Age related macular degeneration (AMD) is the leading cause of irreversible visual loss in the industrialised world. Several theories of pathogenesis have been proposed and these include primary retinal pigment epithelium (RPE) and Bruch's membrane senescence, oxidative injury, primary genetic defects, and primary ocular perfusion abnormalities. In this issue of the BJO (p531), Mori and others explore ocular perfusion abnormalities by examining choroidal blood flow in patients with AMD, using pulsatile ocular blood flow (POBF). They used a Langham OBF computerised tonometer in 10 patients with non-exudative AMD, 11 patients with exudative AMD, and 69 age matched control subjects. They found statistically significant differences in the POBF (lower) and pulse amplitude (lower) in patients with exudative AMD compared with those with non-exudative AMD or with the control subjects. The authors conclude that decreased choroidal blood flow may play a part in the development of choroidal neovascular membranes (CNVM) in AMD. Although the technique of POBF carries some limitations as noted by the authors, this work serves to amplify and corroborate previous studies on the role of ocular perfusion perturbations in AMD. Studies of this sort are important with regard to our understanding of the pathogenesis of AMD.

Classically, investigators have postulated that senescence of the RPE, which metabolically supports the photoreceptors, leads to AMD.12 Senescent RPE accumulates metabolic debris as remnants of incomplete degradation …