Herpetic Stromal Keratitis Recurrence: A Retrospective Case-Control Study

To investigate demographic, clinical, and treatment parameters as potential predictors of early recurrence of herpetic stromal keratitis (HSK) within six weeks of the preceding episode clinical resolution or steroid treatment suspension in adult and pediatric patients.

This retrospective case-control study reviewed patient records from 2014 to 2024 at the University Eye Clinic San Giuseppe, Milan.

Eligible participants presented with clinical or PCR-confirmed HSK and had at least six months of follow-up. Patients were stratified into two groups: cases with early recurrences (≤6 weeks) and controls with no recurrence or late recurrences (>6 weeks). Data on demographic factors, clinical characteristics, and treatment regimens, including antiviral and steroid therapy, were statistically analyzed.

Among 111 HSK episodes from 51 patients (34 from 15 pediatrics), 13 (12%) were associated with early recurrences (4 (12%) in pediatrics). Our results showed statistically significant associations between early recurrence and shorter durations of systemic antiviral (88±169 vs. 309.4±437.1 days, p<0.001) and topical steroids treatment (33±23.6 vs. 199.6±359.2 days, p<0.01). In adults no early recurrences were found after episodes treated with systemic antiviral for more than 91 days and with topical steroids for more than 77 days. Delayed treatment initiation correlated with increased recurrence risk (10.4±10 days vs. 4.4±6 days, p<0.001). Preliminary data suggest an association between the choice of topical steroids and recurrence rates.

The treatment regimen appears to be the primary predictive factor for early recurrences. Our results highlight the impact of treatment timing and duration on HSK recurrence, especially in adults. While the data suggest that extended antiviral and steroid therapies may reduce early recurrences, these observations require confirmation through larger studies.