The Feasibility Study Of Screening Refractive Error In 3～15 Year-old Children Without Cycloplegia

Objective: To investigate the prevalence of refractive error of 3-15-year-oldchildren and their refractive correction;To analysis the influence of cycloplegia in spherical equivalent and cylinder. The mainly objective of this paper is to evaluate the effectiveness and feasibility of refraction screening project, in order to reduce the prevalence of undetected, correctable visual acuity deficits due to refractive error;Try to determine the cut-off points of sreening refractive error without cycloplegia in different ages.Methods: The subjects were random selected from a population-based andcluster sampling research project-The Epidemiologic Survey of Prevalence of Strabismus, Amblyopia and Refractive error of 1~ 15-year old Children in Tianjin, in which there are totally 10,357 eligible children involved. In the following study, there are 6001 children who were sampled by random digits table.Before the formal examinations, the inquirers and ophthalmologists had been trained with the significance, purpose, methods and detailed steps of this project. The inquirers have familiarized with the proper instructions of filling in the questionnaire. The ophthalmologists and optometrists who would examine the children have familiarized with the instruments and have been standardized by a uniform operation guide. We have done the pilot study and adjusted some details of scheme according to the fact.The questionnaire included : general materials ( name, sex, age, nationality, address, school, grade, class, name of parents or guardians and correspondence number, etc), history (birth condition, past eye-related disease), eye disease of parents and the history mother's pregnancy.The eye examinations included: distant visual acuity measurement, cycloplegic retinoscopyand autorefraction, cover test, ocular motility evaluation, stereoscopic acuity, anterior segment, media and fundus.The datum were examined, verified and recorded by the special person. Datum have been input twice to ensure the accuracy. All the management of datum were finished in SPSS 11.5 soft wire, the statistical method included t-test, ANOVA, Chi-square, linear regression and correlation, etc.Results:1. The spherical equivalent decreases gradually with ages;the cylinder diopter and axis have no significant change with ages. As the age increases, the prevalence of myopia increases, hyperopia decreases, however, the prevalence of astigmatism is similar between different ages.2. The spherical equivalent diopter increased after cycloplegia with statistical significance, the change of cylinder diopter and axis is statistical significant. There is significant difference of the spherical equivalent changing magnitude between 3 and 15 years old children;As the age going, the changing magnitude of spherical equivalent after cycloplegia is decreasing.3. There is positive correlation between non-cycloplegic spherical equivalent and cycloplegic spherical equivalent. The Pearson correlation coefficient is statistical significant. There is linear regression between non-cycloplegic spherical equivalent and cycloplegic spherical equivalent. The regression coefficient is statisticalsignificant, we can forecast the cycloplegic refraction by non-cycloplegic refraction and the regression equation.4. When screening for refractive error by autorefraction in non-cycloplegia. the cut-off points must be adjusted with ages. We should increase the cut-off points for myopia and decrease them for hyperopia, however, the cut-off point of screening for astigmatism is the same as usual.Conclusion:1. The prevalence of refractive error in school-age Chinese children is severely high, especially for myopia, which has been a major public health problem in Chinese children. The relevant strategies are needed to reduce the undetected and correctable refractive error.2. There is linear regression and correlation between non-cycloplegic spherical equivalent and cycloplegic spherical equivalent. According to the linear regression equation, we can forecast the cycloplegic spherical equivalent by the non-cycloplegic spherical equivalent in different ages .3. Screening for refractive error in school-age children by autorefractor under non-cycloplegia is feasible and effective. The appropriate cut-off points of screening for myopia and hyperopia must be adjusted with ages. However, the cut-off point for astigmatism is the same as we usually use .