Reduced blood flow and age-related macular degeneration
Reviewed by Khadijah Basheer

This was a prospective cross-sectional study assessing changes in blood flow velocity in patients with age-related macular degeneration (AMD) using a retinal function imager. Sixty eyes with wet AMD were compared to 53 control eyes and the average blood flow velocity in AMD patients was significantly lower. This was particularly noted in arteries. The AMD group was further divided into low and high grade AMD, the latter of which showed a reduction in venous blood flow. The pathogenesis of AMD is thought to be largely associated with the choroid, Bruchs’ membrane and the retinal pigment epithelium and studies have shown a reduction in choroidal blood flow in AMD patients. However, this study claims to show that retinal vascular function is also abnormal. This could suggest a more generalised vascular abnormality in AMD patients. The reasons for reduced blood flow included induced vasodilation from vascular endothelial growth factor or from more generalised perfusion abnormalities such as atherosclerosis and hypertension. The reduction in venous blood flow seen only in the high grade AMD group was thought to be secondary to destruction of the inner retinal tissue and macula oedema. The study findings suggest that the pathological process of AMD is not strictly confined to the choroid and deep retinal layers, however, more investigation needs to be done to determine whether these vascular changes are contributing factors to the pathogenesis or are consequences of them.

Retinal blood flow velocity in patients with age-related macular degeneration.
Burgansky-Eliash Y, Barash H, Nelson D, et al.
CURRENT EYE RESEARCH
2014;39(3):304-11.