Abstract
Abstract: :
Purpose:To study the improvement of visual acuity (VA), low contrast visual acuity (LCVA) and contrast sensitivity (CS) in emmetropic and myopic patients wearing wavefront guided spectacle lenses. Methods:Low and high–order wavefront measurements were acquired from 60 eyes of 30 emmetropic subjects (20/25 or better UCVA, age 19–60) and 20 eyes of 10 myopic patients (–7.25 to –0.25D, age 38–58) using a new wavefront refractor (Ophthonix Inc., San Diego, CA). Based on these wavefront measurements, two sets of spectacle lenses per eye were made using a new programmable lens material (Z–Lens, Ophthonix Inc., San Diego, CA), one set correcting for any low order aberrations only (Placebo), the second set correcting for both low and high order aberrations (Z–Lens). For each eye and each lens set, VA, Low Contrast VA, and CS were determined (VectorVision, Arcanum, OH) in a double masked study. Results:In the emmetropic group, visual acuity (p=0.048), low contrast visual acuity (p=0.002), and contrast sensitivity (p=0.009 @ 6c/d) were significantly improved by correcting high order aberrations with the Z–Lens. Even higher significance levels were found for the vision improvement in myopes (VA: p=0.0008, LCVA: p=0.004, CS p=0.007 @ 6c/d, p=0.004 @ 12c/d, p=0.0009 @ 18 c/d). No placebo effect was found in any of the tests. Conclusions:A new programmable spectacle lens was developed that is capable of correcting patient’s low and high order aberrations. Correcting high order aberrations significantly improves visual acuity, low contrast visual acuity and mid to high frequency contrast sensitivity.
Keywords: refraction • visual acuity • contrast sensitivity