Abstract
Purpose: :
Compare the optical outcomes (aberrations and visual acuity) of wavefront guided surface treatments to thin flap LASIK using the IntraLase laser.
Methods: :
Retrospective study of 240 patients having undergone wavefront guided advanced surface ablation (ASA) and 137 patients having undergone IntraLase based LASIK (iLASIK) with the AMO STAR S4 IR. Surface ablation group was randomly selected from >2000 patients to two equal groups (n=120) for surface treatment with (wASA) or without (nASA) an epithelial flap. Outcome measures for this study were ocular aberrations spherical aberration (SA), coma and total high order aberrations (HOA) as well as best spectacle and uncorrected minimum angle of resolution (Bmar and Umar). All aberration data was recalculated a 5 mm pupil for analysis purposes.
Results: :
There was no significant difference in the efficacy of the treatment of sphere and cylinder between ASA and iLASIK, even when considering wASA and nASA separately. SA increase significantly in all groups following surgery (iLASIK = 0.038±0.098, wASA = 0.112±0.083, nASA = 0.111±0.094 µm) with the iLASIK surgery having a significantly smaller increase that the ASA groups (ANOVA, p<0.001). Improvements in UCVA were not significantly different between the iLASIK and ASA even when considering wASA and nASA separately. Umar at 3 months was significantly better (ANOVA P=0.002) for the wASA group (1.14±0.19 min. arc) than the other two groups (nASA = 1.18±0.23, iLASIK = 1.22±0.19 min. arc). HOA results mirrored SA results across the groups.
Conclusions: :
Current wavefront guided surface and iLASIK refractive surgeries are safe and efficacious in the correction of spherical and cylindrical components of refraction. There is an increase in SA for all treatment groups considered here with iLASIK inducing significantly less SA than surface treatments. The ASA group with epithelial flap had as a group significantly better post op visual acuity than the no flap ASA and iLASIK group.
Keywords: refractive surgery