Optic Disc Fluorescein Leakage and Intraocular Pressure in Primary Open-Angle Glaucoma

Purpose: To investigate the relationship between increased fluorescein leakage of the optic nerve head and intraocular pressure (IOP), visual field defect, vertical cup-to-disc ratio, disc size and systemic blood pressure in primary open-angle glaucoma (POAG). Methods: Twenty-seven patients with POAG (aged 63 +/- 11 years) and 15 control subjects (aged 58 +/- 9 years, p = 0.14) were included in a pilot study. Fluorescein angiography was performed using a Scanning Laser Ophthalmoscope (Rodenstock Instruments, Germany). Fluorescein leakage of the optic disc was quantified using digital image analysis. The change of optic disc fluorescence from 7-8 min to 9-10 min was calculated and correlated to IOP, visual field mean deviation (MD), vertical cup-to-disc ratio, disc size, mean arterial blood pressure (MAP) and ocular perfusion pressure. Results: The change in optic disc fluorescein leakage was significantly increased in patients with POAG compared to control subjects (POAG: 9.7 +/- 6.7%; controls: 3.4 +/- 4.9%, p = 0.0025). In POAG, fluorescein leakage was significantly correlated to IOP (r = 0.42, p = 0.029), but not to MD (r = -0.13, p = 0.51), vertical cup-to-disc ratio (r = 0.11, p = 0.60) disc size (r = -0.22, p = 0.30), MAP (r = -0.16, p = 0.42) or ocular perfusion pressure (r = -0.32, p = 0.10). In control subjects, a significant correlation was found with vertical cup-to-disc ratios (r = 0.59, p = 0.034), but not to IOP (r = -0.07, p = 0.80), MD (r = -0.26, p = 0.42), disc size (r = -0.10, p = 0.76), MAP (r = 0.09, p = 0.77), or ocular perfusion pressure (r = 0.11, p = 0.72). Conclusion: Increased fluorescein leakage of the optic disc was associated with higher IOP levels in patients with POAG. This might reflect a link between vascular damage with increased permeability and uncontrolled IOP.