Influence of Fogging Lenses and Cycloplegia on Peripheral Refraction

Abstract

Purpose To compare objective peripheral refraction measured with an open-field autorefractor without cycloplegia with the values obtained with fogging lenses or with cycloplegia to inhibit accommodation. Methods For one hundred and sixty young adults aged 18 to 28 (mean 21.5 ± 2.3 years) their refraction was measured with the Grand Seiko (GS) autorefractor at the center and at four peripheral locations in the nasal and temporal directions under three different conditions: 1) without cycloplegia (GS); 2) without cycloplegia, but using a +2.00D fogging lens (GS_2D) and 3) with cycloplegia (GS_cycl). Results Mean spherical equivalent refraction (M) was significantly more negative with the GS method in the hyperopic group for central and peripheral refraction, and only at the center and at 10° nasal eccentricity for the emmetropic group ( P<0.05, Kruskal-Wallis). Paired comparison showed that differences of M values across techniques were larger for the GS-vs.-GS_2D comparison in myopes and emmetropes, and for the GS-vs.-GS_cycl one in hyperopes ( P<0.001, Wilcoxon Signed Ranks Test). The gap between M values for all paired comparisons remained almost constant across all eccentric positions under analysis. Conclusions Fogging lenses used with open-field autorefraction up to 20° in the nasal and temporal fields seem to provide similar accommodative relaxation to that provided by a cycloplegic. This is particularly important when refracting emmetropes and hyperopes. Moreover, this behavior seems to be independent of the eccentricity at which measurements are taken.