Abstract
Purpose: :
To determine the role of corneal and internal higher order aberrations on objective depth-of-focus in pseudophakic patients. To assess respective contribution of aberrations to pseudo-accommodation in pseudophakic patients with monofocal aspheric IOLs.
Methods: :
This study included 60 eyes (40 patients) that received an aspherical IOL (AcriSmart 36A® or AcriSmart 46LC® or Quatrix®) after a micro-incision cataract surgery. 6 months postoperatively, total and corneal aberrations for a standardized pupil size of 6 mm were computed using Wavescan Aberrometer (AMO, USA) and Atlas® topographer (Carl Zeiss Meditec, USA). Depth of focus (DOF) and degree of apparent accommodation were obtained when the defocused visual acuity becomes half of the best corrected visual acuity (BCVA) with MTF measurements (defined as the range of defocus in which MTF is greater than 80% of maximal MTF) using the Objective Quality Analysis System® (Visiometrics, Spain).
Results: :
Results demonstrated that DOF appeared to be strongly correlated with SA (r2=0,52 with p=0,002) and with trefoil (r2=0,53 with p=0,001). However, DOF was not correlated with coma values (r2 = 0,002 with p=0,87). Influence of refractive astigmatism will be also presented.
Conclusions: :
Higher order aberrations should be measured preoperatively. Indeed, high level of corneal trefoil may be advantageous for DOF even if we reduced total residual SA close to zero. The relationship of all HOA on image quality and DOF has to be considered.
Keywords: aberrations • cataract • visual acuity