An ex vivo study of the impact of mid-infrared laser on ocular tissues

Abstract

We are searching for the most suitable laser radiation, which will allow us to make thin cuts on the retina and choroid with high accuracy, minimal damage to surrounding tissues, and a sufficient degree of coagulation to prevent hemorrhages. As the first wavelength at which we conducted research, we chose 3.0 µm. This is primarily due to the fact that this wavelength coincides with the peak of the spectral absorption of water. The retina, choroid and sclera of pig eyes were used as biological tissue. The impact of laser radiation on eye tissues was assessed using a scanning electron microscope. According to the results of the experiment, laser radiation with a given wavelength has a deep penetration of radiation into the sclera up to 300 µm, with a crater width of 250–480 microns. Collateral damage in the sclera is less than 80 microns. When exposed to laser radiation on the choroid: the penetration depth was up to 150 µm, the width of the crater was up to 110 µm, collateral damage was up to 70 µm. The retina, when exposed to radiation with the specified settings, is cut through. The higher the energy and frequency of radiation, the deeper its penetration, wider cut and collateral damage to biological tissue.