Abstract / Summary
Purpose: To evaluate the effectiveness of prismatic image relocation for visual rehabilitation in patients with macular disease and central vision loss, focusing on visual acuity, reading-related outcomes, preferred retinal locus (PRL) behaviour, fixation, and functional outcomes.
Methods: A systematic review and meta-analysis was conducted according to PRISMA 2020 and prospectively registered in PROSPERO (CRD420261500738). Scopus, Web of Science Core Collection, PubMed/MEDLINE, and CENTRAL were searched from inception to September 2026. Randomized, non-randomized comparative, pre-post, and case-series studies evaluating prism-based image relocation were eligible. Risk of bias was assessed using RoB 2, ROBINS-I, or the appropriate Joanna Briggs Institute tools. Random-effects meta-analysis was performed when studies were sufficiently comparable.
Results: Eleven studies met the inclusion criteria. Two randomized controlled trials provided comparable data for the primary meta-analysis of distance visual acuity. The pooled point estimate was in the direction of better visual acuity with prism correction but was imprecise and included the null effect (MD, −0.218 logMAR; 95% CI, −0.522 to 0.086), with substantial heterogeneity (I² = 94.5%). The certainty of evidence for the primary outcome was rated as very low. Sensitivity analyses did not materially strengthen the evidence. Observational studies frequently reported favourable visual or functional outcomes, but several were affected by important risks of selection bias, confounding, or absence of appropriate control groups.
Conclusions: The available evidence indicates that prismatic image relocation can modify retinal image position and may provide visual or functional benefit in selected patients with central vision loss, although the certainty of evidence regarding its effect on distance visual acuity is very low.