ABSTRACT
AIM: To compare the binocular and monocular accommodation among normal group, premyopia group and mild myopia group, and to study the characteristics of accommodation in the premyopia group, thus providing clinical evidence for the delay/prevention of myopia and the effective decrease of the incidence of myopia.METHODS: Cross-sectional descriptive study. A total of 179 children who had abnormal/high-risk visual acuity indicated by the vision screening in school from October 2021 to February 2023 were selected, including 92 males and 87 females, aged from 6 to 12(mean 8.55±1.66)years old, then they were referred to the Juvenile Myopia Prevention and Control Center in Cuizu Community Health Service Center. They were divided into normal group(+0.75 D<SE≤+2.00 D), the premyopia group(-0.50 D<SE≤+0.75 D)and the mild myopia group(-3.00 D≤SE≤-0.50 D)according to the diopters after cycloplegia, and binocular myopia grouping is defined by the eye with lower diopter. Binocular positive relative accommodation(PRA), negative relative accommodation(NRA), accommodative facility(AF), and monocular AF and amplitude of accommodation(AA)were examined. The age, binocular and monocular accommodation of different groups were compared.RESULTS: There were no difference in the sex ratio of different groups(χ2=0.167, P=0.920). There was no difference in age between the normal group and the premyopia group(P=0.310), but there were differences between the mild myopia group and the normal group and premyopia group(P=0.018, <0.01); Binocular NRA, PRA, and AF had significance between the normal group and the premyopia group(P<0.01), while there was no significance between the premyopia group and the mild myopia(P>0.05). Monocular AF had significance between the normal group and the premyopia group(P<0.01), while there was no significance between the premyopia group and the mild myopia group(P>0.05); The monocular AA had significance among the three groups(P<0.05).CONCLUSION: Although the diopters was normal, binocular NRA, PRA, monocular and binocular AF had significantly decreased in the premyopia group, and there was no significant difference compared with mild myopia group; monocular AA had decreased in the premyopia group and it was also significantly different from the mild myopia group. The accommodation function should be examined in premyopic children. Recovering the abnormal visual function through visual training may be a way to prevent and control premyopia from progressing to myopia.
ABSTRACT
Low?concentration atropine (LCA; 0.01%) is known to reduce the progression of myopia in axial myopes. The purpose of this study was to understand the role of LCA in premyopic children in preventing progression. Methods: A randomized case–control study of known premyopes was done between the use of LCA and no intervention. A total of 30 children were included in both groups. Results: The mean age in the LCA group was 7.7 ± 2.1 years (5–12 years), and in the control group, it was 7.2 ± 1.9 years (4–12 years). The mean baseline progression per year in the LCA group (before starting the eye drops) was ? 0.72 ± 0.3 D, and in the control group, it was ? 0.69 ± 0.4 D. At the end of the first year, the mean progression in the LCA group was ? 0.31 ± 0.3 D versus ? 0.76 ± 0.4 D, and the axial length increase was 0.12 ± 0.1 mm in the LCA group and 0.21 ± 0.2 mm in the control group. At the end of the second year, the mean progression compared with the baseline in the LCA group was ? 0.6 ± 0.3 D versus ? 1.75 ± 0.4 D, and the axial length showed an increase from baseline in the LCA group by 0.21 ± 0.2 mm, and in the control group, the increase was 0.48 ± 0.2 mm in 2 years. Conclusion: Low?concentration eye drops (0.01%) work in preventing the progression of axial myopia in premyopic children.