Outcome measurements
REFRACTIVE ERROR
From the crossover time point (at the 12th month) to the 18th month, subjects underwent the same standardized ophthalmic examinations as in phase 1. Measurements were taken from 9:00 to 12:00 at the weekend. The measurement of pupil sizes was examined before measuring the axial length (AL) and refractive error. The OPD-Scan III (Nidek, Japan) was applied to measure mesopic and photopic pupil sizes. The protocol parameters of the device were reset before each measurement. We had patients sit directly across from the examiner; participants were asked to fixate on a distant object to relax their accommodation with the left eye that was not being measured. Then, the mesopic (background intensity was 0 μw) pupil size was measured three times and averaged using the OPD-Scan III, followed by photopic illuminance (background intensity as 50 μw). For each set of measurements, the average value of the first three consecutive data captures with differences less than 0.50 mm was used for analyses. We assessed the following parameters using the following equations [

