The study analyzes the anatomical prognosis and mid-term visual in patients who need reimplantation of second B-KPro (Boston keratoprosthesis type 1).

The researchers took a retrospective observation method on 141 eyes (122 patients) that received the first B-KPro from the same institution. The study’s endpoints are final visual acuity 20/200, loss of light perception, and B-KPro retention. The study’s secondary endpoint is the occurrence of any postoperative complications.

Out of the sample, 12% (17 eyes) required next reimplantation. The common reimplantation indication was corneal melt, which was found in 88% of the subjects. The mean time of follow-up after the 2nd reimplantation was 4.4 +/- 2.1 years. The retention rate for the 2nd reimplantation was 79% (based on Kaplan-Meier analysis) over eight years. The common complication was the retroprosthetic membrane found in 53% of the subjects. 41% of the subjects had corneal melt after the 2nd reimplantation. 47% of the subjects had 20/200 after a year from reimplantation. 41.2% lost their light perception. 24% of the subjects developed phthisis and inoperable retinal detachment or endophthalmitis.

The reimplantation is a standard method for saving patients with B-KPro failure. However, the process can affect the ambulatory vision in 1/3rd of the patients. Another quarter of the population might lose their light perception. Retinal detachment and RPM are also other obstacles, but the major cause of anatomical failure is corneal melt.

Ref url: https://bjo.bmj.com/content/early/2020/10/13/bjophthalmol-2020-317598