The Retinal Temperature Rise during Transpupillary Thermotherapy in Albino and Pigmented Rabbits

Kim, Do Gyun; Kim, Ung Soo; Yu, Seung Yung; Kwak, Hyung Woo

Abstract

PURPOSE
we clinically measured the temperature rise in real time and analyzed the difference of albino rabbit and pigmented rabbit in use of the specially designed thermometer. METHODS: Specially designed thermometer was attached into the subretinal pigment epithealial and choroidal space through the suprachoroidal space in three pigment and three albino rabbits, with diode laser of 810 nm wave length, 3 mm spot size. We examined the retinal temperature according to laser irradiance power at each ten seconds during sixty seconds and the laser power setting was 200 mW, 300 mW, 400 mW in pigmeted rabbit and 300 mW, 600 mW, 800 mW in albino rabbit. We analyzed the results based on the measurements at least three times per each irradiance power. RESULTS: In albino rabbit, the maximal range of retinal temperature change was 1.2 degrees C and 1.7 degrees C in 300 mW and 600 mW, 14.1 degrees C in 800 mW power of 810 nm diode laser irradiance. In pigmented rabbit, the maximal range of retinal temperature change was 12.1 degrees C in 200 mW of laser irradiance power, 16.2 degrees C in 300 mW, 24.3 degrees C in 400 mW during sixty seconds in 810 nm diode laser. CONCLUSIONS: We investigated the ratinal temperature at transpupillary thermotherapy in 810 nm wavelength diode laser on rabbits. The difference of retinal temperature change was in accordance with the amount of chorioretinal melanin pigment. Therefore if the laser power setting used in caucasians would be attempted in orientals, it is the point to be considered during transpupillary thermotherapy.