Review of clinical trials addressing the Boston Keratoprosthesis.

Objective: The Boston Keratoprosthesis (KPro) has gained recognition as an alternative for patients with severe corneal disease and a poor probability of success with traditional penetrating keratoplasty. This review summarizes the knowledge clinical trials have brought to KPro and discusses ongoing trials.

Design: Systematic review.

Methods: A literature review across PubMed, Ovid MEDLINE, Cochrane CENTRAL, and ClinicalTrials.gov was performed to identify relevant published clinical trials reporting on the KPro from all years up until September 2021. All published trials were included.

Results: There are 6 published and 6 ongoing clinical trials studying the Boston KPro. The number of patients included per trial ranged from 8 to 37. The average age of patients included per trial ranged from 39 to 62 years. Patients were followed for an average of 36.3 ± 41.8 months. Fifty percent (3 of 6) of KPro clinical trials were randomized. Indication for KPro was reported in 67% of trials (4 of 6), with primary KPro accounting for 22% of unique eyes (13 of 58) and KPro after corneal graft failure accounting for 41% of unique eyes (24 of 58), when reported. Using version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB 2) to assess quality and risk of bias, 50% of trials (3 of 6) had a low risk of bias, 33% (2 of 6) had some bias concerns, and 17% (1 of 6) had a high risk of bias.

Conclusions: There are few clinical trials published and underway on the Boston KPro, and none directly compare KPro outcomes with repeat corneal transplantation. There is a need for long-term clinical trials on the KPro to provide quality evidence for clinical decision making.