Digital Simultaneous Fluorescein and Indocyanine Green Angiography, Autofluorescence, and Red-Free Imaging With a Solid-State Laser-Based Confocal Scanning Laser Ophthalmoscope

In Brief Purpose: To describe and to evaluate a novel confocal scanning laser ophthalmoscope (cSLO) for fluorescence angiography, fundus autofluorescence (FAF), and red-free imaging. Methods: Digital infrared, red-free, FAF, fluorescein, and indocyanine green (ICG) angiography images were obtained with a cSLO in 766 patients. An optically pumped solid-state laser generates the excitation wavelength (488 nm) required for red-free, FAF, and fluorescein angiography images. For ICG angiography and infrared imaging, diode laser sources at 790 and 820 nm are used. Further features include an internal fixation control and a focus range of −24 to +30 diopters. Results: High-image quality is achieved with a resolution of up to 5 μm per pixel in 30- x 30-degree images and allows for accurate delineation of normal and pathologic features. Simultaneous angiography offers high-contrast images. Corresponding display of quasi-simultaneous frames facilitates interpretation. A small focus difference between fluorescein and ICG scans occurs because of chromatic aberrations. Automated alignment and generation of mean images from several single frames allow for acquisition of high-resolution FAF images. Conclusion: Various laser-source related, optical, and electronic innovations improve cSLO fundus imaging for routine clinical application. A solid-state laser has advantages compared to argon gas laser sources, including less space occupation, heat emission, and noise production. Diagnostic fundus imaging was performed in a series of 766 consecutive patients using a novel confocal scanning laser ophthalmoscope. By the exclusive use of solid-state laser sources the instrument generates high-quality, high-resolution simultaneous fluorescein and indocyanine green angiography frames, fundus autofluorescence and red-free images and facilitates routine clinical diagnostic imaging.