Ophthalmic Technology Assessment Boston Keratoprosthesis: Outcomes and Complications A Report by the American Academy of Ophthalmology W. Barry Lee, MD, 1 Roni M. Shtein, MD, MS, 2 Stephen C. Kaufman, MD, PhD, 3 Sophie X. Deng, MD, PhD, 4 Mark I. Rosenblatt, MD, PhD 5 Objective: To review the published literature on safety and outcomes of the Boston type I keratoprosthesis (BI-KPro) for the surgical treatment of corneal opacification not amenable to human cadaveric corneal transplantation. Methods: Searches of peer-reviewed literature were conducted in PubMed and the Cochrane Library in December 2012, July 2013, and January 2014 without date restrictions. The searches were limited to studies published in English and yielded 587 citations. The abstracts of these articles were reviewed, 48 articles were selected for possible clinical relevance, and 22 were determined to be relevant for the assessment objectives. Nine studies were rated as level II evidence and 13 studies were rated as level III evidence. Excluded were level III evidence, case reports, review articles, letters, editorials, and case series with fewer than 25 eyes. Results: In 9 articles, a best-corrected Snellen visual acuity (BCSVA) of 20/200 or better occurred in 45% to 89% of eyes. Five articles described a BCSVA of 20/50 or better in 43% to 69% of eyes, and 4 articles found a BCSVA of 20/40 or better in 11% to 39% of eyes. Retention rates of the BI-KPro ranged from 65% to 100%. Reasons for loss of vision after BI-KPro implantation most commonly included corneal melts resulting from exposure keratopathy, endophthalmitis, and infectious keratitis or corneal ulceration. The 2 most common com- plications after surgery were retroprosthetic membrane formation (range, 1.0%e65.0%; mean  standard deviation [SD], 30.019.0%) and elevated intraocular pressure (range, 2.4%e64.0%; mean  SD, 27.518.1%). The 2 most common posterior segment complications were endophthalmitis (range, 0%e12.5%; mean  SD, 4.64.6%) and vitritis (range, 0%e14.5%; mean  SD, 5.64.7%). Conclusions: The reviewed articles on BI-KPro use suggest that the device improves vision in cases of severe corneal opacification that were not amenable to corneal transplantation using human cadaveric keratoplasty techniques. A number of severe anterior and posterior segment complications can develop as follow-up continues, making ongoing close observation paramount for patients undergoing this surgery. These complications include infection, device extrusion, and permanent vision loss. Ophthalmology 2015;122:1504-1511 ª 2015 by the American Academy of Ophthalmology. The American Academy of Ophthalmology prepares Ophthalmic Technology Assessments to evaluate new and existing procedures, drugs, and diagnostic and screening tests. The goal of an Ophthalmic Technology Assessment is to evaluate the peer-reviewed scientific literature, to distill what is well established about the technology, and to help refine the important questions to be answered by future investigations. After appropriate review by all contributors, including legal counsel, assessments are submitted to the Academy’s Board of Trustees for consideration as official Academy statements. The purpose of this study by the Ophthalmic Technology Assessment Committee Cornea and Anterior Segment Disorders Panel is to review the published literature on safety and outcomes of the Boston type I ker- atoprosthesis (BI-KPro) for the surgical treatment of corneal opacification not amenable to human cadaveric corneal transplantation. Background Prosthokeratoplasty is a form of artificial corneal trans- plantation reserved for the treatment of severe corneal opacification in situations where cadaveric corneal trans- plants have failed or have a very low likelihood of success. Keratoprosthesis (KPro) surgery often is considered a procedure of last resort for patients with bilateral severe corneal opacification after multiple unsuccessful cadaveric corneal transplants. However, indications have broadened to unilateral or bilateral corneal opacification after repeated 1504 Ó 2015 by the American Academy of Ophthalmology Published by Elsevier Inc. http://dx.doi.org/10.1016/j.ophtha.2015.03.025 ISSN 0161-6420/15