Editied by Dr. D. Jinapriya
Glaucoma is a condition where the optic nerve is dying. It is the leading cause of irreversible blindness in the world. Sadly it is known as the "silent thief of vision" because people are not aware they have it until they have lost the majority of their vision. It affects patients of all ages, all races and any gender. With early detection and treatment, significant loss of vision from this condition can be minimized and in many cases prevented.
Types of Glaucoma
There are several types of glaucoma with two main types: open-angle and angle-closure.
Open-angle glaucoma is the most common type of glaucoma where the fluid in the eye drains too slowly through the network of tiny drainage channels, known as the trabecular meshwork. The pressure in the eye increases as the fluid in the eye continues to build. Loss of vision occurs gradually and the vision loss is not always noticed until it becomes irreversible.
Angle-closure glaucoma occurs when access to the tiny drainage channels, known as the trabecular meshwork, becomes blocked which then causes a rise in pressure in the eye. This can happen suddenly in which case it can be a painful "attack of glaucoma" but more often has periodic rises in pressure which are painless.
While anyone may develop glauocoma, the risk factors are:
- Age over 60
- Family history of glaucoma
- Eye pressure over 21mmHg
- Black ethnicity for open angle glaucoma
- Asian ethnicity for closed angle glaucoma
- Near sightedness greater than 6 diopters
- Thin corneas
- Previous eye injury
- Regularly use cortisone/steroid products
To detect glaucoma, the physician will perform the following tests:
- Visual acuity
- Visual field
- Angle assessment
- Dilated eye exam
- Retinal evaluation
- Retinal nerve fibre layer assessment
Treatment of Glaucoma
Once glaucoma has been diagnosed, treatment should begin as soon as possible to help minimize the risk of permanent vision loss. There is no cure for most glaucomas, so treatment focuses on minimizing further damage. Treatment for each individual case depends on the type and severity of the glaucoma. Some of the treatment methods for glaucoma are:
Eye drops or oral medication may be used to either reduce fluid production inside the eye or to help drain from within the eye. Any medication can have side effects and the potential side effects will be discussed with you if these medications are prescribed.
Selective Laser Trabeculoplasty (SLT), Laser Peripheral Iridotomy (LPI), Argon Laser Iridoplasty, and Trans Scleral Diode Laser (TSD) are laser procedures that aim to either increase the outflow of fluid from the eye, open access to the drainage system of the eye or decrease fluid production within the eye.
A Trabeculectomy is performed to create a new channel to drain fluid from the eye and reduce the pressure that causes glaucoma.
A Glaucoma Drainage Device is a valve and tube that bypasses the eye's natural drainage system to create a new outflow pathway and reduce pressure.