Analysis For Causes Of Corneal Melt After The Boston Keratoprosthesis Type I

To evaluate the long-term incidence, risk factors, and management of the corneal melt after Boston type I Keratoprosthesis (B-KPro I).

Chinese PLA General Hospital, one of the leading medical centers in the Asia Pacific region for keratoprosthesis surgery, has accumulated extensive surgical experience and data of long-term close follow-ups, some of which have been previously reported. This study highlights the incidence, onset pattern, risk factors, treatment and outcomes of endophthalmitis after KPro, based on a large case series with long-term follow-up.

A retrospective observational case series. Data were collected regarding demographics, preoperative characteristics, incidence, and outcomes of corneal melt in 102 patients who underwent B-KPro I in the Chinese PLA General Hospital between 2011 and 2018 with 4-11 years of follow-up. 

The most common indication for B-KPro I was chemical burn (n=56; 53.8%) followed by ocular trauma (n=26; 25.0%). During the follow-up (107±25.7 months), a total of 60 corneal melts occurred in 37 eyes (35.6%), with a 20.2% incidence at one year after surgery, 14 of which suffered multiple corneal melts. Patients with multiple corneal allograft failures were at a higher risk of corneal melt. Compared to alkali burns, thermal burns as an indication for surgery elevated the odds ratio of corneal melt (OR, 5.11; 95% CI, 1.05-24.86; P = 0.043).

Corneal melt could reduce the retention time of KPro (P<0.01), and when coexisting with other complications, the retention time was further shortened. The specific pattern of the corneal melt occurrence was identified, with an intensive period of occurrence at one year postoperative. Our results suggested that the risk of corneal melt differed among indications, with thermal burns having the highest odds ratio. In addition, each prior failed keratoplasty could double the risk of the corneal melt after B-KPro I.