Featured Research

from universities, journals, and other organizations

Air exposure between blinks affects deposits on contact lenses

Date:
November 5, 2012
Source:
Wolters Kluwer Health: Lippincott Williams & Wilkins
Summary:
Modern contact lens materials are prone to drying when exposed to air, which contributes to the buildup of deposits on contact lenses, according to a new study.

Modern contact lens materials are prone to drying when exposed to air, which contributes to the buildup of deposits on contact lenses, according to a study -- "The Impact of Intermittent Air Exposure on Lipid Deposition," appearing in the November issue of Optometry and Vision Science, official journal of the American Academy of Optometry.

Related Articles


With significant differences between materials, the buildup of lipid deposits on contact lenses is affected by "intermittent air exposure" between blinks, according to Holly Loretz, PhD, and colleagues of the Centre for Contact Lens Research at University of Waterloo, Ont., Canada. The findings may help in developing new materials that are less prone to drying and lipid deposition -- thus increasing the chances of successful contact lens wear.

Air Exposure Leads to Increased Lipid Deposits on Contact Lenses The researchers built a new experimental setup, called the "model blink cell," to examine factors affecting the buildup of lipid (fatty) deposits on contact lenses. The model blink cell was designed to cycle contact lens materials in and out of an artificial tear solution containing trace amounts of cholesterol or other lipids naturally present in tear fluid.

To mimic the effects of routine lens wear, six different contact lens materials were subjected to simulated blinks and eyelid motion for varying periods. The researchers analyzed the effects of air exposure between "blinks" on the buildup of lipid deposits.

For most of the materials tested, air exposure led to increased lipid deposits. Compared to lenses that remained submerged in the artificial tear solution, the amount of cholesterol deposited on lenses was about three times greater with air exposure. For another type of lipid (phosphatidylcholine), lipid deposition was about 40 percent greater with intermittent air exposure.

Today's sophisticated contact lens materials have molecular characteristics related to "wettability" that seem to contribute to a cycle of lipid deposition that is encouraged by repeated wetting and drying. "This wetting/de-wetting cycle can occur after every blink and therefore thousands of times a day, thus allowing lipid to continuously accumulate on and in the lens material," Dr Loretz and coauthors write.

What does it all mean for contact lens wearers? "Contact lenses gather deposits during wear and contribute to discomfort and how successful the lenses are for the wearer," explains Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science. "Dry eyes can also negatively affect the chances of successful contact lens wear."

Although no laboratory model can fully simulate the effects of real-life contact lens wear, the model blink cell improves on previous approaches by accounting for the drying effects of intermittent air exposure. The effects of drying on lipid deposition may be even more important with today's sophisticated hydrophobic ("unwettable") lens materials.

"The model blink cell device allows clinical researchers to move beyond the current relatively simple in vitro models for studying deposits to a more real-life modeling of a contact lens on the eye, particularly with today's more hydrophobic silicon component hydrogel lenses," Dr Adams adds. "The authors are hopeful that this will allow research that could be expected to provide improved comfort in contact lens wear."


Story Source:

The above story is based on materials provided by Wolters Kluwer Health: Lippincott Williams & Wilkins. Note: Materials may be edited for content and length.


Journal Reference:

  1. Holly Lorentz, Miriam Heynen, Warda Khan, Diana Trieu, Lyndon Jones. The Impact of Intermittent Air Exposure on Lipid Deposition. Optometry and Vision Science, 2012; 89 (11): 1574 DOI: 10.1097/OPX.0b013e31826c6508

Cite This Page:

Wolters Kluwer Health: Lippincott Williams & Wilkins. "Air exposure between blinks affects deposits on contact lenses." ScienceDaily. ScienceDaily, 5 November 2012. <www.sciencedaily.com/releases/2012/11/121105114507.htm>.
Wolters Kluwer Health: Lippincott Williams & Wilkins. (2012, November 5). Air exposure between blinks affects deposits on contact lenses. ScienceDaily. Retrieved November 22, 2014 from www.sciencedaily.com/releases/2012/11/121105114507.htm
Wolters Kluwer Health: Lippincott Williams & Wilkins. "Air exposure between blinks affects deposits on contact lenses." ScienceDaily. www.sciencedaily.com/releases/2012/11/121105114507.htm (accessed November 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, November 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) Researchers find that as people approach new decades in their lives they make bigger life decisions. Video provided by Newsy
Powered by NewsLook.com
Ebola: Life Without School in Guinea

Ebola: Life Without School in Guinea

AFP (Nov. 21, 2014) Following the closure of schools and universities in Guinea because of the Ebola virus, students look for temporary work or gather in makeshift classrooms to catch up on their syllabus. Duration: 02:14 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins