Abstract
Purpose :
To investigate the effect of foveal retinal input and peripheral defocus on early myopia development in children.
Methods :
Eighty-five children aged 6 to 9 years with near emmetropic refractive error (between +1D and -1D) were recruited. Global flash multifocal electroretinogram (MOFO mfERG) were performed at their first visit. Cycloplegic central refraction, axial length and peripheral refraction were checked at the baseline and after 2 years. Peripheral refraction was measured by an open-field autorefractor at 10, 20 and 30 degrees from central fixation in both nasal and temporal fields. Relative peripheral refraction was calculated by subtracting the central measurement from each peripheral measurement.
Results :
At baseline, forty-two children (mean of 7.55 years) and forty-three children (mean of 7.77 years) were defined into strong retinal function (S) and weak retinal function (W) group based on their foveal electrophysiological function and this grouping criterion was reported in our recent paper. There was no significant difference between two subgroups in central refraction, axial length and peripheral refraction. After 2 years, children of S group had central refraction changes of -0.5±0.76D while children in W group showed statistically significant larger changes of -0.93±0.96D (p=0.007). Relative peripheral refraction of W subgroup became more hyperopic than that of S subgroup at each measurement position, and the differences, however, did not reach the significance level with Bonferroni adjustment. The change of central refraction did not correlate with the baseline relative peripheral refraction, while, after 2 years, it had significant correlation with the relative peripheral refraction at 30 degrees in nasal and temporal fields (nasal field r=-0.44, p<0.001; temporal field r=-0.30, p=0.006).
Conclusions :
Foveal retinal electrophysiological changes appear to precede myopia development while peripheral defocus might be the secondary effect concurrent with myopia in children.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.