Both routes have advantages and disadvantages. Intravitreal injection is 100 to 1,000-fold less efficient than subretinal injection. But the subretinal route is more invasive and may not be acceptable in some disorders due to compromised retinal structure.
“Gene therapy may be the only way to treat inherited diseases like LCA, RP, Stargardt’s, choroideremia, X-linked retinoschisis, achromatopisa and red-green color vision deficiency,” Dr. Kiss said. “But if you think about the impact on vision overall, there are many more people with acquired conditions like age-related macular degeneration, diabetic retinopathy or glaucoma. That is where gene therapy may ultimately have its broadest impact.”
Ophthalmologists will not see immediate changes in treatment for the acquired diseases that account for the bulk of ophthalmologic practice, he continued. But clinicians who have patients with inherited ocular disorders should already be adjusting their practice.
“If you have a patient with one of these inherited disorders, the time is now to make sure they are referred to a center where they can enroll in the ongoing clinical trials or be ready for gene therapy as it is approved,” he said. “Gene therapy is about to change the way we treat ocular disease.”