METHOD FOR SELECTING KERATOMETRY DATA FOR MARKING AN ACTUAL ZONE OF CORNEAL ASTIGMATISM WHEN CALCULATING TORICITY OF AN INTRAOCULAR LENS Russian patent published in 2024 - IPC A61B3/00 A61B3/107 

FIELD: medicine; ophthalmology.

SUBSTANCE: invention can be used to select keratometry data for marking an actual corneal astigmatism zone when calculating toricity of an intraocular lens (TIOL). For this purpose, the patient undergoes a corneal topography and its data are used to determine the actual corneal astigmatism zone taking into account the following criteria: zone diameter is 1–5 mm; meridian contains clearly defined and completely rounded lobes; two meridian lobes must meet the following requirements: have maximum size; be rounded and reach the center; be of the same color. After that, the actual zone is marked along the smaller of the two counter-lateral lobes, so that the boundary passes through the widest part of this lobe, provided that two lobes of the actual zone are different colors, then marking is performed on the smallest of them. If a closed lobe is determined only on one side, then marking is performed on one of the largest available lobes. If no lobes are found and the topogram map is similar in principle to the pattern of correct astigmatism, then the actual zone is selected in range of 2–5 mm, wherein a zone with a minimum angle between each semi-meridians is selected.

EFFECT: invention provides higher efficiency of calculating TIOL.

1 cl, 3 ex