This web site is no longer actively maintained.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

Feature Review | Previous Articles
November 2003


Therapeutic Use of Bausch & Lomb PureVision Contact Lenses. Li Lim, Donald Tiang Hwee Tan, and Wing Kwong Chan. CLAO 2001: 27(4):179-185

Kathryn Dumbleton -
BSc (Hons), Uni of Wales1984 MCOptom 1985, MSc Uni of Waterloo 1988

Senior Researcher
Centre for Contact Lens Research (CCLR)
University of Waterloo, Ontario, Canada


Manuscript review by Kathy Dumbleton.

Although required by a relatively small proportion of wearers, contact lenses for therapeutic purposes are a very important indication for contact lens wear. Historically high water or thin, mid water content hydrogel contact lenses were used for these applications 1 since therapeutic lenses are generally worn for prolonged periods and overnight. Unfortunately these lenses were not able to supply sufficient oxygen to prevent overnight corneal swelling and the combined effects of anoxia and already compromised eyes often resulted in complications including infection and inflammation 2,3 . Silicone elastomer lenses were also occasionally used for some conditions, however these lenses, although capable of providing sufficient oxygen to prevent overnight corneal swelling, unfortunately often resulted in lens adhesion and poor wetting 4 .

The introduction of silicone hydrogel lenses has provided clinicians with a viable alternative for their therapeutic cases since the high oxygen transmissibility of these lenses has been shown to result little additional overnight corneal swelling when compared to that measured following sleep with no lens in place. Both CIBA Vision's Focus Night & DayT and Bausch & Lomb's PureVision T lenses, in addition to being currently approved for continuous wear, have also received FDA and CE Mark approval for therapeutic use throughout the U.S., Canada and the European Union.

Since therapeutic treatment with contact lenses is relatively uncommon and varied in nature, it is somewhat difficult to evaluate the efficacy of specific lens types for these patients in clinical practice. In order to investigate this application for silicone hydrogel lenses, a group of clinicians and researchers from the Singapore National Eye Centre conducted a prospective clinical trial to evaluate the efficacy of PureVision T contact lenses in a continuous wear modality for therapeutic indications 5 . Lim and co-authors report on 54 cases in which PureVision T lenses were prescribed for pain relief, enhancement of corneal wound healing, corneal protection, improvement of vision and corneal sealing. The efficacy of the treatment was then rated at the conclusion of the treatment process. Patients rated the amount of pain relief as being: complete, considerable, fair, slight or none. Wound healing was rated by the clinicians as being: completely healed, partially healed, remaining the same or getting worse. In cases of corneal protection, clinicians rated the protection given by the lenses as being: effective, partially effective or not effective. For visual improvement and corneal sealing cases the results were simply reported to be either effective or not effective. In many cases therapeutic lenses were indicated for more than one reason.

Ninety six percent of the 28 patients requiring therapeutic lenses for pain relief reported complete or considerable relief with the PureVision T lenses. 83% of 40 patients requiring lenses for wound healing demonstrated complete healing and 13% demonstrated partial healing. One patient showed no change (2.5%) and one patient's condition became worse, but in this case the lens had been removed prematurely. One hundred percent of the lenses (21 patients) prescribed for corneal protection achieved this goal effectively. Wound sealing was effectively achieved in 4 of the 5 patients requiring this treatment. The unsuccessful patient had a large perforation which required a penetrating keratoplasty. The two bullous keratopathy patients requiring therapeutic lenses for visual improvement both achieved effective results.

There were only two complications reported during the study, one case of sterile peripheral infiltrates and one mechanical disturbance of an epithelial defect as a result of the lens fit being too lose. Both resolved without further sequelae.

The authors concluded that the PureVision T lenses were highly efficacious in bandage lens functions and since conducting the study these lenses have become the authors' primary bandage lens of choice in corneal, external disease and refractive surgery. A comparison with conventional bandage lenses was not made since there was no control group in this study. Consequently historical controls have to be considered when comparing the efficacy of silicone hydrogel therapeutic lenses for the treatment of corneal disturbances. Unfortunately this is problematical since a number of different measures of success have been used in reporting these data and patients' subjective perceptions also vary considerably. In addition, the inclusion and exclusion criteria employed in clinical trials of this nature can have a marked impact on the success of the treatment. In the study conducted with conventional therapeutic lenses by Jackson et al 1 , an overall success rate of 78% for all cases was reported, measured by partial or full goal achievement. Other studies have reported success rates from 60% 2 to 92% 6 .

To date, this is the only study of its kind investigating silicone hydrogel lenses in therapeutic applications. Other studies with both the Focus Night & Day T lenses and PureVision T lenses are sure to follow but in the meantime practitioners can apparently be confident in prescribing these lens types for their patients requiring therapeutic contact lenses.


1. Jackson AJ, Sinton JE, Frazer DG and Morrison E. Therapeutic contact lenses and their use in the management of anterior segment pathology. J Br Contact Lens Assoc . 1996; 19(1):11-19.

2. Dohlman CH. Complications in therapeutic soft contact lens wear. Trans Am Acad Ophthalmol Otol . 1974; 78:399-405.

3. Kent HD, Cohen EJ, Laibson PR and Arentsen JJ. Microbial keratitis and corneal ulceration associated with therapeutic contact lenses. CLAO J .1990; 16(1):49-52.

4. Rae S and Huff J. Studies on the initiation of silicone elastomer lens adnesion in vitro: binding before the indentation ring. CLAO J . 1991; 17(3): 181-186.

5. Lim L, Tan DTH, and Chan WK. Therapeutic use of Bausch & Lomb PureVision T contact lenses. CLAO J . 2001: 27(4):179-185.

6. Smiddy WE, Hamburg TR, Kracher GP, Gottsch JD and Stark WJ. Therapeutic contact lenses. Ophthalmology . 1990; 97(3):291-295.

All rights reserved, copyright 2002 - 2007