Outcomes of Penetrating Keratoplasty and Boston Type 1 Keratoprosthesis in Aniridia-Associated Keratopathy: A Systematic Review and Meta-Analysis

Abstract

Background Congenital aniridia is a rare condition, which may lead to aniridia-associated keratopathy (AAK) and corneal blindness. Our objective was to compare the surgical outcomes of penetrating keratoplasty (PK) and Boston type 1 keratoprosthesis (KPro) implantation in patients with AAK. Design Systematic review and meta-analysis of individual patient data (IPD). Methods The study was preregistered in the PROSPERO database (registration number: CRD420250650812). A comprehensive search of Embase, MEDLINE (via PubMed), and the Cochrane Central Register of Controlled Trials (CENTRAL) was performed up to February 17, 2025. Eligible studies reported clinical outcomes after PK or KPro in patients with AAK, specifically graft survival, success rates, best spectacle-corrected visual acuity (BSCVA), and postoperative complications. Data extraction and synthesis followed the Cochrane Handbook, and risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklists. Results Of the 1,590 studies screened, 26 case series comprising 325 eyes with AAK were included in the meta-analysis. IPD were available from 14 studies. Anatomical success was significantly higher with KPro (0.82%, 95% CI: 0.65 to 0.92) than graft survival after PK (0.38%, 95% CI: 0.13 to 0.72) (P = .009). Cox regression analysis showed a significantly higher hazard of graft failure after PK compared to anatomical failure with KPro (HR = 2.92, 95% CI: 1.24 to 6.84; P = .014). No significant difference was observed in BSCVA improvement between PK (−0.73, 95% CI: −1.55 to 0.09) and KPro (−0.51, 95% CI: −0.82 to −0.20) (P = .48). Similarly, postoperative complication rates did not differ significantly between the two procedures (P = .62). Conclusions In patients with AAK, KPro shows superior anatomical success compared to graft survival following PK. Postoperative improvements in visual acuity and the incidence of complications do not differ significantly between the two procedures. The main limitations of this analysis are the relatively small sample size across studies, the limited duration of follow-up, and the heterogeneity of study designs.