January is Glaucoma Awareness Month. In the latest installment of our conversations with Fort Worth newsmakers, Dr. Sai Chavala, an ophthalmologist in Fort Worth and a professor of surgery at the Burnett School of Medicine at TCU, discusses glaucoma — what it is, who’s vulnerable and how to prevent it.
This conversation has been edited for length and clarity. For an unabridged version, please listen to the audio file attached to this article.
Alexis Allison: So Sai, what is glaucoma?
Dr. Sai Chavala: Glaucoma is a disease that causes damage to the nerve in the eye called the optic nerve. This can be a result of high pressure. And over time, the nerve loses the ability to transmit information from the eye to the brain.
The optic nerve can be thought of as the cable on the back of your television. The cable transmits all of the data that the eye sees to the brain, and unfortunately, in certain patients with glaucoma, over time, they will lose vision because they have high eye pressure that was untreated. Unfortunately, glaucoma is often asymptomatic, meaning patients don’t even know they have the disease until much later in the disease progression.
Allison: You mentioned high pressure in the eye. What causes that?
Chavala: No one knows. But the best way of thinking about it is a sink and a faucet. So the eye, obviously, is not a squished grape. And so in order for it to maintain its shape, there’s fluid that’s produced in the eye to give it its shape and structure. So that’s the faucet part — where the eye actively makes fluid that fills up the eye and gives it its shape. And then there’s a drain part, where there’s a drainage system that removes that fluid. Unfortunately, in glaucoma, the drainage system gets altered, but the faucet flow does not decrease. And so over time, you get higher eye pressure because the drainage system cannot keep up with the production of the fluid in the eye called the aqueous fluid.
Allison: I really love that metaphor. Who is most at risk for developing glaucoma?
Chavala: So African Americans are at risk of developing glaucoma. Patients that have a family history, so having a close family member with a history of glaucoma puts one at risk. And then there’s also changes in the cornea that can put you at risk as well.
And I want to emphasize that often patients don’t know they have glaucoma. There’s really, for the most common type of glaucoma, there’s no symptoms, there’s no eye pain. There’s no real appreciable loss of vision, because glaucoma robs you of your peripheral vision first before it impacts the central vision.
Who’s at risk for developing glaucoma?
- People 55 years and older
- Black, Asian or Latino people
- Family history of glaucoma
- People with certain medical conditions, like diabetes, migraines, high blood pressure and sickle cell anemia
- People whose corneas are thin in the middle
- People with extreme near- or farsightedness
- People whose eyes have been injured
- People who take corticosteroids, especially eye drops, for a long time
Source: Mayo Clinic
Allison: If someone wanted to know if they had glaucoma, how would they go about getting tested?
Chavala: Yeah, I think that’s one of the most important questions to answer. So the definitive way of determining if someone has glaucoma is through a comprehensive eye exam, as well as additional testing that can be done in an eye care professional’s office.
So, eye care professionals will often dilate the eye. And, one, they will measure the eye pressure using a special instrument and that will be able to detect if the eye pressure is elevated. In some cases, the eye pressure remains in a relatively normal range, but you can still develop glaucoma. So it’s important, then, to look at the optic nerve, that nerve that we were talking about before, and that can be done with a dilated eye exam. And having an eye care professional actually look at the structure of the nerve to see if it looks damaged or not.
Then there’s additional tests that can be done that measure the peripheral vision and determine if there’s been vision loss in the peripheral vision. And that can be done easily in an eye care professional’s office.
Allison: What can be done to treat glaucoma?
Chavala: So there’s a variety of treatments. But the No. 1 — I can’t stress this enough — is to get it diagnosed, so seeing an eye care professional. Getting that diagnosis early is extremely important. If the diagnosis is made, we have medications such as eye drops that can be administered at home or wherever the patient is, that can reduce the flow through that faucet. So, reduce the production of the fluid that’s made by the eye.
And then we also have eye drops that can help open up that drainage system. So eye drops are kind of the mainstay of treatment for glaucoma. There’s also lasers that can be done in the office. They’re painless. They’re done just as an outpatient procedure, and they can laser the drainage system so that it works better. And then there’s surgery that would be done in a surgical suite, and they can create new drains in the eye to help reduce the pressure and improve the flow out of the eye.
Allison: You mentioned that an early diagnosis is really important. What are the recommendations in terms of how often someone who’s at risk for glaucoma should get checked for it?
Chavala: If a person is at risk, but does not have a diagnosis, I would say once a year is appropriate. And doing some of the testing, the additional testing that we mentioned as a baseline is very valuable. So once those tests are done, you can compare years later to that first initial baseline test to see if there’s any kind of progression.
As I mentioned, eye pressure is one of the most common risk factors, but you can still have glaucoma without having extremely high eye pressure. So it is really important with the family history to have some of these baseline tests done before the damage ensues.
Once you do have advanced glaucoma, unfortunately, there are no treatments currently that allow us to reverse the vision loss. Once it’s gone, it’s unfortunately gone. Now, my research team and my lab strive to be able to come up with a therapy to replace those degenerated neurons and that optic nerve so that we could one day restore vision or prevent vision loss from those neurons or those cells in the optic nerve that are at risk of dying from high pressure and support them and prevent them from actually dying and preventing further vision loss.
Allison: I hope that those come to fruition. And in the meantime, is there anything that anyone can do to prevent glaucoma?
Chavala: So, again, I think the best therapy right now is early detection. And so getting a comprehensive eye exam. And then if, if the eye care professional feels that drops or lasers or surgery are indicated, to do those, and to really be adamant about a vigilant follow-up, because, again, for most cases, if the diagnosis is made early, it can be prevented. And glaucoma is not a disease that necessarily leads to blindness if it can be treated early and effectively.
Allison: Is there anything else that you’d like us to know?
Chavala: There are a lot of great researchers around the world but importantly, also in Texas and in Dallas/Fort Worth, that are working on therapies to prevent vision loss from glaucoma or diseases like glaucoma. And so I think it’s a very exciting time in the science world, because we’re coming up with new opportunities to improve the drainage system and then also to protect the survival of the neurons in that optic nerve.
Alexis Allison is the health reporter at the Fort Worth Report. Her position is supported by a grant from Texas Health Resources. Contact her at alexis.allison@fortworthreport.org or via Twitter. At the Fort Worth Report, news decisions are made independently of our board members and financial supporters. Read more about our editorial independence policy here.
Republishing is free for noncommercial entities. Commercial entities are prohibited without a licensing agreement. Contact us for details.
