The treatment parameters for retinal photocoagulation have remained relatively constant since the first description of an argon laser (514-nm wavelength) coupled to a slitlamp delivery system in 1970.
1 The 3 separate but interdependent variables available to the clinician are the beam size, power, and duration of the pulse. Typically, for diabetic retinopathy, retinal vascular applications, and the treatment of retinal breaks, the retinal laser spot sizes range from 100 to 500 μm; the pulse durations, from 100 to 200 milliseconds; and the power, from 100 to 750 mW. The clinical appearance of the retinal lesions in these applications ranges from mild gray to a moderate white.
2 For the thermal destruction of tumors and extrafoveal choroidal neovascular membranes, somewhat longer-duration lesions, ranging from 200 to 500 milliseconds, and longer wavelengths in the yellow-red spectrum are often used.
3