W e thank Wong et al. (1) for their interest in our study (2) in which we showed that retinal vessels in diabetic patients with increasing stages of diabetic retinopathy experience a continuously decreasing response to flickering light. We believe that the issue raised by Wong et al. is very important. The study by Nguyen et al. (3) showed that arteriolar and venular calibers are structurally l...

Angiogenesis produces primitive vascular networks that need pruning to yield hierarchically organized and functional vessels. Despite the critical importance of vessel pruning to vessel patterning and function, the mechanisms regulating this process are not clear. Here we show that EphrinB2, a well-known player in angiogenesis, is an essential regulator of endothelial cell death and vessel prun...

APRIL 2009 I RETINA TODAY I 33 P olypoidal choroidal vasculopathy (PCV) is a disease entity initially described by Yannuzzi et al1 in 1990. The prevalence of PCV among patients with age-related macular degeneration (AMD) is estimated to be 30% to 50% in Asian people. PCV consists of an abnormal vascular network with polypoidal lesions at its termini under the retinal pigment epithelium (RPE). C...

in this paper, a novel matched filter based on a new kernel function with cauchy distribution is introduced to improve the accuracy ofthe automatic retinal vessel detection compared with other available matched filter‑based methods, most notably, the methods builton gaussian distribution function. several experiments are conducted to pick the best values of the parameters for the new designedfi...

Retinal vasculitis is a poorly characterized, potentially sight-threatening, inflammatory ocular condition that occurs when there is the presence of abnormal blood vessels in the retina. The annual incidence of retinal vasculitis in the United States is estimated at 1-2 per 100,000 with variation between regions. Because it is not well understood, the definition of “retinal vasculitis” is not w...

Diabetic retinopathy is a disease, which forms a severe threat on sight. It may reach to blindness among working age people. By analyzing and detecting vasculature structures in retinal image the diabetes can be detected in advanced stages by comparing its states of retinal blood vessels. In blood vessel segmentation approach, computer based retinal image analysis can be used to extract the ret...

Inherited retinal degenerations afflict 1 in 3,500 individuals and are a heterogeneous group of diseases that result in profound vision loss, usually the result of retinal neuronal apoptosis. Atrophic changes in the retinal vasculature are also observed in many of these degenerations. While it is thought that this atrophy is secondary to diminished metabolic demand in the face of retinal degene...

The aim of this study was to examine the effects of elcatonin, a synthetic derivative of eel calcitonin, on rat retinal blood vessels, and to determine how diabetes affects the retinal vascular responses. Ocular fundus images were captured with an original high-resolution digital fundus camera in vivo. The retinal vascular responses were evaluated by measuring the diameter of retinal blood vess...