Boston keratoprosthesis type 1 for limbal stem cell deficiency after severe chemical corneal injury: A systematic review

Purpose: To systematically review the published literature on outcomes of Boston keratoprosthesis type 1 for the treatment of limbal stem cell deficiency secondary to severe chemical corneal injury. Methods: Literature searches were conducted in MEDLINE (Ovid), Embase, Web of Science, and the Cochrane Central Register. The main outcome measures assessed were the proportion of eyes with best-corrected visual acuity (BCVA) >= 20/200 and the proportion retaining their original keratoprosthesis, both at the last recorded visit. Results: We identified 9 reports in which outcomes of Boston keratoprosthesis type I implantation after severe chemical injury could be determined, encompassing a total of 106 eyes of 100 patients. There were no randomized controlled studies. The median pre-operative BCVA was hand motion. Vision improved to >= 20/200 in 99/106 (93.4%) eyes after implantation. With a mean follow-up of 24.99 +/- 14 months, 68/106 (64.1%) eyes retained BCVA >= 20/200 at the last examination. Therefore, 68/99 (68.7%) of those who improved to > 20/200 maintained at least this acuity. The originally implanted device was retained in 88/99 (88.9%) recipients for whom retention was reported. The mean time to failure was 22.36 +/- 17.2 months. Glaucomatous optic neuropathy was the most common cause for BCVA <20/200 in eyes that retained the keratoprosthesis (18/27, 66.7%).. Conclusions: Implantation of a Boston keratoprosthesis type I in eyes with corneal blindness after severe chemical ocular injury leads to functional vision in the majority of recipients. Evidence was limited by variability in outcome reporting and an absence of controlled studies.. (C) 2018 Elsevier Inc. All rights reserved.