Acute corneal allograft rejection following SARS-CoV-2 vaccination-A systematic review.

Abstract

All documented cases of acute corneal allograft rejection following SARS‐CoV‐2 vaccination were examined, to characterize possible risk factors and graft outcomes. Comprehensive search (4 electronic databases: PubMed, CENTRAL, ClinicalTrials.gov, Google Scholar, plus manual search in articles' reference lists) until March 1st 2022 to identify studies reporting acute corneal allograft rejection following SARS‐CoV‐2 vaccination; study protocol was developed in line with PRISMA statement. We analysed demographics, allograft type, rejection prophylaxis regime at the time of vaccination, transplantation‐to‐vaccination time (G‐Vt), vaccination‐to‐immune reaction onset time (V‐Rt), management, best‐corrected visual acuity before and after rejection, and graft survival. Of 169 titles/abstracts screened, 16 studies (n = 36 eyes) met the inclusion criteria. Fourteen eyes (38.9%) had received >1 graft, and 11.1% of cases had history of immune reactions; 52.9% of cases occurred after the first dose. Median (P25‐P75) G‐Vt was 48 (10–78) months; median V‐Rt was 9 (7–14) days. In eyes with resolved rejection, median time‐to‐resolution was 3 (1–4) weeks. Four eyes (11.1%) had partial resolution of corneal decompensation, and 5 grafts (13.9%) failed. Acute corneal allograft rejection after SARS‐CoV‐2 vaccination is a rare event, but may occur any time post‐keratoplasty. Early recognition and prompt, aggressive treatment is warranted to optimize vision and graft survival. Well‐known risk factors for rejection may be confounding factors, including the high proportion of cases with a history of previous grafts and the rejection prophylaxis regimes at the time of vaccination. Increasing immunosuppressants in the peri‐vaccination period may decrease the risk of immune reactions, especially in high‐risk cases.