Structure of initial morphometric, optical parameters of cornea in patients with medium degree myopia before refractive surgery. Parity of optimal and possible conditions of surgery
The analysis of the structure of morphometric, anatomical and optical ocular indicators in patients with myopia to 6.0 diopters before performing refractive surgery was made. Clinical material totaled 190 eyes (114 patients) with myopic refractive spheroequivalent of 6.0 diopters and astigmatism of 1.75 diopters. Morphometric and anatomical optic corneal characteristics and optical system of the eye were studied (thickness of the central corneal zone, and its optical power, diameter, width of the pupil in scotopic conditions, the level of higher-order aberrations eye optical system; angle Kappa; codes corneal topography corneal elevation posterior surface of the cornea). In 62.1% of the eyes, the optimal conditions for all investigated indices were determined, in 37.9% only for some of them. In 10.5% of the structure of non-optimal conditions there were deviations in 1-2 features; in 27,4% - on 3 and more indicators. Taking into account the identified baseline indicators, in 37.9% of cases there was a need to make adjustments in the course of operation: to increase the optical zone to perform personalized ablation, to reduce the thickness of valve, shift the ablation zone with the angle kappa. The most common species of deviations from the optimal parameters were: the width of the pupil in scotopic conditions, the optical power of the cornea, the level of higher-order aberrations, SAI index. This created the need to make appropriate adjustments to the course of the operation.