Epidemiological Investigate Of Visual Status And Its Correlation Between Refractive Parameters Of Pupils In ShenZhen

Objective:To investigate the visual and the epidemiological status of refractive among students from two different schools in Shenzhen, analyze the occurrence rate and the refractive components of poor sight in pupils of Shenzhen. To observe the visual quality and related influence factors of the primary school students in Shenzhen, measure the refraction and relative parameters in students from different grades, analyze the difference of the eye biological parameters from them. To undertake visual health management for some students, searching methods for prediction and prevention of myopia, and offerring evidence for the research of school-age children refractive errors and myopia prevention and control.Methods:The method of combination of cross-sectional and longitudinal investigation was adopted in this research. Around 2,000 primary students were selected by chester sampling whose eyesight were exanimated in a municipal key and a provincial key private primary school in Longgang and Futian district. In addition, the analysis of poor eyesight rate in two schools from 2011 to 2014 was conducted and differences between the incidence rate of poor vision and grade was compared. Rrefractive diopter check was taken to analyze in two schools, analyzing the refractive components of poor eyesight. Measuring the contrast visual acuity (CVA) in students from Longgang District respectively in 2011 and 2013, observe the effect of CVA on the incidence of poor vision and refraction, and analyse the relationship between CVA and refraction. Stratified sampling method was used in 1-5 grade in primary school of Futian District, intraocular pressure、axial length and corneal curvature were measured on those pupils,analyze the difference of axial length and corneal curvature in different grades, and its relationship with diopter.Intemational standard visual acuity chart was used to have an eyesight text,as auto-refractomer and Plusoptix vision screening instrument were used to measure the diopter. For some poor eyesight students, if they need, we offerred cycloplegic refraction. Contrast visual acuity was measured by MFVA-200, an electronic vision measuring instrument (offered by Shenzhen Brighteye Medical Company). Axial length and corneal curvature were measured by IOL-Master 500(ZEISS). Final data were the average of three measurements. Excel spreadsheets were created after date collection, SPSS 19.0 statistical software was used to statistical analysis.Results:1. The overall detection rate of poor eyesight of 2013 reached 46.47% in Shenzhen,62.34% in Longgang District and 23.43% in Futian District. Poor eyesight happened more in high grade, puiples in low grade in Longgang District reached to a peak level, comes down and then going up again. Pupils from these two schools in different grades of poor eyesight had significant differences;the poor eyesight rate of mild decreased with the increase of grade, the ratio of the severe vision increased with grade.2. Among the pupils with poor eyesight, hyperopia found mostly in lower grades, with the increase of grade, which reduce gradually as the same time the number of myopia increased. Mild mopia was the majority of all myopia, than moderate myopia, high myopia was the minority.3. The contrast visual acuity of pupils shows:the CVA of low grade students is better than higher grades’, with the increase of grade, pupil’s CVA became worse, boys’CVA is better than girls’. Correlation between the visual quality and diopter was not founded in this research. With the right correction, myopia can get the same visual quality as emmetropia. Whether the visual quality is good or not,it may have no effect on the eyesight and refraction state.4. Along with the increase of grade, students’ ocular axial length increase gradually, the axial length of each grade of myopia were longer than hyperopia and emmetropia. Diopter and anxial length was negatively correlated, and it was slightly negatively correlated with corneal curvature.Conclusion:The rate of poor eyesight among primary school students increased year by year in Shenzhen, together with their grade. Although myopia still accounts for most in primary school, the poor eyesight rate cannot be equal with myopia rate. Contrast visual acuity decreased with grade increasing, boys’CVA is better than girls’. Visual quality has no obvious correlation with the refractive status, because myopic students can obtain good vision quality through the vision correction. The extension of eye axis has a close relationship with the formation of myopia, which was highly negatively correlated with diopter.