Comparison of LASIK using the NIDEK EC-5000 optimized aspheric transition zone (OATz) and conventional ablation profile

PURPOSE: To compare a new ablation algorithm termed the optimized aspheric transition zone (OATz) with the conventional laser ablation profile for correction of myopic astigmatism. METHODS: LASIK using OATz profile #6 or using conventional ablation profile was performed on 98 eyes of 53 patients (OATz #6 group) and 111 eyes of 66 patients (control #6 group), respectively. Further, LASIK using OATz profile #5 or using the conventional ablation profile was performed on 109 eyes of 58 patients (OATz #5 group) and 109 eyes of 75 patients (control #5 group), respectively. The effective optical zone, uncorrected visual acuity, manifest refraction, aberrations, contrast sensitivity, and patient satisfaction at 3 months postoperatively were compared between the OATz #6 and control #6 groups and between the OATz #5 and control #5 groups. RESULTS: The effective optical zones in the OATz #6 group (6.45±0.29 mm) or OATz #5 group (6.40±0.21 mm) were significantly larger than those in the control #6 group (6.33±0.27 mm) or control #5 group (6.26±0.25 mm) (P<.01), respectively. Uncorrected visual acuity and manifest refraction were similar in all groups. The changes in contrast sensitivity were significant and favored the OATz #6 (P<.01) and OATz #5 groups (P<.05). The patient satisfaction survey found no statistical difference at 3 months postoperatively. CONCLUSIONS: Patients treated with the OATz profiles had better visual quality as measured by contrast sensitivity and also had larger effective optical zones as compared with those treated by the conventional ablation profile.