Postoperative Posterior Segment Complications after Boston Type 1 Keratoprosthesis: Incidence, Risk Factors, and Intermediate-term Outcomes.

Purpose To identify the incidence of, risk factors for, and outcomes of posterior segment complications (PSC) after Boston type 1 keratoprosthesis (KPro) implantation. Methods Retrospective, consecutive case series of KPro procedures at the Stein Eye Institute. Data regarding ocular history, intraoperative details, postoperative management, and outcomes were collected. Eyes with at least one PSC (PSC Group) were compared with eyes without PSC (No PSC Group) and risk factors for PSC were determined. Results 95 PSC occurred in 69/169 eyes (40.8%), at a mean of 20.1 months after KPro implantation (0.01 complications/eye-month). The median follow-up after KPro implantation was 44.0 months (range 3.0 - 174.4). The most common PSC were epiretinal membrane (ERM, 16.6%), cystoid macular edema (CME, 12.4%), vitritis (11.2%) and retinal detachment (RD, 9.5%). Previous RD repair, concomitant intraocular lens removal, postoperative aphakia and vitritis were risk factors for RD. Postoperative infectious keratitis was a risk factor for ERM, CME and vitritis. PSC Group had a significantly higher rate of eyes failing to maintain visual acuity ≥ 20/200 (HR = 2.28; 95%CI = 1.35 - 3.85) and KPro retention failure rate (HR = 1.66; 95%CI = 0.95 - 2.91). Conclusion PSC occur in approximately 40% of eyes after KPro implantation, resulting in reduced visual outcomes and KPro retention.