间歇性外斜视合并屈光不正患者集合与调节比率分析

Clinical investigation on AC/A ratio in intermittent exotropia coexisting with ametropia

目的 探讨集合与调节比率（AC/A）与合并屈光不正的间歇性外斜视发生的关系.方法 临床回顾性研究.观察和分析135例2008至2010年在天津市眼科医院就诊的间歇性外斜视患者,根据检影屈光性质将患者分为3组,单纯间歇性外斜视组（屈光度数为-0.50～ ＋3.00 D的3～6岁患者及屈光度数为-0.50～ ＋2.00的7～ 40岁患者）、间歇性外斜视合并近视组（-0.50 ～7.75 D）及间歇性外斜视合并远视组（≥＋3.00D的3～6岁患者及≥＋2.00 D的7～40岁患者）.同视机法测定AC/A,三棱镜中和法测定视远（5 m）和视近（33 cm）斜视度数,比较各组AC/A、视近斜视度及视远斜视度,分析AC/A与屈光度及年龄的相关性.组间数据比较采用方差分析,近视与远视斜视度数的比较采用配对t检验,相关性分析采用线性回归法.结果 单纯间歇性外斜视、间歇性外斜视合并近视及间歇性外斜视合并远视三组患者AC/A比较,差异有统计学意义（2.686±1.372、1.773±1.110、4.581±1.552;F=36.323,P＜0.01）;视远斜视度数比较,差异无统计学意义（40.333Δ±19.474Δ、44.052Δ±23.722Δ、35.590Δ±11.143Δ;F=1.444,P=0.24）;视近斜视度数比较,差异有统计学意义（44.473Δ±19.008Δ、53.621Δ±20.749Δ、34.455Δ±13.292Δ;F=8.762,P＜0.01）.合并近视和合并远视的两组间歇性外斜视患者,AC/A与屈光度数呈负相关（分别为r=0.320,P=-0.469;r=-0.046,P=0.036）.无屈光不正的间歇性外斜视患者,AC/A随年龄的增加而下降（r=-0.320,P=0.019）;在合并近视组及合并近视组,未发现AC/A与年龄存在相关性（r=-0.023,P=0.865;r =0.246,P=0.296）.结论 远视性和近视性屈光不正合并异常高或低的AC/A可能破坏了眼外肌的平衡,易导致外斜视的发生.

Objective To investigate AC/A ratio and coexisting ametropia in intermittent exotropia.To discuss the relation between AC/A ratio and the development of intermittent exotropia.Methods The medical records of 135 patients who had an exotropia were retrospectively reviewed.Patients were divided into 3 groups based on the type of ametropia：exotropia without ametropia（-0.50-＋ 3.00 D between the age of 3-6 years old,-0.50-＋ 2.00 D between the age of 7-40 years old）,exotropia coexisting with myopia （-0.50-7.75 D）and exotropia coexisting with hypermetropia（≥ ＋ 3.00 D of 3-6 years old,≥ ＋ 2.00 D of 7 ～40 years old）.AC/A ratios of all patients were assessed using synoptophore method.Distance and near deviations were assessed using prism cover test.AC/A ratios and deviation angles of 3 groups were compared.The relationship between AC/A ratios and ametropia/age were investigated.Results There were obvious differences in AC/A ratios （2.686 ± 1.372,1.773 ± 1.110,4.581 ± 1.552,F =36.323,P 〈 0.001） and in near deviation angles （44.473Δ ± 19.008Δ,53.621Δ ± 20.749Δ,34.455Δ ± 13.292Δ,F =8.762,P =〈0.001） between 3 groups of patients,no obvious differences were seen in distance deviation angles（40.333Δ ± 19.474Δ,44.052Δ ± 23.722Δ,35.590Δ ± 11.143Δ,F =1.444,P =0.24）.AC/A ratios were negative linear correlated with refractive powers for patients of intermittent extropia coexisting with myopia or with hypermetropia（r =0.320,P =-0.469 and r =-0.046,P =0.036,respectively）.A trend of decline with age was found for AC/A ratios only in patients of intermittent extropia without ametropia（r =-0.320,P =0.019 ; r =-0.023,P =0.865 ; r =0.246,P =0.296 for the other 2 groups,respectively）.Conclusions Myopia and hypermetropia,when coexisting with abnormally low or high AC/A ratio,can destroy the balance between extraocular muscles and induce exophoria to be manifest.