Klistorner A, Graham S L
Save Sight Institute, Department of Ophthalmology, Sydney University, Sydney, Australia.
Ophthalmology. 2000 Dec;107(12):2283-99. doi: 10.1016/s0161-6420(00)00367-5.
Objective perimetry in glaucoma is described using the multifocal pattern visually evoked potential (VEP). A multichannel recording technique was used to improve signal detection in healthy volunteers and assess its ability to detect glaucoma and early changes in patients with suspected glaucoma.
Prospective, case-control study.
Thirty healthy volunteers, 30 patients with suspected glaucoma, and 30 patients with glaucomatous visual field defects were tested.
The VEP was recorded using cortically scaled, multifocal, pseudorandomly alternated pattern stimuli with the VERIS system (Electro-Diagnostic Imaging, Inc., San Francisco, CA). An array of four bipolar occipital electrodes provided four differently oriented channels for simultaneous recording. Signals were compared for different locations within the field up to 26 degrees of eccentricity. Healthy volunteers, patients with suspected glaucoma, and glaucoma patients with established visual field defects were tested, and results were compared with Humphrey visual fields (Humphrey Systems, Dublin, CA) performed on the same day. For reproducibility, five healthy volunteers were each tested on four separate days. The patients with suspected glaucoma and the established glaucoma patients were analyzed for intereye asymmetry of signals, and these data were compared with the asymmetry values of the healthy volunteers.
Multiple recording channels significantly enhanced the recording of signals from parts of the visual field not reliably sampled with a single channel technique in all healthy volunteers, particularly along the horizontal meridian (P: < 0.001). Signal amplitude did not decline with age in healthy volunteers. Recordings showed good reproducibility within individuals. In all 30 glaucoma patients, the Humphrey visual field defects were well demonstrated by the VEP, and topographic location was strongly correlated (r(s) = 0.79). Despite large interindividual variations in amplitude, scotomas were well demonstrated when compared with normal values. In the patients with suspected glaucoma, smaller changes in signal amplitude could be identified in parts of the field still normal on perimetry using intereye asymmetry analysis.
The multifocal, multichannel VEP can objectively detect glaucomatous visual field defects. The nasal step region can be more reliably tested using multiple channels. Asymmetry analysis has the potential to detect early defects. This technique represents a significant step toward the clinical application of objective perimetry in glaucoma.
使用多焦点图形视觉诱发电位（VEP）描述青光眼的客观视野检查。采用多通道记录技术来改善健康志愿者的信号检测，并评估其检测青光眼及疑似青光眼患者早期变化的能力。
前瞻性病例对照研究。
对30名健康志愿者、30名疑似青光眼患者和30名患有青光眼性视野缺损的患者进行了测试。
使用VERIS系统（加利福尼亚州旧金山市电诊断成像公司），通过皮层缩放、多焦点、伪随机交替图形刺激记录VEP。一组四个双极枕叶电极提供四个不同方向的通道用于同步记录。比较视野内不同位置直至26度偏心率处的信号。对健康志愿者、疑似青光眼患者和已确诊视野缺损的青光眼患者进行测试，并将结果与同一天进行的Humphrey视野检查（加利福尼亚州都柏林市Humphrey系统公司）结果进行比较。为评估可重复性，对5名健康志愿者在四个不同日期分别进行测试。分析疑似青光眼患者和已确诊青光眼患者两眼信号的不对称性，并将这些数据与健康志愿者的不对称值进行比较。
在所有健康志愿者中，多通道记录显著增强了单通道技术无法可靠采样的视野部分的信号记录，尤其是沿水平子午线方向（P：<0.001）。健康志愿者的信号幅度不随年龄下降。记录显示个体内具有良好的可重复性。在所有30名青光眼患者中，VEP很好地显示了Humphrey视野缺损，且地形图位置高度相关（r(s)=0.79）。尽管个体间幅度差异很大，但与正常值相比，暗点仍能很好地显示出来。在疑似青光眼患者中，使用两眼不对称性分析可在视野检查仍正常的部分识别出较小的信号幅度变化。
多焦点、多通道VEP可客观检测青光眼性视野缺损。使用多通道可更可靠地测试鼻侧阶梯区域。不对称性分析有检测早期缺损的潜力。该技术代表了青光眼客观视野检查临床应用的重要一步。
