METHOD FOR SELECTING THICKNESS OF TWO INTRASTROMAL SEGMENTS FOR IMPLANTATION IN PATIENTS WITH ASYMMETRIC KERATECTASIAS, AS WELL AS IN THEIR COMBINATION WITH FUCHS CORNEAL DYSTROPHY Russian patent published in 2024 - IPC A61F9/07 A61B3/00 A61F2/14 

FIELD: medicine; ophthalmology.

SUBSTANCE: thickness of two intrastromal segments is selected for implantation in patients with asymmetric keratectasias, as well as in their combination with Fuchs corneal dystrophy. Initially, the patient undergoes visometry with determination of uncorrected and corrected visual acuity, autorefractometry, biomicroscopy and corneal topography with determination of keratectasia shape, minimum thickness of cornea in area of internal diameter of 5 mm and external diameter of 7 mm and topographic astigmatism by weak and strong meridians corresponding to axes of parts of keratectasia in area of diameter 3 mm. If there is a characteristic form of "asymmetric butterfly" or "duck" keratectasia, the thickness of the cornea in the area of the inner diameter of 5 mm and the outer diameter of 7 mm is not less than 350 mcm, and if guttas are visualized on corneal endothelium, then two intrastromal segments with arc length of 160 degrees each are selected. Thickness of the first segment is selected from the spherical refraction component as follows. If the spherical component is from 0 to minus 2 diopters, then the thickness of the first intrastromal segment is 150 mcm; from minus 2 to minus 4 diopters—200 mcm; from minus 4 to minus 6 diopters—250 mcm; from minus 6 to minus 8 diopters—300 mcm, wherein thickness of the second segment is selected by topographic astigmatism as follows. If the topographic astigmatism is from 0 to minus 2 diopters, then the second segment of the same thickness as the first one is selected; from minus 2 to minus 6 diopters—by 50 mcm thicker than the first one, from minus 6 to minus 10 diopters—by 100 mcm thicker than the first one, from minus 10 to minus 6 diopters—by 150 mcm thicker than the first one, at the same time implantation of the first segment selected by spherical refraction component, is carried out in a zone with a smaller curvature of the cornea, and the second segment, selected by topographic astigmatism, in a zone with a greater curvature of the cornea.

EFFECT: method makes it possible to reduce spherical and cylindrical components of refraction, as well as to increase quality of visual-functional rehabilitation of patients with improved quality of vision, wherein the method has no effect on reducing the density of endothelial cells in the postoperative period.

1 cl, 3 ex