Everything you need to know about Glaucoma
Known as the silent blinding disease, Glaucoma is the second most common cause for blindness globally accounting for almost 8 percent of blindness cases.
In India,glaucoma is the main cause for permanent blindness leaving at least 12 millionpeople affected and more than one million people totally blind. Unfortunately,more than 90 percent of glaucoma cases remain undiagnosed in the community.
Glaucoma isactually an eye disease that causes damage of the optic nerve progressively andat the point where the nerve leaves the eye to carry visual information to thebrain. It occurs due to a fluid build up (pressure) within the eye that causesdamage to the optic nerve. The eye makes a fluid called aqueous humor and asnew aqueous flows into the eye, the same amount should get drained out. This iscalled the intraocular pressure that keeps the vision intact.
If thepressure continues to build up, the optic nerve and other parts of the eye willbe damaged resulting in vision loss. As the optic nerve fibers getaffected, the person may develop blind spots in the eye and ultimately becomeblind.
There aremany types of glaucoma:
Primaryopen angle glaucoma: Thisis the most common type of glaucoma and occurs when the eye does not drainfluid normally. Consequently, there is an eye pressure build-up anddamage the optic nerve. Unfortunately, this kind of glaucoma does not give anyindication before and is also painless. The only option is to get regularcheck-ups done to detect early damage. Also, some people are sensitive to evennormal eye pressure and they are susceptible to getting glaucoma.
Angle-closureglaucoma: Whena person’s iris is very close to the drainage angle in the eye, the iris itselfblocks the draining and can cause damage. This is usually an emergency attackbecause there are no symptoms at first. This requires immediate medical carefailing which can lead to blindness. But this condition gives some symptoms,unlike primary open-angle glaucoma. Some of the symptoms are blurred vision,eye pain, headache, nausea and seeing halos around lights.
Normaltension glaucoma: Thisis the third type where people with normal eye pressure also develop blindspots and blurred vision.
There arepeople that have higher than normal eye pressure and are called as glaucomasuspects. They have a higher risk of developing glaucoma and so should bemonitored regularly.
Congenitalglaucoma: This occurs due to increased eye pressure in young children. Thecause is usually a genetic disorder.
Glaucoma canbe diagnosed only with a complete eye examination that involves measuring eyepressure, examining the eye drainage angle, studying the optic nerve and thedamage done to it and measuring the thickness of the cornea.
The usualtreatment for glaucoma is daily use of eye drops which will lower the eyepressure. It can be done through two ways: either by reducing the amount ofaqueous fluid in the eye or by helping the eye drain the fluid better. Thereare two main types of laser surgery to treat glaucoma. They help aqueous drainfrom the eye.
There arespecial surgical procedures too to treat glaucoma:
Trabeculoplasty: This is for people who sufferfrom open-angle glaucoma. A laser is used to make the drainage angle free fromfluids and so the eye pressure is reduced.
Iridotomy: This procedure is for peoplewho suffer from angle-closure glaucoma. The surgeon makes a tiny hole in theiris so that the fluid flow is normal.
There isanother more complex surgery where the surgeon creates a new draining channelfor the fluid so that pressure is normalized. Sometimes the surgeon uses aglaucoma drainage tube in the eye that sends the fluid to a collection areawhich is then absorbed into the blood vessels directly.
Dr.Poonam Yadav, Consultant – Opthalmology, Columbia Asia Hospital SarjapurRoad