Incidence, causative pathogens, risk factors, geographical variations, and outcomes of post-keratoplasty infectious keratitis over the last 15 years: a systematic review and meta-analysis.

PURPOSE: To assess the incidence, risk factors, causative microorganisms, and outcomes of post-keratoplasty infectious keratitis (PKIK), considering the differences in the type of keratoplasty and potential geographical variations.

METHODS

Electronic searches were conducted in four databases (PubMed/MEDLINE, Cochrane, Scopus, and Wiley) for studies reporting PKIK from 2009 to 2024. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines.

RESULTS

Eight studies were eligible for final analysis. The cumulative incidence of PKIK ranged from 1.80% to 18.77%. Compared to penetrating keratoplasty, endothelial keratoplasty showed a trend towards a lower risk of PKIK (log odds ratio - 1.33, 95% confidence interval (CI): - 2.96-0.30, p = 0.108). While gram-positive bacteria were the most common pathogens found to cause PKIK, it was estimated that 21% (95% CI 9-33%) of cases were attributed to fungal infections. Visual inspection of the plots indicates no influence of the geographical study site on the proportion of fungal infections. Several risk factors for PKIK were also identified. Severe visual impairment was commonly observed following treatment of PKIK. Topical quinolone can be used as first-line therapy despite the increasing antibiotic resistance rate of pathogens.

CONCLUSION

In the last 15 years, the cumulative incidence of PKIK has remained relatively low. Endothelial keratoplasty showed a trend towards a lower risk of PKIK compared to penetrating keratoplasty, with gram-positive bacteria remaining the predominant cause.