For Paul Chous, OD, of Chous Eye Care Associates, Inc in Tacoma, Washington, everything is personal. He’s parlayed his personal experience with type 1 diabetes into a specialty optometry practice focusing on diabetic eye care. In his 20-plus years in practice, he’s also become an accomplished author and developed a reputation on the speaking circuit as optometry’s go-to guru for diabetes know-how, using details from his own experiences to humanize the sometimes esoteric lectures on blood glucose level monitoring and inflammatory cytokines.
He’ll be humming that same tune at SECO 2023, but he’s added some new numbers to his repertoire. He also has experience with sleep disorders, which is the catalyst behind his next presentation “Sleep Disorders; What Eyecare Professionals Need to Know,” where he’ll detail his experiences, as both clinician and patient, with obstructive sleep apnea, dyssomnias, and other sleep disorders and how they connect with ocular disease.
You can see Dr Chous at SECO presenting “Diabetes: Then and Now” and “Sleep Disorders; What Eyecare Professionals Need to Know,” both on Saturday, March 4, 2023.
You carved out a niche for yourself as an expert on diabetes and the eye years ago. What’s it like seeing how instrumental an understanding of diabetes is becoming for optometry?
From a personal and professional perspective, it’s really wonderful to see. This was suggested to me 20 years ago by my own endocrinologist who said “you know, I send patients to eye doctors and, half the time, I don’t get letters back. Why don’t you open a practice near me and I’ll send patients to you?” So I did that and, next thing you know, he’s telling all his colleagues in primary care medicine to refer patients to me. That’s how I developed this niche practice and, I think, any optometrist can do as much or as little of diabetes care as they want. It’s almost inevitably foisted upon us just by virtue of the epidemiology. Almost every other patient optometrists see seem to have either diabetes or prediabetes, if they’re older than the age of 18. So, there’s definitely an impact in eye care physicians having an understanding of, not just ocular manifestations, but good systemic care of patients with diabetes.
Today, we have all these new therapies that can help patients with diabetes improve their lives. I think eye care physicians should become familiar with these so we can help patients communicate with their general practitioner or their endocrinologist as to what we’re seeing in their eyes and how they can be managed systemically better.
I think it’s great. It opens up a whole area of preventative health care and nutrition, which I’m keen on. It’s an exciting time. Not only can most cases of blindness from diabetes be prevented, but most diabetes can be prevented if people are educated properly.
This year, you’re speaking on diabetes “then and now” — What are some of the most important recent changes you’ve seen in developing an evidence-based action plan to stave off deleterious ocular/visual effects of diabetes?
The most important development really has been the burgeoning growth of continuous glucose monitoring systems. They actually allow patients to take better day-to-day control of their blood glucose levels. Rather than waiting for a blood test to be drawn and waiting until 3 months after the fact, we now have real-time data that allows you to take steps to improve your blood glucose control. Data is now showing that that’s more important than things like hemoglobin A1C at predicting complications. There’s been a call by researchers to include continuous glucose monitoring in every study that’s done from now on, not just hemoglobin A1C.
The next key development has been anti-vascular endothelial growth factor (VEGF) therapies, which have had a huge effect on preventing vision loss from diabetic macular edema. Now, even those are undergoing a shift to make it easier on patients by using topicals and using longer lasting therapies that you don’t have to inject as often, and gene-based therapies you can implant into the eye.
Optical coherence tomography (OCT) is another breakthrough that has helped us reveal subclinical diabetic macular edema. A lot of patients have macular edema, but it’s not recognized on a clinical exam because it’s so subtle. OCT really does give you a chance to see that. Also, something I’m interested in is retinal diabetic neuropathy, where the neuro elements of the retina thin out. It doesn’t lead to the kind of profound vision loss that you’d classically associate with diabetic retinopathy, but the thinning of the neuroretina is highly associated with neuropathy findings in people with diabetes, including cardiac autonomic neuropathy, which increases the risk of having a cardiovascular death.
We’ve also got these 2 humongous categories in medicine now which have been shown to give patients cardiorenal protection: SGLT2 inhibitors (which dramatically lower the risk of heart attack, stroke, and hospitalization for heart failure), and GLP-1 agonists. Those GLP-1s actually can, in some cases, make the retina get worse. I’m advising on a study about it now. It’s not actually the drug that makes the retinopathy worse, it’s the drop in blood sugar. This is something we’ve known about for 80 years with insulin. If somebody has terrible blood sugar control and you suddenly put them on insulin therapy and improve their blood glucose control dramatically, the retina almost always gets worse. It’s almost as if it gets acclimated to bad blood glucose control, but it’s a temporary effect. These drugs lower cardiovascular risk — one trial shows they reduced all-cause mortality by 50% and major adverse cardiovascular events by 20-30%.1 They are also associated with profound weight loss, rivaling that which can be achieved with bariatric surgery. You can lose between 12 and 75 lbs using these drugs. I see patients now routinely losing 50 lbs. When you lose that much weight, and you have obesity and you’re hyperinsulinemic with profound insulin resistance, it’s remarkable how many other things get better — your blood pressure, lipides, blood glucose control. And that’s when patients’ quality of life improves.
What education do patients require regarding diabetic eye disease that optometrists can deliver?
This is so fundamentally important — we have to constantly remind patients that good vision on an eye chart or in the real world is not the same as having healthy eyes. So, just making sure patients understand that dichotomy, that’s number one. The second thing is that good metabolic control is most beneficial when it’s undertaken early on, because of metabolic memory. I put it this way to patients: Your eye remembers how badly you treated it for the first 8 to 10 years. So, even if you get great blood sugar and blood pressure control 10 years after a diabetes diagnosis, it’s too late. So, the most important part of the PANORAMA Trial (ClinicalTrials.gov Identifier: NCT02718326) was that they showed patients who had severe nonproliferative retinopathy who had excellent glycemic control received zero protection from having that good blood glucose control. They were, in fact, more likely to progress into sight-threatening disease. So, the horse is already out of that barn. My message to ODs and ophthalmologists alike is that we have to get patients to buy in early on to tight glucose control because of metabolic memory. Make sure these patients get seen on a regular basis and understand that what they do now is going to pay off 30, 40, or 50 years down the line.
Every patient is different. What motivates some patients might not motivate others. For men who have retinopathy, I sometimes ask about erectile dysfunction. Those can actually go hand in hand. It’s amazing how often when men hear that, they say “oh wow, I should really get better control of my blood glucose because my sex life will improve.” Well, yeah, but we know they want to keep their vision too, and stay alive! That’s a motivator for some patients — and that’s what you have to do. You have to motivationally interview your patients. Find some thread within their life that motivates them to want to live longer and healthier. It could be seeing their grandchildren, or seeing their children as they get older.
How can modern structural testing for diabetic retinopathy, such as electroretinogram (ERG) and OCT, and OCT angiography (OCT-A) change decision making in the optometrist’s office?
OCT is, from my point of view, far more useful than OCT-A. You don’t need OCT-A to see diabetic retinopathy. OCT shows you the neuro-retina. Every OD, if possible, should have access to an OCT. Ideally, have one in your practice. You can buy a second hand OCT, that’s what I did for my first OCT. It’s not that expensive. Things like ERG, or color vision testing that’re more elaborate — I’m being persuaded that these things are more and more important. I’m currently consulting for a company developing a device that appears to predict which patients are actually going to need invasive therapy, such as laser or anti-VEGF therapy, based on the electrophysiology of the retina that you can measure in your office in about a minute, and the cost is not prohibitively high. Something like this can help optometrists make decisions about who needs to be seen more often, how often they need to be seen, and when they should be referred to a retina specialist for consideration for treatment.
You’re also speaking this year on sleep disorders and the eye — what’s the connection here?
Everything! It turns out, if you have sleep apnea, or clinical insomnia, or just don’t get enough hours of sleep per night, or even if you sleep too long, the risk for all the major eye diseases goes up. That includes glaucoma, macular degeneration, diabetic retinopathy, and dry eye.
What made me interested in this talk was an incident I had with an emergency room doctor — a glaucoma suspect — who came into my office for a visual field exam. He fell asleep at the perimeter in the middle of an exam. I said to him “what’s the deal, are you sleeping?” He told me that the night before, he only got an hour of sleep. There was another incident with an internal medicine doctor who was sleep deprived — I came in and asked “how’re you doing?” and he started to cry in my exam chair. He said he’d been up for 72 straight hours and was overwhelmed, had too many patients and said ‘I screamed at my favorite nurse in my hospital. She’s the nicest lady I ever met and I screamed at her. I’ll never be able to forgive myself.” I didn’t give him an eye exam that day. I sent him home to get some rest. When he returned, he didn’t have any memory of coming to see me or our conversation that day. There are a lot of sleep deprived physicians out there.
Sleep apnea is probably the most worrisome, followed by hyposomnia. Too little sleep at night promotes insulin resistance syndrome and diabetes. And if you look at any common eye disease and lack of sleep, there are associations between the two, and optometrists need to be aware of them. There are some pretty easy tools for optometrists to assess for sleep disorders, including the STOP-BANG apnea inventory and the ESAP (easy sleep apnea predictor), both of which I’ll discuss at my SECO talk.
- Husain M, Birkenfeld AL, Donsmark M, et al. Oral semaglutide and cardiovascular outcomes in patients with type 2 diabetes. N Engl J Med. 2019;381:841-851. doi:10.1056/NEJMoa1901118