Gene therapy holds promise for treating diseases that affect the retina, leading to visual impairment and blindness. Although early attempts at gene therapy have been accompanied by severe adverse effects, improvements in delivery systems have made significant progress in developing gene therapies for retinal diseases. The accessibility of the retina makes it an ideal target for gene therapy due to the limited immune response in the eye. Gene therapy approaches for both inherited and acquired retinal diseases have shown promise, with clinical trials underway to test their safety and effectiveness. Different factors, such as the type of delivery system and route of administration, need to be considered in the development of gene therapy approaches for retinal diseases.
Viral vectors, including adeno-associated viruses and lentiviruses, are commonly used in gene therapy for retinal diseases. These vectors can selectively express therapeutic genes in target tissues such as the retina while minimizing immune responses. Nonviral delivery systems, such as nanoparticles and liposomes, are also being investigated for gene therapy. Subretinal, intravitreal, and suprachoroidal injections are common methods used to administer viral vectors for retinal diseases, each with its advantages and limitations.
Inherited retinal diseases, caused by genetic mutations, have been the primary target of gene therapy approaches. Recent advancements in the development of gene therapies for inherited retinal diseases have shown promising results, with improvements in visual function observed in clinical trials. Gene therapy for acquired retinal diseases, such as age-related macular degeneration and glaucoma, aims to target common dysfunctional pathways using approaches that may provide more durable suppression of disease-related proteins.
Several gene therapy approaches are being developed for glaucoma, a leading cause of irreversible blindness in older individuals. These approaches target factors involved in the loss of retinal ganglion cells and may offer a more durable alternative to current glaucoma treatments. Despite the progress in gene therapy for retinal diseases, challenges related to efficacy, safety, manufacturing, cost, accessibility, and the necessity of viable target cells remain. Addressing these challenges will be crucial for the successful implementation of gene therapy for retinal diseases.
Ongoing clinical trials and research efforts are expected to lead to more approved gene therapies for retinal diseases in the coming years. With the potential for gene therapies to provide long-term benefits and overcome limitations of current treatments, these approaches hold promise for improving the quality of life for individuals with retinal diseases. As more gene therapies are developed and approved, the accessibility and affordability of these treatments are expected to improve, offering hope for those affected by retinal diseases.
