What is Glaucoma?
Glaucoma isn’t any one disease in particular, but a group of diseases that can damage the eye’s optic nerve which will result in vision loss. If detected early, the eyes can be protected against serious vision loss. It is often, but not always, characterized by an increased amount of fluid within the eye resulting in increased eye pressure.
Signs and Symptoms
At first, glaucoma may not present with symptoms. It can cause no pain, and vision remains normal. Without treatment, those with glaucoma will slowly lose their peripheral vision. The patient may miss objects to the side and out of the corner of the eye. “Tunnel Vision” is a common occurrence. Eventually, all vision may deteriorate.
Progression of Glaucoma over a period of time
Pictured above are a variety of optic nerves.
The first and second pictures are variances of healthy optic nerves.
The third and fourth pictures show damage to the optic nerve from glaucoma.
How do we detect Glaucoma?
- Visual Acuity - A test using an eye chart that measures how well a person sees at distance.
- Visual Field Test - A test that measures the peripheral vision (side vision). A loss of peripheral vision can be an indicator of glaucoma.
- Dilated Eye Exam - The pupils are dilated using special eye drops, then a magnifying lens is used to exam the eye for damage. Blurred vision results for several hours.
- Tonometry - An instrument is used to measure the pressure inside the eye. Increased intraocular pressure can be a sign of glaucoma.
- Pachymetry - An instrument is used to measure the thickness of the cornea. The eyes are numbed and an ultrasonic wave instrument is used.
Medication is available in the form of both eye drops as well as pills. It is the most common early treatment for glaucoma. If the medication is taken in compliance, they can often lower eye pressure or cause the eye to produce less fluid. Since glaucoma often has no symptoms, it is important to continue using the medication prescribed.
This is a procedure that helps fluid drain from the eye. Numbing drops are applied to the eye and the patient sits facing the laser machine. The doctor will hold a special lens to the eye and a high intensity beam of light is directed through the lens onto the meshwork inside the eye. Flashes of bright green or red light may be seen. The laser will make several evenly spaced holes that will expand the drainage holes in the meshwork of the eye, allowing the fluid to drain more properly.
This type of surgery allows the fluid to leave the eye by making a new opening. Surgery is often an option when medicines and laser surgery have failed to control the pressure. It is performed in an operating room and is more extensive. This type of surgery is performed on one eye at at a time (if glaucoma is present in both eyes) and the operations are six weeks apart.
(This page was adapted from the National Eye Institute)