Photothermal, cryogenic, and diathermic effects of retinal adhesive force in vivo.

Argon laser photocoagulation, cryoretinopexy, and diathermy of moderate intensity is applied to 140 rabbit eyes. Retinal adhesive force is measured from 1 day to 6 months following the treatment, using the authors' new in vivo method. A small retinal detachment is induced within the area surrounded by the burns. At the moment when the detachment starts to expand beyond the burns, subretinal pressure is measured using a resistance servo-nulling method. Retinal adhesive force is then calculated according to Laplace's law and compared with that of untreated eyes. Both photocoagulation and diathermy enhanced adhesiveness within 24 hours to 128% and 122%, respectively, of normal levels. Cryoretinopexy reduced the retinal adhesiveness during the first week, but afterwards generated as much adhesiveness as the other two methods. Beyond 6 months, under the conditions described here by the authors, the adhesive force was stronger after diathermy (279%) than after cryoretinopexy (214%) or laser photocoagulation (220%).