扩瞳试验在Alzheimer病诊断中的意义

Pupil dilation test in the diagnosis of Alzheimer's disease

目的 探讨扩瞳试验在Alzheimer病 (AD)诊断中的意义。 方法 在滴入 0 0 1%托吡卡胺 7～ 10min后 ,用双侧瞳孔红外线同步记录分析仪自动记录并分析滴药眼的瞳孔直径扩大程度(按对照侧校正 )。共测定AD 5 2例 ,血管性痴呆 (VD) 33例和健康对照 (HC) 5 8例。利用受试者工作特性曲线 (ROC)确定最能明显区别AD与HC的分界线 ,计算敏感度、特异度和Kappa值 ,评估扩瞳试验的诊断价值。 结果 ,AD患者滴药眼的瞳孔明显扩大 ,与VD或HC差异有极显著性 (P <0 0 1) ,其中以第 18min时的差别最为显著。如以瞳孔扩大 15 %作为分界线 ,敏感度均为 0 81,特异度分别为 0 82和 0 79,Kappa值分别为 0 6 7和 0 6 0。 结论 扩瞳试验可以作为筛选早期AD的一个手段 ,也可在鉴别AD与VD时作参考。

Objective To determine whether pupil response to dilute tropicamide could be used as a diagnostic test for Alzheimer's disease (AD). Methods Pupil diameters of both eyes were measured simultaneously by an infra red automatic pupil diameter recorder and analyzer every 0 1 second for 30 minutes after instillation of 0 01% tropicamide to one eye and normal saline to the other. Three groups of patients were studied: 52 patients with AD, 33 with vascular dementia (VD), and 58 elderly controls. The percent change in pupil diameter of the treated eye was examined automatically by the analyzer. After finding the cut off point for differential diagnosis by receiver operator characteristic curve (ROC), its sensitivity, specificity and Kappa coefficient were calculated. Results Mean percent change in diameters of the treated eye showed a trend of fastest maximum dilation in AD group, and was significantly different from other groups at all the measurement time points after 10th minute instillation. The difference was most significant at the 18th minute after instillation, and 15% was used as a cut off point, the sensitivity was 0 81,specificity 0 79 0 82, and Kappa coefficient 0 62 0 67. Conclusions Pupil dilation test could be used as a screening method in the diagnosis of Alzheimer's disease, or as a tool for differential diagnosis between AD and VD.