Glaucoma causes and treatment
Bangalore Baptist Hospital
Hebbal, Bengaluru Feb 9, 2017
What Is Glaucoma?
Glaucoma is a group of diseases that cause damage to the optic nerve at the level of its exit point from the eye. The optic nerve acts as a relay between the eye and the brain, taking the visual information perceived by the eye to the brain. Glaucoma is known as ‘the silent thief of sight’ because of its slow and usually symptomless nature. Unfortunately, the damage and loss of vision caused by glaucoma is permanent.
What Are The Risk Factors?
The most important risk factor of developing glaucoma is a high intra-ocular pressure (the internal pressure in the eye). This pressure is maintained by the production and absorption of clear fluid inside the eye. The impedance of the absorption of this fluid causes the intra-ocular pressure to rise.
Age also plays a role and glaucoma is usually seen in people above 40 years of age (although it can affect all age groups). Diabetics are at a higher risk of developing glaucoma. Glaucoma can also run in families, so a person whose parent or sibling has glaucoma is at a higher risk of developing it.
How Is Glaucoma Diagnosed?
- Examining the eye with a slit lamp and looking at the retina and the optic disc (the point where the optic nerve exits the eye at the back)
- Measuring the intra-ocular pressure (tonometry)
- Special lens examination of the angle of the anterior chamber (gonioscopy). This helps in determining whether the type of glaucoma is open angle or angle-closure
- Computerized visual field testing to determine the extent of damage done by glaucoma
- Central corneal thickness measurement (pachymetry) which helps to adjust the eye pressure correctly
- Occasionally more advanced tests such as retinal nerve fiber layer analysis may be needed to diagnose early stages of glaucoma or monitor ongoing damage
What Is The Treatment For Glaucoma?
The treatment is based on the various types of glaucoma.
- Primary open angle glaucoma
- Primary angle-closure glaucoma (PACG)
- Secondary glaucoma
The primary open-angle glaucoma is a chronic type that causes slow, painless loss of vision that starts from the periphery (the sides) and finally affects the central vision. By the time the vision loss is noticed, the damage done is usually quite severe. It is usually treated by reducing the eye pressure with anti-glaucoma eye drops. Laser therapy or surgery may be needed if the eye pressure is not satisfactorily controlled with eye drops.
The primary angle closure glaucoma (PACG) can be painful and can cause significant loss of vision in its acute stage. In its early stage it may cause occasional blurring of vision and mild eye-ache and headache. It needs to be treated with laser therapy and medication. PACG may also require surgery as a treatment option.
The secondary glaucoma is usually seen when the eye pressure increases because of other eye conditions such as eye inflammation, eye injuries, long-term usage of corticosteroids (eye drops or tablets) or hypermature cataracts.