« Pigment dispersion and Artisan phakic intraocular lenses: Crystalline lens rise as a safety criterion | Main | Choosing the Location of Corneal Incision Based on Preexisting Astigmatism in Phacoemulsification »
May 23, 2005
Effect of cataract surgery incision location and intraocular lens type on ocular aberrations
JCRS April 2005
This study comprised 74 subjects; 17 were phakic with no ocular pathology, 20 had implantation of a Pharmacia 722C PMMA IOL through a scleral tunnel, 21 had implantation of an Alcon AcrySof IOL through a scleral tunnel, and 16 had implantation of an AcrySof IOL through a corneal incision. Visual acuity and contrast sensitivity testing, ocular optical quality measurement using Hartmann-Shack wavefront sensing, and corneal surface measurement with a videokeratoscope were performed in all cases.ResultsThere were significant differences between groups in the total root-mean-square (RMS) wavefront aberration over a 6.0 mm pupil (F = 3.91; degrees of freedom = 3,70; P<.05) mediated at the 4th-order RMS, specifically spherical and tetrafoil aberrations. The PMMA–scleral group had the least aberrations and the AcrySof-corneal group the most. For a 3.5 mm diameter pupil, the total higher-order RMS wavefront aberration was not significantly different between the groups (P>.05). There were no differences between groups in corneal shape, visual acuity, or contrast sensitivity.ConclusionsImplantation of the spherical PMMA IOL led to a slight reduction in total wavefront aberration compared to phakic eyes. AcrySof IOLs induced more aberrations, especially spherical aberration. Corneal-based incisions for IOL implantation compounded this increase. Studies of the optical performance of IOLs in vivo should use wavefront sensing as the main outcome measure rather than visual measures, which are readily confounded by multiple factors.
Posted by mehdi khanlari at May 23, 2005 11:06 PM