| Objective: To study the distribution of refractive states of children aged 3-15 in Shiyan city,and analyze the correlation between refractive states and various eye biological parameters,so as to provide clinical basis for personalized prevention and treatment of myopia for students aged 3-15 in Shiyan City.Methods: A cross-sectional study.A total of 512（1024 eyes）3-15 years old students with ametropia who were admitted to the ophthalmology Clinic of Shiyan People’s Hospital from June 2020 to March 2021 were randomly selected and divided into 4 groups according to age: 3-6 years old group,6-9 years old group,9-12 years old group,12-15 years old group.Divided into male and female groups by sex;According to the diopter,they were divided into 5 groups: hyperopia（> + 0.50d）,emmetropia（+ 0.50 d ～-0.50d）,light myopia（-0.50 d ～-3.00d）,medium myopia（-3.25 d ～-6.00d）and high myopia（<-6.00d）.The axial length（AL）,anterior chamber depth（ACD）,lens thickness（LT）,horizontal corneal curvature（K1）and vertical corneal curvature（K2）were measured by Crystal Star 900.Lens refractive force（LP）was calculated by bennett-Rabbetts formula.SPSS 23.0 statistical software was used for analysis.The count data were uniformly described by means ± standard deviation（’ X ± S ’）,and the rate was expressed.Boys and girls refractive parameter comparison using independent sample T test,different equivalent ball lens dioptre between groups of various kinds of biological parameters（such as: corneal radius of curvature,axial length,ratio of axial ratio and the lens dioptre）is using single factor analysis of variance,the difference of the different equivalent spherical mirrors the correlation between diopter and refractive parameters using linear regression analysis.P<0.05 was considered as statistically significant difference.Results:（1）The incidence of hyperopia was highest in 3-6 years old group（273/374,72.99%）,and lowest in 12-15 years old group（17/186,9.14%）,and the difference was statistically significant（X2=143.125,P=0.000）.The incidence of myopia was the highest in 12-15 years old group（147/186,79.03%）,and the lowest in3-6 years old group（29/374,7.75%）.The difference was statistically significant（X2=225.750,P=0.000）.The incidence of myopia in female students was lower than that in male students（P=0.020）.There were statistically significant differences in incidence of myopia between male and female students in different age groups.The incidence of myopia increases gradually in children after the age of 6,and the increase is the largest.（2）With the increase of age,the average equivalent spherical lens of male and female students showed a decreasing trend,with statistical significance.The ocular axis increased with age（P=0.000）,and the ocular axis（AL）of boys was larger than that of girls at different ages（P=0.000;P = 0.000;P = 0.002;P = 0.003）.With the increase of age,the mean radius of corneal curvature（CR）tended to be stable（P=0.66）.The axial ratio（AL/CR）increased with age（P=0.000）,and the axial ratio（AL/CR）of boys aged 3-15 was higher than that of girls aged 3-15（P=0.002;P =0.001;P = 0.000;P = 0.000）.Lens refractive power（LP）decreased with age（P=0.000）,and the LP of male lens was lower than that of female lens（P=0.002;P =0.001;P = 0.000;P = 0.000）.（3）The differences in equivalent spherical refraction（SE）,eye axis（AL）,mean corneal radius of curvature（CR）,axial rate ratio（AL/CR）and lens refractive power（LP）between refractive groups were statistically significant（P<0.01）,and the differences in the correlation between refractive parameters and equivalent spherical refraction（SE）were not the same between refractive groups.The different equivalent spherical lens diopters in the myopic group corresponded to different axial rate ratios,with all hyperopic eyes having an axial rate ratio（AL/CR）below 3.0 and all myopic eyes in all three groups with different equivalent spherical lens diopters（SE）above3.0.Each unit increase in axial length（AL）was associated with a-1.85 unit change in equivalent spherical lens diopters（SE）,while each unit decrease in lens refractive power（LP）corresponded to 0.5D change in equivalent spherical refraction.Conclusions: In this study,the refractive status of children aged 3-15 in Shiyan city changed with age,and the increase rate of myopia increased from 6 years old to 6years old,suggesting that 6-9 years old is the active stage for the occurrence of myopia,and after 6 years old is the key stage to control the development of myopia.After 3 years old,was moderate corneal curvature,eye axial growth mainly fall in the refractive power of the lens to compensate,eye axis on the rise along with the age growth,the lens refractive power showed a trend of decrease and axial growth trend with the decreasing equivalent ball for eyeglasses,the decrease trend and lens refractive power,shiyan mean women children ocular axial length are less than men,The mean value of lens refractive power is higher than that of male lens,and both coordinate and affect the development of myopia.Using axial ratio to evaluate the occurrence and development of myopia is more reliable and sensitive than using axial ratio to evaluate the occurrence and development of myopia.As the age increases,the axial ratio increases,and the equivalent spherical lens intensity decreases,the axial ratio increases.Axial ratio greater than 3 can be considered as a high risk index for the development of emmetropia to myopia,and the magnitude of axial ratio can be used to judge the severity of myopia. |
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