The pattern electroretinogram in glaucoma patients with confirmed visual field deficits
The pattern electroretinogram in glaucoma patients with confirmed visual field deficits
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DOI：
10.1167/iovs.05-0238
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发表时间：
2005-07-01
影响因子：
4.4
通讯作者：
Ritch, R
中科院分区：
文献类型：
--
作者：
Hood, DC;Xu, L;Ritch, R
目的.为了更好地了解图形视网膜电图（PERG）振幅与静态自动视野计测量的视力丧失之间的关系。在15名患者（31-77岁）和16名正常人（26-65岁）中记录了短暂PERG。只有当存在异常椎间盘、异常24-2 Humphrey视野结果（模式标准偏差、青光眼半视野测试和群集）和异常多焦视觉诱发电位时，才认为患眼有青光眼性损害。患者的所有较差（受影响较大）的眼睛和6只较好的眼睛符合这些标准。测量PERG的N95振幅，从接近50 ms的正峰（P50）到接近95 ms的谷值，并测量N95与P50的比值（N95振幅除以P50振幅）。首先，4只（26.7%）较差眼睛的PERG在正常范围内。总体而言，符合青光眼损伤标准的21只眼睛中有6只（28.6%）在两个PERG指标上均正常。由于正常个体比患者年轻，因此在年龄适当的对照组中可能会有更多的正常PERG。第二，当敏感度绘制在线性图上时，N95振幅与视野敏感度非线性相关。小磁场损失与PERG振幅不成比例的大损失相关。第三，患者双眼的PERG非常相似，即使视野显示出非常不同的损伤水平。这些结果是一致的观点，非常早期的损害可以影响PERG，甚至在视野显示出损失。与此同时，很明显，具有明确的脑损伤的患者可以具有正常外观的PERG。提出了解释这些调查结果。
Purpose. To better understand the relationship between the amplitude of the pattern electroretinogram (PERG) and visual loss, measured with static automated perimetry.Methods. Transient PERGs were recorded in 15 patients (31-77 years) and 16 normal individuals (26-65 years). An eye was considered to have glaucomatous damage only if there was an abnormal disc, an abnormal 24-2 Humphrey visual field result (pattern stand deviation, glaucoma hemifield test, and cluster) and an abnormal multifocal visual evoked potential. All the worse (more affected) eyes of the patients and six of the better eyes met these criteria. The N95 amplitude of the PERG was measured from the positive peak (P50) at similar to 50 ms to the trough at similar to 95 ms. The ratio of N95 to P50-the N95 amplitude divided by the P50 amplitude-was also measured.Results. First, the PERG was within normal limits for 4 (26.7%) of the worse eyes. Overall, 6 (28.6%) of the 21 eyes that met the criteria for glaucomatous damage had normal PERGs on both PERG measures. Because the normal individuals were younger than the patients, an even larger number of normal PERGs might be expected with an age-appropriate control group. Second, the N95 amplitude was nonlinearly related to visual field sensitivity when sensitivity was plotted on a linear plot. Small field losses were associated with disproportionately large losses in PERG amplitude. Third, the PERG from both eyes of a patient were very similar, even when the visual fields suggested very different levels of damage.Conclusions. These results are consistent with the view that very early damage can affect the PERG, even before the visual field shows a loss. At the same time, it is clear that patients with clear glaucomatous damage can have normal-appearing PERGs. An explanation is proposed to account for these findings.