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Melanie Cole (Host): Glaucoma is a leading cause of blindness in the United States. Without treatment, those with glaucoma slowly lose their peripheral vision and in time may lose all vision. Here to tell us about this is Dr. Carson Bee. He's an Assistant Professor at UAB Medicine's Callahan Eye Hospital and Clinics. Dr. Bee, explain a little bit about glaucoma. What do we know now about it that we didn't know twenty years ago?

Dr. Carson Bee, MD (Guest): Absolutely. So glaucoma is a heterogeneous group of diseases where damage occurs in a very characteristic way to the optic nerve, the structure in the back of the eye that carries all the sensory information from the eye back to the brain. Like you mentioned, the damage typically causes peripheral vision loss early on, and over time that can progress to central vision loss and even complete blindness if left untreated.

It's often associated with a high intraocular pressure, also known as IOP, and glaucoma is the leading cause of blindness here in the United States, as well as the entire world. About three million Americans currently have glaucoma, and that number is expected to more than double by the time we hit 2050 because of our aging population and demographics.

It's typically painless and slowly progressive over the course of many years, and about half of Americans with glaucoma don't even know they have it.

One of the main challenges with glaucoma is we've known for some time that there's an association between high eye pressure, damage to the optic nerve, and loss of vision, but we're still struggling to understand exactly what happens, what causes it, why some people are more susceptible to others, and how to go about best treating our patients.

So in that sense, not a whole lot has changed in the treatment of glaucoma from twenty years ago to now. The only known treatment is to lower the intraocular pressure. Of course there's lots of fancy new surgeries and tools and ways to do that, but the end result at its core, the treatment is the same, lowering the eye pressure as much as possible.

Melanie: Is it genetic, Dr. Bee? And what are some other risk factors people might have?

Dr. Bee: It certainly can be genetic. There's strong evidence that genetics influences who will go on to develop glaucoma, and we've known for a long time that having a family history is an important risk factor for glaucoma. Therefore it's important for anyone with a family history, especially in first degree relatives, to have their eyes dilated and examined on an annual basis to check for any early signs of glaucoma.

Other risk factors include African or Caribbean descent, individuals with high intraocular pressure, ages greater than forty to fifty years old, people who are myopic, also known as nearsightedness, and as we mentioned before, also those with a family history.

These are all risk factors for the most common form of glaucoma that we see, primary open angle glaucoma, but there are several dozen different types of glaucoma, including glaucoma that can affect infants and children, and people from all walks of life.

Melanie: How important is early diagnosis as being crucial to improve outcome prediction? Speak a little bit about glaucoma screening and diagnostic techniques and how they've improved over the years.

Dr. Bee: Absolutely. So one of the challenges with diagnosing glaucoma is that there's no black and white test that we can use that will tell us if a patient has it or not. We have to kind of put together the big picture what the optic nerve looks like, how the patient's vision is functioning, what their intraocular pressure is, how thick or thin their corneas are.

We've come a long way in diagnostic testing over the past fifteen to twenty years. We've begun to incorporate an exam called an OCT which actually scans the thickness of the nerve tissue in the back of the eye and tells us- and compares that thickness to a subset of controls, and that's one way we can tell if a patient's nerve thickness or the healthiness of their optic nerve is different or more damaged than it should be.

It's extremely important for glaucoma to be diagnosed early because glaucoma damage is damage to the optic nerve, and we know that nerve damage at this point in time cannot be restored. That's why we recommend a screening annual eye exam for most patients above the age of forty, as well as any patient that has a family history of glaucoma. If we can catch the glaucoma early on before it causes significant vision loss, then we have a much greater chance of keeping our patients seeing and functioning well for the rest of their life.

Thankfully in most cases, that does happen with glaucoma in this country, but of course the patients that present to us late and have very constricted visual field, it becomes much more of a challenge to preserve their vision and oftentimes those are the patients that do go blind.

In terms of screening, I think we're much better now than we were in the past. Optometrists and ophthalmologists are typically on the front line, just general eyecare providers, they're at the front lines of looking for glaucoma before they refer them to somebody like me, a glaucoma specialist. And it's important that a dilated exam be done if possible in order for the clinician to fully assess all the ocular tissues, particularly the optic nerve in the back of the eye.

Melanie: What are some current issues in medical or surgical management? Assess for us, Dr. Bee, the appropriateness of specific treatments you'd use once you detect what's going on, such as checking the intraocular eye pressure every few months, or surgical interventions. Tell us a little bit about what you do next.

Dr. Bee: Sure. So like we discussed before, the only treatment for someone with glaucoma is to lower the eye pressure, and in some patients, their pressure starts at forty or fifty, and a normal eye pressure being between ten and twenty-one millimeters mercury. Other patients may be progressing or worsening at a pressure of twenty-five. So oftentimes, the first line of treatment or therapy for glaucoma is glaucoma eyedrops. There have been many studies over the years that have demonstrated that eyedrops work just as well as an invasive eye surgery in keeping the pressure down.

In patients where the pressure does not decrease enough with our various eyedrops, there are certain laser treatments that are available to us. The most common laser is called SLP laser and works to open the natural drainage pathway in the eye to lower the eye pressure that way, to kind of improve outflow capacity.

Finally if that does not do the trick, then oftentimes a glaucoma surgery is indicated because the pressure is high, and because the natural drain may not be functioning as well as we would like, most glaucoma surgeries center around creating a new drain within and external to the eye to drain the fluid- the aqueous fluid from the front of the eye to a reservoir outside of the eye, and allow the pressure to come down that way.

It's also an exciting time in glaucoma surgery because of the recent advent of an entirely new sub-category of procedures called minimally invasive or micro invasive glaucoma surgery. These procedures allow for augmenting or creation of new drainage pathways and seem to have a much safer risk profile and recovery is much quicker as well.

So in many patients who need to have glaucoma surgery, we're now recommending or at least considering these minimally invasive options which sometimes leads to better outcomes, safer procedures, and an increased or improved recovery time.

Melanie: What are some of the clinical challenges and priorities in managing glaucoma patients that you see?

Dr. Bee: I would say one of the biggest challenges is with eyedrops. Many of our patients are elderly, they're unable to maintain a complex regimen of two or three or four different eyedrops put in at various times of the day. Some of our patients have dementia and have to rely on caregivers to give them eyedrops. Eyedrops also have to be spaced about five minutes apart. You let the first one sit and soak and absorb into the eye before you put the next one in so you don't wash the first one out. So it can be very challenging for many of our patients to stay compliant.

Many studies that have analyzed the compliance and adherence of our patients to eyedrops have shown that most of our patients do a very poor job of getting the medical treatment that they need on a daily basis.

The other challenge is that glaucoma drops, it's not something you just take for a week and then you can stop. This is something you have to take continuously every day, every month, every year, and that can be certainly very challenging for many of our patients. What's interesting is most of our patients will take their eyedrops the day before they come see us in the office, and they'll show up with an eye pressure that's actually pretty good because they were using their eyedrops within the last day. But then they go home, and they may only take their drops three days out of a week, or every other night, and clinically you can see them getting worse, yet the parameter that we look at very closely, the eye pressure, is actually doing quite well when we see them in the office.

So it can be a challenge to counsel patients, to identify patients that are not being compliant with their medication regimen, and kind of working with them to come up with a treatment plan to best preserve their eyesight and preserve their vision. Oftentimes that means becoming more aggressive or performing something like a procedure that will work for them rather than relying on them to treat themselves.

Melanie: Looking forward to the next ten years or so in the field, give us a little blueprint for future research. Are you developing tests that can identify patients at a higher risk? Give us a little blueprint.

Dr. Bee: I would say there is certainly a lot of exciting research going on in the glaucoma world. There are a couple of new eyedrops out on the market that work in ways that we had not been able to employ before medication-wise, and we're just beginning to understand how those might impact and improve eye pressure and therefore glaucoma for many of our patients.

Here at UAB, we also have a robust glaucoma research department. A lot of the research focuses on analyzing the biomechanical nature of the optic nerve, and the way it forms, and the strengths of the structures around the optic nerve. We know that many patients are susceptible to low or even normal eye pressures and sustain glaucoma damage. What is it about those optic nerves that makes them so sensitive whereas another patient who can walk around with a pressure of thirty-five, thirty, and never have damage? What is the difference between those structures? So there's a lot of biomechanical research being done into the stress and the strain applied to these tissues, and why some are better than others, and the idea is that over time we may be able to identify therapeutic treatments that could potentially protect our patients' nerve tissues from becoming glaucomatous and therefore losing vision.

I would also say that there are many new exciting surgical advances on the horizon. The MIGS category - micro invasive glaucoma surgery - is still relatively new and there are multiple devices coming up down the horizon. And for patients that need surgery, I think we may be reaching a point where we're able to offer procedures that are much more safe and almost hopefully and potentially revolutionary, kind of like what cardiac stints did for open heart surgery, where many patients could just have stints of this big invasive procedure that carried with it a lot more risk and a lot more complications.

So many glaucoma specialists are hoping that the next wave of procedures will have a similar revolution.

Melanie: In summary, Dr. Bee, tell other physicians what you'd like them to know about Pell City Clinic of UAB Medicine's Callahan Eye Hospital and Clinics, and when you feel that it's really important that they refer.

Dr. Bee: Certainly. So in the Birmingham metro area, the only glaucoma specialists in town are located here at UAB at the Callahan Eye Hospital. There are a total of seven of us with a diverse training and expertise, and my partners and I also see patients at many satellite clinics located throughout the state such as Pell City.

We also have every ophthalmology sub-specialty here within the building, and so we can take care of our patients regardless of what's going on with their eyes. In terms of other physicians, really the best time and the appropriate time to refer a patient in for a complete eye exam is when any complaint goes beyond watering, scratching, or itchiness. The eye can be a very complex structure that's difficult to examine in the primary care clinic, but as eye providers of course, we have the benefit of microscopes, a lot of advanced tests and equipment to try and help us figure out what's going on. There can be so many different problems with the eye, and it's oftentimes very difficult to tell unless they have a full eye exam.

So any patient that really complains of vision loss should probably be referred to have things looked at. Thankfully, most eye conditions if caught early can be appropriately treated and managed and vision maintained and preserved.

Melanie: Thank you so much, Dr. Bee, for being on with us today and sharing your expertise and telling us about some of the research that's going on in the world. It's a very exciting time. A community physician can refer a patient to UAB Callahan Eye Hospital by calling the 844-UAB-EYES. That's 844-325-8620. You're listening to UAB Medcast. For more information on resources available at UAB Medicine, you can go to uabmedicine.org/physician. That's uabmedicine.org/physician. This is Melanie Cole. Thanks so much for listening.