Comparative study of retinal injuries induced by a 420-750 nm supercontinuum source and a 532 nm laser

With the rapid developments and widespread applications of supercontinuum (SC) sources, ocular damage induced by this new light source becomes possible and receives our concern. To explore the ocular damage effect of an SC source, a series of experiments were conducted in a chinchilla grey rabbit model to determine the in-vivo retinal damage thresholds induced by a 420-750 nm SC source and a 532 nm laser. For the SC source, the beam divergence and the corneal 1/e² beam diameter were 3.8 mrad and 2.45 mm, respectively. The determined ED₅₀ values given in terms of total intraocular energy (TIE) for exposure durations of 0.1, 1.0, and 10.0 s were 1.57, 12.1, and 86.0 mJ, respectively. For the 532 nm laser, the beam divergence and the corneal 1/e² beam diameter were 0.9 mrad and 2.25 mm, respectively. The determined ED₅₀ value for an exposure duration of 0.1 s was 1.39 mJ. By employing the retinal thermal action spectrum in the ICNIRP guidelines, the damage thresholds for SC sources could be compared with the exposure limits for incoherent and laser radiation. Between the 420-750 nm SC source and the 532 nm laser, no significant difference could be found for the damage effects including damage threshold, retinal lesion size, and histological damage characteristics.