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Glaucoma: Avoidable blindness

DNIS News Network - An alarming number of people in India are losing eyesight due to a silent but preventable disease called Glaucoma; according one estimate 1.54 million Indians have lost vision due to this disease.

Glaucoma has emerged as a significant global health problem, but it is particularly severe in India and accounts for 12.8 per cent of total cases of blindness, said Dr. M.S. Sachdev, Chairman and Medical Director of Centre for Sight. Glaucoma, he said, is a group of eye diseases that gradually steals sight without warning and often without symptoms.

Vision loss is caused by damage to the optic nerve. This nerve acts like an electric cable with over a million wires and is responsible for carrying the images we see to the brain. On why is it so widespread in India, he said, “Lack of awareness about the Glaucoma is the main reason behind its high prevalence in India. Clinically detectable visual field disturbance requires destruction of 30 per cent or more of the optic nerve. Patients are unaware of -the problem until 90 per cent or more of the optic nerve is destroyed.”

“As the visual field constriction starts from the periphery, patient’s central vision remains intact till the end. When the central vision goes off, it is already too late,” he added. Failure of early detection adds to the problem of controlling glaucomatous blindness. Glaucoma in India is said to be the second major cause for blindness after cataract. On the measures need to deal with the disease, Dr. Sachdev said, “It is a major public health problem having a long pre-symptomatic phase during which treatment prevents further progression.”

He suggested an aggressive awareness campaign in the media, and a conscious effort by general medical practitioners towards increasing patient awareness and guiding them to an ophthalmologist. A regular screening program also needs to be planned for early detection of glaucoma especially in forty years plus population segment. Latest and more efficient screening techniques for detection of visual field defects or other indicators of optic nerve damage are available now.

Dr. Sachdev advised that once a patient is diagnosed with glaucoma, he or she should get immediate relatives checked for glaucoma. “We should be targeting the high-risk groups. We should rely on case detection in the clinic. We have to improve the rigor with which we seek evidence of either open angle or angle closure glaucoma amongst individuals in poor countries who present to ophthalmic facilities for other reasons,” he said suggesting a strategy to prevent the disease from growing any further.

On recent treatment trends, he said: “We have a simple preventive therapy for a significant proportion of this disease in the form of peripheral iridotomy. We have a surgical intervention that slows the rate of disease groups in the form of trabeculectomy. The most significant change in the technique of glaucoma surgery in the past 10 years has been the introduction of agents that strongly affects the way wounds heal. Postoperative treatment with 5-FU (5- Fluorouracil) or MMC (Mitomycin –C) is effective in preventing bleb failure in high-risk cases.”