LAUSR

ABSTRACT Purpose: To investigate the association between keratoconus (KC) and allergic diseases. Methods: In a prospective age- and sex-matched case–-control study clinical data of 885 KC patients and 1526 controls were evaluated regarding the presence of various allergic diseases. Severity of KC and ophthalmic parameters of KC patients were compared between KC patients with and without allergic diseases. Results: The prevalence of allergic diseases was significantly higher in KC patients. KC patients with vernal keratoconjunctivitis (VKC) or allergic conjunctivitis (AC) had significantly thinner and steeper corneas in comparison with non-allergic KC patients. Only VKC and AC were significantly associated with KC severity. Conclusions: Patients with VKC or AC were at increased risk of KC. They had more severe KC and should be closely followed up and intensively treated.