INTRODUCTION
There are nearly 36 million individuals who are blind worldwide, and corneal disease is the fifth most common cause of blindness following cataract, uncorrected refractive error, glaucoma and age-related macular degeneration. According to the 2018 EBAA (Eye Bank Association of America), the most common indication for any corneal transplantation in the United States is endothelial dysfunction while keratoconus and corneal infections are the most common indications in other regions. Although corneal graft survival rates are high in these conditions, the survival rates in eyes with high risk of graft failure are significantly lower and, in some cases, so poor that traditional keratoplasty is not indicated. Professor Claes Dohlman developed the Boston Kerato-prosthesis type 1 at the Massachusetts Eye and Ear Infirmary in the 1970s. Since the FDA approved the Boston Kerato-prosthesis type 1 in 1992, its use has increased tremendously for the last two decades not only in the United States but also in other countries. The most common indication for the Boston Keratoprosthesis in many long-term studies is multiple graft failure with 50–65% of eyes reaching a visual acuity of 20/200 or better at 3 years follow-up and a device retention rate of 80–87.8%.