Visual field loss in optic disc drusen patients correlates with central retinal artery blood velocity patterns.

PURPOSE: (1) To characterize the retrobulbar circulation in patients with optic disc drusen (ODD) using colour Doppler imaging; (2) to explore the differences in retrobulbar hemodynamics in patients with primary open-angle glaucoma (POAG).
METHODS: Retrospective analysis using three diagnostic groups: patients with ODD, age-matched healthy controls and age- and visual defect-matched patients with POAG. Subjects with history of ocular trauma or ocular diseases including vascular-related diseases were excluded. Kruskal-Wallis and Spearman's correlation tests were performed to compare and explore the correlations between the hemodynamic parameters and visual field damage.
RESULTS: Sixty patients were included and equally divided between the three groups. Patients with ODD had lower systolic and diastolic flow velocities in the central retinal artery (CRA) when compared to healthy individuals, but no difference was found with the glaucoma group (p < 0.005 versus healthy; p range 0.30-0.37 versus POAG). The systolic shift in flow patterns correlated with the extent of visual field defect in ODD patients (p < 0.001, r = -0.78, confidence interval: -0.43 to -0.92), but not in POAG (p = 0.73). Short ciliary arteries from ODD patients had lower mean systolic flow velocities when compared to both healthy individuals and patients with POAG (p < 0.01 versus healthy; p ≤ 0.04 versus POAG). The ophthalmic artery in ODD group had significantly higher mean blood velocities than in the POAG (p = 0.04), while showing a significant overlap in Doppler waveform variables to the control group (p range 0.08-0.97).
CONCLUSIONS: Similar to patients with glaucoma, individuals with ODD have low blood flow velocities in the vessels around the optic nerve head. Unlike patients with glaucoma, however, their CRA's blood flow velocity patterns correlate with the extent of the visual field defects.