STUDY OF OPTICAL TRANSMISSION SPECTRA AND SURFACE TREATMENT PARAMETERS OF INTRAOCULAR LENSES

Abstract

Manufacturers of intraocular lenses are constantly improving the parameters of artificial lenses, functionally bringing them closer to their natural counterpart. In this work, an experimental study of a number of important physical and technical parameters of intraocular lenses of the world's leading manufacturers, affecting the quality of vision of operated patients, was carried out. The transmission spectra of optical radiation of intraocular lenses in the range of 200–800 nm were investigated. In the short-wavelength part, the measurement results showed a high efficiency of the protective properties of intraocular lenses from ultraviolet radiation. It is shown that radiation with a wavelength of up to 350 nm is completely absorbed by the lens material, and the transmission of waves with a wavelength of 400 nm is 20 %. Further, up to a wavelength of 550 nm, an increase in the transmittance of the studied intraocular lens to 100 % is observed, after which it gradually decreases to the end of the visible range to 85%. The work also investigated the influence of the quality of the surface treatment of intraocular lenses on the likelihood of secondary cataract development in the long-term period. According to postoperative statistics, the likelihood of secondary cataract is 20–35 %. The appearance of areas of optical opacity is due to various factors, one of which is the quality of the surface treatment of intraocular lenses. The smoothness of the surface profile of the lens depends on the model, manufacturing technology and material of the artificial lens. The study of the quality of surface treatment of soft and hard intraocular lenses was carried out by atomic force microscopy. An analysis of the results of scanning the surface of intraocular lenses and a statistical analysis of 630 clinical cases of secondary cataract in the long-term postoperative period (6 months or more) showed their relationship. If the height of irregularities (protrusions) on the lens surface increases to 70 nm or more, the likelihood of secondary cataract in the postoperative period increases from 6 to 15 %.