Abstract
Purpose: :
To study changes in retinal blood flow velocity in patients with age related macular degeneration (AMD). We used the Retinal Function Imager (RFI, Optical Imaging Ltd., Rehovot, Israel), a new, non-invasive diagnostic approach for measuring blood flow velocity.
Methods: :
Thirty nine eyes of 33 AMD patients and 43 eyes of 26 healthy individuals over the age of 50 were recruited for this study. All patients were scanned by the RFI with analysis of blood flow velocity of secondary and tertiary branches of arteries and veins. Differences among groups were assessed by mixed linear models.
Results: :
The average velocity in AMD patients was significantly lower compared to controls in arteries (3.6±1.4 vs. 4.5±1.0 mm/sec, p=0.005) and veins (2.6±0.9 vs 3.1±0.6 mm/sec, p=0.04). Subdividing the vessels segments into groups by diameter, the velocity decrease was evident in both arterial groups (5-10, 10-15 µ ) as well as in veins 5-10 µ in caliber. Among the 39 AMD eyes, 23 eyes had nonexudative AMD while 16 had signs of exudative AMD. When comparing the velocity between these two AMD groups no significant differences in any of the retinal blood flow velocity parameters was detected.
Conclusions: :
Decreased blood flow velocity in retinal arteries and veins in patients with AMD were found. Despite the fact that AMD is essentially a choroidal disease, retinal vessels show a functional abnormality, which suggest that there is a more generalized vascular abnormality in this disease.
Keywords: imaging/image analysis: clinical • age-related macular degeneration