[Mid- and Longterm Experiences with the Boston-Keratoprosthesis. The Cologne and Salzburg Perspective].

Eyes with severe corneal opacifications and insufficient prognosis for high-risk corneal transplantation can be considered for the implantation of a Boston-keratoprosthesis. Since 2013, this technique of "artificial" corneal replacement is provided to high-risk eyes at the Department of Ophthalmology, University of Cologne and for 9 years at the University of Salzburg. In the meantime, a type I Boston keratoprosthesis (BI-KPro) has been implanted in 24 eyes in Cologne and in 28 eyes in Salzburg. In this article, results and complications according to BI-KPro are discussed, both from the literature in PubMed, as well as from our own experiences. Twenty-four eyes of 22 patients had been provided with a BI-KPro since September 2013, of which only one keratoprosthesis could not be obtained thus far, and an increase in visual acuity could be achieved in 23 eyes (96%). On average, 1.5 revisions per eye were required during the postoperative course. Since 2007, a BI-KPro has been implanted in 28 eyes in Salzburg. In 62% (16 of 26 eyes), visual acuity increased postoperatively, with a complication rate of 81% in a longer follow-up period. In both cohorts, the spectrum of complications ranged from retroprosthetic membrane formation, to secondary glaucoma, to infectious keratitis with or without graft melting, to vitritis, to endophthalmitis. The range of possible complications according to BI-KPro is broad, but the BI-KPro represents currently the most widely used form of artificial corneal replacement in high-risk eyes and leads to visual improvement in most patients.