Bach Michael, Unsoeld Anke S, Philippin Heiko, Staubach Flemming, Maier Philip, Walter Hans S, Bomer Thomas G, Funk Jens
Universitäts-Augenklinik, Killianstrasse 5, 79106 Freiburg, Germany.
Invest Ophthalmol Vis Sci. 2006 Nov;47(11):4881-7. doi: 10.1167/iovs.05-0875.
The conversion rate from untreated ocular hypertension (OHT) to glaucoma is only approximately 1% per year. Discrimination of nonconverters and potential converters would help reserve preventative treatment for those who need it and thus avoid unnecessary side effects and expenditure for those who do not. This prospective study was designed to assess the pattern electroretinogram (PERG) as an early indicator of dysfunction preceding glaucoma.
Ninety-five eyes of 54 patients with intraocular pressure > or =25 mm Hg (or > or =23 mm Hg with additional risk factors), normal visual fields, normal optic disc cupping, and visual acuity > or =0.8 were evaluated. Every 6 months during a median follow-up of 8.2 years, the PERG and visual fields were obtained besides other standard diagnostics. PERGs were recorded in steady state mode in response to checkerboard stimuli at 15 reversals/s, and the amplitudes in response to check sizes of 0.8 degrees and 16 degrees as well as the ratio of the amplitude of responses to 0.8 degrees over that to 16 degrees checks were determined.
Glaucomatous visual field defects developed in eight eyes. For the PERG to 0.8 degrees checks and for the PERG ratio, analysis of the receiver-operating characteristic (ROC) yielded steadily increasing ROC areas before conversion (i.e., an increasing ability of the PERG to predict nonconversion or conversion). One year before conversion, the ROC area of the PERG ratio was 0.78; at a threshold of 1.06 this corresponded to a sensitivity of 80% and a specificity of 71%.
The PERG can help to predict stability or progression to glaucoma in OHT at least 1 year ahead of conversion.
未经治疗的高眼压症（OHT）每年转化为青光眼的比率仅约为1%。区分不会转化和可能转化的患者，将有助于为需要的人保留预防性治疗，从而避免给不需要的人带来不必要的副作用和费用。本前瞻性研究旨在评估图形视网膜电图（PERG）作为青光眼之前功能障碍的早期指标。
对54例眼压≥25 mmHg（或有其他危险因素时≥23 mmHg）、视野正常、视盘杯盘比正常且视力≥0.8的患者的95只眼进行评估。在中位随访8.2年期间，每6个月除进行其他标准诊断外，还获取PERG和视野检查结果。以15次反转/秒的频率，采用稳态模式记录对棋盘格刺激的PERG，测定对0.8度和16度方格大小刺激的反应幅度，以及对0.8度方格刺激的反应幅度与对16度方格刺激的反应幅度之比。
8只眼出现青光眼性视野缺损。对于对0.8度方格刺激的PERG和PERG比值，受试者操作特征（ROC）分析显示在转化前ROC面积稳步增加（即PERG预测不转化或转化的能力增强）。在转化前一年，PERG比值的ROC面积为0.78；阈值为1.06时，对应敏感度为80%，特异度为71%。
PERG至少可在转化前1年帮助预测高眼压症患者青光眼的稳定性或进展情况。
