Spectral dependence of retinal thermal injury

The action spectrum for light-induced damage to the retina results from wavelength dependent transmission of the pre-retinal ocular media, wavelength dependent absorption in retinal chromophores, and chromatic aberration of the eye optics. While various light/tissue interaction mechanisms have been implicated, thermal mechanisms dominate in the visible and near-infrared spectrum for all exposure durations shorter than a few seconds and longer than 1 ns. A number of investigators have measured the transmission of the eye and the spectra of retinal absorbers, and thermal models based on these data predict the broad features of the action spectrum. This paper reports dose-response data for 100 ms duration retinal exposure in rhesus monkey to laser irradiation from a tunable Ti:Sapphire laser and from fixed-wavelength lasers over the wavelength range from 413 to 1319 nm. The wavelength dependence of these data is well predicted by the thermal action spectrum.