One-year Result of LASIK using 5.0 mmOptical Zone Ablation

ABSTRACT

The stability, efficacy, predictability, and safety of LASIK with 5.0 mm zone ablation was assessed and the relation between the amount of correction and the amount of ablation was also evaluated to determine how much we need to ablate the corneal stroma. In this study, we present our data on the 125 cases of myopic correction by LASIK, using ExciMed UV 200LA[Summit Technologies Inc. USA]. The patients were divided into 4 groups with preoperative myopia. About 90% of myopic error at the corneal plane was ablated and uncorrected visual acuity[UCVA], best corrected visual acuity[BCVA], intraocular pressure[IOP], and manifest refraction[MR] were checked 1 week, 1 month, 3 months, 6 months, 9 months, and 1 year after LASIK. Spherical refraction improved from -11.94D preop to -0.53D postop one year. 57.1% of eyes was within+/-0.50D and 85.7% was within+/-1.0D of emmetropia one year after LASIK. UCVA of 0.5 or better was achieved in 74.3% of eyes that is because preoperative BCVA was below 0.5 in many cases. BCVA was improved or unchanged, in 90.0% of the eyes one year after LASIK. In eyes with -20.0D of preoperative spherical value or less, ablation of about 90% of spherical value at the corneal plane made 102.9% of attempted correction 9 months after LASIK and 98.3% of attempted correction 1 year after LASIK. In eyes over -20.0D, 89.8% of attempted correction was achieved 9 months after LASIK. In conclusion, this study suggest that the ablation of 90% of preoperative myopic error at the corneal plane is reasonable for LASIK using 5.0 mmablation zone.