Featured Research

from universities, journals, and other organizations

Morning vs nighttime replacement affects adverse events with extended-wear contact lenses

Date:
December 10, 2012
Source:
Wolters Kluwer Health: Lippincott Williams & Wilkins
Summary:
For people using 30-day extended-wear/continuous-wear (EW/CW) contact lenses, replacing lenses at night doesn't lower the risk of complications compared to changing lenses monthly, suggests a new study. In contrast, replacing lenses every morning reduces the overall rate of "ocular adverse events."

For people using 30-day extended-wear/continuous-wear (EW/CW) contact lenses, replacing lenses at night doesn't lower the risk of complications compared to changing lenses monthly, suggests a new study.

In contrast, replacing lenses every morning reduces the overall rate of "ocular adverse events," reports the study by Jerome Ozkan, Boptom of Brien Holden Vision Institute, Sydney, and colleagues. The researchers write, "Contact lens wearers on an EW/CW schedule should be advised to minimize lens handling prior to sleep to reduce the risk of complications."

Morning or Night versus Monthly Lens Replacement

The "proof of concept" study evaluated the effects of morning versus night replacement and lens handling in 215 patients using silicone hydrogel EW/CW contact lenses. Extended/continuous wear lenses are designed to be worn continuously for up to a month, including overnight. But in the study, patients put in fresh EW/CW lenses every day -- either at night before going to sleep or in the morning after waking.

At regular clinic visits, adverse events were compared for patients who replaced their lenses in the morning or at night. Adverse event rates were compared to those in a similar, previously studied group of patients who wore EW/CW lenses continuously for a month.

The results showed a lower overall adverse event rate for patients who replaced their lenses each morning: about four percent, compared to nearly nine percent with one month of continuous wear. Morning lens replacement was specifically associated with a lower rate of mechanical adverse events, such as scratches and abrasions of the cornea: less than one percent, compared to a little over five percent with monthly replacement.

In contrast, the adverse event rate for patients who replaced their lenses nightly was about eight percent -- not significantly different from the rate for monthly lens replacement. Inflammatory adverse events (such as redness and irritation of the eye) were somewhat less common with morning lens replacement, although the difference was not significant.

Lens Handling Linked to Contamination Microbiology studies in a subgroup of patients found that lenses were frequently colonized with Staph bacteria after handling. In the one-month study, there were no major complications, including the rare but serious infection microbial keratitis.

Extended wear/continuous wear contact lenses are a convenient alternative to daily-wear lenses, avoiding the need for daily lens removal, cleaning, and replacement. Although EW/CW lenses are generally safe, the risk of complications is higher than with daily-wear lenses. Extended wear may provide more time for bacteria to colonize the lens and cause infections.

"The benefit of a fresh lens at night might be partially negated by contamination of the contact lens due to lens handling prior to overnight eye closure," comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science. "At night, with closed eyes, there is less oxygen getting to the cornea and reduced 'lid wiper' cleaning effect on the lenses."

The new study suggests that replacing lenses in the morning reduces complications related to EW/CW lens wear. "Unfortunately, replacing lenses at night does not appear to have any beneficial effect, perhaps due to the side effects of handling lenses just prior to overnight eye closure," Dr Ozkan and coauthors write. They suggest that, when users do replace EW/CW lenses, they should do so in the morning -- and in any case, should avoid handling lenses before they go to sleep at night.


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. Jerome Ozkan, Mark D.P. Willcox, Percy Lazon de la Jara, Preeji S. Mandathara, Varsha M. Rathi, Varghese Thomas, Brien A. Holden. The Effect of Daily Lens Replacement During Overnight Wear on Ocular Adverse Events. Optometry and Vision Science, 2012; 89 (12): 1674 DOI: 10.1097/OPX.0b013e31827731ac

Cite This Page:

Wolters Kluwer Health: Lippincott Williams & Wilkins. "Morning vs nighttime replacement affects adverse events with extended-wear contact lenses." ScienceDaily. ScienceDaily, 10 December 2012. <www.sciencedaily.com/releases/2012/12/121210101337.htm>.
Wolters Kluwer Health: Lippincott Williams & Wilkins. (2012, December 10). Morning vs nighttime replacement affects adverse events with extended-wear contact lenses. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2012/12/121210101337.htm
Wolters Kluwer Health: Lippincott Williams & Wilkins. "Morning vs nighttime replacement affects adverse events with extended-wear contact lenses." ScienceDaily. www.sciencedaily.com/releases/2012/12/121210101337.htm (accessed July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Xtreme Eating: Your Daily Caloric Intake All On One Plate

Xtreme Eating: Your Daily Caloric Intake All On One Plate

Newsy (July 30, 2014) The Center for Science in the Public Interest released its 2014 list of single meals with whopping calorie counts. Video provided by Newsy
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:
from the past week

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