Purchase this article with an account.
M.V. Subbaram, S.M. MacRae, G. Yoon, I.G. Cox; Role of Spherical Aberration on Refractive Outcome After Custom LASIK Procedure . Invest. Ophthalmol. Vis. Sci. 2005;46(13):4362.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To analyze the role of spherical aberrations (HOA) on customized LASIK refractive outcome. Methods: Data from 330 myopic eyes, treated with customized ablation, with Technolas 217z, was followed through six months post–LASIK. Data was classified according to the amount of preoperative myopia, spherical aberration (SA), and change in astigmatism. The manifest and wavefront predicted phoropter refractions (PPR) were represented using power vectors: MSE (mean spherical equivalent), J0 (astigmatism at 0 or 90º), and J45 (oblique astigmatism). The role of SA on post–LASIK manifest refraction was analyzed using ANOVA. Results: 1) Increased SA was associated with increased sphere treatment magnitude (r=0.65, p<0.0001). Greater post–LASIK positive SA was significantly correlated to post–LASIK hyperopia (r=0.45, p<0.0001). 2) Change in SA (post – pre LASIK), or ΔSA, was lower among eyes with high preoperative SA and greater among those with lower preoperative SA (r=–0.35, p<0.0001). Eyes with negative preoperative SA had greater ΔSA than those with positive spherical aberration (t>3.26, p<0.0001). Among eyes with high preoperative positive SA (>0.35 um), ΔSA was inversely correlated to the postoperative hyperopia (r=0.32, p=0.028). 3) ΔSA was significantly correlated to ΔMSE (r>0.62, p<0.0001) and ΔJ0 (r>0.51, p<0.001) among eyes with post–LASIK hyperopia and low astigmatism (r=–0.35, p<0.0001). Δ3rd RMS and ΔSA were significantly correlated to ΔMSE (r>0.53, p<0.001) and ΔJ45 (r>0.42, p=0.003) among eyes with high post–LASIK astigmatism (>0.75 D). Conclusions: Post–LASIK SA was significantly correlated to post–LASIK hyperopia. Eyes with greater preoperative positive SA, have a greater reduction in SA but also tend to be more hyperopic. Eyes with greater negative SA tend to become more emmetropic or myopic. Increased 3rd RMS was associated with post–LASIK residual astigmatism. The role of HOA, especially SA, on post–LASIK refractive outcome is discussed from a biomechanical perspective.
This PDF is available to Subscribers Only