What is Glaucoma?

A Nerve Tissue Disease
Glaucoma is caused by nerve tissue damage. This nerve tissue is made of neurons, the same material your brain is made of. The tissue that is lost is the tissue that connects your eye to your brain. Many other eye diseases cause damage to this tissue, but are characteristically different than glaucomatous damage. Why the nerve tissue becomes damaged is not totally understood, although research points to decreased blood flow to the tissue and increased pressure inside the eye.

A Multi-Factorial Disease
To fully monitor glaucoma, we look at 8 or so different factors, each with their own unique test. Some tests must be rechecked more often than others. Not all the tests will be done on your first visit. To read more about the different factors, click here.

A Silent Disease
Patients do not notice they have glaucoma until 95% of nerve tissue has been irreversibly lost. For this reason, many people are blind from glaucoma despite it being highly preventable.

A Preventable Disease
Preventable treatment for glaucoma is excellent! There are 5 different classes of drugs that slow the progression of glaucoma, each class containing several FDA-approved medicines. You may hear some say 'glaucoma is a great disease to have'; there is some truth in this dark humor because glaucoma is very preventable relative to most eye diseases. Treatment stops glaucoma from progressing but does not reverse damage to nerve tissue previously caused by the disease. So the trick is to visit your eye care professional regularly to know if you have the disease!

A Disease of Progression
Many patients begin as 'glaucoma suspects' because early diagnosis of glaucoma relies on seeing it progress from early to early-moderate stage. This is also why it is helpful to not change providers too often, and if you must change eye care providers, try to get them copies of your previous records.

Multiple Types of Glaucoma
There are many types of glaucoma, but the most common is primary open-angle glaucoma. When someone says 'glaucoma', it is typically assumed they are referring to this most common type. Other types of glaucoma include Iridocyclitic glaucoma (also known as neovascular or diabetic glaucoma) and angle-closure glaucoma. These forms of glaucoma are very different and are not multifactorial.

The Stages of Glaucoma
To learn more about the stages of glaucoma and the tests we do at each stage, click here.


Lysle Shaw-McMinn, O.D.
May 10, 2014