Evaluation of keratoconus by videokeratography in subjects with vernal keratoconjunctivitis (VKC)

Background: to assess demographic variables and the incidence of keratoconus in patients with vkc and to evaluatethe characteristics of vernal keratoconjunctivitis (vkc) associated with keratoconus.methods: one hundred and fifty patients with vkc were studied at ophthalmology department of shaheed sadoughimedical center between october 2004 and june 2005. both eyes of vkc patients were evaluated by orbscan topographyfor the diagnosis of keratoconus. corneal topography maps were examined with modified robinowitz-mcdonnelltest. the characteristics of vkc were recorded in keratoconus patients.results: the study included 93 male and 57 female subjects. the patients mean age was 13.07 ± 4.71 (range 8-24)years. the clinical forms of vkc were as follows: 45.2% mixed, 38% palpebral and 16.7% limbal types. fifty four(36%) of 150 subjects with vkc had complications of pseudogerontoxon, punctate keratitis and shield ulcer. eightyfoureyes (42 subjects) of 150 patients with vkc were detected as having keratoconus by videokeratography maps(28%). there were 27 males and 15 females in keratoconus group. 16.7% of the eyes had mild, 33.3% had moderateand 50% had severe keratoconus. eyes with severe keratoconus presented at younger age (12.7 ± 3.35 years) than moderatekeratoconus (18.3 ± 2.15 years). keratoconus was more common in male gender, long-standing disease, mixedand palpebral vkc.conclusion: screening of keratoconus subjects with corneal topography allows early detection and management ofkeratoconus. the higher incidence of keratoconus in our study is due to videokeratography study of early keratoconus.