Retroprosthetic Membrane Is Associated With Subsequent Development of de Novo Angle Closure in Eyes With Boston Keratoprosthesis.

Purpose: Boston keratoprosthesis (KPro) is a widely used treatment for corneal diseases unsuitable for traditional keratoplasty. Postoperative complications, notably retroprosthetic membrane (RPM) formation and secondary glaucoma, significantly affect patient outcomes. Anterior segment optical coherence tomography (AS-OCT) enables precise visualization of KPro-related complications, such as angle closure and RPM formation. This study aimed to investigate the association between RPM formation and de novo angle closure in eyes with Boston KPro.

Methods: A retrospective analysis of patients who underwent Boston KPro type 1 implantation was conducted. Patients with preoperative angles documented by AS-OCT and a minimum 1-year follow-up with serial AS-OCT imaging were included. Demographic data, surgical details, visual acuity, intraocular pressure, and complications were recorded. The presence of RPM and angle closure was assessed clinically and via AS-OCT.

Results: This study included 18 eyes from 18 patients who underwent KPro implantation with a follow-up period averaging 4.7 years. Preoperative visual acuity was poor (20/400 or worse) in all eyes, with an improvement in 78% of cases to 20/200 or better postoperatively. Complications included angle closure in 61% of eyes, with a significant association between retroprosthetic membrane (RPM) formation and angle closure (P = 0.0012). De novo glaucoma developed in 4 eyes, primarily associated with RPM and angle closure, and was managed medically.

Conclusions: This study highlights a significant association between RPM formation and de novo angle closure in eyes with Boston KPro. Our study findings strongly suggest that RPM formation plays a role in inducing angle closure, contributing to glaucoma development, and is the first study to provide AS-OCT evidence of potential causality. Understanding these associations can improve patient care and outcomes after KPro implantation. Strategies aimed at reducing RPM formation could potentially mitigate other KPro-related complications, including angle closure and de novo glaucoma.