FIELD: medicine.
SUBSTANCE: method involves changing cornea curvature and refraction force in opticalcornea center by applying laser in situ keratomilesis (Lasik). Central optical ablation diameter makes zones of 6.0 mm. Thermokeratoplasty is carried out on cornea periphery by contactless infrared laser radiation action exerted upon the cornea on Yttrium-Erbium glass. Radiation parameters are wavelength of 1.54 mcm, pulse energy 150-165 mJ/cm2, pulse exposure time 0.5-1.0 ms, beam diameter of 20-300 mcm. Laser coagulates are arranged sector-by-sector in chess-board order in weak cornea axis with diameters from 9.0 to 10.5 mm behind the cornea cover formed in Lasik operation. Coagulates number varies from 2 to 4 in each sector row in internal row and from 1 to 2 in external row corresponding to astigmatism degree. The number of rows is 2 to 4. Distance between the neighboring laser coagulates is not less than one coagulate diameter.
EFFECT: improved safety conditions; reduced risk of traumatic complications; excluded repeated operations necessity.
Authors
Dates
2007-01-10—Published
2005-06-15—Filed