What is MacTel?
MacTel is an orphan retinal disease that progressively destroys the macula, the central portion of the retina responsible for sharp vision. Over time, patients experience blurred or distorted central vision, impacting daily activities such as reading and recognising faces.
Until now, treatment options for MacTel were virtually non-existent, making the development of ENCELTO a significant milestone in ophthalmic research.
The ENCELTO device, approved by the US FDA, delivers ciliary neurotrophic factor (CNTF) — a naturally occurring protein that protects retinal neurons from degeneration. The device houses genetically modified retinal pigment epithelial cells inside a tiny collagen capsule, implanted at the back of the eye.
This capsule design shields the cells from immune rejection while ensuring continuous, localised CNTF release, enabling long-term neuroprotection for photoreceptor cells crucial to vision.
Study Findings
Across 47 international trial sites, 228 MacTel patients participated in the two-year study. Results showed that ENCELTO significantly slowed the degeneration of the ellipsoid zone — a retinal layer whose damage signals photoreceptor loss.
In one trial, the implant reduced ellipsoid zone loss by 54.8%, while the second reported a 30.6% reduction compared to sham-treated eyes. Both results were statistically significant, confirming the implant’s protective effect.
Expert Insights
“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, USA.
He added, “It’s the first time we’ve seen a therapy meaningfully alter the course of MacTel, confirming that neuroprotection is a powerful strategy for degenerative retinal diseases.”
Next Steps
While the ENCELTO implant is already FDA-approved, experts stress the importance of further long-term studies to monitor its efficacy and safety. Indian ophthalmologists are closely watching developments, as the therapy could potentially be evaluated for other retinal conditions in the future.
More details on MacTel and eye health can be found at the All India Ophthalmological Society and the Ministry of Health and Family Welfare portals.