Visual field defects after temporal lobe resection: a prospective quantitative analysis.
OBJECTIVE
To evaluate and quantify prospectively visual field changes in patients undergoing temporal lobe resections for intractable epilepsy.


BACKGROUND
Visual field abnormalities occur after temporal lobe resections for epilepsy; however, we have not encountered published reports using automated static visual field analysis.


METHODS
Humphrey visual fields (program 30-2) were obtained before and after partial temporal lobe resection in 32 consecutive patients with intractable epilepsy. A quantitative point-by-point analysis was made in the affected superior quadrant, and the defects were averaged for the whole patient group.


RESULTS
Thirty-one patients developed a visual field defect, but none was aware of the defect. The points nearest fixation were relatively spared. The defects were greatest in the sector closest to the vertical meridian in the eye ipsilateral to the resection. The ipsilateral and contralateral mean field defects also differed in both topography and depth. A significant correlation was found between the extent of lateral temporal lobe resection and the degree of the defect in the contralateral eye.


CONCLUSIONS
There are differences in the shape and depth of the ipsilateral and the contralateral field defects not previously reported. These findings demonstrate that certain fibers from the ipsilateral eye travel more anteriorly and laterally in Meyer's loop, and support the hypothesis that visual field defects due to anterior retrogeniculate lesions are relatively incongruous because of anatomic differences in the afferent pathways. Automated perimetry is a sensitive method of evaluating and quantifying visual field defects.
Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212, USA.
T S
TS
Hughes
B
B
Abou-Khalil
P J
PJ
Lavin
T
T
Fakhoury
B
B
Blumenkopf
S P
SP
Donahue
D000293:Adolescent; D000328:Adult; D001331:Automation; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D013702:Temporal Lobe / Q000503:physiopathology / Q000601:surgery*; D014786:Vision Disorders / Q000453:epidemiology / Q000209:etiology*; D058609:Visual Field Tests; D014794:Visual Fields