Abstract
Abstract: :
Purpose: To determine whether Ginkgo biloba extract (GBE) can improve the multifocal visual evoked potential (mfVEP) responses in patients with normal tension glaucoma. Methods: Seventeen normal tension glaucoma patients with maximum recorded intraocular pressure ≤ 21 mmHg were enrolled in this study. Patients received GBE (Vitamin Research Products, Inc. Carson City, NV) 120 mg bid for a period of 1 month after the baseline mfVEP was taken. The mfVEPs were obtained from each eye using a pattern–reversal dartboard array, 44.5 deg in diameter, and containing 60 sectors. Recording electrodes were placed at the inion (I) and 4 cm above the inion, and also at two lateral locations up 1 cm and over 4 cm from I [1]. The mfVEP was repeated after GBE treatment and responses were compared to the baseline. The ratios of the mfVEP amplitudes between the two days (GBE / baseline) were calculated for each location and compared to normal variation [2]. The average of ratios from 60 locations were also calculated and compared to normal variation. Results: Of the 2040 (60 responses x 34 eyes) pairs of responses, 114 (6%) showed a significant (p < 0.05) increase in amplitudes and 109 (5%) showed a significant decrease in amplitudes. The average of the ratios (GBE / baseline) for each eye of all patients did not exceed the confidence levels for test–retest variation in normal subjects [2]. Conclusions: GBE did not improve the overall mfVEP responses in patients with normal tension glaucoma. Ref. 1.Hood et al (2002) Arch Ophthalmol. 2. Chen et al (2003) J Glaucoma.
Keywords: electrophysiology: clinical • visual fields • VEI