Time and location analysis of lesion formation in photocoagulation

Fourteen eyes from seven owl monkeys were used for study of the time and location within the retinal layers of the formation of the white reactions produced by photocoagulation with green (530.9 nm), yellow (568.2 nm), or red (647.1 nm) krypton wavelengths. Locations on the retina with equivalent conditions of absorbance were chosen. The white reaction formed in the first 100 ms of application. The depth at which the most damage occurred depended on the wavelength used. The final shape of the lesion depended on the location (in depth) of the white reaction first formed and on the power of the laser beam. The cauterizing power of the krypton yellow was evident.