Navigation Links
Air exposure between blinks affects deposits on contact lenses
Date:11/5/2012

Philadelphia, Pa. (November 5, 2012) - 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. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

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 depositionthus 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."

To read the article "The Impact of Intermittent Air Exposure on Lipid Deposition", please visit http://journals.lww.com/optvissci/Fulltext/2012/11000/The_Impact_of_Intermittent_Air_Exposure_on_Lipid.6.aspx

Optometry and Vision Science for the iPad app is available as a free download from the iTunes App Store. For a limited time, all users will have free full content to the current issue. After the free introductory period, American Academy of Optometry members and subscribers will continue to enjoy full access via a simple login process. Each issue will be posted on the same schedule as the current online and print editions.


'/>"/>
Contact: Connie Hughes
Connie.Hughes@wolterskluwer.com
646-674-6348
Wolters Kluwer Health
Source:Eurekalert

Related medicine news :

1. Redheads May Face Higher Risk of Melanoma, Even Without Sun Exposure
2. Gestational exposure to urban air pollution linked to vitamin D deficiency in newborns
3. Pregnancy exposures determine risk of breast cancer in multiple generations of offspring
4. Lights off? International experts call attention to dangers of exposure to light at night
5. Prenatal exposure to pesticide additive linked with childhood cough
6. Repeated exposure to traumatic images may be harmful to health
7. Use of regional PACS network associated with lower repeat rates, costs and less radiation exposure
8. Study suggests possible association between cardiovascular disease, chemical exposure
9. Frequent MRI Scanner Exposure Might Affect Memory: Study
10. Mold Exposure in Infancy May Raise Asthma Risk
11. Chronic exposure to staph bacteria may be risk factor for lupus, Mayo study finds
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... 2016 , ... Conventional wisdom preaches the benefits of moderation, whether it’s a ... the bar too high can result in disappointment, perhaps even self-loathing. However, those who ... , Research from PsychTests.com reveals that behind the tendency to set ...
(Date:6/24/2016)... ... ... was in a crisis. Her son James, eight, was out of control. Prone to extreme ... “When something upset him, he couldn’t control his emotions,” remembers Marcy. “If there was ... other children and say he was going to kill them. If we were driving ...
(Date:6/24/2016)... , ... June 24, 2016 , ... Comfort Keepers® of ... Cancer Society and the Road To Recovery® program to drive cancer patients to and ... other adults to ensure the highest quality of life and ongoing independence. Getting ...
(Date:6/24/2016)... ... June 24, 2016 , ... The Haute Beauty Network, affiliated ... Weintraub as a prominent plastic surgeon and the network’s newest partner. , ... most handsome men, look naturally attractive. Plastic surgery should be invisible.” He stands ...
(Date:6/24/2016)... ... June 24, 2016 , ... Venture Construction Group (VCG) sponsors Luke’s ... June 20th at the Woodmont Country Club at 1201 Rockville Pike, Rockville, Maryland, 20852. ... helping service members that have been wounded in battle and their families. Venture Construction ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... -- According to a new market research ... Safety Pen Needles), Needle Length (4mm, 5mm, 6mm, 8mm, ... Purchase (Retail, Non-Retail) - Trends & Global Forecasts to ... for the forecast period of 2016 to 2021. This ... 2021 from USD 1.65 Billion in 2016, growing at ...
(Date:6/23/2016)... HOUSTON , June 23, 2016  MedSource ... platform as its e-clinical software solution of choice.  ... the best possible value to their clients by ... nowEDC.  The preferred relationship establishes nowEDC as the ... pricing for MedSource,s full-service clients.  "nowEDC has long ...
(Date:6/23/2016)...  In a startling report released today, National Safety Council ... a comprehensive, proven plan to eliminate prescription opioid overdoses. ... states are tackling the worst drug crisis in recorded U.S. history, ... Kentucky , New Mexico , ... the 28 failing states, three – Michigan , ...
Breaking Medicine Technology: