PURPOSE: To evaluate corneal topographic indices and the prevalence of keratoconus in patients with vernal keratoconjunctivitis (VKC) and to compare these with normal individuals. METHODS: One-hundred twelve consecutive patients with VKC and 112 age- and sex-matched healthy individuals were included in this prospective study. Demographic characteristics were recorded, and complete ophthalmic examinations were performed for all participants. A Sirius topographer was used to assess all participants. Data regarding keratoconus and corneal topographic indices were compared between the two groups. RESULTS: Sixty-five of the 224 eyes of the 112 patients with VKC were of the tarsal type, 101 were of the limbal type, and 58 were of the mixed type of VKC. Central corneal thickness was significantly lower in the VKC group than in the control group (P<
0.004). Symmetry index back, keratoconus vertex front, keratoconus vertex back, Baiocchi Calossi Versaci (BCV) (front and back indices), and the root mean square of higher-order aberrations (RMS/A) (anterior and back indices) values were significantly higher in the VKC group than in the control group (P<
0.004). There were no significant differences between the two groups in terms of corneal volume, symmetry index front values, simulation keratometry1, or simulation keratometry2 (P>
0.05). CONCLUSION: Patients with VKC assessed using keratoconus screening indices exhibited more abnormal corneal topographic changes and higher rates of keratoconus compared to the control group. Topographic analysis may be useful for evaluating corneal changes and for the early diagnosis of keratoconus in patients with VKC.