Peripheral optical quality and myopia progression in children

To investigate the peripheral optical quality and its relationship with axial elongation, myopic progression in Japanese children. Twenty-nine Japanese children, ages 10 to 12 years old, with baseline refraction from +0.75D to -5.5 D, were included and followed for 9 months. The central and peripheral point spread functions (PSFs; 0A degrees, 10A degrees, 20A degrees, 30A degrees nasally) were obtained at 0.25 D steps around +/- 2.5 D of best-focus PSF (BF-PSF) using double-pass PSF system. Modulation transfer function (MTF) area of the BF-PSF was calculated from BF-PSF to represent the peripheral optical quality. Relative peripheral defocus (RPD), the refraction of anterior/posterior focal lines, MTF area, and their correlations with myopia progression were analyzed. The average refractive change in 9 months was -0.5 +/- 0.8 D. The change in axial length was significantly positively correlated with the amount of myopic progression (P = 0.0058) and RPD (P = 0.0007, 0.0036 and 0.0040, at 10A degrees, 20A degrees, 30A degrees respectively) at the initial visit, but did not correlate with the peripheral MTF area. Myopic progression of more than 0.5 D with axial elongation was observed in seven children (MP group). The RPDs at 20A degrees and 30A degrees in the MP group were significantly more hyperopic than in the non-MP group (P = 0.002 and 0.007), whereas there was no significant difference in axial length, and central and peripheral MTF area between the MP and non-MP groups. MP group had more hyperopic focal lines compared with non-MP group at 20A degrees and 30A degrees. These results suggest that the progression of axial myopia in children is associated with hyperopic RPD and refraction of focal lines, not with peripheral optical quality.