Predictive Factors of Suboptimal Response to Topical 0.1% Cyclosporine A Cationic Emulsion in Pediatric Vernal Keratoconjunctivitis: A Real-World Retrospective Study

Introduction: Vernal keratoconjunctivitis (VKC) is a chronic, recurrent ocular surface disease of childhood that often requires long-term anti-inflammatory therapy beyond topical corticosteroids. This study aimed to identify the clinical predictors of suboptimal treatment response with 0.1% cyclosporine A cationic emulsion (CsA CE) in a real-world pediatric cohort. Methods: This was a retrospective, single-center study including patients aged 4-18 years with moderate or severe VKC, evaluated at a multidisciplinary ophthalmology clinic between January 2021 and December 2024. All patients received 0.1% CsA CE (administered four times daily). Demographic, clinical, and anamnestic data were collected. Disease severity was assessed using the Bonini grading scale, which provides a semiquantitative evaluation of ocular signs and symptoms. Statistical analysis was performed using univariate and multivariate Cox regression. For significant parameters, ROC curves were generated and optimal cut-off values were identified using the Youden's Index. Results: A total of 101 patients were included (mean age 8.86 ± 3.31 years; 27 females). Over a mean follow-up period of 1.44 ± 1.13 years, 18 patients (17.8%) required escalation to 1% CsA galenic eye drops, of whom seven were further switched to 0.1% tacrolimus galenic eye drops. On multivariate analysis, the baseline composite clinical score was the strongest predictor of suboptimal treatment response. Notably, the clinical signs score alone demonstrated superior discriminative ability (AUC 0.732) compared to the total score (AUC 0.714). Optimal cut-off values were identified as 7 for clinical signs and 15 for the overall score. Conclusions: Baseline disease severity, particularly the score for clinical signs, is a reliable predictor of response to 0.1% CsA CE. In patients exceeding the identified thresholds, early therapeutic escalation may be warranted to improve disease control and prevent structural complications.