Morong Sharon, Westall Carol A, Nobile Rita, Buncic J Raymond, Logan William J, Panton Carole M, Abdolell Mohamed
Department of Ophthalmology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Doc Ophthalmol. 2003 Nov;107(3):289-97. doi: 10.1023/b:doop.0000005338.51554.e3.
Vigabatrin (gamma-vinyl-GABA) is an antiepileptic drug successful in the management of infantile spasms. Photopic ERGs were tested in children followed longitudinally before and during vigabatrin treatment.
Subjects were 26 infants (age range 1.5-24 months, median 7.6 months) on vigabatrin treatment who had been tested on multiple visits (two to four visits; mean, three visits). Eighteen of these were assessed initially before starting vigabatrin therapy and eight were assessed within 1 week of initiation of the drug. ERGs were recorded at 6-month intervals. Standard ISCEV protocol with Burian-Allen bipolar contact-lens electrodes (standard flash 2.0 cd.s/m2) was used. Although ISCEV standards were followed, a higher flash intensity (set at 3.6 cd.s/m2) was chosen for single-flash cone assessment to provide a better definition of OPs. Photopic OPs were divided into categories of early OPs and late OP (OP4). Responses were compared with age corrected limits extrapolated from our lab control database.
Results showed differential effects of vigabatrin on the summed early OP amplitudes versus the late OP (OP4) and cone b-wave amplitude. The early OPs showed significant decrease (p = 0.0005, repeated measures analysis of variance) after 6 months and remained decreased for the duration of treatment. There was no significant change seen in the late OP. The cone b-wave amplitude showed initial increase (p = 0.04) after 6 months, followed by a decrease after 18 months; a trend similar to that of the late OP.
Early photopic OPs were disrupted more than the late OP, suggesting relative deficit in the ON (depolarizing) retinal pathways.
氨己烯酸（γ-乙烯基-GABA）是一种成功用于治疗婴儿痉挛症的抗癫痫药物。在氨己烯酸治疗前和治疗期间，对儿童进行了纵向随访，并检测了明视视网膜电图。
研究对象为26例接受氨己烯酸治疗的婴儿（年龄范围1.5 - 24个月，中位数7.6个月），这些婴儿接受了多次检查（两到四次检查；平均三次检查）。其中18例在开始氨己烯酸治疗前进行了初始评估，8例在开始用药后1周内进行了评估。视网膜电图每隔6个月记录一次。使用标准的国际临床视觉电生理学会（ISCEV）方案，采用Burian-Allen双极接触镜电极（标准闪光强度2.0 cd.s/m²）。尽管遵循了ISCEV标准，但为了更好地定义光感受器电位（OP），在单闪光视锥细胞评估中选择了更高的闪光强度（设定为3.6 cd.s/m²）。明视OP分为早期OP和晚期OP（OP4）两类。将反应与从我们实验室对照数据库外推的年龄校正限值进行比较。
结果显示，氨己烯酸对早期OP总和振幅与晚期OP（OP4）及视锥细胞b波振幅有不同影响。6个月后，早期OP显著降低（P = 0.0005，重复测量方差分析），并在治疗期间持续降低。晚期OP未见显著变化。视锥细胞b波振幅在6个月后最初升高（P = 0.04），随后在18个月后降低；这一趋势与晚期OP相似。
早期明视OP比晚期OP受到的破坏更大，提示视网膜ON（去极化）通路存在相对缺陷。
