This web site is no longer actively maintained. Please visit for up to date information.
Powered by Google
This Month
Ocular Surface Characteristics of the Asian Eye
Meeting Synopsis
Academy 2010
pective Analysis of Risk Factors Associated With Contact Lens Induced Inflammatory Events During Continuous Wear
Feature Review
Adequate tear mixing under a soft contact lens may play an important role in minimizing certain > more
Tell a friend
> Home
> About Us
> Affiliates
> Contact Us
> Disclaimer
> Site Map


The Silicone Hydrogels website is partially supported through an educational grant from CIBA VISION

March 2004



Joel A. Silbert, Bethany James Pennsylvania College of Optometry



To objectively and subjectively compare two continuous wear (CW) silicone hydrogel lenses during a 30 day wear period.

20 healthy subjects, all previously adapted soft lens wearers, with manifest refraction between -1.00 D. and -7.50 D. and with less than 1 D. of astigmatism, wore lenses on a 30 day CW schedule, with weekly followup. In this single masked study, patients were randomly assigned to a Bausch & Lomb PureVisionT lens in one eye, and a Ciba Focus Night & DayT in the other. Subjective responses were evaluated through standardized questionnaires. Physiological responses, lens movement and post-lens debris were evaluated through pachymetry and biomicroscopy respectively. RESULTS. 17 subjects completed the CW trial. One dropout was due to an unexplained persistent headache, one due to a CLPU (contact lens peripheral ulcer), and one due to a preseptal cellulitis secondary to a foreign body unrelated to lens wear. Neither lens demonstrated a significant difference between initial and final pachymetry, with slight adaptive increases in overnight edema compared to baseline. Lens movement for each lens remained constant throughout the study. Mild hyperemia was noted in 32% of subjects, with increasing levels of deposits by week four. Dryness levels and comfort were similar in both lens types. Other than one case of CLPU, there were no cases of infiltrative keratitis, CLARE, CLPC, MK, or SEAL in this short-term study.
Bacterial products alone failed to produce corneal lesions in contact lens wearing eyes. Corneal ulcers may be produced only in the presence of live S. aureus, and a superficial trauma on the corneal surface was required to generate such corneal ulcer. The corneal lesions demonstrated mild to moderate inflammatory reaction clinically; they occurred more frequently in peripheral cornea than in central cornea and healed without the need of antibiotics.
Both lenses displayed good clinical performance, subjective comfort, and physiological tolerance, with no significant hypoxia differences between lens types or after lens wear compared to baseline. Subjective symptoms of dryness were the most reported. Subjects exhibited no significant lens preference. Although both products can be safely prescribed for up to 30 days continuous wear, individual patient prescribing patterns should be followed, with close monitoring of all subjects on a continuous wear regimen.
Download PDF of Poster:
What are the factors contributing to the occurrence of contact lens induced peripheral ulceration (CLPU):- 81 KB
You will need Version 4 or later of Adobe Acrobat Reader to view some documents on this site. You can get the latest version from the Adobe Home site. 


All rights reserved, copyright 2002 - 2007