Martins Alessandra, Balachandran Chandra, Klistorner Alexander I, Graham Stuart L, Billson Francis A
Save Sight Institute, Department of Clinical Ophthalmology and Eye Health, University of Sydney, Sydney Eye Hospital, Sydney, New South Wales, Australia.
Clin Exp Ophthalmol. 2003 Aug;31(4):354-6. doi: 10.1046/j.1442-9071.2003.00669.x.
The purpose of this study was to investigate the influence of pupil diameter on the amplitude and latency of multifocal visual evoked potentials (mfVEP). The multifocal objective perimeter (Accumap; Objectivision) was used to stimulate the visual field at 56 sites extending to 32 degrees using a pseudo-random pattern stimulus. The mfVEP were recorded using bipolar occipital electrodes, 7 min/eye. Ten normal subjects were recruited from the community and one eye was randomly selected for testing. The mfVEP were recorded at four different pupil diameters (2 mm, 4 mm, 6 mm, 8 mm), obtained by applying tropicamide (0.5%) or pilocarpine (2%) in different dilutions. Appropriate refractive correction was provided to overcome cycloplegia and achieve a visual acuity of 6/7.5 or better. Analysis revealed that at most pupil diameters the normalized full field amplitude did not show significant variation, except at the most miotic pupil diameter (2 mm), where the amplitude became reduced, based on 2-way anova and Tukey's T method. There was, however, significant correlation between latency and pupil area (correlation coefficient: upper field -0.63, lower field -0.76). The results suggest that even in the presence of mydriatics or miotics, the mfVEP test can be used to assess diseases that affect amplitude, provided near correction is used. The interpretation of latency, however, must be made with caution, as a borderline conduction defect with a dilated pupil may appear normal.
本研究的目的是调查瞳孔直径对多焦视觉诱发电位（mfVEP）的波幅和潜伏期的影响。使用多焦客观视野计（Accumap；Objectivision），采用伪随机模式刺激，在延伸至32度的56个位点刺激视野。使用枕部双极电极记录mfVEP，每只眼睛记录7分钟。从社区招募了10名正常受试者，随机选择一只眼睛进行测试。在四个不同的瞳孔直径（2毫米、4毫米、6毫米、8毫米）下记录mfVEP，这些直径是通过应用不同稀释度的托吡卡胺（0.5%）或毛果芸香碱（2%）获得的。提供适当的屈光矫正以克服睫状肌麻痹，并使视力达到6/7.5或更好。分析显示，基于双向方差分析和Tukey's T方法，除了在最小瞳孔直径（2毫米）时波幅降低外，在大多数瞳孔直径下，标准化全视野波幅没有显著变化。然而，潜伏期与瞳孔面积之间存在显著相关性（相关系数：上半视野为-0.63，下半视野为-0.76）。结果表明，即使使用散瞳剂或缩瞳剂，只要使用近视力矫正，mfVEP测试仍可用于评估影响波幅的疾病。然而，对潜伏期的解释必须谨慎，因为瞳孔散大时临界传导缺陷可能看起来正常。
