Prismatic Image Relocation in Macular Disease: Effects on Visual Function and the Preferred Retinal Locus—A Systematic Review and Meta-Analysis

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Abstract
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, with searches conducted between 2 and 15 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 an exploratory meta-analysis of distance visual acuity. The pooled point estimate favoured prism correction (MD, −0.218 logMAR), but the Hartung–Knapp-adjusted 95% confidence interval was extremely wide (−2.188 to 1.753) and included the null effect, 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. Evidence concerning PRL relocation and fixation behaviour was sparse, heterogeneous, predominantly non-randomized, and unsuitable for quantitative synthesis. Conclusions: Current evidence is insufficient to establish the routine efficacy of prismatic image relocation for improving distance visual acuity in patients with macular disease and central vision loss. Prism correction may nevertheless provide visual or functional benefit in selected individuals and may be considered as an individualized component of structured low-vision rehabilitation.

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