Comparison of Temperature Measurements and Fundus Reflectometry in Laser Coagulationl

In light coagulation, thermal Parameters play an important role for the biological reaction. Therefore, we measured the temperature increase and the whitening of the coagulation site simultaneously during the coagu-lation. Microthermocouples [I] were developed as shown in figure 1. The diameter of the tip ranges between 5 and 10 pm, the response time of this element is in the region of 1 msec. We designed a technique to insert this thermocouple into the globe through a trepanation at the Pars plana (fig. 2). The tip is advanced by a step motor and can be positioned exactly by a micromanipulater anywhere within the posterior pole. Coagulation of 500,um in diameter were set in rabbit eyes with an argon laser coagu-lator using a slitlamp contact lens arrangement. The temperature in the center of the lesion at the interface between the PE and retina is moni-tored during and after the coagulation (fig. 3). To demonstrate our method, figure 4 shows a typical temperatur