them.
Refractive errors, cataract and infectious ocular conditions
including toxoplasmosis also cause blindness but with conventional management
like surgery (we do referrals for cataract and refractive surgeries) and timely
interventions with eye glasses and medications, their type of blindness are
manageable and curable! With our comprehensive eye examination and detailed
family medical history, we provide secondary preventive eye care services to
help us fight blindness and visual impairment.
Still on the issue of secondary preventive eye care for cataract, the major cause of blindness both in Nigeria and globally...
Cataract surgery is not within the scope of Optometry
practice in Nigeria for now and to access cataract surgery on the Island
happens only during free medical outreaches. For those who need cataract surgery
we refer and the closest referral hospitals are found in Port-Harcourt and the
cost of surgery there is very expensive. Access to surgery in Port-Harcourt
town is poor because of urbanization and increasing population.
Cataract causes 43% of severe visual impairment in Nigeria and contributes about 35% of global cause of blindness. The prevalence of cataract is high on the Island. Of every 10
patients, 40 years and above, 5 have varying stages of cataract eye disease on
the Island and that is a red flag! To help in this area, we are developing a
process where we can invite cataract surgeons to the Island periodically, who
will provide very affordable, cost-effective cataract surgeries for residents.
It is a work in progress.
d) Tertiary prevention:
“all the measures available to reduce or limit impairments and disabilities, and to promote the patients’ adjustment to irremediable conditions.”
Intervention that should be accomplished in the stage
of tertiary prevention are disability limitation and rehabilitation. It is used
when the disease process has advanced beyond its early stages and cure cannot
be achieved.
Glaucoma, retinopathies, age related ocular degenerations and
maculopathies can cause devastating irreversible blindness and make patients
become despondent and even suicidal. Others are ocular surgery complications.
We provide free counseling services for these patients. We also advise them on
how to embrace the new realities of sub-normal to no vision at all. It is the
most challenging task Dr. VESEC has embarked on since inception. We do not wish
to leave anyone behind, not even the blind or those with low vision. Of those
with low vision, we provide a very effective referral system to further
buttress our position on not leaving anyone behind.
To be continued…
1) WHO 2002 report
References and links
1) WHO 2002 report
2) Prevalence of Blindness and Visual Impairment in Nigeria: The National
Blindness and Visual Impairment Survey. Fatima Kyari et al and the Nigeria
National Blindness and Visual Impairment Study Group. IOVS, May 2009, Vol. 50,
No. 5.
3) Causes of Blindness and Visual Impairment in Nigeria: The Nigeria National Blindness and Visual Impairment Survey. Mohammed M. Abdull et al. IOVS, September 2009, Vol. 50, No. 9.
4) International Agency for the Prevention of Blindness 2010 Report
5) Glossary Terms used in Health for All series (N°9). Geneva: WHO; 1984.
6) Herman E. Hilleboe, M.D., M.P.H., F.A.P.H.A. MODERN CONCEPTS OF PREVENTION IN COMMUNITY HEALTH. VOL. 61. NO. 5, A.J.P.H. 1000-1006: MAY. 1971). (https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.61.5.1000)
3) Causes of Blindness and Visual Impairment in Nigeria: The Nigeria National Blindness and Visual Impairment Survey. Mohammed M. Abdull et al. IOVS, September 2009, Vol. 50, No. 9.
4) International Agency for the Prevention of Blindness 2010 Report
5) Glossary Terms used in Health for All series (N°9). Geneva: WHO; 1984.
6) Herman E. Hilleboe, M.D., M.P.H., F.A.P.H.A. MODERN CONCEPTS OF PREVENTION IN COMMUNITY HEALTH. VOL. 61. NO. 5, A.J.P.H. 1000-1006: MAY. 1971). (https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.61.5.1000)
