RESUMO
To compare spherical aberration and contrast sensitivity with two different types of aspheric posterior chamber intraocular lenses [PCIOLs]: Tecnis Z9000 versus Akreos AO. Thirty-four eyes of 34 patients undergoing phacoemulsification for senile cataracts were randomly assigned to implantation of Tecnis Z9000 or Akreos AO PCIOLs. Outcome measures included best-corrected visual acuity [BCVA], spherical aberration [SA] with 4 and 6 mm pupil diameters and contrast sensitivity under photopic and mesopic conditions at spatial frequencies of 1, 2, 5, 10 and 20 cycles per degree [cpd] three months postoperatively. Mean BCVA was 0.08 +/- 0.08 logMAR in the Tecnis Z9000 group and 0.11 +/- 0.09 logMAR in the Akreos AO group [P=0.33]. SA was less with Tecnis than Akreos AO with 4 and 6 mm pupil diameter [0.14 +/- 0.10 micro m vs 0.28 +/- 0.09 micro m, P < 0.001 and 0.30 +/- 0.18 micro m vs 0.33 +/- 0.08 micro m, P=0.4, respectively]. Contrast sensitivity was significantly higher in the Tecnis Z9000 group at 1, 2, 5 and 10 cpd under photopic and at 1, 2 and 10 cpd under mesopic conditions. Tecnis Z9000 IOL seems to entail better visual outcomes in terms of spherical aberration and contrast sensitivity as compared to Akreos AO