September 2016
Volume 57, Issue 12
Open Access
ARVO Annual Meeting Abstract  |   September 2016
Vector Analysis in Refractive Surgery with Femto-LASIK
Author Affiliations & Notes
  • Azyadeh Camacho Ordoñez
    Hospital de la luz, Mexico, Mexico
  • Oscar Fernandez
    Hospital de la luz, Mexico, Mexico
    Hospital de la luz, Mexico, Mexico
  • Footnotes
    Commercial Relationships   Azyadeh Camacho Ordoñez, None; Oscar Fernandez, None; ELISA ALEGRIA GOMEZ, None
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science September 2016, Vol.57, 4888. doi:
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      Azyadeh Camacho Ordoñez, Oscar Fernandez, ELISA ALEGRIA GOMEZ; Vector Analysis in Refractive Surgery with Femto-LASIK. Invest. Ophthalmol. Vis. Sci. 2016;57(12):4888.

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      © ARVO (1962-2015); The Authors (2016-present)

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Purpose : To determinate the induced and residual astigmatism after Femto-LASIK surgery

Methods : A total of 66 eyes from 33 subjects were included, mean age was 27.7±5.7 years, with a spherical refractive error range -10.50 to +4.50D and cylindrical power -0.50 to -6.50D. Subjects were divided in three groups according to preoperative cylinder: group I <1 diopter (D), group II 1-2D and group III >2D. The flap was made with VisuMax Femtosecond laser and underwent LASIK correction on STAR S4 IR laser platform. The calculation of induced and residual astigmatism was made with a vector analysis performed by a mathematical formula described by Holladay and Hersh with double angle graphic at first week, one and three months.

Results : The average preoperative astigmatism was -2.66x173, after surgery the induced astigmatism was -0.17x117 at week one, -0.23x105 at first month and -0.16x13 at third month; the residual astigmatism was -0.26x50 at first week, -0.31x173 at first month and -0.27x170 at third month. The induced sphere was -0.97 at first week, -0.69 at first month and -0.68 at third month. The residual sphere was -0.50, -0.65 and -0.56 respectively.
Induced and residual astigmatism were -0.04x124 and -0.01x160 in group I, -0.04x181 and 0.04x177 in group II, -0.10x156 and 0.11x160 in group III at third month respectively.

Conclusions : The induced and residual astigmatism at third month with Femto-LASIK was minimum. The residual astigmatism was higher in patients with >2D preoperative cylinder. The induced and residual sphere at third month was 0.56 and 0.68 respectively.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.


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