Novel imaging techniques for diabetic macular edema

Retinal edema should be defined as any increase of water of the retinal tis sue resulting in an increase in its volume. It may be of cytotoxic or vasog enic origin. Development of vasogenic macular edema is dependent on a serie s of factors such as blood pressure, blood-retinal barrier permeability, re tinal cell damage, retinal tissue osmotic pressure and retinal tissue compl iance. Objective measurements of retinal thickness are now possible using t he Retinal Thickness Analyser. Localised measurements of blood-retinal barr ier permeability may also be obtained using the Retinal Leakage Analyser, a modified confocal scanning laser fluorometer, while obtaining simultaneous ly angiographic images of the choroid and retina. These new imaging techniq ues show that cytotoxic and vasogenic retinal edema may occur independently in the early stages of diabetic retinopathy. These findings offer new perp ectives for designing novel therapeutic strategies.