Revista Brasileira de Oftalmologia (Oct 2010)
Impacto da análise do "wavefront" na refratometria de pacientes com ceratocone Impact of the wavefront analysis in refraction of keratoconus patients
Abstract
OBJETIVO: Verificar se a aberrometria ocular total (análise da frente de onda ou wavefront) possibilita a melhora na acuidade visual corrigida (AVc) com lentes esfero-cilíndricas, obtida com a refratometria manifesta em casos de ceratocone com algum grau de intolerância ao uso de lentes de contato. MÉTODOS: Os prontuários de 46 pacientes (89 olhos) referidos com diagnóstico de ceratocone e intolerantes ao uso de lentes de contato, submetidos ao exame de aberrometria ocular total seguido de refração manifesta, foram estudados de forma retrospectiva. A AVc (logMAR) com a correção existente antes do exame foi comparada com a obtida com a nova refração manifesta, realizada, considerando-se os dados objetivos da aberrometria. O teste não-paramétrico de Wilcoxon para amostras pareadas foi utilizado para verificação de diferenças estatisticamente significantes na AVc. RESULTADOS: Houve uma melhora estatisticamente significante na AVc com a nova refração manifesta (pOBJECTIVE: 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.
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