Light coagulation is a new therapeutic measure in ophthalmology. Started in 1948 by Dr. Meyer-Schwickerath, light coagulation is based on the principle of focusing the sun's rays to produce heat.1 Since its inception early prototypes of the light coagulator have given way to the present day precisely engineered instrument. Basically it is an ophthalmoscope with an exceptionally powerful light source. Almost the entire energy radiated is within the visible range, or at least in that part of the spectrum to which the media of the eye are transparent. The light source is a lamp in which the rare gas, xenon, contained in a quartz bulb under high pressure, is excited to incandescence by an electric current.
Scarring depends on absorption of the light by the choroid. Thus, coagulation is only possible if the retina is not elevated. When elevation is present, surgery to evacuate subretinal fluid is indicated before
TASSMAN WS. Indications for Light Coagulation of the Retina. Arch Ophthalmol. 1960;64(4):616-617. doi:10.1001/archopht.1960.01840010618021