Korean J Ophthalmol.  2008 Dec;22(4):251-254. 10.3341/kjo.2008.22.4.251.

Pattern Visual Evoked Potential as a Predictor of Occlusion Therapy for Amblyopia

• Chung W
• Hong S
• Lee JB
• Han SH

• KMID: 1084213
• DOI: http://doi.org/10.3341/kjo.2008.22.4.251

Abstract

PURPOSE: This study was conducted to investigate the role of the pattern visual evoked potential (pVEP) as a predictor of occlusion therapy for patients with strabismic, anisometropic, and isometropic amblyopia. The secondary aim was to compare the characteristics of pVEP between strabismic and anisometropic amblyopia. METHODS: This retrospective comparative case series included 120 patients who had received occlusion therapy or a glasses prescription for correction of strabismic, anisometropic, and isometropic amblyopia (20 patients had strabismic amblyopia, 41 patients had anisometropic amblyopia, and 59 patients had isometropic amblyopia). For each patient, the value of the P100 latency on pVEP at the time of the initial diagnosis of amblyopia was collected. Subsequently, the P100 latency was compared according to types of amblyopia. Fifty of 120 patients (7 patients with strabismic amblyopia, 21 patients with anisometropic amblyopia, and 22 patients with isometropic amblyopia) who were followed-up for longer than 6 months were divided into two groups based on the value of their P100 latency (Group 1, P100 latency 120 msec or less; Group 2, P100 latency longer than 120 msec.) The amount of visual improvement after occlusion therapy or glasses was compared between two study groups. RESULTS: The mean P100 latency was 119.7+/-25.2 msec in eyes with strabismic amblyopia and 111.9+/-17.8 msec in eyes with non-strabismic (anisometropic or isometropic) amblyopia (p=0.213). In Group 1, the mean visual improvement after occlusion therapy or glasses was 3.69+/-2.14 lines on Dr. Hahn's standard test chart; in Group 2, the mean improvement was 2.27+/-2.21 lines (p=0.023). CONCLUSIONS: The P100 latency on pVEP at the time of initial diagnosis was significantly related to the visual improvement after occlusion therapy or glasses in patients with strabismic, anisometropic, and isometropic amblyopia. Therefore, it was presumed that patients with a delayed P100 latency might have less visual improvement after occlusion therapy or glasses. In addition, there was no apparent difference in P100 latency between patients with strabismic and non-strabismic (anisometropic or isometropic) amblyopia.

Keyword

Amblyopia; P100 latency; Visual evoked potential

MeSH Terms

Adolescent
Amblyopia/*physiopathology/*therapy
Anisometropia/physiopathology/therapy
Child
Child, Preschool
Evoked Potentials, Visual/*physiology
Female
Humans
Male
Retrospective Studies
*Sensory Deprivation
Strabismus/physiopathology/therapy
Treatment Outcome
Visual Acuity

Figure

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  Fig. 1 Vision improvement according to initial P100 latency. In patients with a P100 latency shorter than 120 msec, the vision was improved by 3.69±2.14 lines on Dr. Hahn's standard test chart, and in patients with a P100 latency longer than 120 msec, the vision was improved by 2.27±2.21 lines (p=0.023).

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