Peripheral refraction in Japanese schoolchildren with low to moderate myopia.

PURPOSE

To report the profile of peripheral refraction in Japanese children with mild to moderate myopia and compare it with reported data from other countries.

STUDY DESIGN

Cross-sectional study.

METHODS

Subjects were 76 Japanese children with myopia (mean± SD [range] spherical equivalent, -3.04±0.98 [-0.50 to -4.50] D; mean age, 10.0±1.5 [6-12] years). We performed cycloplegic refraction using an open-field autorefractor FR-5000 (Grand Seiko) while the subject looked at external fixation targets located at 0, ±15, ±30 degrees from the center along the horizontal meridian. Only the right eye data were analyzed after converting the readings to the power vector of M (spherical equivalent), J, and J.

RESULTS

The profile showed a clear hyperopic shift of M from the fovea to the peripheral retina, although a wide inter-subject variation existed. At the gaze positions of ±30 degrees, the mean relative M were +1.16±0.89 D and +1.64±1.02 D (nasal and temporal retina, respectively). Those for J were -0.94±0.30 D and -0.70±0.30 D (nasal and temporal retina, respectively). The mean J remained small (≦ 0.17 D) within this range of eccentricity. There was no correlation between the relative M at the gaze position of -30 degrees and on-axis refraction, axial length, or children's age (p > 0.05).

CONCLUSIONS

The profile of peripheral refraction was similar to that reported in children with moderate to high myopia in other East Asian countries. In this cohort, we did not find evidence supporting a hypothesis that greater myopia and longer axial length are associated with a greater peripheral hyperopic shift of the refraction.