Glaucoma is the leading cause of irreversible blindness, affecting nearly 60 million people worldwide and leading to blindness in 8 million people. Glaucoma awareness and understanding is important since many people go blind slowly without noticing until the very end. It’s equally important to distinguish the type of glaucoma that one has because the treatments are different.
There are two main types of glaucoma: open-angle glaucoma (OAG) and closed-angle glaucoma (CAG). The majority of glaucoma worldwide is OAG (2/3). OAG occurs more frequently in African Americans, men, and in older aged individuals. CAC occurs more frequently in woman and in Asian populations. Although there are less people with CAG, 50% of glaucoma blindness occurs in CAG.
So what’s the difference?
We all have a drainage system in our eyes called the trabecular meshwork (TM), which one can think of as a sink drain. Just like a sink, it can get clogged at different levels and lead to increased eye pressure resulting in glaucoma. In OAG, the clog is deep in the TM and the appearance looks completely normal. However, in CAG, the clog is at the surface and the TM is not visible because it is blocked by the iris (colored portion of the eye).
Ultimately, the treatment in both types of glaucoma is to lower the pressure in the eye. In CAG, the pressure can increase quickly and it is important to try to open up the TM by performing a laser called a laser peripheral iridotomy (LPI). On the other hand, in OAG, the pressure rise is usually gradual and often responds to eye drops that lower the pressure in the eye. In some cases of OAG, we perform a different laser called selective laser trabeculoplasty (SLT), which lowers the pressure by clearing the clog deep in the TM.
There are some medications that are contraindicated in certain types of glaucoma. If you are on any type or steroid (oral or inhaled) your eye doctor should know because it can increase the eye pressure in both OAG and CAG. There are many psychiatric drugs and urinary drugs that may only be a problem in CAG. Importantly, if you have had a LPI, then many of these drugs can still be taken safely in CAG.
Make sure to ask your doctor what type of glaucoma you have and if any of your medications are contraindicated. For more information on glaucoma, glaucoma surgeries, or other services, please contact us at (203) 878-1236 in any one of our 4 offices in Milford, Orange, Branford, or Shelton. We are looking forward to hearing from you soon.
Blog posted by Dr. Omar Faridi, a board certified ophthalmologist and fellowship trained medical and surgical glaucoma specialist. For more information on glaucoma, or any of the services we offer, please contact us (203) 878-1236 at any of our 4 offices in Milford, Orange, Branford, or Shelton. We’re looking forward to hearing from you soon.