Eye Damage Control by Reduced Blue Illumination

Abstract

Abstract: : Purpose:To demonstrate that a short wavelength cut-off filter (yellow transmission) could reduce short-wavelength retina/RPE damage threshold. Methods: Six normal eyes of three cynomolgus monkeys were subjected to macular irradiation to accumulate 20, 35 and 60 J cm^-2 energy densities. Before and at 48 hours and 30 days after irradiation of a 2.8 mm region within the macular arcade, lesions were measured. Measures were fundoscopy, fluorescein angiography and long wavelength scanning by the Heidelberg Retinal Tomograph (HRT) unit. The lesions, which were produced, were scored (Dawson, et al. Exp. Eye. Res. (2002) 73, 137-147) and compared to irradiant energy density of the blue source (LED, Nichia NSPB500S). The dominant wavelength was 469 nm at 50 milliamps forward current. Results: The exposure at the 20 J cm^-2 produced no detectable result at 48 hours or 30 days. Exposure at 35 J cm^-2 showed definite lesion production without yellow filter. With the filter added there was one indication of minor change. At 60 J cm^-2 there was extensive heavy, enduring damage without the filter and with the filter damage was present but significantly attenuated. The values of energy density accumulated are all measured before the short wavelength cut-off filter. Conclusions: These results strongly support the conclusion that short wavelength rejection (attenuation) reduces the frequency of damage by exposure.

Keywords: retina