Comparing the contrast sensitivity of a modified prolate anterior surface IOL and of two spherical IOLs.

PURPOSE To compare the contrast sensitivity of an intraocular lens (IOL) with a modified prolate anterior surface (Tecnis Z9000, Pfizer), with 2 standard spherical IOLs (Sensar AR40e Opti-Edge IOL, AMO and AcrySof Natural SN60AT IOL, Alcon). METHODS In this prospective study, 98 eyes of 71 patients received 1 of 3 IOLs at random. After 6 months, best corrected visual acuity, pupil size and contrast sensitivity under mesopic and photopic conditions were measured. RESULTS No statistically significant differences in preoperative and postoperative refractive error and best corrected visual acuity existed between the groups. When comparing the Tecnis IOL with the AR40e IOL, contrast sensitivity testing showed significantly better results in the Tecnis group at 3 and 12 cpd in photopic conditions; at 3, 12 and 18 cpd in photopic with glare; at 3, 12 and 18 cpd in mesopic and at 12 and 18 cpd in mesopic with glare. The Tecnis IOL provided significantly better contrast sensitivity at almost all spatial frequencies in any lighting condition in comparison with the SN60AT IOL. CONCLUSION Implantation of a modified prolate IOL may improve quality of vision as demonstrated by our clinical results of contrast sensitivity testing. In this study, we found a better performance of the Tecnis IOL under both photopic and mesopic conditions, compared to the results of the AR40e and the SN60AT IOL.