CORNEAL ABRASION ASSOCIATED WITH CONTACT-LENS CORRECTION OF KERATOCONUS - A RETROSPECTIVE STUDY

Background. Corneal abrasion is a frequently encountered complication of contact lens wear, but we are not aware of any previous study of re lative frequency comparing keratoconic to nonkeratoconic patients. Met hods. We retrospectively studied the incidence of corneal abrasion dur ing 2 months of contact lens practice. Results. 784 contact lens-relat ed patient visits (494 total patients); patients were assessed by 3 op tometrists and 13 abrasions (11 patients) were diagnosed. Only the tot al number of individual patients and the first abrasion for each patie nt were statistically considered; the overall frequency of abrasion wa s therefore 11/494 (2.3%)/2 months. The frequency of abrasion was 5/68 (7.4%)/2 months for keratoconic patients and 6/426 (1.4%)/2 months fo r nonkeratoconic patients and this difference was significant (chi2 te st: p < 0.01). Among nonkeratoconic patients, the frequency of abrasio n was 2/246 (0.8%)/2 months with hydrogel contact lens wear and 4/178 (2.2%)/2 months with rigid gas permeable (RGP) contact lens wear, but this difference did not achieve significance (chi2 test: p = 0.10). Id entified risk factors included: Contact lens wear; a torn lens and che mical keratitis for hydrogel lens wearers; an adherent ''bound'' lens and keratoconus for rigid lens wearers. Conclusion. Keratoconus appear s to be a statistically significant risk factor for corneal abrasion a mong contact lens wearers.