WIDESPREAD CHOROIDAL INSUFFICIENCY IN PRIMARY OPEN-ANGLE GLAUCOMA

Purpose: The purpose of this study was to investigate choroidal perfus ion in glaucoma, using histological and angiographic techniques. Metho ds: We examined the choroidal vasculature in clinicopathological slide s from 25 cases of primary open-angle glaucoma, five cases of optic at rophy, and 18 normal eyes, We measured choroidal thickness at fixed di stances from the disk margin with light microscopy. Using a quantitati ve computer image analysis system, we established the depth of all ves sels and the best fitting diameter and width-to-length ratio for each vessel in three pairs of eyes. Separate statistical analyses were done on the parapapillary area and the whole choroid. We compared standard fluorescein angiographic measures to peak choroidal filling time in a further 78 glaucoma and 84 normal eyes. Results: Choroids were signif icantly (similar to 50 mu m) thinner in glaucoma than in normal or opt ic atrophy irrespective of fundal position. Vessel frequency and mean diameter, relative to normal, showed greatest decrease near the chorio capillaris. Peak choroidal filling was the only fluorescein angiograph ic measure that was significantly delayed in glaucoma irrespective of age. Conclusions: Reduced choroidal thickness in primary open-angle gl aucoma is primarily due to loss of the innermost choroidal vessels. Ov erall size decreases without significant flattening. These changes are not seen with optic atrophy alone and may be correlated with the dela yed choroidal perfusion seen in fluorescein angiography.