A groundbreaking development in eye research is offering new hope for millions facing vision loss from degenerative retinal conditions. Researchers at the Korea Advanced Institute of Science and Technology (KAIST), led by Professor Jin Woo Kim, have developed an innovative approach that promotes retinal nerve regeneration, potentially restoring vision rather than merely slowing disease progression.
The key discovery centers on the protein PROX1 (prospero-related homeobox 1), which accumulates in Müller glia cells—the supportive cells in the mammalian retina—following injury or degeneration. In highly regenerative animals like zebrafish, PROX1 remains low in these cells, allowing them to dedifferentiate into progenitor-like states and generate new neurons. In mammals, including humans, PROX1 acts as a molecular barrier, preventing this natural repair process and leading to permanent damage in conditions such as age-related macular degeneration (AMD), retinitis pigmentosa, diabetic retinopathy, and glaucoma.
The team identified that PROX1 transfers intercellularly from nearby retinal neurons to Müller glia in damaged mouse retinas, suppressing regeneration. By blocking this transfer, the researchers restored the regenerative potential of Müller glia.
Their treatment uses a neutralizing antibody (developed by Celliaz Inc., a biotech startup spun out from the lab) that binds to PROX1, sequestering it and preventing its accumulation in Müller glia. In initial tests on disease-model mice, direct administration of the antibody significantly promoted neural regeneration. More impressively, when delivered via gene therapy—using adeno-associated virus (AAV) to enable the retina to produce the anti-PROX1 antibody—mice with retinitis pigmentosa showed sustained retinal neuron production, photoreceptor layer restoration, and vision recovery lasting over six months.
This marks the first successful demonstration of long-term neural regeneration in mammalian retinas, as detailed in a study published in Nature Communications on March 25, 2025 (DOI: 10.1038/s41467-025-58290-8). The effects were observed in multiple mouse models of retinal degeneration, with vision improvements measured through behavioral and functional tests.
Celliaz Inc. is now optimizing the PROX1-neutralizing antibody, referred to as CLZ001, for enhanced efficacy and safety. The company plans to complete preclinical studies in various animal models before advancing to human clinical trials, with a target start date around 2028.
This research represents a paradigm shift from current therapies, which primarily manage symptoms or halt progression through anti-VEGF injections or other means, to one that actively reverses damage by harnessing the retina’s latent regenerative capacity. While still in early stages and limited to preclinical models, experts view it as a promising avenue for addressing untreatable degenerative retinal diseases.
The breakthrough has garnered attention in media outlets, including a CBS News segment in April 2025 where optometrist Dr. James Dello Russo highlighted its potential to transform treatment for conditions like macular degeneration and glaucoma.
As development continues, this approach could one day provide a viable option for patients at risk of irreversible blindness, offering renewed optimism in the field of vision restoration.
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