John A. Moran Eye Center retinal specialist and researcher Paul S. Bernstein, MD, PhD, diagnosed John Ehrman with a rare eye disease known as Macular Telangiectasia Type 2 (MacTel) in 2014.
The disease causes a gradual loss of central vision, and for Ehrman had produced a row of black dots in his vision that he refers to as his “Orion’s belt.”
There were no treatments available, but at Bernstein’s request, the retired elementary school librarian, his two brothers, and his four sons agreed to participate in an international research effort, known as the MacTel Project. On Thursday, their efforts marked an important milestone. Ehrman became the first patient in the Mountain West to receive the newly approved first and only treatment for MacTel.
Dubbed ENCELTO, a capsule no bigger than a grain of rice implanted into Ehrman’s left eye should slow his disease progression by 30-50%.
“I’ve always been a just kind of do what you gotta do kind of person; you have to deal with things,” said Ehrman of the surgery. “I don’t want my eyes to get worse. I want to keep driving on road trips, and I want to keep riding my bike. I want to be able to see well and know that my vision is stabilized.”
As he prepared to implant the device in a one-hour surgery, Bernstein described the day as a full-circle moment.
“It's been fantastic to be involved in a project researching a disease we knew very little about that has gone all the way to a new therapy I can offer my patients,” he said.
MacTel Research at Moran
When Bernstein started training as an ophthalmologist, MacTel was what physicians refer to as an “orphan disease."
“It was rare; it was hard to diagnose, and there was little we could do about it,” recalled Bernstein, Moran Eye Center vice-chair for clinical and basic science research.
In the early 2000s, advances in ophthalmic imaging that could produce 3D images of the eye, known as optical coherence tomography, as well as a much newer form of imaging called Fluorescence Lifetime Imaging Ophthalmoscopy, allowed for easier diagnosis.
The MacTel project recruited Bernstein for his research expertise in carotenoids, such as lutein and zeaxanthin, which play a vital role in eye health. Both come from dietary sources: dark green leafy vegetables and orange and yellow fruits and vegetables. Both are also known to get depleted early on in MacTel. The project also aimed to begin tracking large families with a history of the disease to understand its genetic basis.
“I had just seen a mother-daughter pair of MacTel patients when they called me,” said Bernstein. “Today at Moran, we now have the largest cohort of patients, more than 150, at a U.S. academic center, with patients coming in from all over the Mountain West. In 2019, we identified the family with the first identified gene for MacTel. That led us to understand, in part, what’s causing the disease: a disorder of metabolism of the amino acid serine.”
The First Therapy
Approved by the FDA in March 2025, the first therapy for MacTel is an encapsulated cell-based gene therapy. The tiny capsule, placed into the eye, contains cells genetically modified to continually produce human ciliary neurotrophic factor (CNTF), a protein that supports the health of certain cells in the retina.
Moran’s history with the device dates back more than 20 years.
“We were part of some of the initial studies here to test this for age-related macular degeneration and inherited retinal disease like retinitis pigmentosa,” said Bernstein. “It did not move forward for those diseases. But there was some evidence starting to come through from basic science work from the MacTel Project at that time that CNTF might be helpful.”
Bernstein was one of the high enrollers in phase three clinical trials for testing ENCELTO for MacTel.
What’s Next
Ehrman is no stranger to understanding the problems associated with diseases that run in families. He and his two brothers survived prostate cancer in their 40s. And he remembers his grandmother, now deceased, had vision problems he now thinks could have clearly been MacTel. So far, his brothers and sons have not been diagnosed with the disease, Ehrman said.
After a career working in elementary schools, Ehrman and his wife have big plans to enjoy their retirement.
“I want to ride my bike 50 miles in 50 states, and I’ve been working on that for a few years now,” said Ehrman, 72. “I’m almost halfway there. We are also hoping to travel overseas on a trip to Europe.”
He hopes that with ENCELTO, he’ll have enough runway to do it all without worrying that his vision will get worse. Bernstein will implant a second ENCELTO in Ehrman’s right eye in January.
While the device is potentially life-changing for MacTel patients, it isn’t the only iron in the fire. Many hope high-dose treatments of serine, which plays a vital role in protein synthesis and other cellular functions, could produce a second treatment for MacTel.
“I was involved in preliminary studies of therapeutic doses of serine, and I am looking forward to being a part of an upcoming larger clinical trial,” said Bernstein. “Science is always advancing.”