Realtime Temperature Control towards Gentle Photocoagulation of the Retina

摘要: Retinal laser photocoagulation is the most successful therapy in medicine and well established for a variety of retinal diseases. However, induced temperature increase so far unknown. In order to probe this rise, pulsed radiation repetitively applied excite pressure waves at chorioretinal complex simultaneously during heating time. The are detected with an ultrasonic transducer embedded contact lens which placed on cornea anyway treatment. From amplitudes transient retina deduced. A Nd:YLF (527 nm) pulse duration 200 ns was used thermoelastic expansion, freshly enucleated porcine eyes served as model. Irradiation constant power 175 mW onto 400 μm spots medium pigmented lead rise 35 K after 500 ms approximately logarithmic over time expected from heat diffusion theory. Applying pulses different powers, we found 0.18 K/mW end irradiation period. These first measurements demonstrate possibility realize non-invasive real monitoring irradiation. data achieved show very promising towards realization automatic dosimetry control almost independent individual eye’s transmission pigmentation.