METHOD FOR SURGICAL CORRECTION OF PRESBYOPY COMBINED WITH SPHERICAL HYPERMETROPIA WITH PRESERVING CORNEAL SURFACE ASPHERICITY Russian patent published in 2014 - IPC A61F9/07 A61F9/01 

FIELD: medicine.

SUBSTANCE: for the purpose of correction presbyopy combined with spherical hypermetropia, an eye cornea is exposed to an eximer laser light at a wave length of 193-222 nm, pulse energy of 0.8-2.1 mJ, laser spot diameter of 0.5-1.5 mm, pulse length of 5-8 nm, pulse repetition frequency of 30 to 500 Hz. This expose aiming at a sequential corneal abrasion is combined with forming optical surfaces and transition surfaces. The first cylindrical convex optical surface is formed within the entire optical cornea (OC). The second optical surface is formed as a convex ellipsoid of rotation with a negative conic constant within -0.1 to -0.4. A diameter of the second optical surface is related to an OC diameter as a value within the range of 0.85 to 0.95 of the OC diameter. Then, the transition surfaces (TS) are formed. The first TS is formed as a portion of a convex outer surface of the first O-toroid. The first TS is formed so as its outer border is coupled with the intact cornea. The second TS is formed as a portion of a concave inner surface of the second O-toroid. The second TS is formed so as its inner border is coupled with the outer border of the first optical surface. The outer border of the second TS shall be coupled with the inner border of the first TS.

EFFECT: method enables minimising the amount of the resected eye tissue, provides high far and near visual functions with no additional spectacle correction with decreased light cap.

22 dwg, 3 ex