Comparative study of higher-order aberrations after conventional laser in situ keratomileusis and laser epithelial keratomileusis for myopia using the technolas 217z laser platform.

Abstract

PURPOSE:

To examine changes in higher-order aberrations (HOAs) after PlanoScan laser in situ keratomileusis and (LASIK) and laser epithelial keratomileusis (LASEK).

DESIGN:

Prospective, comparative study.

METHODS:

Myopic patients undergoing LASIK (65 eyes of 36 patients) and LASEK (50 eyes of 28 patients) at a private practice were selected randomly. Surgery was performed using the Technolas 217z laser (Bausch & Lomb, Surrey, United Kingdom). Main outcome measures included uncorrected visual acuity (UCVA), manifest refractive spherical equivalent (MRSE), and aberrometry (Zywave; Bausch & Lomb, Rochester, New York, USA) and were recorded before surgery and at three and 12 months after surgery.

RESULTS:

There was no statistical difference between both groups in terms of MRSE (P = .91), ablation depth (P = .47), scotopic pupil size (P = .38), or optical zone (P = .07). Before surgery, there was no statistical difference in root mean square (RMS) of total (P = .70), third- (P = .79), fourth- (P = .23), and fifth- (P = .33) order aberrations and individual terms. Three months after surgery, RMS of total HOA was raised significantly more (P = .03) after LASIK (1.46-factor increase) than LASEK (1.25-factor increase). One year after surgery, a reduction in total HOAs was observed in 13.8% of LASIK- and 48.5% of LASEK-treated eyes compared with preoperative levels.

CONCLUSIONS:

Postoperative increases in total HOA and vertical coma were significantly greater in LASIK- than in LASEK-treated eyes. Postoperative reduction in total HOAs was observed in a number of eyes with high preoperative levels and occurred more frequently in LASEK-treated eyes.

• Authors: Caitriona Kirwan, Michael O'Keefe
• Journal: American journal of ophthalmology (Am J Ophthalmol) Vol. 147 Issue 1 Pg. 77-83 (Jan 2009) ISSN: 1879-1891 [Electronic] United States
• PMID: 18775529 (Publication Type: Comparative Study, Journal Article)

Topics

• Adult
• Corneal Topography
• Humans
• Keratectomy, Subepithelial, Laser-Assisted
• Keratomileusis, Laser In Situ
• Lasers, Excimer (therapeutic use)
• Middle Aged
• Myopia (physiopathology, surgery)
• Postoperative Complications
• Prospective Studies
• Refraction, Ocular
• Refractive Errors (etiology, physiopathology)
• Visual Acuity (physiology)