RT Journal Article
SR Electronic
T1 Recovery of visual-field defects after occipital lobe infarction: a perimetric study
JF Journal of Neurology, Neurosurgery & Psychiatry
JO J Neurol Neurosurg Psychiatry
FD BMJ Publishing Group Ltd
SP 695
OP 702
DO 10.1136/jnnp.2010.214387
VO 82
IS 6
A1 Mehmet Çelebisoy
A1 Neşe Çelebisoy
A1 Ece Bayam
A1 Timur Köse
YR 2011
UL http://jnnp.bmj.com/content/82/6/695.abstract
AB Objective To assess the temporal course of homonymous visual-field defects due to occipital lobe infarction, by using automated perimetry.Methods 32 patients with ischaemic infarction of the occipital lobe were studied prospectively, using a Humphrey Visual Field Analyser II. The visual field of each eye was divided into central, paracentral and peripheral zones. The mean visual sensitivity of each zone was calculated and used for the statistical analysis. The results of the initial examination, performed within 2 weeks of stroke, were compared with the results of the sixth-month control. The lesions were assigned to the localisations, optic radiation, striate cortex, occipital pole and occipital convexity, by MRI.Results A statistically significant improvement was noted, especially for the lower quadrants. Lesions of the occipital pole and convexity were not significantly associated with visual-field recovery. However, involvement of the striate cortex and extensive lesions involving all the areas studied was significantly associated with poor prognosis.Conclusions Homonymous visual-field defects in our patients improved within 6 months. Restoration of the lower quadrants and especially the peripheral zones was noted. Incomplete damage to the striate cortex, which has a varying pattern of vascular supply, could explain this finding. Magnification factor theory, which is the increment of the receptive-field size of striate cortex cells with visual-field eccentricity, may explain the more significant improvement in the peripheral zones.