Surgical Implant Slows Vision Loss in Rare Eye Disease: NEJM Evidence Study - Video

In a new development for patients suffering from macular telangiectasia type 2 (MacTel), a rare and progressive retinal disease, a surgically implanted neuroprotective device has been shown to slow vision loss. The findings, published in NEJM Evidence, are based on two Phase III clinical trials evaluating the effectiveness of ENCELTO—a device that delivers a therapeutic protein directly to the retina to preserve central vision.

MacTel is a degenerative condition that gradually destroys central vision, severely impacting quality of life. Until now, there have been no approved treatment options for this orphan retinal disorder. The ENCELTO device offers a novel approach: it is surgically implanted and continuously releases ciliary neurotrophic factor (CNTF), a protein known to protect retinal neurons.

The two randomized trials enrolled 228 participants across 47 international sites and followed them over 24 months. The study showed that the implant could significantly slow photoreceptor cell degeneration compared to sham-treated eyes.

The ENCELTO implant consists of genetically modified retinal pigment epithelial cells housed within a tiny, collagen-based capsule. This design shields the cells from immune rejection while enabling the sustained release of CNTF directly to the retina.

In one trial, ENCELTO led to a 54.8% reduction in the rate of ellipsoid zone loss—a key structural indicator of photoreceptor degeneration. The second trial also demonstrated a significant reduction of 30.6%, supporting the treatment’s efficacy.

"This is a step toward redefining how we think about vision loss. Instead of waiting for cells to die, we're learning how to protect and preserve them," said Professor Martin Friedlander of Scripps Research, US. "This is the first time we've seen a therapy meaningfully alter the course of MacTel. It confirms that neuroprotection can be a powerful strategy to preserve vision in degenerative retinal conditions," he added.

The research underscores the potential of neuroprotective strategies in managing vision-threatening conditions.

Reference: https://evidence.nejm.org/doi/full/10.1056/EVIDoa2400481