@article {1363256, title = {Retention of the Boston keratoprosthesis type 1: multicenter study results}, journal = {Ophthalmology}, volume = {120}, number = {6}, year = {2013}, month = {2013 Jun}, pages = {1195-200}, abstract = {OBJECTIVE: To report the retention rate of the Boston keratoprosthesis type 1 and to identify risk factors for keratoprosthesis loss. DESIGN: Cohort study. PARTICIPANTS: A total of 300 eyes of 300 patients who underwent implantation of the Boston keratoprosthesis type I device between January 2003 and July 2008 by 19 surgeons at 18 medical centers. METHODS: Forms reporting preoperative, intraoperative, and postoperative parameters were prospectively collected and subsequently analyzed at a central data collection site. MAIN OUTCOME MEASURES: Keratoprosthesis retention. RESULTS: A total cumulative number of 422 life-years of device implantation are included in this analysis. The average duration of follow-up was 17.1 {\textpm} 14.8 months, with a range of 1 week to \>6.1 years. Ninety-three percent of the 300 Boston keratoprosthesis implants were retained at their last follow-up, corresponding to a retention time of 396 patient-years or 1.42 years/keratoprosthesis. The probability of retention after 1 year and 2 years was 94\% and 89\%, respectively. During the study period, 21 (7\%) eyes failed to retain the device; the reasons for keratoprosthesis loss include sterile keratolysis (9), fungal infections (8), dense retroprosthetic membranes (3), and bacterial endophthalmitis (1). Multivariate analysis demonstrated 3 independent risk factors for keratoprosthesis loss: autoimmune cause (hazard ratio [HR], 11.94; 95\% confidence interval [CI], 3.31-43.11), ocular surface exposure requiring a concomitant tarsorrhaphy (HR, 3.43; 95\% CI, 1.05-11.22), and number of prior failed penetrating keratoplasties (HR, 1.64; 95\% CI, 1.18-2.28). CONCLUSIONS: The Boston keratoprosthesis type 1 seems to be a viable option for eyes that are not candidates for penetrating keratoplasty (PK). Ocular surface disease due to an autoimmune cause demonstrated the lowest retention rate. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.}, keywords = {Adolescent, Adult, Aged, Artificial Organs, Child, Cohort Studies, Cornea, Corneal Diseases, Corneal Transplantation, Female, Follow-Up Studies, Graft Rejection, Graft Survival, Humans, Intraoperative Complications, Male, Middle Aged, Postoperative Complications, Prospective Studies, Prosthesis Implantation, Risk Factors, Young Adult}, issn = {1549-4713}, doi = {10.1016/j.ophtha.2012.11.025}, author = {Ciolino, Joseph B and Belin, Michael W and Todani, Amit and Al-Arfaj, Khalid and Rudnisky, Christopher J and Boston Keratoprosthesis Type 1 Study Group} }