Assessment of relative peripheral refraction in children with low myopia and pre-myopia using multispectral refraction topography.

The purpose of this study was to assess the retinal relative peripheral refraction (RPR) in children with low myopia and pre-myopia, and investigate the differences in RPR using multispectral refraction topography (MRT). Ninety-five children were enrolled in the Department of Ophthalmology, Jinshan Hospital affiliated to Fudan University. MRT could measure total RPR (TRPR) of the 53° range centered on macular fovea. TRPR divided into four quadrants: superior RPR (RPR-S), inferior RPR (RPR-I), temporal RPR (RPR-T) and nasal RPR (RPR-N). The MRT analysis report also showed RPR in the visual field of 15° (RPR-15), 30° (RPR-30) and 45° (RPR-45) centered on the macular fovea, respectively. RPR-(15-30), RPR-(30-45) and RPR-(15-45) were calculated. TRPR (R =  - 0.264, P = 0.010), RPR-I (R =  - 0.261, P = 0.011), RPR-T (R =  - 0.240, P = 0.019), RPR-45 (R =  - 0.211, P = 0.040), RPR-(30-45) (R =  - 0.232, P = 0.023) and RPR-(15-45) (R =  - 0.243, P = 0.018) were negatively correlated with spherical refraction. Spherical equivalent of low myopia group was significantly less than pre-myopia group (- 1.18 ± 0.57 D vs. 0.13 ± 0.31 D, P < 0.001) whereas axial length of low myopia group was significantly longer than pre-myopia group (24.14 ± 0.70 mm vs. 23.35 ± 0.60 mm, P < 0.001). TRPR of low myopia group and pre-myopia group was 0.52 ± 0.62 D and 0.32 ± 0.41 D, respectively, without sigficant difference (P = 0.075). All the RPRs were hyperopia in the children with low myopia and pre-myopia, except for RPR-T in pre-myopia group. RPR-I in low myopia group was significantly larger than that in pre-myopia group (0.42 ± 0.72 (95% CI 0.22, 0.62) D vs. 0.04 ± 0.67 (95% CI - 0.17, 0.25) D, P = 0.010). In conclusion, RPRs become more hyperopia with the changing trend from pre-myopia to myopia. Children with low myopia and pre-myopia have relative peripheral hyperopia. Furthermore, children with low myopia have larger relative peripheral hyperopia compared with pre-myopia.