Abstract
Purpose: :
To investigate the effect of prism correction on objective refraction and pupil diameter.
Methods: :
Twenty eyes of 12 healthy subjects were included in this study. Mean spherical equivalents were -1.48 ± 2.00 D in left eyes. The measurements were performed with disposable soft contact lens in myopic subjects. Before examination, the eye position evaluated by Alternate Prism Cover Test (mean -5.42±6.50 Δ at far, -10.67±-8.71 Δ at near). Subjects with prism lens corresponding to their angle were measured objective refraction and pupil diameter using WAM-5500 (Grand Seiko Co., Ltd.) at near (30 cm) and far (5 m) distance.
Results: :
The pupil diameter with prism lens was 4.68±0.88 mm, which was statistically greater than that without prism lens 4.38±0.71mm at near distance (Wilcoxon test, p < 0.05).There was no statistically significant effect of prism correction on objective refraction (Wilcoxon test, p > 0.05).
Conclusions: :
Prism correction affect pupil diameter at near distance. These results suggest that it is necessary to take care in examination with prism lens.
Keywords: pupil • refraction