In recent years, ophthalmology has emerged as one of the most promising frontiers in gene therapy. The eye's unique characteristics – coupled with increasing research efforts into the field – are leading to promising treatments for a variety of genetic eye diseases previously considered untreatable. The potential impact is expansive, too. Once researchers establish the principle that works, the same technique can be applied to many eye diseases, not just those caused by genetic mutations. For example, gene therapy has shown promise to treat acquired retinal diseases, such as glaucoma, that have a complex origin.
Eyes are well-suited for cell and gene therapy for a variety of reasons. First, the eye’s immune system is relatively tolerant (although there have been cases where gene therapy can cause inflammation requiring steroid treatment), making it easier to introduce and maintain gene therapies. Second, it is easily accessible for diagnosis, treatment, and observation, allowing for non-invasive monitoring of treatment efficacy. Third, the eye’s unique structure allows for localized delivery of therapies to specific tissues, such as the retina. And fourth, the ocular barriers separate the eyes from the rest of the body, limiting the immune response in the eye and protecting other tissues.
Given these conditions, it is not surprising that there were 159 gene therapy clinical trials targeting ophthalmic disorders up to the end of 2022, with the majority focusing on retinal and optic nerve disorders. While most ophthalmology gene therapies studies use genetically engineered viruses to deliver therapeutic genes to the eyes, in March 2025 the FDA approved the first gene-modified cellular therapy product for ophthalmology: Neurotech Pharmaceuticals’ cell therapy for macular telangiectasia type 2 (MacTel). The drug, Encelto, is delivered in a tiny implanted membrane that encapsulates the retinal pigment epithelial cell, which has been genetically engineered to express the protein ciliary neurotrophic factor. That protein helps photoreceptors in the eye survive longer, slowing down the disease.
Envisioning a bright future
The cell and gene therapy market today is calculated at about $25 billion, and projected to reach $117.46 billion by 2034, growing at a CAGR of 18.7 percent from 2025 to 2034. The rapid growth is driven by an increasing burden of cancer and other targeted diseases, rapidly expanding research and robust pipeline, substantial funding by venture capitalists, and technological innovations. Ophthalmology is poised to capture the biggest share of that growth after oncology, with ophthalmic drugs anticipated to expand at a significant CAGR of 12.8 percent during this same period – especially with the growing emphasis on developing targeted gene therapies.
While growing at a rate that inspires hope, gene therapy for eye diseases is still in its infancy. Formidable challenges, including unpredictable immune responses, and long-term safety and efficacy, persist. Increased clinical research is exciting, but the industry must maintain the utmost care. Site experience with small molecules and antibodies, for instance, is vastly different compared to gene therapy expertise. Unique and significant health risks demand proper safety practices not only for patients, but for everyone associated with the trial – and this starts before a single patient enrolls with the independent biosafety reviews. By investing time and resources in cell and gene therapies for ophthalmology diseases, we can envision a brighter, healthier future for all.
