Clinical Experience with Gene Therapy for Autosomal Recessive RPE65-Related Retinal Dystrophy in the United Arab Emirates.

PURPOSE: To report the Cleveland Clinic Abu Dhabi experience of subretinal voretigene neparvovec-rzyl (VN) gene therapy for Arabian patients with autosomal recessive RPE65-related inherited retinal dystrophy.

DESIGN

Retrospective case series

PARTICIPANTS

Nine patients (6 families; 3 male patients) with RPE65-related retinal dystrophy who underwent VN gene therapy (pars plana vitrectomy and subretinal injection) at Cleveland Clinic Abu Dhabi between 2020 and 2024.

METHODS

Preoperative and postoperative best-corrected visual acuity (BCVA), ophthalmic examination, full-field stimulus threshold testing (FST), and multimodal retinal imaging (photography, OCT, and short-wave autofluorescence).

MAIN OUTCOME MEASURES: Best-corrected visual acuity, clinical findings, FST, and multimodal retinal imaging.

RESULTS

Eight patients were Emirati, and 1 was Bahraini. All were treated bilaterally. Age at first eye treatment ranged from 11 to 56 years (mean, 24.2 years), and second eye treatment was 7 to 11 days later. No intraoperative surgical complications occurred. Follow-up after treatment ranged from 13 to 71 months (mean, 38.8 months). Postoperative systemic steroid withdrawal-related effects and transient intraocular pressure elevation were observed in 1 patient each. Two patients developed lens opacities that were not visually significant. All eyes of all patients developed postoperative chorioretinal atrophy (CRA). At the last follow-up, BCVA improved in 5 patients (55.6%), remained stable in 2 patients (22.2%), and decreased in 2 patients (22.2%) who had progressive central CRA. Full-field stimulus threshold improved in all but the 2 oldest at treatment (41 and 56 years old), who showed some decline.

CONCLUSIONS

Voretigene neparvovec-rzyl treatment improved scotopic vision (FST) in all patients treated before age 40 years and often improved BCVA. Postoperative CRA was universal; ethnicity and sunny climate may have been contributing factors. The possibility of postoperative BCVA loss related to central CRA is an important preoperative counseling point, particularly when preoperative BCVA is functionally useful.

FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.