TENSILE STRENGTH OF CHORIORETINAL LESIONS PRODUCED BY PHOTOCOAGULATION, DIATHERMY, AND CRYOPEXY

The tensile strength of chorioretinal lesions produced by photocoagulation, diathermy, and cryopexy over the tapetum lucidum of cats' eyes was measured with the help of an analytical balance. Using 5 mm.-wide strips of tissue, 2 days after these procedures the adhesion was I5 to 40 mg., i.e. much lower than over the untreated areas. From the 7th to the 21st day there was a gradual increase in the strength of the adhesion until it reached its maximum of i85 to 365 mg. Over the tapetum nigrum, the adhesion was much stronger, although no actual measurements could be performed because of the fragility of the retina, which tore before actual separation was achieved. The adhesion was slightly stronger after photocoagulation than after diathermy and cryopexy in that order.