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Femtosecond corneal lenticule extraction compared to conventional LASIK in refractive surgery

Session Details

Session Title: Refractive Femtosecond

Session Date/Time: Sunday 06/10/2013 | 17:00-18:30

Paper Time: 17:12

Venue: Elicium 2 (First Floor)

First Author: : O.Kostin RUSSIA

Co Author(s): :    S. Rebrikov   A. Ovchinnikov   A. Stepanov        

Abstract Details

Purpose:

Comparative estimation of corneal flap forming with Moria microkeratome and VisuMax femtosecond laser including flap thickness, refraction, visual acuity, changes of contrast sensitivity and higher order aberrations after LASIK and FLEx operations for myopia and myopic astigmatism.

Setting:

S. Fyodorov IRTC Eye Microsurgery, Ekaterinburg Branch

Methods:

Two groups were enrolled, 70 eyes in each. Standard LASIK was performed in Group 1 and FLEx in Group 2. In both groups before and in 1 month after surgery wavefront aberrations were measured in Malacara notation with WASCA aberrometer (Carl Zeiss Meditec, Germany). Flap thickness at the corneal center and 1, 2, and 3 mm from the center was measured in both groups with Visante OCT (Carl Zeiss Meditec) in High Resolution Corneal Quad and High Resolution Corneal Single modes. Contrast sensitivity was measured in both groups with CSV-1000 unit (VECTORVISION). Follow-up was 1 month.

Results:

Uncorrected visual acuity before surgery in Groups 1 and 2 was 0.05 ± 0.07 and 0.06 ± 0.02; after surgery it made 0.99 ± 0.05 and 0.95 ± 0.09, respectively (p>0.05). Spherical equivalent in Groups 1 and 2 was -4.13 ± 2.08D; -3.78 ± 1.47D before surgery and made after surgery 0.02 ± 0.16 D; 0.03 ± 0.14 D, respectively (p>0.05). Corrected visual acuity in Groups 1 and 2 before surgery was 0.98 ± 0.05; 0.99 ± 0.02 and made after surgery 0.99 ± 0.07; 0.98 ± 0.04 (p>0.05). RMS HO before surgery in Groups 1 and 2 was 0.18 ± 0.07 µm; 0.17 ± 0.09 µm and has increased to 0.37 ± 0.11 µm; 0.29 ± 0.07 µm after surgery (p<0.05). The value of spherical aberration in Groups 1 and 2 before surgery was -0.12 ± 0.19 µm; -0.11 ± 0.15 µm and has increased negatively in both groups after surgery up to -0.53 ± 0.30 µm; -0.24 ± 0.28 µm (p<0.05). Flap thickness was irregular in Group 1 and regular in Group 2. Contrast sensitivity has returned to preoperative level within follow-up period.

Conclusions:

1. VisuMax femtosecond laser microkeratome gives a possibility to perform FLEX operations without excimer laser. 2. . VisuMax femtosecond laser microkeratome creates corneal flaps with exactly preset thickness parameters unlike mechanical microkeratome. 3. FLEX operation provides visual acuity up to best corrected preoperative level with restoration of contrast sensitivity under mesopic conditions by 1 month post-op.

Financial Interest:

NONE