Bilateral Acute Iris Transillumination and Bilateral Acute Depigmentation of the Iris: A Systematic Review and Meta-Analysis.

PURPOSE: To systematically review and quantitatively synthesize the available evidence on bilateral acute iris transillumination (BAIT) and bilateral acute depigmentation of the iris (BADI), with particular emphasis on demographic characteristics, clinical findings, glaucoma-related outcomes, and potential disease modifiers.

METHODS

PubMed, Web of Science, and the Cochrane Library were systematically searched from database inception to May 1, 2026. Case reports, case series, and cohort studies reporting clinically diagnosed BAIT or BADI were included. Random-effects meta-analyses were performed for studies including at least four patients. Patient-level data from smaller case reports and case series (<4 patients) were aggregated separately to provide complementary descriptive estimates. Between-study heterogeneity, prediction intervals, and small-study effects were evaluated, and study-level random-effects meta-regression analyses were performed for BAIT.

RESULTS

Thirty-six BAIT studies and 18 BADI studies met the inclusion criteria. The primary meta-analysis included 153 BAIT patients (302 eyes) and 70 BADI patients (137 eyes). BAIT showed numerically higher pooled baseline intraocular pressure (21.93 vs. 14.94 mmHg), ocular hypertension frequency (48.9% vs. 9.2%), antiglaucoma medication use (48.6% vs. 12.2%), and glaucoma surgery rate (21.8% vs. 0.8%) than BADI. Meta-regression identified baseline intraocular pressure as a significant predictor of both glaucoma surgery and antiglaucoma medication requirements, while higher female proportion was associated with lower baseline intraocular pressure.

CONCLUSIONS

Separate pooled analyses suggest a greater glaucoma-related burden in BAIT, characterized by more pronounced intraocular pressure elevation and greater treatment requirements. However, the observed differences between these clinical entities should be interpreted as descriptive patterns rather than direct between-group effect estimates.