Digital imaging of central serous retinopathy using infrared illumination

When used with an infrared laser, scanning laser technology allows imaging of subretinal structures. In the indirect mode (scattered light), drusen, subretinal edema, and other changes in the retinal pigment epithelial complex can easily be visualized as pseudoprominent structures. This study was undertaken to determine the role of infrared imaging in central serous retinopathy. A total of 22 patients affected by acute central serous retinopathy were recruited for the study. All patients underwent fluorescein angiography (488 nm) and infrared imaging (788 nm) using a scanning laser ophthalmoscope (SLO 101; Rodenstock). The confocal mode was used for the fluorescein angiography, but the indirect mode was applied for infrared imaging. In all patients, serous detachment could be visualized by infrared imaging as pseudoprominent, oval-shaped structures. The size was at least one disk diameter and correspondend very well to the clinical appearance. In all patients, late-phase (20 min) fluorescein studies revealed the typical focal leakage with progressive hyperfluorescence. In six patients (27%) the extent of the serous detachment could be seen in a slightly hyperfluorescent rim. Digital image analysis showed that the extent of the serous detachment in the fluorescein angiogram was similar to the size of the thickened structures in the infrared image (r2 = 0.94). This initial study suggests that noninvasive infrared imaging can be a very useful indicator of serous detachment. Further studies regarding the influence of medical or laser treatment must be carried out to prove the clinical relevance.