Indocyanine Green Angiography Of The Optic Disk In Gaucomatous Eyes

PURPOSE To investigate the characteristics of the blood supply of optic disk in glaucomatous eyes by indocyanine green angiography (ICGA) and whether indocyanine green angiographic anormalies of optic disk are different among chronic primary angle-closure glaucoma (CACG), primary open angle glaucoma (POAG) and normal tension glaucoma (NTG).METHODS 80 eyes of 47 patients with glaucoma (31 eyes of 18 patients with POAG , 27 eyes of 14 patients with NTG and 22 eyes of 15 patients with CACG ) and 44 normal eyes of 39 control subjects were tested by simultaneous ICGA and fluorescein angiography (FFA) with Heidelberg retina angiograph (HRA). The occurrence and extent of peripapillary atrophy and indocyanine green angiographic anormalies of optic disk were compared between glaucoma and control group, and among the three types of glaucoma as well.RESULTS The occurrence and area of alpha zone atrophy andthe area of total peripapillary atrophy was higher and bigger in glaucoma group than in control group. There was significant difference in the areas of alpha zone atrophy and total peripapillary atrophy among the three types of glaucoma. The areas of alpha zone atrophy and total peripapillary atrophy were bigger in POAG and NTG eyes than in CACG eyes. There was no difference in the areas of alpha zone atrophy and total peripapillary atrophy between POAG and NTG eyes. There was no significant difference in the occurrence and area of beta zone atrophy among the three types of glaucoma. Two types of peripapillary defects were identified in the late-phase ICGA. The first was hypofluorescent area in the peripapillary region. It was bigger and more common in eyes with glaucoma. There was no difference in the occurrence or extent of hypofluorescent areas among the three types of glaucoma. Its occurrence and extent correlated with age and refractive error. Its extent correlated with alpha zone peripapillary atrophy and beta zone peripapillary atrophy. The second defect was hypofluorescent halo adjacent to and extending around the full circumference of the optic disk margins. There was no difference in the occurrence between glaucoma and control group, and among the three types of glaucoma as well. Its occurrence correlated with age. There was no correlation in the occurrence between hypofluorescent area and hypofluorescent halo. The area of beta zone atrophy correlated with the mean deviation of the visual field. There was no correlation between the mean deviation of the visual field and other parameters.CONCLUSIONS The decreased vascularity in the peripapillary choroidal circulation occures more frequently in glaucoma eyes than innormal eyes. It also occures in CACG eyes , but less apparently than in POAG and NTG eyes, which suggestts the extent of vascular factors involved in the development of the optic disk damage in CACG is less than POAG and NTG .