Two-Port Vitrectomy-free Subretinal Gene Therapy for Bietti Crystalline Dystrophy

To evaluate the safety and feasibility of a modified two-port, vitrectomy-free subretinal injection technique for gene therapy in patients with Bietti crystalline dystrophy.

Nineteen patients with Bietti crystalline dystrophy underwent subretinal gene delivery using a two-port, vitrectomy-free surgical approach. Intraocular pressure was controlled via anterior chamber paracentesis. Patients were monitored for immune response, retinal integrity, cataract development, and visual changes during follow-up up to 2 years.

The patients' ages ranged from 32 to 62 years (mean, 44±8 years, 10 males). All procedures were completed without intraoperative complications. The surgery time ranged from 9 to 14 minutes. Subretinal bleb resolved within 4 hours in 18 eyes and 72 hours in one eye, with delayed resolution after bed rest. No cataract formation was observed during follow-up. Visual acuity improved in 15 of 19 eyes (79%) at 6 months, 11 of 18 eyes (61%) at 1 year, and 5 of 10 eyes (50%) at 2 years. Three eyes (3/10, 30%) with visual decline at 2 years were not associated with cataract formation.

This simplified, vitrectomy-free subretinal delivery technique appears feasible and safe. This approach may reduce early cataract risk; however, these observations remain preliminary and require confirmation in comparative studies with longer follow-up.