Expert Q&A: A Clinician’s Experience With Macular Telangiectasia Type 2

Written by Rachel Reiff Ellis
Medically Reviewed by Brunilda Nazario, MD on August 13, 2025
6 min read

Experts estimate only 0.1% of people ages 43-86 — about 250,000 people — have macular telangiectasia type 2 (MacTel), a rare eye disease affecting your central vision. But doctors are learning more about the disease each year. In March 2025, the FDA approved the first treatment for slowing progression of MacTel.

Avnish Deobhakta, MD, associate professor of ophthalmology and associate fellowship director of surgical retina at The New York Eye and Ear Infirmary of Mount Sinai has treated about 15 people with MacTel over the last decade. Here he answers common questions about the disease and shares his insight on MacTel’s impact on those living with it.

MacTel is a disease that affects both of your eyes. Specifically, it affects cells at the center part of your retina, called the photoreceptors. These are cells in your eye that receive light. Alongside these cells are supportive cells called the Müller cells, which play an active role in the regulation of the death and survival of photoreceptors. When you have MacTel, your photoreceptor cells and Müller cells both start to degenerate. This starts to affect your central vision: how well you can see when you're reading something, your contrast sensitivity, whether you can see well in certain light settings, and how well you tolerate glare. 

I know using the word degeneration to describe what happens in your eye with MacTel makes people think of macular degeneration, but it’s a different condition. We used to think of MacTel as being part of macular degeneration because it does center around parts of the retina called the macula. But in reality, we think it's a very distinct entity. There may be some genetic connections, but this degenerative process is only of those particular photoreceptor and supportive cells around the center part of the retina. 

You don’t get MacTel because of anything you did. We don't even believe that there's an environmental facet to it, either. There have been some studies that have connected some genes to it. But in reality, it's hard for us to say that those genes really directly caused MacTel. We do think that there's just something more vulnerable for certain people about the photoreceptive cells that are so important to the retina. We can’t point to one action, like smoking, and say that will cause MacTel type 2. It's just something that happens to some people. 

MacTel is a progressive disease, but the progression is slow. Some of the other types of degenerations can happen really quickly, and you can lose your vision within six months. That's not what happens here. It takes years, even decades, for symptoms to progress. But the problem, of course, is that it’s not stoppable. So we can't actually give you a treatment that's going to stop MacTel, but we can say it's going to be a slow process. 

I try to see people in my office every four to six months. Often when people have lived with the disease for a long time, they may skip these visits. I think it’s because they figure since there isn’t a way to reverse the disease itself, regular checkups aren’t important. But if you develop complications, like new blood vessel growth in your eye, these complications can cause issues. New blood vessels, which we call neovascularization, is very similar to wet macular degeneration, and treatment for that — eye injections — can be successful. But we need to be able to pick up on that when it happens so we can treat you and see you more frequently. We don't want someone to lose vision due to a complication that we could have treated.

Encelto is a type of cellular therapy. That means it uses cells modified to do something they otherwise don't do, which is to secrete a factor, or molecule, that helps photoreceptors and Müller cells stop or slow down their degeneration. It’s an implant you get in your eye that has modified cells in it. These cells release the helping medicine into your eye directly and continuously. What we found was that this treatment actually slowed down the progression of damage in the retina that we see by a substantial margin, around 50%. So if we're talking about a decade-long disease and you're slowing the rate of retinal damage by about 50% over two years, that -- over multiple two year periods -- is a big deal. So even though Encelto isn't a cure, I'm excited it exists. Because we finally have something that can make a dent in the progression of the disease. 

You have a surgery during which a doctor puts the device into the vitreous cavity of your eye, which is the back of your eye. You shouldn’t feel the implant afterward, and you can’t see it in your eye. Of course, once you put something in your body, it can always have issues. But they're rare with this implant. It’s possible for it to extrude (come out), and it can get infected or cause irritation. But we always weigh risks and benefits carefully. And what we know is that this medicine does actually have an impact on the disease, which is great. Still, eye procedures can feel scary for many people, and that’s OK. What I always point out is there’s no urgency to put it in. It's not like you can't do it tomorrow if you say no today. We can always talk and revisit the idea later. 

Many people struggle with the idea they're going to start losing part of their central vision. It becomes hard to read or see things clearly. Letters appear crooked. It's hard to see things you once enjoyed, like paintings at a museum. MacTel is most commonly diagnosed in later years, so it’s understandable that in your fifth or sixth or seventh decade of life, it’s hard to face losing an ability you’ve always had. One person I see with the disease is a physician, and her biggest frustration is that for the last 10 years, it's been very difficult to read her notes. It's also hard for her to drive because of the glare off other cars. She talks about constantly needing better lighting, bigger fonts, and more contrast in order to function. 

Living with MacTel today is different from living with it yesterday, in part because we now have a treatment for slowing disease progression. Having no cure for MacTel doesn’t mean there’s no hope. Most of the things we deal with in the retina don't have a cure. Other common conditions like diabetes and diabetic retinopathy don’t have cures, so we learn to manage them. Years ago, we didn't have a treatment for MacTel, and now we have one. Back in the day, we had no treatments for macular degeneration and suddenly we have a whole host of them decades later. And it all started with one. Also, there's great support out there for people living with MacTel. In fact, part of the reason we have such great research for this particular disease is because there were some people with means and resources who really pushed for treatment, because one of their family members was affected. There's always hope.