Ke-Ke Zhao1, Yuan Yang2,3, Hong Wang1, Lu Li1, Zhao-Yang Wang2,3, Fan Jiang1, Ji-Fang Qu1. 1. Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China. 2. Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China. 3. Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai 200011, China.
Abstract
AIM: To measure and analysis axial length (AL)/corneal radius of curvature (CRC) ratio and other refractive parameters, provide a medical reference range for refractive development evaluation and earlier visual impairment screening of 3 to 4y kindergarten students. METHODS: Between April and June 2017, a total of 4350 participants aged 3- to 4-year-old (8700 eyes) from 10 cluster random sampling kindergartens in Shanghai, Pudong District were involved. According to the measurement and analysis of the unaided visual acuity (VA), AL, CRC, AL/CRC ratio, astigmatism and other refractive parameters, the data distribution and reference range were obtained. RESULTS: Uncorrected VA of examined children was 0.23±0.08 (logMAR, mean±SD) [95% confidence interval (CI) range ≤0.36]; AL was 22.10±0.79 mm (95%CI 20.55-23.65); CRC was 7.86±0.26 mm (95%CI, 7.35-8.37); AL/CRC ratio was 2.81±0.12 (95%CI, 2.57-3.05). The median of astigmatism was -0.5 D, a total of 56.3% had astigmatism <-0.50 D, 85.3%<-1.00 D, 6.7%>-1.50 D; 71% were astigmatism with the rule. Eye-specific analyses were conducted. Statistical difference of VA was in right and left eyes. There were no significant differences between two eyes of AL, CRC, AL/CRC ratio and astigmatism (P>0.05). CONCLUSION: VA and AL/CRC ratio reference could be used to assess refractive development in children and screening uncorrected refractive errors or amblyopia. Astigmatism needs to be considered in the diagnosis.
AIM: To measure and analysis axial length (AL)/corneal radius of curvature (CRC) ratio and other refractive parameters, provide a medical reference range for refractive development evaluation and earlier visual impairment screening of 3 to 4y kindergarten students. METHODS: Between April and June 2017, a total of 4350 participants aged 3- to 4-year-old (8700 eyes) from 10 cluster random sampling kindergartens in Shanghai, Pudong District were involved. According to the measurement and analysis of the unaided visual acuity (VA), AL, CRC, AL/CRC ratio, astigmatism and other refractive parameters, the data distribution and reference range were obtained. RESULTS: Uncorrected VA of examined children was 0.23±0.08 (logMAR, mean±SD) [95% confidence interval (CI) range ≤0.36]; AL was 22.10±0.79 mm (95%CI 20.55-23.65); CRC was 7.86±0.26 mm (95%CI, 7.35-8.37); AL/CRC ratio was 2.81±0.12 (95%CI, 2.57-3.05). The median of astigmatism was -0.5 D, a total of 56.3% had astigmatism <-0.50 D, 85.3%<-1.00 D, 6.7%>-1.50 D; 71% were astigmatism with the rule. Eye-specific analyses were conducted. Statistical difference of VA was in right and left eyes. There were no significant differences between two eyes of AL, CRC, AL/CRC ratio and astigmatism (P>0.05). CONCLUSION: VA and AL/CRC ratio reference could be used to assess refractive development in children and screening uncorrected refractive errors or amblyopia. Astigmatism needs to be considered in the diagnosis.