Abstracts

To evaluate the visual field defects in patients who underwent SAH (selective amygdalohippocampectomy) for intractable epilepsy using automated static visual field testing.
[italic]Background: [/italic]Visual field defects, specifically contralateral upper quadrant homonymous quadrantanopsia, are well known complications after conventional temporal lobectomy, however, few studies have evaluated visual field defects after SAH using automated static visual field perimetry., We evaluated 6 adult patients with history of intractable temporal lobe epilepsy who had SAH within the last 3 years using neuro-ophthalmologic evaluation and automated Humphrey visual field analysis post-operatively. All patients were diagnosed with mesial temporal lobe sclerosis and had their surgery at our institution using the same image guided surgical technique, in which an incision is made in the middle temporal gyrus to locate the temporal horn, then the amygdala and 3 cm of hippocampus are removed using the microscope. After obtaining written consents, all patients were questioned about visual complaints and were examined for visual fields by confrontation using finger counting, visual acuity ocular motility, pupil size and reactivity and fundoscopy. Humphrey automated visual field analysis was then performed using the 24-2 program that tests 54 points that straddle the horizontal and vertical meridians. The visual field for each eye was divided into 4 quadrants. The depth of any identified defect was determined by calculating the algebraic difference between measured value and expected value and was displayed on a grid corresponding to the location of the test points creating a map that showed the location and extent of the visual field defects. The pattern deviation was then averaged in the quadrant contralateral to surgery, separately for the ipsilateral and contralateral eye. Deviations less than -5 were displayed (Figure)., 4 patients had left and 2 had right SAH. None had identifiable visual field defects by history or confrontation visual field exam. All had identifiable visual field defects in the contralateral superior quadrant by perimetry. 4 had incomplete contralateral superior quadrantonopsia and 2 had only small peripheral defects in the contralateral superior quadrants. The defect affected mostly the medial sector near the vertical meridian and was steeper in the ipsilateral eye., Visual field defects are an expected complication of SAH. The expected defects are predominantly incomplete contralateral superior quadrantonopsias, similiar to those previously reported with conventional anterior temporal lobectomy.[figure1],