Hatton D D, Buckley E, Lachiewicz A, Roberts J
University of North Carolina, Chapel Hill, USA.
J AAPOS. 1998 Oct;2(5):298-302. doi: 10.1016/s1091-8531(98)90087-8.
The purpose of this study was to determine whether the high rates of ocular problems described in previous retrospective reports of individuals with fragile X syndrome were present in a prospective sample of young boys. Fragile X syndrome is currently considered the leading hereditary cause of mental retardation, with prevalence estimates of 1:2500 to 1:5000 males.
Forty-eight boys with fragile X syndrome between the ages of 2.5 and 11 years were evaluated for ocular abnormalities. They received complete ophthalmic evaluations including assessment of visual acuity, cycloplegic refraction, ocular motility assessment, and dilated fundus examination.
Approximately 25% of the children had clinically significant ocular findings that included refractive errors (17%, primarily hyperopia and astigmatism) and strabismus (8%). Of the 42 children with quantifiable visual acuities, only 1 child, with diagnoses of nystagmus and hyperopia, had a Snellen visual acuity that was not within normal limits for his age. Three of the 5 children with gross measures of visual acuity had clinically significant findings: 2 had hyperopia greater than 3.5 diopters and 1 had esotropia. The other 2 children with gross measures of acuity and the 1 child without visual acuity assessment had cycloplegic refractions of +1.25 to +1.5 and ocular motility appeared normal.
These results suggest that previous reports of high rates of vision problems, particularly strabismus, in boys with fragile X syndrome may have resulted from selection bias. Although we did observe a higher prevalence of strabismus than that found in the general population (8% vs 0.5% to 1%), the proportion of children having strabismus in our sample was much smaller than that reported in other studies of children with fragile X syndrome (30% to 40%). However, 17% of the sample did have significant refractive errors. In addition to evaluating the ocular motility of children with fragile X syndrome, cycloplegic refraction should also be performed to determine whether refractive problems are present.
本研究旨在确定在一个前瞻性的年轻男孩样本中，是否存在先前关于脆性X综合征个体回顾性报告中所描述的高比例眼部问题。脆性X综合征目前被认为是智力发育迟缓的主要遗传原因，据估计男性患病率为1:2500至1:5000。
对48名年龄在2.5至11岁之间的脆性X综合征男孩进行眼部异常评估。他们接受了全面的眼科检查，包括视力评估、睫状肌麻痹验光、眼球运动评估和散瞳眼底检查。
约25%的儿童有具有临床意义的眼部检查结果，包括屈光不正（17%，主要为远视和散光）和斜视（8%）。在42名有可量化视力的儿童中，只有1名被诊断为眼球震颤和远视的儿童，其斯内伦视力不在其年龄的正常范围内。在5名有粗略视力测量的儿童中，有3名有具有临床意义的检查结果：2名远视度数大于3.5屈光度，1名有内斜视。另外2名有粗略视力测量的儿童以及1名未进行视力评估的儿童，其睫状肌麻痹验光结果为+1.25至+1.5，眼球运动似乎正常。
这些结果表明，先前关于脆性X综合征男孩视力问题（尤其是斜视）高比例的报告可能是由于选择偏倚。虽然我们确实观察到斜视的患病率高于一般人群（8%对0.5%至1%），但我们样本中患有斜视的儿童比例远低于其他脆性X综合征儿童研究报告的比例（30%至40%）。然而，17%的样本确实有明显的屈光不正。除了评估脆性X综合征儿童的眼球运动外，还应进行睫状肌麻痹验光以确定是否存在屈光问题。
