The Epidemiology Of The Development Of Visual Acuity And Amblyopia Of 3～15-year Children In Some District Of Tianjin

Objective: To describe and analysis the circumstance of visual acuities and amblyopia of children of 3~15-year old in a certain district of Tianjin, and to discuss the relationship between the development of visual acuities and amblyopia , and other correlation factors.Methods: The data of subjects were sampled from the materials of population-based and cluster sampling of 10,000 eligible children in the project- The Epidemiologic Survey of Prevalence of Strabismus, Amblyopia and Refractive error of 1-15-year Children in Tianjin (ESPSARC, Tianjin). The subjects included 6001 children of age group 3—15 years old (3032 boys and 2969 girls) and were sampled by the method of random digits table. Before the examinations, all children were enrolled. Clinical examinations were conducted byophthalmologists, doctor assistants and optometrist in temporary stations in school classrooms, preschool classrooms or community halls. Ophthalmological examinations were made up of the examinations of distant visual acuity which included uncorrected and corrected visual acuity with ETDRS eye chart, refraction before and after cycloplegia, cover-uncover test, ocular movement, stereoscopic visual acuity, the examinations of anterior segment and fundus. The data were examined and inputted into computer, statistical analyses were performed using computer software-SPSS 11.5.Results:l.The percentages of corrected visual acuity better than 0.5, 0.63and 0.8 in better-seeing eye are positively correlated with the age (r!=0.760, r2=0.888, r3=0.907, P< 0.01).2. The prevalence of children with subnormal visual acuity is negatively correlated with the age (r=—0.92, /><0.01). There is no significant difference between male and female(t=0.203, /M).84), but statistically significant difference is found between left and right eyes (t=—4.100, /M).001).3. The prevalence of amblyopia is 4.63%. The comparison among different age-groups showed that the prevalence in the pre-school group is higher than the primary school group and the junior-high-school group, the differences are significant^^O.OOS , P2=0.004). Ametropic amblyopia is the most common type of amblyopia (54.68%), next ones are anisometropic amblyopia (35.61%), strabismic amblyopia (9.35%), and form deprivation amblyopia (0.36%).4. There are statistically significant differences in the distributions of age , gender and corrected visual acuity of subnormal eye between amblyopia and unexplained causes of subnormal visual acuity .Conclusion: The development of visual acuity of children is continuously perfected , the visual growth of 3~7 years old children is fleet, to 8~9 years old the growth is near to the maturity, so the standard for normal visual acuity must be age-specific .The Children with unexplained causes of subnormal visual acuity should be examined further and followed up to make sure the causes of the subnormal visual acuity.