Nomogram adjustment of laser in situ keratomileusis for myopia and myopic astigmatism with the Alcon LADARVision system

J Refract Surg. 2004 Jul-Aug;20(4):364-70. doi: 10.3928/1081-597X-20040701-10.

Abstract

Purpose: To evaluate the visual and refractive results of conventional (non-wavefront) laser in situ keratomileusis (LASIK) for treatment of myopia and myopic astigmatism using the Alcon LADARVision 4000 excimer laser system and nomogram adjustment techniques.

Methods: A retrospective analysis of 499 eyes that had LASIK for myopia and myopic astigmatism was performed. Preoperative manifest spherical equivalent refraction ranged from -0.43 to -6.00 D and preoperative astigmatism ranged from 0 to -4.75 D. Patients were evaluated during 3 months following surgery.

Results: One month after surgery, 72% of eyes examined (298/415 eyes) had uncorrected visual acuity (UCVA) of 20/20 or better. Three months after surgery, 83% of eyes examined (216/261 eyes) had UCVA of 20/20 or better. One and three months after surgery, 82% and 83% of eyes, respectively, were within +/-0.50 D of attempted correction; 97% of eyes were within +/-1.00 D at both 1 and 3 months. No eye lost more than 1 line of best spectacle-corrected visual acuity (BSCVA) at 3 months after surgery. At the 3-month examination, 83% of eyes had UCVA better than or equal to preoperative BSCVA.

Conclusions: Conventional LASIK to correct myopia and myopic astigmatism was safe and effective using the Alcon LADARVision 4000 excimer laser system. Outcomes were substantially improved throughout development of an accurate nomogram, derived from continually updated regression analysis of previous refractive results.

MeSH terms

  • Adult
  • Aged
  • Astigmatism / physiopathology
  • Astigmatism / surgery*
  • Cornea / physiopathology
  • Cornea / surgery
  • Follow-Up Studies
  • Humans
  • Keratomileusis, Laser In Situ / methods*
  • Middle Aged
  • Myopia / physiopathology
  • Myopia / surgery*
  • Refraction, Ocular / physiology
  • Retrospective Studies
  • Treatment Outcome
  • Visual Acuity / physiology