Surgical implant may help slow vision loss from rare eye disease: Study

A surgically implanted device may slow vision loss caused by macular telangiectasia type 2 (MacTel), a rare, degenerative eye disease with no previously approved treatments, according to new research.

The study, published in NEJM Evidence, reported results from two Phase III clinical trials of ENCELTO, a neuroprotective implant that continuously releases a therapeutic protein to preserve vision. The randomised trials, conducted across 47 sites worldwide, followed 228 participants with MacTel over a 24-month period and found the device could meaningfully slow disease progression.

“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 US FDA-approved device delivers ciliary neurotrophic factor (CNTF), a naturally occurring protein known to protect retinal neurons. ENCELTO also contains genetically modified retinal pigment epithelial cells enclosed in a tiny collagen-based capsule implanted at the back of the eye. The capsule shields the cells from immune rejection while enabling continuous, localised delivery of CNTF.

The trials found ENCELTO significantly slowed the loss of photoreceptors, light-sensing nerve cells crucial for central vision, compared with sham-treated eyes that underwent simulated procedures without receiving treatment.

In one trial, the implant reduced the rate of ellipsoid zone loss, a marker of photoreceptor degeneration by 54.8 per cent. The second trial showed a 30.6 per cent reduction, which researchers said was smaller but still statistically significant.

(Agency inputs)