Peripheral Refraction And The Development Of Myopia In Singaporean Chinese Children

Abstract

Purpose: : Peripheral refraction has been used to infer retinal shape and as a surrogate for peripheral image blur. Relative peripheral hyperopia has been proposed to stimulate myopia onset and progression. We describe peripheral refraction and its associations with central refractive error in a longitudinal cohort of young Singapore Chinese children.

Methods: : 187 children aged 40 months or over in the Strabismus, Amblyopia and Refractive error in Singapore Children (STARS) study were included. Peripheral refraction after pupil dilation used an infrared autorefractor (Grand Seiko Autorefractor WAM-5500). 5 measurements were captured: central, 15° and 30° eccentricities in the nasal and temporal visual fields. Mean follow-up was 1.26 years (0.5 to 2.0).

Results: : The mean age was 7.2 years. At baseline 97 were myopic (central spherical equivalent, SE, ≤0.5D) and 90 emmetropic (SE -0.49 to +1.0D ) or hyperopic (SE > +1.0D). Of the 90 who were emmetropic or hyperopic at baseline, 66 became myopic on follow-up, while 24 remained emmetropic or hyperopic. All emmetropic children who later "became myopic" or "remained emmetropic" had relative peripheral myopia at all 4 peripheral eccentricities at baseline. At follow-up, those who "remained emmetropic" retained relative peripheral myopia at all 4 peripheral eccentricities while those who "became myopic" developed relative peripheral hyperopia at the nasal (+0.44 ± 0.72 vs. -0.09 ± 0.72 D, p=0.003) and temporal 30° (+0.13 ± 0.74 vs. -0.37 ± 0.93 D, p=0.01) and thus more closely resembled those who had been myopic at the outset. Baseline peripheral refraction was not an independent predictor of later development of myopia.

Conclusions: : Young Singapore Chinese children with myopia had relative hyperopia in the periphery compared to those who remained emmetropic. Those who became myopic during the course of the study had relative baseline peripheral refractions that did not differ from those that remained emmetropic. Our study provides additional insights into possible early refractive and shape changes in the development of myopia.

Keywords: myopia • refractive error development • refraction