Wang Li-Li, Wang Wei, Han Xiao-Tong, He Ming-Guang
Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou 510060, Guangdong Province, China.
Int J Ophthalmol. 2018 Aug 18;11(8):1377-1383. doi: 10.18240/ijo.2018.08.20. eCollection 2018.
To investigate the influence of astigmatism on visual acuity in school-aged children, and to define a cutoff for clinically significant astigmatism.
This is a population-based, cross-sectional study. Among 5053 enumerated children aged 5-15y in Guangzhou, 3729 (73.8%) children aged 7-15 with successful cycloplegic auto-refraction (1% cyclopentolate) and a reliable visual acuity measurement were included. Ocular measurement included external eye, anterior segment, media and fundus and cycloplegic auto-refraction. Primary outcome measures included the relationship between severity and subtypes of astigmatism and the prevalence of visual impairment. Three criteria for visual impairment were adopted: best-corrected visual acuity (BCVA) ≤0.7, uncorrected visual acuity (UCVA) ≤0.5 or <0.7 in the right eye.
Increases of cylinder power was significantly associated with worse visual acuity (UCVA: β=0.051, <0.01; BCVA: β=0.025, <0.001). A substantial increase in UCVI and BCVI was seen with astigmatism of 1.00 diopter (D) or more. Astigmatism ≥1.00 D had a greater BCVI prevalence than cylinder power less than 1.00 D (OR=4.20, 95%CI: 3.08-5.74), and this was also true for hyperopic, emmetropic and myopic refraction categories. Oblique astigmatism was associated with a higher risk of BCVI relative to with the rule astigmatism in myopic refractive category (OR=12.87, 95%CI: 2.20-75.38).
Both magnitude and subtypes of astigmatism influence the prevalence of visual impairment in school children. Cylinder ≥1.00 D may be useful as a cutoff for clinically significant astigmatism.
探讨散光对学龄儿童视力的影响，并确定具有临床意义的散光的临界值。
这是一项基于人群的横断面研究。在广州5053名登记的5至15岁儿童中，纳入了3729名（73.8%）7至15岁成功进行睫状肌麻痹自动验光（1%托吡卡胺）且视力测量可靠的儿童。眼部检查包括眼外、眼前节、眼内介质和眼底以及睫状肌麻痹自动验光。主要观察指标包括散光的严重程度和亚型与视力损害患病率之间的关系。采用了三种视力损害标准：最佳矫正视力（BCVA）≤0.7、右眼未矫正视力（UCVA）≤0.5或<0.7。
柱镜度数增加与视力下降显著相关（UCVA：β=0.051，P<0.01；BCVA：β=0.025，P<0.001）。散光1.00屈光度（D）及以上时，UCVI和BCVI显著增加。散光≥1.00 D的BCVI患病率高于柱镜度数小于1.00 D的情况（OR=4.20，95%CI：3.08 - 5.74），在远视、正视和近视屈光类别中也是如此。在近视屈光类别中，相对于顺规散光，斜轴散光与BCVI风险更高相关（OR=12.87，95%CI：2.20 - 75.38）。
散光的程度和亚型均影响学龄儿童视力损害的患病率。柱镜≥1.00 D可作为具有临床意义的散光的临界值。
