Major article
Multifocal visual evoked potential and automated perimetry abnormalities in strabismic amblyopes

Presented at the Annual Meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, Florida, May 1-5, 2005.
https://doi.org/10.1016/j.jaapos.2007.04.017Get rights and content

Purpose

To compare visual field abnormalities obtained with standard automated perimetry (SAP) to those obtained with the multifocal visual evoked potential (mfVEP) technique in strabismic amblyopes.

Methods

Humphrey 24-2 visual fields (HVF) and mfVEPs were obtained from each eye of 12 strabismic amblyopes. For the mfVEP, amplitudes and latencies were analyzed and probability plots were derived. Multifocal VEP and HVF hemifields were abnormal if they had clusters of two or more contiguous points at p < 0.01, or three or more contiguous points at p < 0.05 with at least one at p < 0.01. An eye was abnormal if it had an abnormal hemifield.

Results

On SAP, amblyopic eyes had significantly higher foveal thresholds (p = 0.003) and lower mean deviation values (p = 0.005) than fellow eyes. For the mfVEP, 11 amblyopic and 6 fellow eyes were abnormal. Of the 11 amblyopic eyes, 6 were abnormal on SAP. The deficits extended from the center to mid periphery. Monocular mfVEP latencies were significantly decreased for amblyopic eyes compared with control eyes (p < 0.0002).

Conclusions

Both techniques revealed deficits in visual function across the visual field in strabismic amblyopes, but the mfVEP revealed deficits in fellow eyes and in more amblyopic eyes. In addition, mfVEP response latencies for amblyopic eyes were shorter than normal.

Section snippets

Subjects

Twelve subjects aged 19 to 70 years with strabismic amblyopia were recruited from the Eye Clinic at Columbia Presbyterian Hospital and from the private practice of one of the authors (HE). Informed consent was obtained from all subjects before participation. Procedures adhered to the tenets of the Declaration of Helsinki and the protocol was approved by the Columbia University Medical Center Institutional Review Board for Human Research. In addition, the study and data collection complied with

Results

All 12 subjects had reliable SAP results for both amblyopic and fellow eyes. The criteria for reliability were fewer than 20% fixation losses, 33% false-positive and false-negative responses. For the HVF, foveal thresholds were significantly higher for amblyopic eyes compared with fellow eyes (Wilcoxon matched pairs test, p = 0.003) and mean deviation values were significantly lower (Wilcoxon matched pairs test, p = 0.005). Figure 3A shows the foveal threshold values for the amblyopic and

Discussion

We investigated the effects of strabismic amblyopia on visual function across the visual field with conventional perimetry and the mfVEP technique. On SAP, foveal sensitivity and the mean deviation were significantly decreased in the amblyopic eye compared with the fellow eye. For five patients, the mean deviation was also significantly decreased compared with HVF norms. In addition, 50% of the amblyopic eyes had visual field deficits as defined by cluster criteria. These deficits affected the

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    • Cited by (0)

    Supported by a grant from the National Eye Institute EY 02115 Bethesda, Maryland, by unrestricted funds from Research to Prevent Blindness, New York, New York, and a grant from The Starr Foundation.

    This study was conducted at the Department of Ophthalmology, Columbia University, New York, New York.

    The authors have no proprietary interests in the development or marketing of any of the materials mentioned in this study.

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    Copyright © 2008 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.