A controlled study was designed to evaluate light coagulation as treatment for presumed histoplasmic chorioretinitis. Twenty-nine patients were selected. Allocation of patients to a treatment or an untreated control group was made by using a table of random numbers. Results in the two groups were compared over a one-year observation period. The study was designed to minimize measurement and observation bias and the effect of interim remissions and exacerbations of the disease. The results indicate that this therapy is of no value in the long-term management of this disease.
Watzke RC, Leaverton PE. Light Coagulation in Presumed Histoplasmic ChoroiditisA Controlled Clinical Study. Arch Ophthalmol. 1971;86(2):127-132. doi:10.1001/archopht.1971.01000010129002