Contrast sensitivity in extended wear of the Boston IV lens.

Journal Article (Journal Article)

Over a one-year period we evaluated subjective and objective factors associated with extended wear of Boston IV rigid gas permeable contact lenses. Patients wore the lens on an extended wear schedule, with removal at 2-week intervals for cleaning. We performed keratometry and endothelial cell counts and measured visual acuity, contrast sensitivity, refraction, and corneal thickness at the initial visit (with patients wearing their former glasses or soft or hard lenses) and again at 6 and 12 months (with patients wearing the Boston IV lens). Twenty-four of 31 patients (77%) completed the study. All measured parameters were checked for statistically significant change over time. Contrast sensitivity increased at all spatial frequencies tested, with the largest increments occurring at higher frequencies (P less than .001). The other parameters showed no significant changes (P greater than .05). Our data support the use of contrast sensitivity for qualitative assessment of visual function among contact lens wearers and suggest that contrast sensitivity testing may prove to be a more effective means of evaluating visual acuity in contact lens wearers over time than Snellen acuity.

Full Text

Duke Authors

Cited Authors

  • Ziel, CJ; Gussler, JR; Van Meter, WS; Schmeisser, E; Litteral, G

Published Date

  • 1990

Published In

Volume / Issue

  • 16 / 4

Start / End Page

  • 276 - 278

PubMed ID

  • 2249346

International Standard Serial Number (ISSN)

  • 0733-8902


  • eng

Conference Location

  • United States