Temporal summation of normal eyes and impaired regions of the visual field
Ogawa, T.; Furuno, F.; Seki, A.; Suzumura, H.; Yabuki, K.; Matsuo, H.
Nippon Ganka Gakkai Zasshi 88(9): 1216-1223
1984
ISSN/ISBN: 0029-0203 PMID: 6524546 Document Number: 238662
In order to confirm whether temporal summation is more suitable to detect early pathological changes in the visual field than conventional perimetry, temporal summation in 3 normal subjects was studied at retinal positions 0.degree., 10.degree., 20.degree., 30.degree. on the 180.degree. meridian of the right eyes with background luminances of 3.2 cd/m2, 0.03 cd/m2 and stimulus sizes of the 10', and 104'. Stimulus duration were 1, 1.8, 3.8, 12, 15, 28, 54, 110, 224, 444 and 915 ms. Temporal summation in the impaired regions of the visual field was also examined in cases of intraocular diseases, including central chorioretinopathy, retinitis pigmentosa and glaucoma, and in cases of visual pathway diseases, including retrobulbar optic neuropathy, pituitary tumor, cerebral tumor and vascular disturbance of the brain. In the temporal summation in normal eyes, at 3.2 cd/m2 with the background luminance, Tc, was .apprx. 78 ms with the 104' stimulus size and .apprx. 162 ms with the 10' stimulus size. At 0.03 cd/m2 background luminance, Tc was .apprx. 139 ms with the 104' stimulus size and about 220 ms with the 10' stimulus size. The smaller size and darker adaptation extended Tc, with results corresponding well to previous reports. The influence of retinal position on temporal summation was negligible. Temporal summation in the impaired regions of the visual field, except 2 of 6 eyes in 6 cases with glaucoma, a decrease was shown in the summation coefficient and extention of Tc, there were no noticeable changes in the temporal summation of impaired regions of the visual field. Apparently, temporal summation is a visual function largely unaffected by impairment in the visual field due to intraocular or visual pathway diseases.