Agreement Between Quantitative Analysis of Fundus and Angiographic Images by Photoshop Software and Clinical Judgment

To evaluate the agreement between a new method for quantitative analysis of fundus or angiographic images using Photoshop software and clinical judgment. Four hundred eighteen fundus and angiographic images of diabetic patients were evaluated by three retina specialists and then by computer using Photoshop 7.0 software. Four variables were selected for comparison: amount of hard exudates (HE) on color pictures, amount of HE on red-free pictures, severity of leakage, and size of foveal avascular zone. Available programs in the software such as color selection, luminosity channel, and histogram and tools such as magnetic lasso and magic wand were used for measurement. Coefficients of agreement and kappa measurements were calculated. Agreement (kappa) between the two methods in the amount of HE on color and red-free photographs were 85% (0.69) and 79% (0.59), respectively. This agreement for severity of leakage was 72% (0.46). In the evaluation of the foveal avascular zone size with two methods of quantification using the magic and lasso software tools the agreement was 54% (0.09) and 89% (0.77), respectively. Quantitative measurement of fundus and angiographic image variables such as HE, leakage, and foveal avascular zone can be performed precisely using Photoshop software.