A Prospective Evaluation of Asphericity–adjusted LASIK With the Allegretto–wave and the M2 in 105 Eyes

Abstract

Abstract: : Purpose: To evaluate the safety and efficacy of asphericity–adjusted LASIK surgery, utilizing the Allegretto–wave 400 Hz system and the M2 microkeratome. Methods: 105 consecutive LASIK cases for myopic astigmatism underwent treatment with asphericity adjustment to the pre–operative flattest keratometry (Q–value 0.15 to –0.46), based on 20 degrees topographic measurement. We evaluated pre– and post–operative refraction, asphericity (Q value), total higher order aberrations (RMSH), contrast sensitivity and possible complications. Follow–up was 3–7 months (4.5). Results: 96 eyes were included. The mean values were: refractive error sphere: –3.80D (–0.50 to –6.75D) and cylinder: –0.85D (plano to –3.75D). UCVA improved from 20/200 to 20/18. At 3 months, 92% of the eyes were 20/20, 57% 20/15, and 34% 20/10. 100% of the eyes were within +/–0.50 D of the refractive goal at 3 months. There was no loss of BSCVA in any cases. Q value changed from a mean of –0.3 to –0.11. There was a positive shift of Q value proportionate to the amount of refractive error corrected. The mean RMSH decreased from 0.25 to 0.10. CS showed no statistical change. Conclusions: Asphericity–adjusted LASIK with the Allegretto–wave system (a 0.9mm flying spot and 400Hz) and the M2 appears to eb safe and very effective for correction of myopic astigmatism. It has demonstrated in this limited study clinical ability to reduce higher order aberrations following LASIK possibly through limiting the change in Q value.

Keywords: refractive surgery: LASIK • astigmatism