Document Type : Review Article
Authors
1
NanoBiotechnologists Fardanegar Co., Yazd Science and Technology Park, Yazd, Iran.
2
Stem Cell Biology Research Center, Yazd Reproductive Sciences Instute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
3
Stem Cell Biology Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
4
Biotechnology Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
5
Tissue Engineering and Applied Cell Sciences Department, School of Advanced Medical Technologies, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
10.22034/jrb.2026.07.V2I1A6
Abstract
Age-related macular degeneration and retinitis pigmentosa represent the leading causes of permanent blindness globally, now affecting more than 200 million people as of 2026, a burden that weighs heavily on healthcare systems and families alike. The Argus II and PRIMA implants, which operate through retinal surface contact, fail to provide significant visual results because their limited electrode distribution (under 100 contacts for Argus II, 378 for PRIMA) can only produce visual output matching 20/1260 acuity at maximum. This limitation arises from their design, which activates ganglion cells instead of targeting the retinal inner layers. Over the past several years, researchers have shown that hydrogels such as gelatin methacryloyl and hyaluronic acid can maintain lab-grown retinal pigment epithelium cells from patients’ own reprogrammed stem cells alive and functioning for over one year. These cells form tight barriers (electrical resistance across them exceeds 300 Ω·cm²) and respond to light in ways confirmed by sensitive electrode recordings. In preclinical porcine models, whose eyes closely resemble human eyes in size, vision improvements of 20-30% on motion tests have been demonstrated, with better preservation of the light-sensing cell layer. Smart drug-releasing coatings further help by reducing scar tissue buildup to under 15%. The research pathway from laboratories to clinical applications requires standardized cell production followed by safety testing in limited volunteer cohorts, leading to trials that demonstrate actual improvements in vision. If successfully developed and scaled, these implants could potentially reduce the treatment burden compared to current wet AMD management methods that require patients to receive frequent injections. This approach represents a paradigm shift in vision loss management by establishing methods to both prevent vision loss and restore lost vision
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