Eye Diseases What is Glaucoma?

The human eye produces a fluid called aqueous humor which provides nutrition to the inside of the eye. This fluid keeps moving out of the eye through channels in the angle of the eye. In a normal eye, the amount of fluid produced balances out the amount of fluid flowing out of the eye. That keeps the pressure inside the eye (intraocular pressure) stable. With advancing age and various other conditions, these channels get blocked or compromised and the fluid starts collecting in the eye. This results in raised pressure within the eye. The raised pressure then starts damaging the Optic nerve. The Optic nerve is responsible for carrying the signals of light from the eye to brain thus making vision possible. The damage thus caused to the Optic nerve leading to a decrease in the field of vision and sight is called Glaucoma.

What are the types of Glaucoma?

There are three major categories of Glaucoma. These are:

A. Primary Open Angle or Chronic Glaucoma -

This is the most common form of glaucoma. Damage to the vision in this type of glaucoma is gradual and generally painless. The affected person normally remains completely unaware of the disease, until the optic nerve is already damaged badly. A comprehensive and detailed examination by an eye specialist is required to diagnose and manage this condition before it progresses to cause significant and permanent damage.

B. Closed Angle or Acute Glaucoma -

In this type of glaucoma, the intraocular pressure increases very rapidly due to a sudden and severe block of fluid drainage system within the eye. Significant symptoms like pain, watering, red eye and reduced vision appear immediately, indicating the presence of acute glaucoma. This condition has to be treated quickly by an ophthalmologist otherwise blindness may occur.

C. Other Types of Glaucoma -

These are Congenital Glaucoma, Pigmentary Glaucoma and Secondary Glaucoma.

What are the usual features of Glaucoma?

Common types of glaucoma three common features -

(1) Increased Intraocular Pressure - This is measured with Goldmann Applanation Tonometer.

(2) Cupping or Atrophy of the Optic Nerve - This is the drying up or damage of the optic nerve as a consequence to the damage suffered because of high pressure in the eye. This is evaluated by examination of the Fundus of the eyes.

(3) Visual Field Defects - This is basically the presence of missing or blind areas in the field of sight even though the person may be seeing well otherwise. This condition is assessed by doing the Field of Vision on an instrument called as the Perimeter.

What are the symptoms of Glaucoma?

Glaucoma in early stages generally does not show any noticeable symptoms. It is possible that a person suffering from Chronic Open Angle Glaucoma to be completely unaware of the disease. Chronic glaucoma generally progresses too slowly to get noticed. Some common symptoms of chronic glaucoma could be -

. Inability to adjust the eyes to darkened rooms such as theaters.
. Subtle problems in ability to see in night.
. Frequent changes in eyeglass (reading) prescription.
. Gradual loss of peripheral vision.

In the case of Acute Glaucoma (Angle Closure) which results from rapid increase in the intraocular pressure, there could be severe symptoms. Common symptoms suggesting the presence of acute glaucoma could be -

. Blurred vision.
. Seeing rainbow colored halos around lights in the evenings.
. Headaches.
. Severe eye pain, facial pain accompanied by blurred vision.
. Redness in the eye with sudden loss of vision.
. Nausea and vomiting.

Which are the High Risk Groups to get Glaucoma?

. People belonging to families with a history of glaucoma.
. People suffering from diabetes.
. People having high minus or plus numbered glasses.
. Everybody over forty years of age.
. People suffering from hypertension.
. Anybody who has undergone any kind of eye surgery.
. People with thyroid gland related ailments.
. People with over mature cataracts.
. People with any injury to the eye.
. People with a history of prolonged use of steroid eye drops.

Is Glaucoma curable?

Glaucoma cannot be cured. But it can be controlled and further damage to the optic nerve can be slowed down or halted. This control can only be sustained through very disciplined and regular treatment as advised by the ophthalmologist. It is life long process.

What are the Treatment Options for Glaucoma?

a) Medication
The chronic open angle variety glaucoma which has not progressed too far can be controlled by the use of eye drops alone. These drops may have to be put 2-4 times a day. In case of higher intraocular pressure, the patient may have to use more than one type or combination of eye drops.

(b) Laser treatment
Laser treatment is a must for acute type and angle closure variety of glaucoma. Laser treatment is also done to control pressure in open angle type glaucoma. Laser treatment is also done for patients who have a high risk of developing Acute Angle Closure Glaucoma, as a prophylactic or preventive measure.

(c) Surgery
In those cases where eye drops and laser treatment do not prove sufficient to control the pressure, surgery is done to create an alternate pathway for the fluid to drain out.