Sustained improvement in dark-adapted sensitivity but not BCVA after voretigene neparvovec treatment in a mainland Chinese child with biallelic RPE65-associated LCA2: a case report

Inherited retinal dystrophies (IRDs) represent heterogeneous genetic eye disorders frequently linked to RPE65 mutations. Voretigene neparvovec (VN, Luxturna), an AAV2-mediated gene therapy, remains the sole approved drug for biallelic RPE65 -associated IRDs. This study presents 3-, 6- and 22-month follow-up findings of the first mainland Chinese patient with compound heterozygous RPE65 -related Leber congenital amaurosis type 2 (LCA2) receiving sequential bilateral subretinal Luxturna injections. Binocular full-field stimulus threshold (FST) improvement was documented, and rod-dominant visual function improvement was verified via chromatic threshold difference analysis. No treatment-related adverse events were noted at the 3-month follow-up, while bilateral chorioretinal atrophic lesions, classified as treatment-emergent ocular findings with undetermined causal correlation to gene therapy, were detected at the 6-month visit, and these lesions further enlarged at the 22-month follow-up. Long-term assessment confirmed persistent improvement in dark-adapted visual function but not best-corrected visual acuity (BCVA). This single case demonstrates the favorable sustained dark-adapted rod function improvement of voretigene neparvovec in this Han Chinese patient with LCA2. Although obvious improvement in nyctalopia after early gene therapy has been observed in this patient, all FST data in this study are binocular integrated measurements that cannot be separated to evaluate individual monocular function. Further controlled cohort studies enrolling more Han Chinese participants are still required to verify whether early intervention provides more prominent and definitive relief of nyctalopia for patients carrying biallelic RPE65 variants.