1.Comparison of myopia prevalence among normal, exophoria and intermittent exotropia children
Nixian YU ; Fang XIE ; Wei ZHANG
Recent Advances in Ophthalmology 2017;37(5):438-441
Objective To discuss the difference of myopia prevalence and spherical equivalent among normal,exophoria and intermittent exotropia children.Methods The children aged between 6 years old to14 years old were divided into 3 groups of orthophoria (n =151),exophoria (n =180) and intermittent exotropia (n =168) based on the result of cover-uncover test.Intermittent exotropia group was divided into three types of basic,convergence insufficiency and divergence excess.Diopter values were retrospectively reviewed,and results were recorded with the average data after the objective optometry of cycloplegia.Results Myopia prevalence of intermittent exotropia of different ages was higher than normal and exophoria (all P < 0.05),but no difference between exophoria and normal (all P > 0.05).There were statistical significant differences in overall prevalence among three groups (intermittent exotropia and orthophoria:P =0.000,intermittent exotropia and exophoria:P =0.000,orthophoria and exophoria:P =0.034).Average spherical equivalent was (0.08 ± 0.99) D in orthophoric group,(-0.16 ± 1.16)D in exophoric group and (-1.23 ± 1.57)D in intermittent exotropic group,there was statistical difference among three groups (P =0.000).The differences were also statistical significant between orthophoria group and exophoria group (P =0.015),intermittent exotropia group and orthophoria group (P =0.000),exophoria group and intermittent exotropia group (P =0.000).In the group of intermittent exotropia,average spherical equivalent was (-1.68 ± 1.61) D in convergence insufficient group,(-1.14 ± 1.44) D in basic group and (-0.85 ± 1.50) D in divergence excessive group,there was statistical difference among three groups (P =0.000).The spherical equivalent in convergence insufficient group was lower than the basic group (P =0.000)and divergence excessive group (P =0.041).Conclusion The myopia prevalence and degree of intermittent exotropia are all higher than normal and exophoria in children.