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Updated: Oct 25, 2026
An Alternative and Validated Injection Method for Accessing the Subretinal Space via a Transcleral Posterior Approach
Published on: December 7, 2016
Functional response, retinal structure and safety of subretinal gene augmentation in retinitis pigmentosa: A
Kai-Yang Chen1, Hoi-Chun Chan2, Chi-Ming Chan3
1Department of General Medicine, Chang Gung Memorial Hospital (Linkou branch), Taoyuan, Taiwan.
Introduction:
Subretinal adeno-associated virus (AAV) gene delivery is being investigated for retinitis pigmentosa (RP), yet functional efficacy, retinal structural effects, and delivery-associated safety remain uncertain. We synthesised clinical evidence across these outcomes.
Methods:
Six databases were searched through January 2026, with an update on September 28, 2026. Random-effects meta-analyses evaluated subretinal AAV gene augmentation; mechanistically distinct therapies were synthesised narratively. Outcomes included microperimetry, best-corrected visual acuity (BCVA), full-field stimulus threshold (FST), retinal thickness, and adverse events. Follow-up and sensitivity analyses explored variability.
Results:
Thirteen reports representing 12 studies were included; eight contributed quantitative data. Microperimetry improved by 6.72 dB (95% CI 6.45-6.98; four studies; I2 = 0%), with most observed gains within six months. Time-stratified sensitivity estimates ranged from 2.77 dB at one month to 6.79 dB at 12 months, without establishing within-patient trajectories. BCVA improved by 4.12 ETDRS letters (95% CI 3.45-4.80; four studies; I2 = 0%), below a conventional five-letter benchmark. Exploratory meta-regression suggested greater acuity gains with follow-up (0.27 letters/month), but cluster-robust inference was nonsignificant (p = 0.10). FST did not improve in two studies. Central retinal thickness decreased by 33.7 μm from baseline (95% CI -37.3 to -30.1; three studies), without establishing treatment-attributable thinning. Ocular adverse events occurred in 29.4% (95% CI 19.1-42.5%), and serious adverse events in 19.4% (95% CI 12.8-28.2%). Small early-phase cohorts, heterogeneous comparators, and insufficient delivery-specific comparisons constrained interpretation.
Conclusion:
Subretinal AAV augmentation showed preliminary functional signals, but clinically meaningful benefit and structural safety remain uncertain. Controlled studies should standardize endpoints and clarify vector-, dose-, and procedure-related risks.
