GLAUCOMA

Glaucoma is a disease of the optic nerve, the cord that connects your eyeball to your brain. A disease of the optic nerve is called an “optic neuropathy” and glaucoma is the most common optic neuropathy. Other optic neuropathies include:

·       Arteritic ischemic optic neuropathy (Giant Cell Arteritis, Temporal Arteritis)

·       Nonarteritic ischemic optic neuropathy 

·       Nutrient deficient optic neuropathy

There are many different types of glaucoma. The most common, primary open angle glaucoma, or POAG, is characterized by an open angle (the area where the aqueous fluid drains into the trabecular meshwork). Angle closure glaucoma is less common. If your eyeball is short and you are farsighted (your prescription begins with “+” then you may be at risk for acute angle closure . This happens then the pupil enlarges and the iris bunches sup into the angle where the aqueous usually drains. This leads to the fluid in the front of the eye not having a place to drain, and your intraocular pressure becoming very high. Comprehensive eye exam and steady regular eye care are crucial to find out if you have narrow angles which can lead to narrow angle glaucoma. In this case, even if you have a regular eye pressure, you may need a laser or eye drops to lower the eye pressure.

POAG can have elevated or normal eye pressure, and an enlarged or normal optic nerve. Most typically, the cup to disc ratio is enlarged. When Dr. Rapoport looks inside your eye, the optic nerve looks like a donut. In a normal eye, the “donut hole” is about 0.3 of the entire donut. In a patient with glaucoma, that hole is enlarged, anywhere from 0.6 to 0.99. This signifies thinning of the optic nerve. Regular eye exams are crucial to know your eye pressure and whether you have any risk factors for developing angle closure glaucoma, normotensive glaucoma, or primary open angle glaucoma.

There is an entity called normal pressure glaucoma, in which the optic nerve is thinned and there is progressive peripheral vision loss, but the eye pressure is of a normal range. In these patients the goal intraocular pressure is even lower. Regular eye pressure in the eye is anywhere between 8-22mmHg, and elevated eye pressure is greater than 22mmHg, but in an eye that already has glaucoma, the goal eye pressure is in the low teens.