Addressing the underlying genetic causes of disease

Inherited retinal diseases (IRDs) are caused by genetic changes (mutations) that affect the normal development and function of retinal cells. Gene therapy aims to address these underlying genetic causes by delivering genetic material or instructions to retinal cells to support or restore their function.

Depending on the condition and the genetic change involved, gene therapy approaches may include:

• Gene replacement: Delivering a functioning copy of a faulty or missing gene to help cells produce the proteins they need.
• Gene addition: Introducing genetic instructions to support retinal cell function.
• Gene editing or modification: Changing or correcting specific genetic sequences.
• Gene-based protection: Delivering instructions intended to help protect retinal cells from further damage.

The goal is to slow or prevent disease progression and, where possible, preserve or improve visual function. The potential benefits depend on the condition, the gene involved and the stage of retinal damage.

Gene therapy is one of the most significant areas of innovation in retinal research. It has already led to approved treatment for certain inherited retinal conditions, while other approaches are being investigated for a growing number of IRDs. For people living with inherited retinal diseases, these advances offer new possibilities for treating the underlying causes of disease rather than only managing symptoms.

Delivering genetic material safely and effectively to retinal cells is a key area of research.

Many retinal gene therapies use specially modified viral vectors, such as adeno-associated viruses (AAVs), which can deliver genetic material to targeted cells without causing disease.

Delivery methods may include:

• Injection beneath the retina (subretinal delivery)
• Injection into the eye cavity (intravitreal delivery)
• Other emerging delivery approaches

Researchers continue to improve delivery methods to reach more retinal cells and expand treatment possibilities.

The approval of the first gene therapy for an inherited retinal disease marked an important milestone in retinal medicine, demonstrating the potential of gene-based treatments. However, while some gene therapies are now available for specific conditions, many others remain in clinical development and are being evaluated through research and clinical trials.

Ongoing research is addressing important questions, including which patients are most likely to benefit, when treatment should be given, how long its effects last and how therapies can be developed for a wider range of genes and conditions.

Challenges in Gene Therapy

Despite its promise, gene therapy faces several challenges. These include the genetic complexity of inherited retinal diseases, identifying eligible patients, access to genetic testing, manufacturing and delivery of treatments, and the need for long-term monitoring. Ensuring equitable access to approved and emerging therapies worldwide also remains a significant priority.

Retina International advocates for research and healthcare systems that support timely diagnosis, appropriate care pathways and access to treatments for people who may benefit.

The Role of Patients in Gene Therapy Research

People living with inherited retinal diseases and their representative organisations play an essential role in advancing gene therapy research. Their involvement helps ensure that research considers outcomes that matter to patients, including visual function, quality of life, treatment expectations, access and affordability.

Patients can contribute through clinical trial participation, patient registries, natural history studies, research consultations and patient advisory groups. Their experiences and perspectives help shape research priorities and inform the development of treatments that respond to real-world needs.

Future Directions

Gene therapy continues to evolve as researchers explore new technologies and approaches. Future areas of development include expanding treatments to more retinal genes, improving delivery methods, combining gene therapy with other treatments, strengthening early diagnosis through genetic testing and developing more personalised approaches to care.

Collaboration between patients, researchers, clinicians, industry and policymakers will be essential to translating scientific advances into meaningful and accessible treatments for people affected by inherited retinal diseases.