Abstract
Abstract: :
Purpose:To investigate the binocular summation of the detection and resolution thresholds values on the binocular visual field. Methods:Detection and resolution thresholds were measured with the Octopus 201 combined with the space synoptophore, which we placed in the cupola of the Octopus 201. Using three types of parallel line targets with widths of 10', 2.5'and 1.43'visual angles, we measured the detection and resolution thresholds under the monocular and binocular fusion conditions in four normal subjects. To measure the monocular fields under the binocular condition, the background illumination of the cupola was projected onto the non-tested eye using a half mirror. Using the SARGON program, we designed a program to test 27 points, 17 of which were located in the central 6° visual field and ten on the horizontal meridian subtending 8°, 10°, 12°, 16° and 20°. Results:There were no differences between the detection and resolution thresholds using the 10'width parallel line. However, resolution thresholds were higher than the detection thresholds using 2.5'and 1.43'width parallel lines. In both the detection and resolution thresholds, the binocular visual sensitivity was higher than the monocular visual sensitivity. With increasing eccentricity from the fovea, the amount of binocular summation increased. The binocular summation ratios of the resolution threshold were higher than the detection thresholds using 10'and 2.5'width parallel lines. However, the resolution threshold was lower than the detection threshold using the 1.43'width parallel line. Conslusions: In the binocular visual field, binocular summation of the detection and resolution thresholds varied as a function of the line width. The binocular summations of both thresholds increased depending on the eccentricity from the fovea.
Keywords: binocular vision/stereopsis • visual fields • perimetry