Abstract
Purpose::
To demonstrate the relation between preoperative higher order aberrations and postoperative sphere, astigmatism and higher order aberrations.
Methods::
We analyzed the relationship between preoperative individual higher order aberrations and postoperative sphere, astigmatism and higher order aberrations when treating with Bausch and Lomb wavefront guided Zyoptix customized ablation in 330 eyes of 183 subjects analyzed preop, 1,3 and 6 months postoperatively. Statistical evaluation using a generalized linear mixed effects model and generalized estimating equation were use to analyze the data. The level of significance was P ≤0.05 for all associations.
Results::
Preoperative vertical coma (Z,3,1,1) was associated with postop horizontal coma and vertical coma. Preoperative horizontal coma (Z 3,1,0) was associated with postoperative horizontal coma. Both vertical and horizontal coma were under corrected. Horizontal and vertical trefoil were associated with postoperative horizontal and vertical trefoil respectively which resulted from an under correction of each Zernike term. Preoperative secondary astigmatism terms (Z,4,2,0 and Z,4,2,1) was associated with the identical postoperative secondary astigmatism term and these associations were also related to under corrections of the respective Zernike terms. Preoperative coma affects postoperative astigmatism and postoperative defocus. Preoperative spherical aberration affects postoperative coma. Eyes with greater preoperative horizontal coma were more likely to have postoperative astigmatism. (All values p ≤ 0.05)
Conclusions::
Customized treatment of preoperative higher order aberrations causes secondary effects on sphere, cylinder and postoperative higher order aberrations. Refinement of higher order aberration correction algorithms results in improved predictability.
Keywords: refractive surgery: other technologies