SURGICAL METHOD FOR CORRECTING HYPERMETROPIC ASTIGMATISM

摘要

FIELD: medicine.;SUBSTANCE: method involves treating eye cornea with ultraviolet pulsating laser radiation having Gauss energy density distribution over beam cross-section. Beam diaphragm is tuned on laser radiation ablation threshold to form round spot of 0.3-1.2 mm diameter and energy of 0.7-1.4 mJ per pulse, pulse duration of 4-7 ns and pulse succession frequency from 100 to 300 Hz. Cornea treatment is concentrated in scanning grid points arranged in equilateral triangles. Treatment points form flat irregular figure built with broken lines in each of symmetric segments turned with their arc-like sides to opposite sides. Symmetry axis transecting the treatment segments is directed so that it coincides the weak astigmatism axis. The scanning grid is shifted several times. The treatment is carried out on the following scanning grid having its points between those of the previous one.;EFFECT: enhanced effectiveness in obtaining uniform surface after treatment; shorter operation time.;3 dwg