Topographic corneal changes in patients with vernal keratoconjunctivitis.
PURPOSE: To carry out a case-control clinical study in patients with vernal keratoconjunctivitis, aiming at information about the anterior corneal curvature and visual performance using a quantitative corneal descriptor analyzer (Holladay Diagnostic Summary). METHODS: We examined 342 eyes of 171 patients divided into 2 groups. Group 1 with 142 eyes of 71 patients with a clinical diagnosis of vernal keratoconjunctivitis (cases) and Group 2 with 200 eyes of 100 patients (controls) from the Department of Ophthalmology/"Santa Casa" of São Paulo. Patients were submitted to a complete examination and corneal topography with a quantitative corneal surface contour descriptor (Holladay Diagnostic Summary). Clinical and topographic criteria were established to diagnose keratoconus in both groups. RESULTS: The frequency of patients with a clinical diagnosis of keratoconus associated with vernal keratoconjunctivitis in Group 1 was 9.85% (7 patients). According to topographic criteria, the frequency in Group 1 was 22.53% (16 patients). In Group 2, no patient presented biomicroscopic, refratometric or topographic characteristics of keratoconus. All studied topographic variables, including corneal asphericity, presented statistical significance (p<0.05) between the two groups. CONCLUSION: Results of this study suggested high frequency of patients with keratoconus associated with vernal keratoconjunctivitis. Visual performance is compromised by aberrations and changes in corneal asphericity and other topographic variables.