Retroprosthetic membrane formation in Boston keratoprosthesis type 1: Incidence, predisposing factors, complications, and treatment

Objective. - Evaluate the incidence and risk factors for retroprosthetic membrane (RPM) formation after Boston keratoprosthesis type 1 (BKpro), identify the associated complications and describe the treatments offered. Methods. - Retrospective cohort study. In total, 133 eyes of 115 patients who underwent BKpro at Centre Hospitalier de l'Universite de Montreal (CHUM) from 2008 to 2017, with a minimum follow-up of 1 year, were included in the study. Records were examined, and data was collected, including RPM incidence, preoperative and intraoperative risk factors, postoperative complications and treatments offered. Results. - Mean follow-up was 5.5 years. Thirty-nine percent (n = 52) eyes developed RPM. No particular etiology was significatively associated with RPM formation. Simultaneous lensectomy or IOL extraction were respectively positively and negatively correlated with RPM formation. As for postoperative complications, the strongest correlation was found between RPM formation and retinal detachment. RPM formation was also positively associated with hypotony and corneal melt. Nd:YAG membranotomy was the most frequently used treatment, in 83 % of eyes with RPM (n = 24), with resolution in 58 %. Conclusion. - Over one third of BKpro patients will develop a RPM, thus requiring monitoring for associated retinal detachment. IOL extraction appears to be protective, whereas lensectomy appears to increase RPM formation. Nd:YAG membranectomy is used as an initial, non-invasive approach. (c) 2023 Elsevier Masson SAS. All rights reserved.