Relative peripheral hyperopia leads to greater short-term axial length growth in White children with myopia

Purpose: Controversy exists regarding the influence of peripheral visual experience on the onset and progression of childhood myopia. This longitudinal, observational study evaluated the relationship between relative peripheral refraction (RPR) and changes in refractive error and axial length (AL) over 12 months in White children aged 6-7 and 12-13 years with a range of baseline refractive errors. Methods: Cycloplegic baseline autorefraction at horizontal retinal eccentricities of 0 degrees and +/- 30 degrees were recorded with the Shin-Nippon NVision-K 5001 while AL was measured using the Zeiss IOLMaster 700. Measurements were repeated after 12 months on a subgroup. Refractive data were transposed into power vectors as mean spherical equivalent (M), J 0 and J 45. RPR was calculated by subtracting central from peripheral measurements. Participants were defined as myopic (M = -0.50 D), premyopic (- 0.50 D < M = +0.75 D), emmetropic (+0.75 D < M < +2.00 D) or hyperopic (M = +2.00 D). Results: Data were collected from 222 and 245 participants aged 6-7 and 12-13 years, respectively. Myopic eyes demonstrated, on average, more hyperopic RPR. Emmetropes and premyopes displayed emmetropic RPR, and hyperopes showed a myopic RPR. Fifty-six 6-to 7-year- -olds and seventy 12-to 13-year-olds contributed 12-month repeated measures. Longitudinal data demonstrated a significant relationship between a more hyperopic RPR in the nasal retina and greater short-term axial elongation in teens with myopia at baseline (beta = 0.69; p = 0.04). Each dioptre of relative peripheral hyperopia in the nasal retina was associated with an additional 0.10 mm (95% CI: 0.02-0.18 mm) annual increase in AL. Conclusions: Hyperopic RPR in the nasal retina of myopic children is indicative of increased risk for rapid axial elongation and may be a useful metric to support decision-making in myopia management.