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.