Weiner A, Sandberg M A
Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston 02114.
Invest Ophthalmol Vis Sci. 1991 Sep;32(10):2842-5.
Foveal cone electroretinograms (ERG) were elicited with a stimulator-ophthalmoscope from 24 normal subjects with a 4 degrees stimulus flickering at 42 Hz and centered within a 12 degrees steady surround. The stimulus and surround were presented at retinal illuminances of 4.8 log td and 5.5 log td, respectively, to facilitate visualization of the fundus. Several consecutive averaged responses were evaluated to determine whether increasing duration of light exposure causes an increase in amplitude, as previously found for the full-field cone ERG. On average, amplitude increased by 27% over time, and the linear regression of amplitude on recording number accounted, on average, for 42% of the amplitude variability between consecutive responses. Two subjects had amplitudes that were initially subnormal, based on previously published norms, but that value increased to within the normal range in subsequent recordings. These findings show that a significant change in the cone ERG occurs in the fovea with increasing duration of light exposure at these retinal illuminances, and suggest that, when the stimulator-ophthalmoscope is used, consecutive foveal cone ERGs should be obtained from patients with suspected macular disease to avoid a false diagnosis of retinal malfunction.
使用刺激检眼镜对24名正常受试者进行中央凹视锥细胞视网膜电图（ERG）检查，刺激光斑为4度，以42Hz闪烁，位于12度稳定背景中央。刺激光斑和背景的视网膜照度分别为4.8 log td和5.5 log td，以利于眼底观察。评估了几个连续的平均反应，以确定光暴露时间的增加是否会像之前在全视野视锥细胞ERG中发现的那样导致振幅增加。平均而言，振幅随时间增加了27%，振幅与记录次数的线性回归平均解释了连续反应之间振幅变异性的42%。根据先前发表的标准，两名受试者的振幅最初低于正常水平，但在随后的记录中该值增加到正常范围内。这些发现表明，在这些视网膜照度下，随着光暴露时间的增加，中央凹视锥细胞ERG会发生显著变化，并表明，当使用刺激检眼镜时，对于疑似黄斑疾病的患者，应获取连续的中央凹视锥细胞ERG，以避免对视网膜功能障碍的误诊。
