Study evaluates factors influencing bleb propagation in subretinal gene therapy for IRD

The formation and propagation of blebs in subretinal gene therapy for IRDs can be predicted based on factors such as patient age, retinotomy location, disease indication, and the direction of fluid injected into the subretinal space, according to a study.

This retrospective review of all subretinal gene therapy procedures performed between September 2018 and March 2020, included 70 eyes of the 46 patients with IRD.

The results demonstrated that the desired injection volumes and foveal treatment were successfully achieved in all eyes, regardless of the specific indication for IRD. However, the researchers found that bullous foveal detachment was associated with retinotomy performed closer to the fovea, posterior bleb bias, and greater bleb volumes.

The study also found that blebs exhibited anterior or posterior bias based on the specific disease indication and patient age. Retinotomy locations within 3.7mm (approximately 2 disc diameters) from the fovea were found to favor foveal detachment. The use of multiple retinotomies and blebs allowed for greater surface area coverage in some cases, but intersecting blebs did not propagate further.

Reference
Sisk RA, Berger TA, Williams ER, et al. Intraoperative Bleb Behavior in Subretinal Gene Augmentation Therapy for Inherited Retinal Diseases. Retina. 2023 Jun 8. doi: 10.1097/IAE.0000000000003857. Epub ahead of print. PMID: 37315516.