Harrison J M, van Heuven W A
Department of Ophthalmology, The University of Texas Health Science Center at San Antonio, 78284-6230, USA.
Ophthalmology. 1999 Apr;106(4):790-7. doi: 10.1016/S0161-6420(99)90168-9.
Prior clinical observations led the authors to examine electrophysiologic measures of retinal (electroretinogram [ERG]) and retinal pigment epithelial (electro-oculogram [EOG]) function in patients infected with human immunodeficiency virus (HIV) who either had or did not have cytomegalovirus (CMV) retinitis in order to determine if the ERG or EOG measures were differentially affected in CMV retinitis.
Cross-sectional study.
Forty-one HIV-infected patients (20 with and 21 without CMV retinopathy) were evaluated.
ERGs and EOGs were recorded. Patients' fundi were evaluated by indirect ophthalmoscopy or fundus photography.
The ERG a- and b-wave amplitudes and EOG light/dark amplitude ratio (L/D ratio) from the eyes of all patients were compared with values 2 standard deviations from the mean of a normal sample. The area of the retinal lesions was estimated from fundus photographs or from careful drawings made during indirect ophthalmoscopy.
The majority of the eyes (64.5%) of the patients with CMV retinitis had subnormal L/D ratios, and most eyes (95%) of patients without CMV retinitis had normal L/D ratios. Only six eyes (four with and two without CMV retinopathy) had subnormal a-wave amplitudes, and there was no significant correlation between a-wave amplitude and the L/D ratio for patients with CMV retinitis. Most eyes (80.6%) of the patients with CMV retinitis had subnormal b-wave amplitudes, but there was no significant correlation between b-wave amplitude and L/D ratio in the patients with CMV retinitis. In three patients with CMV retinitis selected to exemplify the range of effects on the ERG and EOG, the b-wave amplitude loss was roughly proportional to the area of retina visibly affected in indirect ophthalmoscopy. One patient had a nonrhegmatogenous retinal detachment.
Middle retinal function, as reflected in the b-wave amplitude, and retinal pigment epithelial function, as reflected in the L/D ratio, were both compromised in CMV retinitis, but the effect on function in the two layers of the retina appeared independent because there was no significant correlation between the L/D ratio and b-wave amplitude. The decrease in L/D ratio was not secondary to loss of photoreceptor function and probably represents a dysfunction of the retinal pigment epithelium because there was no significant correlation between a-wave amplitude, which was normal in most cases, and L/D ratio. The inner retinal pathology of CMV retinitis is visible clinically and was associated with decreases in b-wave amplitude in this and previous studies. The significant independent retinal pigment epithelial dysfunction demonstrated in this study may be an important predisposing factor to retinal detachment in CMV retinitis.
先前的临床观察促使作者对感染人类免疫缺陷病毒（HIV）且患有或未患有巨细胞病毒性视网膜炎（CMV）的患者进行视网膜（视网膜电图[ERG]）和视网膜色素上皮（眼电图[EOG]）功能的电生理测量，以确定ERG或EOG测量在CMV视网膜炎中是否受到不同影响。
横断面研究。
对41例HIV感染患者（20例患有CMV视网膜病变，21例未患有）进行了评估。
记录ERG和EOG。通过间接检眼镜或眼底摄影对患者的眼底进行评估。
将所有患者眼睛的ERG a波和b波振幅以及EOG明/暗振幅比（L/D比）与正常样本均值的2个标准差范围内的值进行比较。根据眼底照片或间接检眼镜检查时绘制的仔细图像估计视网膜病变的面积。
患有CMV视网膜炎的患者中，大多数眼睛（64.5%）的L/D比低于正常，而未患有CMV视网膜炎的患者中，大多数眼睛（95%）的L/D比正常。只有6只眼睛（4只患有CMV视网膜病变，2只未患有）的a波振幅低于正常，且CMV视网膜炎患者的a波振幅与L/D比之间无显著相关性。患有CMV视网膜炎的患者中，大多数眼睛（80.6%）的b波振幅低于正常，但CMV视网膜炎患者的b波振幅与L/D比之间无显著相关性。在3例被选来举例说明对ERG和EOG影响范围的CMV视网膜炎患者中，b波振幅损失大致与间接检眼镜检查中可见的视网膜受影响面积成比例。1例患者发生了非孔源性视网膜脱离。
CMV视网膜炎会损害视网膜中层功能（以b波振幅反映）和视网膜色素上皮功能（以L/D比反映），但对视网膜两层功能的影响似乎是独立的，因为L/D比与b波振幅之间无显著相关性。L/D比降低并非继发于光感受器功能丧失，可能代表视网膜色素上皮功能障碍，因为大多数情况下正常的a波振幅与L/D比之间无显著相关性。CMV视网膜炎的视网膜内层病变在临床上可见，并在本研究及以往研究中与b波振幅降低有关。本研究中显示的显著独立的视网膜色素上皮功能障碍可能是CMV视网膜炎中视网膜脱离的重要易感因素。
