Ma Martin Ming-Leung, Long Wen, She Zhihui, Li Wanping, Chen Xuhui, Xie Lingmei, Scheiman Mitchell, Liu Yuling, Chen Xiang
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
Department of Optometry and Optical, Guangzhou Business Vocational School, Guangzhou, China.
Clin Exp Optom. 2019 Mar;102(2):166-171. doi: 10.1111/cxo.12838. Epub 2018 Sep 11.
The frequency of convergence insufficiency was determined in a sample of Chinese high school students. The associations between the frequency of convergence insufficiency, gender, refractive error and accommodative insufficiency were investigated.
This was a single-site, prospective cross-sectional study. In total, 928 eligible teenagers (mean age 15.9 ± 0.8) from a local high school in Guangzhou, Guangdong Province, China participated in this study. Refraction and binocular vision tests were performed on all eligible participants. The following three signs were used to classify participants: sign 1, exophoria at near at least 4 greater than at far; sign 2, receded near point of convergence (≥ 6 cm break point); and sign 3, insufficient near positive fusional vergence (that is, failing Sheard's criterion or ≤ 15 break point). Diagnostic groups of convergence insufficiency classification were defined as follows: (1) 3-Sign convergence insufficiency (all three signs present); (2) 2-Sign convergence insufficiency (sign 1 plus sign 2 or 3); (3) 1-Sign convergence insufficiency (sign 1 only); and (4) no convergence insufficiency (that is, participants not classified into one of the above groups).
The number and frequency of individuals with 3-Sign, 2-Sign, and 1-Sign convergence insufficiency as well as no convergence insufficiency group were 25 (2.7 per cent), 119 (12.8 per cent), 303 (32.6 per cent) and 481 (51.8 per cent), respectively. Gender (χ = 36.6, df = 3, p < 0.001), refractive error grouping (χ = 37.7, df = 9, p < 0.001) and accommodative insufficiency (χ = 15.4, df = 3, p = 0.002) were all significantly associated with convergence insufficiency. Male gender, hyperopia, or accommodative insufficiency were more likely to be classified with 3-Sign convergence insufficiency. The frequency of accommodative insufficiency was 9.5 per cent (88 of 928 participants).
Compared to the data from school- and clinic-based populations in the USA and South Africa, the data from this sample of Chinese high school students showed a lower frequency of 3-Sign convergence insufficiency (2.7 per cent). Convergence insufficiency was associated with refractive error, gender and accommodative insufficiency.
在中国高中生样本中确定集合不足的发生率。研究集合不足发生率与性别、屈光不正和调节不足之间的关联。
这是一项单中心前瞻性横断面研究。来自中国广东省广州市一所当地高中的928名符合条件的青少年（平均年龄15.9±0.8岁）参与了本研究。对所有符合条件的参与者进行了屈光和双眼视觉测试。使用以下三个体征对参与者进行分类：体征1，近距外隐斜至少比远距大4棱镜度；体征2，集合近点后移（≥6厘米破裂点）；体征3，近距正融合性聚散不足（即未达到谢尔德准则或≤15棱镜度破裂点）。集合不足分类的诊断组定义如下：（1）三体征集合不足（三个体征均存在）；（2）双体征集合不足（体征1加体征2或3）；（3）单体征集合不足（仅体征1）；（4）无集合不足（即未被分类到上述任何一组的参与者）。
三体征、双体征和单体征集合不足以及无集合不足组的个体数量和发生率分别为25例（2.7%）、119例（12.8%）、303例（32.6%）和481例（51.8%）。性别（χ²=36.6，自由度=3，p<0.001）、屈光不正分组（χ²=37.7，自由度=9，p<0.001）和调节不足（χ²=15.4，自由度=3，p=0.002）均与集合不足显著相关。男性、远视或调节不足更有可能被分类为三体征集合不足。调节不足的发生率为9.5%（928名参与者中的88例）。
与美国和南非基于学校和诊所人群的数据相比，来自该中国高中生样本的数据显示三体征集合不足的发生率较低（2.7%）。集合不足与屈光不正、性别和调节不足有关。
