Efficiency of using Contoura protocol on Wavelight EX 500 for the correction of myopia and myopic astigmatism

    Abstract

    Efficiency of using Contoura protocol on Wavelight EX 500 for the correction of myopia and myopic astigmatism

    Zagrebneva M.M.

    Orenburg branch of S.N. Fedorov NMRC «MNTK «Eye Microsurgery» of the Ministry of health of Russia

    Purpose. To study the results of applying Contoura technique (Topography-Guided/Topo-G) during FemtoLasik surgery performed according to aberrations of corneal wavefront using Topolyzer-Vario ALLEGRO topograph in patients with various degrees of myopia and myopic astigmatism.

    Material and methods. 160 patients (319 eyes) were operated on using Contoura technique. The age of patients ranged from 20 to 50 y.o., the follow-up period was 1 year. Myopic astigmatism averaged 3.75 D (1.0 to 6.5). Visual acuity with correction before surgery averaged 0.78±0.04. Corneal valve 90 μm thick was formed by femtosecond laser Femto LDV Z8 (Ziemer). Excimer laser correction was performed on WaveLight EX500 (Alcon) with 500 Hz frequency, 6.5 mm diameter of the optical zone of, and a total ablation zone of 9.0.

    Results. Analysis of the of postoperative results in different periods showed no prominent differences in subjective and objective refraction as compared to predicted result. This is due to the accuracy of preoperative diagnostics, type of algorithm, and ablation parameter chosen by the surgeon.

    Average postoperative binocular visual acuity measurements in the distance without correction was 0.89±0.05, after 1 month – 0.92±0.05 and remained stable throughout the observation period. There were no complaints of visual discomfort during twilight and at night. All the patients subjectively noted an increase in color brightness and contrast.

    Conclusions. Using Contoura technique gives high functional results, enhances spatial and contrast sensitivity.

    Key words: FemtoLasik, aberration, wavefront, myopic astigmatism.