Optic disc fluorescein leakage and intraocular pressure in primary open-angle glaucoma

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).

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.

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).

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.