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Impact of the wavefront analysis in refraction of keratoconus patients

OBJECTIVE: To verify if the total ocular aberrometry (wavefront analysis) facilitates manifest refraction and improvement in best spectacle distance corrected visual acuity (BSCDVA) with sphero-cylindrical lenses, in keratoconus cases with some degree of contact lenses intolerance. METHODS: Retrospective chart review of 46 patients (89 eyes) referred with keratoconus and contact lenses intolerance was performed. Ocular aberrometry with ray tracing was followed by manifest refraction. BSCDVA (logMAR) with the previous correction was compared with the one obtained based on the wavefront auto-refraction. The nonparametric test of Wilcoxon for paired samples was used to test statistically significant differences in BSCDVA. RESULTS: There was a statistically significant improvement in BSCDVA with the new manifest refraction (p <0,0001). The average BSCDVA changed from 0,37 or 20/47 (varying between 1,3 and 0; standard deviation [SD] = 0,25) with previous refraction to 0,23 or 20/34 (varying between 1 and 0,1; SD = 0,21). 52 eyes (58,4%) of 28 patients showed improvement in BSCDVA with the new refraction. The average improvement was 0,13 logMAR (1,3 lines on Snellen chart), varying between zero and 0,6 (6 lines), with standard deviation of 0,16. Eight patients had significant anisometropia that limited the prescription of glasses. CONCLUSION: Aberrometry facilitated the refraction, determining significant improvement in visual acuity with sphero-cylindrical lenses in keratoconus patients intolerant to contact lenses. The anisometropia was a limiting factor in the prescription of glasses.

Corneal wavefront aberration; Keratoconus; Contact lenses; Refraction, ocular; Visual acuity


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