Predictibilidad en la inducción de aberración esférica basada en la asfericidad corneal post LASIK en miopes

Oscar Enrique Piñeros Sánchez

Resumen


Purpose: To determine the predictability of postoperative ocular spherical aberration (Z 4,0) based on postoperative corneal asphericity (Q value) in patients with myopic astigmatism.

Design: Case series, retrospective.

Methods: Wavefront-guided laser in situ keratomileusis (LASIK) was performed in 40 eyes of 23 patients using the Schwind Esiris Excimer Laser. Patients were evaluated preoperatively and 3 months postoperatively. Spherical aberration was measured with a COAS Shack-Hartmann wavefront sensor, and determined for a 6 mm analysis diameter zone. Corneal asphericity was measured with the Orbscan II topographer. Correlation and linear regression analysis was performed. A P value less than 0.05 was considered statistically significant.

Results: Treated eyes had a mean manifest spherical error of –2.98 + 1.36 Diopters (D), and a mean manifest astigmatic error of 0.52 + 0.46 D. The mean Q was -0.30 + 0.13 preoperatively and +0.03 + 0.22 postoperatively. Th e mean spherical aberration was 0.054 + 0.109 microns preoperatively and 0.262 + 0.135 microns postoperatively. We found a positive statistically significant correlation between postoperative Q value and postoperative spherical aberration (r=0.367) (P=0.02). The postoperative Q value showed a low correlation with postoperative spherical aberration (R2=0.14).

Conclusions: There was an increase in corneal asphericity and spherical aberration after surgery. Postoperative corneal asphericity is mildly associated with postoperative spherical aberration. Predictability of postoperative spherical aberration in terms of correlation with postoperative Q value was poor, suggesting that corneal asphericity is not a major predictor of spherical aberration induction.


Palabras clave


Lasik, myopia, astigmatism, corneal asphericity, spherical aberration.

Texto completo:

PDF

Referencias


Porter J, Guirao A, Cox IG, Williams DR. Monochromatic aberrations of the human eye in a large population. J Opt Soc Am A 2001;18:1793-1803.

Artal P, Guirao A. Optical aberrations and the aging eye. Int Ophthalmol Clin 2003;43:63-77.

Applegate RA, Marsack JD, Ramos R, Sarver EJ. Interaction between aberrations to improve or reduce visual performance. J Cataract Refract Surg 2003;29:1487–1495.

Gatinel D, Hoang-Xuan T, Azar D. Determination of corneal asphericity after myopia surgery with the excimer laser: A mathematical model. Ophthalmol Vis Sci 2001;42:1736-1742.

Anera R, Jimenez J, Jimenez L, Bermudez J, Hita E. Changes in corneal asphericity after lasik. J Cataract Refract Surg 2003;29:762-768.

Hersh P, Fry K, Blaker W. Spherical aberration after laser in situ keratomileusis and photorefractive keratectomy. Clinical results and theoretical models of etiology. J Cataract Refract Surg 2003;29:2096-2104.

Marcos S. Aberrations and visual performance following standard laser vision correction. J Refract Surg 2001;17:S596-S601.

Marcos S, Cano D, Barbero S. Increase in corneal asphericity after standard Lasik for myopia is not inherent to the Munnerlyn algorithm. J RefractSurg 2003;19:S592-S596.

Kohnen T, Bühren J, Kühne C, Mirshahi A. Wavefront-Guided LASIK with the Zyoptix 3.1 System for the Correction of Myopia and Compound Myopic Astigmatism with 1-Year Follow-up. Ophthalmology 2004;111:2175–2185.

Yoon G, MacRae S, Williams D, Cox I. Causes of spherical aberration induced by laser refractive surgery. J Cataract Refract Surg 2005;31:127-135.

Holladay J, Janes J. Topographic changes in corneal asphericity and eff ective optical zone after lasik. J Cataract Refract Surg 2002;28:942-947.

Calossi A. Corneal asphericity and spherical aberration. J Refract Surg 2007;23:505-514.

Mrochen M, Seiler T. Infl uence of corneal curvature on calculation of ablation patterns used in photorefractive laser surgery. J Refract Surg 2001;17:S584-587.

Roberts C. Th e cornea is not a piece of plastic. J Refract Surg 2000;16:407-413.

Artal P, Berrio E, Guirao A, Piers P. Contribution of the cornea and internal surfaces to the change of ocular aberrations with age. J Opt Soc Am A Opt Image Sci Vis 2002;19:137-143.

Subbaram MV, MacRae S, Slade SG, Durrie DS. Customized LASIK treatment for myopia: relationship between preoperative higher order aberrations and refractive outcome. J Refract Surg 2006;22:746-753.

Arba S, Ortueta D. Correlation Among Ocular Spherical Aberration, Corneal Spherical Aberration, and Corneal Asphericity before and after LASIK for Myopic Astigmatism with the SCHWIND Amaris platform. J Refract Surg 2011;27:434-443.

Gatinel D, Azar DT, Dumas L, Malet J. Effect of anterior corneal surface asphericity modifi cation on fourth-order zernike spherical aberrations. J Refract Surg 2014;30:708-715.


Enlaces refback

  • No hay ningún enlace refback.


Copyright (c) 2017 Oscar Enrique Piñeros Sánchez

Licencia de Creative Commons
Este obra está bajo una licencia de Creative Commons Reconocimiento-NoComercial 4.0 Internacional.