METHOD FOR PREOPERATIVE CALCULATION AND MODIFICATION OF INTRAOCULAR LENS BY LASER ABLATION Russian patent published in 2019 - IPC A61F9/08 A61F2/16 A61F9/13 

FIELD: medicine.

SUBSTANCE: invention relates to methods for preoperative calculation and modification of an intraocular lens by laser ablation. True refraction of the eye is determined in the patient according to refracto- and keratometry data. It involves keratotopography, aberrometry, calculating a spherical intraocular lens (IOL) from hydrophobic acrylic or polymethylmethacrylate (PMMA) according to known formulas for cataract surgery. To optical power of the calculated lens is added from 0.5 to 4 dioptres. Visually perceptible radial notch on the front surface of the upper part of the lens is superimposed by the cutting tool. Front surface of the lens with a center located along the visual axis of the eye is ablated with an excimer laser with wavelength of 193 nm. For distance vision is exposed in circular zone with diameter of 3–4.5 mm. For near vision, the exposure is performed in a circular zone with an inner diameter of 3–4.5 mm and an outer diameter of 4.5–6.5 mm. Diameter of circular zone coincides with internal diameter of annular zone.

EFFECT: enlarging indications for performing the operation, obtaining high clinical and functional results, reducing frequency and value of inaccuracies in correcting deficiencies of eye refraction, such as myopia, hypermetropia and astigmatism, correction of presbyopia.

1 cl, 1 dwg