Infrared photography of the ocular fundus has been explored to define its usefulness. Standard fundus photography equipment was used with color infrared sensitive film and appropriate filters to eliminate the blue end of the visual spectrum. Resulting photographs encompassed a spectrum of 500 to 900 mμ wavelengths, including most of the visible light spectrum and extending well beyond it into the near-infrared spectrum. Color infrared photography possesses the unique properties of color distortion, altered contrast, and increased penetration through tissue. Color distortion, although occasionally vivid, was not helpful in characterizing tissue type of lesions. Contrast was most evident with deeply pigmented structures which absorb infrared wavelengths. Pigmented tumors were better defined with infrared photography. The penetration property produced striking results; choroidal vasculature was depicted regularly, even when not visible clinically. Partial penetration has promise for clinical application.
Dallow RL. Color Infrared Photography of the Ocular Fundus. Arch Ophthalmol. 1974;92(3):254-258. doi:10.1001/archopht.1974.01010010262020