Figure 2

Comparison between fundus photography and slit lamp videography for a right eye with macular hole and epiretinal membrane (here at same magnification, but original images captured at the settings given below - all figures in this article inverted as seen through the slit lamp). Top left: 50° posterior pole image - taken with a fundus camera (Zeiss, FF 450, dilated pupil, image inverted for comparison with slit lamp imaging).- Top right: Attempt to capture the pathological process in only one video image taken with the slit lamp (+90D lens, 12x magnification, slit wide open, white light). This image suffers from poor contrast. Reflexes which often disturb slit lamp fundus images are minor in this case. - Bottom left: Mosaic arrangement of 3 video images taken with the slit lamp (+90D lens, 20x magnification, green light) showing the clinically relevant area within the temporal vessel arcade. Single images were arranged with the program Hugin® and further processed with Power Point®. Disease-related features (macular hole, epiretinal membrane) stand out at greater contrast than in the classic fundus photograph top left. - Bottom right: showing the fundus area illuminated by projecting a 3.5 mm circular aperture on the fundus through different fundus lenses (from outer to inner black ring - the higher the lens power, the larger the illuminated fundus area - for comparison see Figure 3). By applying magnification factors given for the respective lenses in a schematic eye (see text) the ring diameters are 4.7 mm (+90D lens), 3.1 mm (+60D lens) and 2.1 mm (+40D lens) and their relation is 2.25 : 1.5 : 1.0. The white ring indicates a circle of 3.5 mm diameter on the retina.