Glaucoma is a condition where the intra-ocular pressure of the eye is sufficiently high to cause damage to the optic nerve. Blindness from glaucoma is one of the leading causes of blindness, common in adults over the age of forty. It can be prevented if the condition is diagnosed at an early stage.
In a normal eye, a clear transparent fluid called ‘aqueous humor’ is secreted and continuously drained out via microscopic channels inside the eye and then into the blood vessels. If these vessels are blocked due to any reason, the fluid starts accumulating within the eye and pressure starts building up. If this pressure is not controlled, it causes damage to the optic nerve of the eye, leading to blindness.
Glaucoma can be broadly divided into two main categories: “open-angle” and “closed-angle” (or “angle closure”) glaucoma.
Open-angle chronic glaucoma is the most common type where the loss of vision is gradual and painless. Usually it is detected when patients come to the eye doctor for a routine eye check up.
- Gradual diminution of vision with blurred or foggy vision.
- Frequent change of eye-glass with no significant improvement in vision.
- Mild chronic headache, scotomas in peripheral visual field.
- Coloured halos around lights.
Acute / Closed Angle Glaucoma : in certain individuals, the angle from where fluid drains from the eye is genetically narrow. It can be blocked suddenly due to many reasons resulting in sudden increase in eye pressure.
- Severe pain in the eye with headache and facial pain.
- Sudden blurring of vision.
- Cloudy vision with halos around the lights.
- Redness in the eye with nausea and vomiting.
The aim is to reduce the eye pressure to a level that will not cause damage to the optic nerve. This prevents further loss of vision but the damage already done cannot be reversed.
The modalities of treatment are
- Instilling eye drops regularly as prescribed by the eye doctor to reduce and control intra-ocular fluid pressure.
- Using tablets over a short span of time to decrease the pressure during acute attacks or to help in bringing down the pressure when eye drops alone are not sufficient
- Laser treatment – two types:
This procedure is done for acute or narrow angle glaucoma with laser. A ‘hole’ or opening is made in the iris to relieve the blockage of the drainage channels.
This is useful in open angle glaucoma cases. Here the laser is used to open the blocked passages in the eye, thereby facilitating the aqueous fluid from within to reach the outside of the eye.
Surgery for Glaucoma or Trabeculectomy
It is a surgery where an additional channel is created surgically to drain the excess fluid bypassing the abnormally blocked channels. It is useful for most types of glaucoma.
The best defense against glaucoma is a regular eye check–up, especially after the age of forty. All adults should have a regular eye checkup especially if they belong to families with a history of glaucoma.
Glaucoma drainage devices
Glaucomahese are typically reserved for patients with severe uncontrolled glaucoma who have failed previous glaucoma surgery. In addition, the devices appear to be advantageous as a primary procedure in pa¬tients with a high likelihood of trabeculectomy failure, including neovascular and uveitic glaucomas . They are commonly used in the management of congenital and developmental glaucomas Additional indications include traumatic glaucoma, aphakic and pseudophakic glaucoma, post-keratoplasty glaucoma, and other secondary glaucomas. Recently, interest has increased in using these devices as a primary surgical procedure for uncontrolled primary open-angle glaucoma. Your eye surgeon will be the best to guide on these devices.