Fluorescein leakage of the optic disc in glaucomatous optic neuropathy

Purpose: To identify and quantify the role of capillary leakage of the optic nerve head in digital fluorescein angiography in normal subjects and patients with open-angle glaucoma. Methods: We conducted a prospective cross-sectional study in the Department of Ophthalmology of the Technical University of Aachen. Thirty patients with primary open-angle glaucoma (POAG) and 30 healthy age-matched subjects were included. Fluorescein angiograms were performed using the scanning laser ophthalmoscope. The fluorescence of the optic nerve head and the surrounding retina (ratio of leakage) was measured using digital imaging analysis in the late phases of the angiogram (9-10 min). Results: The ratio of optic nerve head fluorescence to retinal reference loci was significantly increased (p=0.01) in patients with glaucoma (POAG, 1.38 +/- 0.34) compared with normal subjects (1.20 +/- 0.19). Intraocular pressure (p=0.0001), visual field indices (mean deviation, p < 0.0001; pattern standard deviation, p < 0.0001; corrected pattern standard deviation, p < 0.0001), and cup to disc ratios (p=0.02) differed significantly between the groups. Age and systolic and diastolic blood pressure showed no significant differences between groups. Conclusion: Fluorescein angiography revealed significantly increased vascular leakage of glaucomatous optic nerve heads. An endothelial disruption and fluorescein leakage might be the result of mechanical stress at the level of the lamina cribrosa and/or a sign of ischemic damage. This measurement approach might enable us to judge the severity of optic nerve head leakage, and it is a potential way to evaluate therapeutic regimens.