Does Gene Therapy Have Potential for Glaucoma?
It has been reported there is increasing evidence for the efficacy of different glaucoma gene therapies. This research, however, is still in its nascent stages and must go through human clinical trials. The use of gene therapy to treat ocular disease is not new. There have been 34 gene therapies that have received FDA approval to treat ocular disease. Intravitreal or subretinal injections of adeno-associated viruses is the most common gene therapy approach for delivering gene therapy to the retinal ganglion cells. One intravitreal injection can last over 7 months and adeno-associated virus genes begin to be expressed 2-3 weeks after injection.
A large number of genes are involved in glaucoma. Genome-wide association studies have identified 170 genetic loci associated with an increased risk of developing primary open-angle glaucoma. Most of the people in those studies were of European or Asian descent. A recent study found that unique gene variants are involved in glaucoma in Black patients, the largest population affected by glaucoma. (1) Because of the many genes involved when using that therapy to treat glaucoma, the objective is to target the final common endpoint in order to lower the intraocular pressure. (2)
Advantages and Disadvantages of Gene Therapy
The hope is that gene therapy for glaucoma will offer a new treatment option for a disease that unfortunately is incurable. Although earlier treatment may prevent damage, it is unknown if gene therapy can reverse damage. Gene therapy is designed to target the underlying disease cause, but treatments can be created to specifically target any gene. It should be recognized, however, that gene therapy provides no guarantee of cure or beneficial results since research in this arena has only started and treatment may be ineffective. Gene therapy may produce an immune response and the long-term effects are unknown. Additional limitations of some gene therapies are the viral vector issues such as toxicity, immune and inflammatory responses, gene control and targeting issues, limited quantities of the engineered genes, high cost, ethical restrictions and complexity. Even with all these challenges, there is still immense hope that gene therapies are destined to become an important addition or even alternative to current treatments in glaucoma.
- Life Science, January 2024
- Neural Regen Res, 2024