A new laser of high pulse repetition rate, typically 50 to 100 Hertz, for retinal photocoagulation offers significant advantages over conventional continuous or single-pulse light sources. High collimation permits one to generate very small burns. Optical aberrations of the eye media are neutralized for the most part by the application of Goldmann's mirror contact glass. In combination with a specially designed optical aiming and viewing system of high image quality, it is therefore possible to treat microlesions in the most peripheral parts of the retina with high accuracy and at low pulse energies. A foot pedal allows a very fine and continuous control of the laser output. A second observer is able to follow operations through a two-way eyepiece. The role of astigmatism caused by tilting the contact glass is discussed.
Fankhauser F, Lotmar W, Roulier A. Photocoagulation Through the Goldmann Contact GlassIII. Clinical Experience With an Apparatus Using a Quasi-Continuous Laser Source. Arch Ophthalmol. 1968;79(6):674-683. doi:10.1001/archopht.1968.03850040676005