METHOD OF CORRECTING MIXED ASTIGMATISM Russian patent published in 1994 - IPC

FIELD: medicine, in particular, ophthalmic surgery. SUBSTANCE: new method prescribes incising upper wall of tunnels disposed on side of cornea and extending along meridians with maximum refraction force starting from periphery to center of optical zone in diametrically opposite segments of cornea. Ratio of number of incised tunnels to that of intact ones is to be calculated by using following equation: NP/NT - NP = (RM/RH) NP/NT-NP=(RM/RH)·γ, where NT represents total number of tunnels, NP denotes number of incised tunnels, RM stands for myopic refraction, RH signifies hypermetropic refraction, and g is correction factor relating to diameter of optic zone (0.5 per each 0.1 surplus magnitude of diameter of optic zone), depth of incision of tunnels (90 %, 70 %, 50 % etc. of cornea thickness) and their total number (0.05 per each incised tunnel). EFFECT: reduced rate of operative traumatism and higher efficiency of surgical correction of astigmatism.