Evaluation of short pulse laser damage to the retinal pigment epithelium layer

Evaluation of short pulse laser damage to the retinal pigment epithelium layer
Ramos S, Reh M, Zeck G, Heussner N
Biophotonics: Photonic Solutions for Better Health Care VI. 2018 April; 10685.

Novel products using nanosecond laser pulses such as LiDAR sensors gain more interest in the consumer industry. These products are in line with the coming trend and are assumed to gain economic importance in the future. The performance of such devices conforms to the maximum permissible exposures (MPE) of the laser safety standard. The accuracy of the standard can be improved by laser-induced damage measurements. Approaching this subject we present our own first ns-measurements of tissue damage in the mammalian eye and the interpretation of this data. The irradiation experiments were performed by means of a Q-switched, frequency-doubling Nd: YAG laser (532nm wavelength, 6 ns pulse). Freshly isolated bovine eyes were used as models for threshold determination of laser-induced thermo-mechanical damage. After removal of the neural retina the retinal pigment epithelium layer attached to the sclera was irradiated. Three spot diameters (150 µm 250 µm and 290 µm) were used. The evaluation of the data leads to the following ED50 values: 3.55 µJ (150 µm), 6.50 µJ (250 µm) and 16.34µJ (290 µm). Based on the measurements, different options of data analysis are explained and used.