Clinical Trial: Spherical Aberration and Contrast Sensitivity in IOLs
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: Spherical Aberration and Contrast Sensitivity in Eyes Implanted With Aspheric and Spherical Intraocular Lenses: Clinical Comparative Study
Brief Summary:
Purpose: To determine whether implantation of an intraocular lens (IOL) with a modified anterior aspheric surface results in reduced spherical aberration and improved contrast sensitivity after cataract surgery.
Design: Prospective, comparative, interventional case series.
Methods: In an intraindividual randomized prospective study of 25 patients with bilateral cataract, an IOL with a modified anterior surface (Tecnis Z9001, AMO- Group 1) was compared with biconvex lens with spherical surfaces (ClariFlex®, AMO- Group 2). Ocular aberrations for a 5.0 mm pupil and 6.0 mm pupil were measured with Hartmann-Shack aberrometer. Quality of vision was measured by visual acuity and contrast sensitivity under mesopic and photopic conditions. All patients were followed for 3 months.
Detailed Summary:
With improvement in the quality of life and the resulting expansion of the elderly population, the prevalence of cataract cases will continue to rise. The population is on average older, and the environment has become more demanding for older people, who therefore need to regain excellent quality of vision. Advances in both IOL and phacoemulsification technology have enable cataract surgery to evolve from a procedure concerned with the safe removal of the cataract to a procedure refined to achieve the best possible postoperative refractive result.
Snellen visual acuity insufficiently describes the quality of the eye's optics before and after cataract surgery. 1-3 Multiple scientific studies have demonstrated that contrast sensitivity represents a robust indicator of functional vision. 4-7 The contrast sensitivity function, measured under varying conditions of luminance and glare, establishes the limits of visual perception across the spectrum of spatial frequencies.
Studies have demonstrated a nearly linear decline in image quality with age, suggesting a significant increase in the optical aberrations in the eye over time. 8-9 Advances in wavefront technology have opened a new door to the measurement of ocular aberrations. 9-10 Also, this technology allowed the development of a new type of IOL designed to compensate for the positive spherical aberration of the cornea, which is one of the most important aberrations contributing to visual deterioration of the pseudophakic eye. 11-14 Based on these findings, the approach to compensate for increasing spherical aberration in older eyes is to develop an IOL that introduces negative spherical aberration into the system. Such an IOL, the Tecnis Z9001® IOL (Model Z9001, Advanced Medical Optics, Santa Ana, CA), has been developed by AMO. This is a polysiloxane foldable 3-piece
Sponsor: Federal University of Minas Gerais
Current Primary Outcome: To determine whether implantation of an intraocular lens (IOL) with a modified anterior aspheric surface results in reduced spherical aberration and improved contrast sensitivity after cataract surgery [ Time Frame: within the first 30 days of surgery ]
Original Primary Outcome: Same as current
Current Secondary Outcome:
Original Secondary Outcome:
Information By: Federal University of Minas Gerais
Dates:
Date Received: December 18, 2007
Date Started: February 2005
Date Completion:
Last Updated: October 17, 2008
Last Verified: December 2007
