Myopia evolution in pre-school children after full optical correction

Abstract

The optical correction of myopia is a controversial procedure in immature human eyes due to the limited knowledge of the mechanisms regulating emmetropization and to the lack of controlled clinical trials. The authors reviewed retrospectively the records of 42 myopic children (16 males and 26 females, mean age 34 months, range 17-54) for whom full optical correction was prescribed and refraction evaluated with cycloplegic autorefractometry. The mean Spherical Equivalent (SphEq) at the diagnosis (To) was 6.062±3.67 diopters. Eighteen patients had isomyopic (±1D difference SphEq), 15 anisomyopic and 9 antimetropic eyes. No differences were found at To in the mean sphere, cylinder, SphEq and age of first correction between males and females. Follow-up was 42±17 and 47±23 months respectively for each sex (T1). Compliance with spectacles was generally good. At T1, the mean SphEq was significantly reduced in the whole group (-5.32±3.39, P<0.001). However, analyzing the sexes separately, it was found that only spherical progression was halted in males, whereas females showed a significant reduction both in sphere (p<0.001) and in cylinder (p<0.001). Final visual acuity was 0.86±0.18 and 0.86±0.26 (p: n.s.). The authors conclude that full optical correction did not exacerbate myopia progression in infants. Females showed a higher plasticity to the emmetropization process. Myopia increased mostly in undercorrected patients, and decreased with spectacles in 61% of isomyopic, 73% of anisomyopic and 77% of antimetropic patients. These observations support the hypothesis that visual input can modulate eye growth, calling for an early correction strategy for controlling myopia in infants.