ABSTRACT

PURPOSE: To evaluate the clinical performance of Monocurve and Bicurve (Soper-McGuire design) rigid gas-permeable contact lens fitting in patients with keratoconus. METHODS: A prospective and randomized comparative clinical trial was conducted with a minimum follow-up of six months in two groups of 63 patients. One group was fitted with Monocurve contact lenses and the other with Bicurve Soper-McGuire design. Study variables included fluoresceinic pattern of lens-to-cornea fitting relationship, location and morphology of the cone, presence and degree of punctate keratitis and other corneal surface alterations, topographic changes, visual acuity for distance corrected with contact lenses and survival analysis for remaining with the same contact lens design during the study. RESULTS: During the follow-up there was a decrease in the number of eyes with advanced and central cones fitted with Monocurve lenses, and an increase in those fitted with Soper-McGuire design. In the Monocurve group, a flattening of both the steepest and the flattest keratometric curve was observed. In the Soper-McGuire group, a steepening of the flattest keratometric curve and a flattening of the steepest keratometric curve were observed. There was a decrease in best-corrected visual acuity with contact lens in the Monocurve group. Survival analysis for the Monocurve lens was 60.32% and for the Soper-McGuire was 71.43% at a mean follow-up of six months. CONCLUSIONS: This study showed that due to the changes observed in corneal topography, the same contact lens design did not provide an ideal fitting for all patients during the follow-up period. The Soper-McGuire lenses had a better performance than the Monocurve lenses in advanced and central keratoconus.

Keywords: Keratoconus; Contact lenses; Clinical evolution; Corneal topography; Visual acuity

RESUMO

OBJETIVOS: Avaliar comparativamente aspectos clínicos da adaptação de lentes rígidas gás-permeáveis Monocurva externa e Bicurva, desenho Soper-McGuire, em pacientes portadores de ceratocone. MÉTODOS: Estudo clínico, prospectivo e randomizado, com acompanhamento mínimo de seis meses, de dois grupos compostos por 63 indivíduos, um adaptado com Monocurva externa e o outro com Bicurva Soper-McGuire. RESULTADOS: No decorrer do estudo, observou-se redução do número de olhos com cones avançados e centrais adaptados com Monocurva externa e aumento de número de adaptados com Bicurva Soper-McGuire. A Monocurva determinou aplanamento do meridiano mais plano e do mais curvo da córnea, ao passo que a Soper-McGuire determinou encurvamento do meridiano mais plano e aplanamento do mais curvo da córnea. Houve redução da acuidade visual corrigida com lentes no grupo Monocurva. A estimativa de permanência no uso da lente inicialmente adaptada foi igual a 60,32% no grupo Monocurva e 71,43% no grupo Soper-McGuire. CONCLUSÕES: O estudo mostrou que devido às variações observadas na topografia corneal, o mesmo desenho de lente de contato usado no início da adaptação não proporcionou a melhor relação lente X córnea com o passar do tempo. A lente Soper-McGuire demonstrou melhor desempenho clínico do que a Monocurva em ceratocones avançados e centrais.

Descritores: Ceratocone; Lentes de contato; Evolução clínica; Topografia da córnea; Acuidade visual

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