To analyze the clinical aspects and risk factors for recurrent herpes simplex keratitis (HSK) after penetrating keratoplasty (PKP).

Records from 78 eyes of 41 patients who underwent PKP for HSV keratitis with a mean follow-up duration of 31.83±21.35 months (24~97 months) were reviewed. The clinical aspects of recurrent keratitis, rejection, and survival rate were evaluated. Previous operation history, preoperative inflammation and neovascularization, graft size, suture methods, and antiviral use were analyzed to elucidate the risk factor for recurrent HSK after PKP.

HSK recurred in 47.4% of the patients at a mean time of 18.36±21.02 months after PKP. The mean duration of keratitis was 2.16±1.71 months and the mean frequency of recurrence was 1.41±0.69 times. Epithelial keratitis developed in 46.2% of the patients, and epithelial keratitis combined with stromal inflammation developed in 36.5%. Previous graft failure due to recurrent HSK and preoperative inflammation were significant risk factors for recurrent HSK after PKP ( p =0.019, p =0.006). There were no statistically significant differences in graft rejection and survival rate between the two groups with and without recurrent HSK.

The majority of cases of recurrent HSK after PKP were epithelial keratitis or epithelial keratitis combined with stromal inflammation, and risk factors for the recurrence of HSK were previous graft failure due to recurrent HSK and preoperative inflammation.