Evaluation of ocular surface parameters in inactive vernal keratoconjunctivitis: a cross-sectional study

Vernal keratoconjunctivitis (VKC) is a chronic allergic ocular surface disease, and it remains unclear whether dry eye findings persist once the disease becomes inactive. We aimed to evaluate ocular surface parameters in patients with inactive VKC compared with healthy controls, and to explore whether the limbal and palpebral subtypes differ. In this cross-sectional study, 21 patients with inactive VKC (11 limbal, 10 palpebral) and 21 age- and sex-matched healthy controls were included. Tear breakup time (TBUT), Schirmer test, tear osmolarity, and central corneal sensitivity were assessed by a single examiner in a fixed test sequence, from the least to the most invasive, in one randomly selected eye per participant. Comparisons were performed between the VKC and control groups and between VKC subtypes. TBUT was lower in the VKC group compared with controls (median 7.5 s, IQR 5.0 to 9.0 vs. 10.0 s, IQR 8.0 to 14.0, p = 0.003). Schirmer test values were also lower in the VKC group, although the difference was not statistically significant ( p = 0.066). Tear osmolarity and corneal sensitivity were similar between the groups. In the subgroup analysis, TBUT differed significantly among the groups ( p = 0.011). Both limbal and palpebral VKC subtypes had lower TBUT values than controls (Bonferroni-adjusted p = 0.037 and p = 0.049), and no difference was detected between the two VKC subtypes. In this cohort, clinically inactive VKC was associated with reduced tear film stability. Tear osmolarity, Schirmer test results, and corneal sensitivity did not differ significantly from controls, although the small sample size limited the ability to detect differences.