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Risk Behaviors for Contact Lens–Related Eye Infections Among Adults and Adolescents — United States, 2016

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Abstract

What is already known about this topic? In 2015, CDC established that there were approximately 41 million contact lens wearers aged =18 years in the United States, the majority of whom engaged in behaviors that put them at risk for serious eye infections. What is added by this report? In 2016, there were an estimated 3.6 million adolescents aged 12–17 years in the United States who wore contact lenses. Of the adolescents who wore contact lenses, 85% reported at least one behavior that put them at risk for a contact lens–related eye infection, compared with 81% of young adults, and 88% of older adults. What are the implications for public health practice? Although adolescent contact lens wearers engage in some healthier contact lens hygiene behaviors than do their adult counterparts, there is room for improvement in order to prevent potentially serious outcomes including blindness. Prevention efforts should focus on encouraging contact lens wearers to replace their contact lens storage case regularly and to avoid sleeping or napping in contact lenses. © 2017 Department of Health and Human Services, All rights reserved.
Morbidity and Mortality Weekly Report
Weekly / Vol. 66 / No. 32 August 18, 2017
U.S. Department of Health and Human Services
Centers for Disease Control and Prevention
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and Control Among Adults Aged ≥18 Years —
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Environment — Wisconsin, August 2016
864 QuickStats
Continuing Education examination available at
https://www.cdc.gov/mmwr/cme/conted_info.html#weekly.
Contact Lens Health Week —
August 21–25, 2017
August 21–25, 2017, marks the fourth annual Contact
Lens Health Week. In collaboration with partners from the
clinical, public health, industry, and regulatory sectors, CDC
is promoting healthy wear and care practices to reduce the risk
for eye infections among the approximately 45 million persons
in the United States who wear contact lenses. Research after
outbreaks of rare but serious eye infections in the United States
has indicated that these infections occur most often in contact
lens wearers who do not take proper care of their contact lenses,
indicating a need to promote safer wear and care (1,2).
A report in this issue of MMWR describes CDC’s first-
ever population-based estimates of contact lens–related risk
behaviors in persons aged 12–17 years (referred to here as
adolescents) in the United States. Approximately six in seven
adolescents reported at least one behavior (e.g., sleeping in
lenses, swimming, or not replacing lenses and storage cases
as recommended) putting them at risk for a serious contact
lens–related eye infection. Encouraging adolescents to adopt
healthy contact lens wear and care habits might help them
maintain healthy habits into adulthood.
Although most contact lens wearers receive the benefits of
vision correction, contact lenses can pose an infection risk,
especially if they are not worn and cared for properly. Practicing
proper contact lens hygiene and regularly visiting an eye care
provider are important behaviors for keeping contact lens
wearers’ eyes healthy. Additional information on Contact Lens
Health Week and the proper wear and care of contact lenses is
available at https://www.cdc.gov/contactlenses.
References
1. Verani JR, Lorick SA, Yoder JS, et al.; Acanthamoeba Keratitis
Investigation Team. National outbreak of Acanthamoeba keratitis
associated with use of a contact lens solution, United States. Emerg
Infect Dis 2009;15:1236–42. https://doi.org/10.3201/eid1508.090225.
2. Chang DC, Grant GB, O’Donnell K, et al.; Fusarium Keratitis
Investigation Team. Multistate outbreak of Fusarium keratitis
associated with use of a contact lens solution. JAMA 2006;296:953–63.
https://doi.org/10.1001/jama.296.8.953.
Risk Behaviors for Contact
Lens–Related Eye Infections Among
Adults and Adolescents —
United States, 2016
Jennifer R. Cope, MD1; Sarah A. Collier, MPH1;
Hannah Nethercut, MPH1; Jefferson M. Jones, MD1;
Kirsten Yates, MPH1; Jonathan S. Yoder, MSW, MPH1
Contact lens–related eye infections, which can lead to serious
outcomes, including blindness, are associated with several risk
factors, including sleeping in lenses, exposing lenses to water,
not adhering to replacement schedules, and reusing disinfect-
ing solution (1). In some studies, adolescent and young adult
contact lens wearers have been reported to be more likely than
older adult contact lens wearers to develop eye infections (2,3)
and more likely to have poor contact lens hygiene practices (2).
Morbidity and Mortality Weekly Report
842 MMWR / August 18, 2017 / Vol. 66 / No. 32 US Department of Health and Human Services/Centers for Disease Control and Prevention
The MMWR series of publications is published by the Center for Surveillance, Epidemiology, and Laboratory Services, Centers for Disease Control and Prevention (CDC),
U.S. Department of Health and Human Services, Atlanta, GA 30329-4027.
Suggested citation: [Author names; first three, then et al., if more than six.] [Report title]. MMWR Morb Mortal Wkly Rep 2017;66:[inclusive page numbers].
Centers for Disease Control and Prevention
Brenda Fitzgerald, MD, Director
William R. Mac Kenzie, MD, Acting Associate Director for Science
Joanne Cono, MD, ScM, Director, Office of Science Quality
Chesley L. Richards, MD, MPH, Deputy Director for Public Health Scientific Services
Michael F. Iademarco, MD, MPH, Director, Center for Surveillance, Epidemiology, and Laboratory Services
MMWR Editorial and Production Staff (Weekly)
Sonja A. Rasmussen, MD, MS, Editor-in-Chief
Charlotte K. Kent, PhD, MPH, Executive Editor
Jacqueline Gindler, MD, Editor
Teresa F. Rutledge, Managing Editor
Douglas W. Weatherwax, Lead Technical Writer-Editor
Soumya Dunworth, PhD, Kristy Gerdes, MPH, Teresa M. Hood, MS,
Technical Writer-Editors
Martha F. Boyd, Lead Visual Information Specialist
Maureen A. Leahy, Julia C. Martinroe,
Stephen R. Spriggs, Tong Yang,
Visual Information Specialists
Quang M. Doan, MBA, Phyllis H. King,
Paul D. Maitland, Terraye M. Starr, Moua Yang,
Information Technology Specialists
MMWR Editorial Board
Timothy F. Jones, MD, Chairman
Matthew L. Boulton, MD, MPH
Virginia A. Caine, MD
Katherine Lyon Daniel, PhD
Jonathan E. Fielding, MD, MPH, MBA
David W. Fleming, MD
William E. Halperin, MD, DrPH, MPH
King K. Holmes, MD, PhD
Robin Ikeda, MD, MPH
Rima F. Khabbaz, MD
Phyllis Meadows, PhD, MSN, RN
Jewel Mullen, MD, MPH, MPA
Jeff Niederdeppe, PhD
Patricia Quinlisk, MD, MPH
Patrick L. Remington, MD, MPH
Carlos Roig, MS, MA
William L. Roper, MD, MPH
William Schaffner, MD
In 2015, CDC reported the number and demographics of
adult contact lens wearers in the United States to define the
population at risk for contact lens–related eye infections (4);
however, this estimate did not include adolescents. To better
understand this group of younger contact lens wearers and
guide prevention efforts, a population-based survey was used
to assess contact lens wear, care behaviors, risk factors, and
demographics among persons aged 12–17 years (referred to as
adolescents in this report), young adults aged 18–24 years, and
older adults aged ≥25 years in the United States. In 2016, an
estimated 3.6 million adolescents (14.5%) wore contact lenses.
Of the adolescents who wore contact lenses, 85% reported at
least one behavior that put them at risk for a contact lens–
related eye infection, compared with 81% of young adults, and
88% of older adults. These findings can inform the creation of
age-specific targeted prevention messages aimed at contact lens
wearers and establish a baseline for evaluating trends in contact
lens wear, care habits, and contact lens–related risk behaviors.
To describe contact lens wear and care behaviors, risk fac-
tors, and demographics for adolescents and adults in the
United States, the Porter Novelli 2016 summer HealthStyles
and YouthStyles survey, an online survey of 4,548 U.S. adults
(aged ≥18 years) and 1,618 U.S. adolescents (aged 12–17 years)
was used. Adolescent participants lived in the households of
the adult participants.* The 2016 Porter Novelli Styles survey
* Porter Novelli Public Services. Summer HealthStyles and YouthStyles 2016
methodology; Washington, DC.
participants were part of the GfK KnowledgePanel, a nationally
representative online panel with members recruited through
probability-based sampling by postal address. Computer and
Internet access were provided to complete the survey where
needed. For completing this survey and others, households
received rewards points, which they could redeem for prizes
generally worth less than $500. The sample was weighted
on nine factors (sex, age, household income, race/ethnicity,
household size, education, census region, metropolitan status,
and prior Internet access) to match the Current Population
Survey conducted by the U.S. Census Bureau. Participants
were asked to provide demographic and contact lens wearing
information. If they wore contact lenses, they were asked about
contact lens hygiene behaviors and risk factors associated with
contact lens–related eye infections. The question regarding
contact lens hygiene behaviors was “When you wear contact
lenses, which of these actions do you do on a regular basis
(sometimes, most of the time, or always)?”
In 2016, an estimated 3.6 million adolescents aged
12–17 years (14.5% of adolescents), 7.5 million young adults
aged 18–24 years (24.4% of young adults), and 33.9 million
older adults aged ≥25 years (15.5% of adults) in the United
States wore contact lenses. Among lens wearers, 90.4% of
adults and 87.8% of adolescents reported wearing soft contact
lenses (lenses made of soft, flexible plastics that allow oxygen
to pass through to the cornea). No significant demographic
differences between adolescent contact lens wearers and adoles-
cent nonwearers were observed (Table 1). By race, older adult
Morbidity and Mortality Weekly Report
MMWR / August 18, 2017 / Vol. 66 / No. 32 843
US Department of Health and Human Services/Centers for Disease Control and Prevention
TABLE 1. Demographic characteristics of adolescent contact lens wearers (aged 12–17 years), by type of contact lens, compared with adolescent
nonwearers, young adult lens wearers (aged 18–24 years), and older adult lens wearers (aged ≥25 years) — United States, 2016*
Characteristic
% (95% CI)
Adolescent soft CL
wearers
(n = 119)
Adolescent gas
permeable or other
CL wearers
(n = 16)
All adolescent
CL wearers§
(n = 135)
Adolescent
nonwearers
(n = 810)
Young adult
CL wearers
(n = 124)
Older adult
CL wearers
(n = 571)
Sex
Female 52.6 (41.6–63.5) 48.2 (11.8–84.5) 52.3 (41.6–62.9) 48.8 (44.7–52.8) 69.3 (56.8–81.8) 65.2 (60.4–70.0)
Male 47.4 (36.5–58.4) 51.8 (15.5–88.2) 47.7 (37.1–58.4) 51.2 (47.2–55.3) 30.7 (18.2–43.2) 34.8 (30.0–39.6)
Race/Ethnicity
White, non-Hispanic 49.9 (39.0–60.7) 42.3 (6.7–77.9) 48.4 (37.9–58.9) 55.0 (50.9–59.2) 56.7 (42.7–70.6) 66.9 (61.8–71.9)
Hispanic 26.6 (16.1–37.1) 15.7 (0.0–34.4) 25.6 (15.8–35.4) 22.4 (18.5–26.2) 21.1 (9.2–33.0) 11.4 (8.3–14.5)
Black, non-Hispanic 12.0 (3.4–20.6) 42.0 (4.9–79.2) 15.8 (6.4–25.2) 13.5 (10.4–16.6) 7.1 (0.6–13.6) 10.3 (7.2–13.4)
Other or multiracial 11.5 (3.9–19.2) 10.3 (3.4–17.2) 9.1 (6.7–11.5) 15.2 (3.3–27.0) 10.7 (6.5–14.9)
Metropolitan living area
Metro 90.5 (84.8–96.3) 56.9 (18.5–95.3) 86.3 (78.1–94.5) 85.0 (81.8–88.1) 93.6 (86.2–100.0) 86.2 (82.7–89.7)
Nonmetro 9.5 (3.7–15.2) 43.1 (4.7–81.5) 13.7 (5.5–21.9) 15.0 (11.9–18.2) 6.4 (0.0–13.8) 13.8 (10.3–17.3)
Geographic region
Northeast 16.2 (8.0–24.5) 11.6 (0.0–28.7) 15.9 (8.2–23.5) 16.9 (13.9–19.8) 27.5 (15.7–39.2) 17.7 (14.0–21.3)
Midwest 27.4 (18.9–35.9) 22.5 (0.0–50.8) 26.8 (18.5–35.1) 20.4 (17.3–23.4) 24.3 (12.7–35.9) 23.5 (19.4–27.5)
South 36.5 (25.8–47.2) 54.7 (19.8–89.7) 38.3 (27.6–48.9) 37.7 (33.7–41.7) 33.8 (20.6–47.0) 35.6 (30.9–40.4)
West 19.9 (10.5–29.3) 11.2 (0.0–27.1) 19.1 (10.4–27.7) 25.0 (21.3–28.7) 14.4 (4.3–24.6) 23.2 (18.9–27.5)
Abbreviations: CI=confidence interval; CL=contact lens.
* Based on responses to Porter Novelli 2016 summer HealthStyles and YouthStyles surveys with questions on contact lens use and wearer/nonwearer demographics.
Other indicates contact lens wearers who said they wore a type of contact lens not included among the survey choices.
§ Some individual columns do not sum to 100.0 because of rounding.
lens wearers were more likely to be white than were adolescent
lens wearers. No significant geographic region or metropolitan
residency differences were observed for either adolescents or
adults, regardless of lens-wearing status.
At least one contact lens hygiene risk behavior was reported
by older adult (87.5%), young adult (80.9%), and adolescent
(85.3%) lens wearers (Table 2). The most frequently reported
risk behaviors in adolescents were not visiting an eye doctor as
least annually, sleeping or napping in lenses, and swimming
in lenses (Table 2). Among young adults and older adults, the
most frequently reported risk behaviors were replacing lenses
at intervals longer than those prescribed, replacing lens stor-
age cases at intervals longer than those recommended, swim-
ming in lenses, and sleeping or napping in lenses. Adolescents
were significantly less likely to report replacing lenses at
intervals longer than prescribed and replacing lens storage
cases at intervals longer than recommended. Although both
adults and adolescents most commonly reported purchasing
contact lenses through their eye care provider, both young
adults and older adults were more likely than adolescents
to purchase lenses on the Internet. A higher percentage of
young adults (14.6%, 1.1 million) and older adults (11.4%,
3.9 million) than adolescents (4.2%, 152,000) reported ever
experiencing a red or painful eye that required an eye care
provider visit.
Discussion
An estimated one in seven adolescents and one in six adults in
the United States wore contact lenses in 2016, and approximately
six of seven lens wearers reported at least one behavior putting
them at risk for a serious contact lens–related eye infection. Lens
wearers most commonly reported sleeping or napping in lenses,
swimming in lenses, and replacing both lenses and lens storage
cases at intervals longer than those recommended.
A previous study suggested that adolescents and young
adults have lower compliance with contact lens hygiene recom-
mendations and have a greater risk for corneal inflammatory
events, a category of eye problems that includes serious eye
infections (3). Young adults in this survey were significantly
more likely to replace lenses and cases at intervals longer than
those recommended than were adolescents. These findings
might reflect the fact that most adolescents are still living with
their parents who might help to reinforce good contact lens
hygiene practices whereas young adults might have recently
left home and are no longer subject to parental reminders (2).
Young adults also might have fewer resources (e.g., money
and transportation) to regularly visit eye care providers and
obtain hygiene education or regularly replace contact lenses,
lens storage cases, and solution (3). Young adults have been
reported to have poor planning and a more impulsive lifestyle
in relation to contact lens hygiene, possibly related to crowded
Morbidity and Mortality Weekly Report
844 MMWR / August 18, 2017 / Vol. 66 / No. 32 US Department of Health and Human Services/Centers for Disease Control and Prevention
living conditions (e.g., dormitories, living with roommates,
and sharing bathrooms), alcohol consumption, and attitudes
conducive to taking greater risks (2). A higher percentage of
young adults also reported ever having a red or painful eye
while wearing contact lenses, suggesting that poor hygiene
practices might lead to complications.
Engaging in risky contact lens behaviors can lead to poten-
tially serious eye infections (1). Substantial percentages of
adults and adolescents reported noncompliance with recom-
mended contact lens storage case and lens replacement sched-
ules. Infrequent contact lens storage case replacement has been
associated with microbial keratitis (5), and lens wearers who
do not replace their lenses as often as recommended report
more complications and eye discomfort (6). Not replacing
contact lenses and contact lens storage cases as often as recom-
mended increases the risk for contact lens–related eye infections
because recurrent handling of the contact lenses and storage
cases presents the opportunity to introduce microorganisms;
in addition, the moist surfaces of the lens and storage case
provide an environment favorable to microbial growth (7).
Exposing contact lenses to water through swimming or show-
ering increases the risk for infection because microorganisms
living in water can be transferred to the eye. Even household
tap water, although safe for drinking, contains microorganisms
that can contaminate lens cases and contact lenses and cause
eye infections, especially when not replaced at recommended
intervals (8). Sleeping in contact lenses was another commonly
reported risk behavior. Although some soft and rigid contact
lenses have Food and Drug Administration approval for over-
night wear, sleeping in any type of contact lens increases the
risk for eye infections (9).
The findings in this report are subject to at least five limita-
tions. First, respondents were part of a larger survey that was
not specifically focused on contact lens behaviors. Therefore,
participants might not have been representative of contact lens
wearers in the United States. Second, adolescents were sampled
through convenience sampling, specifically those living in the
household of an adult taking the larger survey. This sampling
method led to a small sample size of adolescent respondents.
In addition, the number of young adults in the sample was
small. Third, the sampling method differed from a sample in
a previous report (4) that also asked risk behavior questions
in a different manner (i.e., “ever” versus “regular” behaviors)
and produced differences in the percentage of respondents
reporting outcomes and behaviors. Fourth, because data were
self-reported, respondents might have been reluctant to report
risk behaviors because of social desirability bias. Finally, for
the contact lens hygiene and outcomes questions, no period
was stipulated; this might affect the comparison among age
groups because the duration of contact lens use might differ
and individual practices can change over time.
Although adolescent contact lens wearers reported engag-
ing in some healthier contact lens hygiene behaviors than
their adult counterparts, there is still room for improvement
to prevent potentially serious outcomes, including blindness.
Prevention efforts should focus on encouraging contact lens
TABLE 2. Prevalence of risk behaviors* for contact lens–related eye infections and outcomes among adolescent (aged 12–17 years), young
adult (aged 18–24 years), and older adult (aged ≥25 years) contact lens wearers — United States, 2016
Characteristic
% (95% CI)
Adolescent CL wearers Young adult CL wearers Older adult CL wearers
Risk factor/Behavior
Sleeping or napping in CLs 29.8 (19.7–40.0) 33.3 (20.9–45.7) 32.9 (28.3–37.5)
Topping off solution10.6 (4.9–16.2) 19.1 (8.4–29.8) 11.0 (7.8–14.3)
Replacing lenses at intervals longer than prescribed 23.7§,¶ (14.7–32.6) 52.4 (38.8–66.1) 44.5 (39.7–49.4)
Did not visit eye doctor at least annually 43.9 (33.1–54.6) 24.0 (11.8–36.1) 29.6 (25.0–34.3)
Replacing CL case at interval longer than recommended 22.8§,¶ (14.5–31.2) 40.5 (27.2–53.7) 41.7 (36.9–46.5)
Storing lenses in tap water 9.5 (3.3–15.7) 11.0 (2.1–19.9) 2.3 (0.8–3.8)
Rinsing lenses in tap water 7.1 (2.7–11.5) 12.1 (3.2–21.0) 6.2 (4.2–8.2)
Swimming in CLs 27.2 (18.4–36.0) 28.1 (16.3–40.0) 33.2 (28.7–37.7)
Any risk behavior 85.3 (78.7–91.9) 80.9 (70.0–91.8) 87.5 (84.2–90.7)
Source of purchase
Eye care provider office 68.0 (58.2–77.9) 65.5 (52.7–78.4) 65.4 (60.6–70.2)
Retail store without eye exam 15.8 (9.4–22.2) 22.5 (11.4–33.7) 21.3 (17.1–25.5)
Internet 10.5 (5.1–15.8) 20.6 (9.6–31.5) 18.8 (14.9–22.6)
Other 3.6 (0.0–7.4) 1.7 (0.5–3.0)
Ever had a red/painful eye while wearing CLs that required a doctor visit 4.2 (0.7–7.8) 14.6 (5.1–24.1) 11.4 (8.1–14.8)
Abbreviations: CI=confidence intervals; CL=contact lens.
* As assessed by the question “When you wear contact lenses, which of these actions do you do on a regular basis (sometimes, most of the time, or always)?”
Adding new solution to existing solution in the contact lens case instead of emptying and cleaning the case before adding new solution.
§ p-value <0.05 compared with young adult CL wearers.
p-value <0.05 compared with older adult CL wearers.
Morbidity and Mortality Weekly Report
MMWR / August 18, 2017 / Vol. 66 / No. 32 845
US Department of Health and Human Services/Centers for Disease Control and Prevention
Summary
What is already known about this topic?
In 2015, CDC established that there were approximately
41 million contact lens wearers aged ≥18 years in the
United States, the majority of whom engaged in behaviors
that put them at risk for serious eye infections.
What is added by this report?
In 2016, there were an estimated 3.6 million adolescents aged
12–17 years in the United States who wore contact lenses. Of
the adolescents who wore contact lenses, 85% reported at least
one behavior that put them at risk for a contact lens–related eye
infection, compared with 81% of young adults, and 88% of
older adults.
What are the implications for public health practice?
Although adolescent contact lens wearers engage in some
healthier contact lens hygiene behaviors than do their adult
counterparts, there is room for improvement in order to prevent
potentially serious outcomes including blindness. Prevention
efforts should focus on encouraging contact lens wearers to
replace their contact lens storage case regularly and to avoid
sleeping or napping in contact lenses.
wearers to replace their contact lens storage case regularly and
to avoid sleeping or napping in contact lenses. There are insuf-
ficient data regarding the appropriate frequency of lens case and
contact lens replacement, but contact lens wearers who do not
follow recommended lens replacement schedules have more
complications and self-reported discomfort than contact lens
wearers who follow the replacement recommendations (6).
Existing health communication strategies known to influ-
ence behavior change in adolescents (e.g., appeals to vanity
and social norms marketing) can be applied to communica-
tion efforts focusing on contact lens hygiene behaviors in this
population (10). Additionally, encouraging adolescents to
adopt healthy contact lens wear and care habits early might
help them maintain these habits into young adulthood, when
the frequency of reported risk behaviors increases. Prevention
messages targeting young adults can be shaped around the
lifestyle changes known to occur in this population.
https://www.cdc.gov/contactlenses/show-me-the-science.html.
Conict of Interest
CDC receives an annual contribution from the Contact Lens
Institute to support CDC’s Healthy Contact Lens Program. The
Contact Lens Institute had no involvement in the survey questions,
analysis, drafting, or review of this manuscript.
1Division of Foodborne, Waterborne, and Environmental Diseases, National
Center for Emerging and Zoonotic Infectious Diseases, CDC.
Corresponding author: Jennifer R. Cope, jcope@cdc.gov, 404-639-3286.
References
1. Stapleton F, Keay L, Jalbert I, Cole N. The epidemiology of contact lens
related infiltrates. Optom Vis Sci 2007;84:257–72. https://doi.
org/10.1097/OPX.0b013e3180485d5f
2. Wagner H, Richdale K, Mitchell GL, et al.; CLAY Study Group. Age,
behavior, environment, and health factors in the soft contact lens risk
survey. Optom Vis Sci 2014;91:252–61.
3. Chalmers RL, Wagner H, Mitchell GL, et al. Age and other risk factors
for corneal infiltrative and inflammatory events in young soft contact
lens wearers from the Contact Lens Assessment in Youth (CLAY) study.
Invest Ophthalmol Vis Sci 2011;52:6690–6. https://doi.org/10.1167/
iovs.10-7018
4. Cope JR, Collier SA, Rao MM, et al. Contact lens wearer demographics
and risk behaviors for contact lens-related eye infections—United States,
2014. MMWR Morb Mortal Wkly Rep 2015;64:865–70. https://doi.
org/10.15585/mmwr.mm6432a2
5. Stapleton F, Edwards K, Keay L, et al. Risk factors for moderate and
severe microbial keratitis in daily wear contact lens users. Ophthalmology
2012;119:1516–21.https://doi.org/10.1016/j.ophtha.2012.01.052
6. Dumbleton KA, Woods CA, Jones LW, Fonn D. The relationship
between compliance with lens replacement and contact lens-related
problems in silicone hydrogel wearers. Cont Lens Anterior Eye
2011;34:216–22. https://doi.org/10.1016/j.clae.2011.03.001
7. Kilvington S, Powell CH, Lam A, Lonnen J. Antimicrobial efficacy of
multi-purpose contact lens disinfectant solutions following evaporation.
Cont Lens Anterior Eye 2011;34:183–7. https://doi.org/10.1016/j.
clae.2011.02.010
8. Zimmerman AB, Richdale K, Mitchell GL, et al. Water exposure is a
common risk behavior among soft and gas-permeable contact lens
wearers. Cornea 2017;36:995–1001. https://doi.org/10.1097/
ICO.0000000000001204
9. Dart JK, Radford CF, Minassian D, Verma S, Stapleton F. Risk factors
for microbial keratitis with contemporary contact lenses: a case-control
study. Ophthalmology 2008;115:1647–54. https://doi.org/10.1016/j.
ophtha.2008.05.003
10. Farrelly MC, Duke JC, Nonnemaker J, et al. Association between The
Real Cost media campaign and smoking initiation among youths—
United States, 2014–2016. MMWR Morb Mortal Wkly Rep
2017;66:47–50. https://doi.org/10.15585/mmwr.mm6602a2
... In fact, it has been estimated that contact lens wear accounts for approximately 35-65% of all corneal infections in major US hospitals (16-18). With approximately 45 million contact lens wearers in the US coupled with 99% of surveyed contact lens wearers reporting at least one contact lens hygiene behavior associated with an increased risk of infection (19), it is likely that cases of contact-lens associated IK will continue to rise. ...
Article
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Background Infectious keratitis (IK) is a blinding disease and an important cause of ocular morbidity. Understanding regional trends in IK are important to understand the epidemiology and clinical outcomes of this disease. Methods In this 10-year retrospective review, patient characteristics including sociodemographic factors, medical history, and ocular history were collected as well as the clinical course and outcomes. This study particularly focused on these characteristics as it relates to treatment failure in IK, as defined as requiring more than 2 weeks to heal or surgical intervention, likelihood of having microbiology cultures collected, surgical intervention, and presenting disease severity. Results 935 cases of IK were identified at the University of Rochester. Age (p=0.004), history of prior corneal transplant (p=0.009), severe vision loss on presentation (p<0.001), large ulcer size (p=0.001), and fungal (p=0.001) or protozoan (p=0.009) infections were all significantly associated with treatment failure. Both ulcer size (p<0.001) and severity of vision loss (p<0.001) were associated with a higher likelihood of having microbiology cultures as well as surgical intervention. Patients’ whose home address was greater than 60 miles from the University were also more likely to present with a more severe ulcer (p<0.001) and undergo a surgical intervention (p=0.05). In studying the impact of race and ethnicity, Black patients were less likely to receive corneal cultures compared to White patients (p=0.02). Conclusions This study defined the patient characteristics and clinical course of patients with IK over 10 years at the University of Rochester providing insight into regional trends of the patient population as well as clinical outcomes.
... More than 80% of adolescent and adult CL wearers report having participated in at least one risky habit that increases the chance of eye infections and vision loss. 15 With minimal health information provided to consumers by CL retailers, it is entirely up to the eye care professional to provide the necessary education about safe CL wear to Plano lens wearers. Considering the potential risks and the lack of substantial evidence supporting the efficacy of Altius sport-tinted lenses, the question remains: Do the rewards truly outweigh the risks? ...
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This editorial examines a recent addition to the CL market: a tinted "performance" lens, used to enhance vision and reduce glare during sporting activity. We discuss the pros and cons and evidence supporting its use.
... CL-related IK tends to affect younger patients and working adults more commonly due to their higher social and occupational needs for CL [8,14]. This could have a considerably negative effect on work productivity and economy as a result of lost working days. ...
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Background/Objectives To examine the clinical characteristics, risk factors and outcomes of contact lens-related bacterial keratitis (CLBK) in a large UK tertiary referral centre. Subjects/Methods A retrospective analysis of all patients who presented to the Queen’s Medical Centre, Nottingham, UK, with suspected CLBK between October 2015 to September 2022 (a 7-year period) was performed. Relevant data on demographic factors, CL wear behaviour, causes, clinical characteristics, and outcomes were analysed. Results We included 138 patients with CLBK; the mean age was 42.0 ± 17.8 years and 74 (53.6%) patients were male. Most CLBK were related to soft CL wear (94.5%), particularly monthly disposable (42.5%) and daily disposable (24.4%) CLs. Poor CL wear behaviour/hygiene was documented in 57.1% cases. Among the 64 (46.4%) microbiological-positive cases (n = 73 organisms), Pseudomonas aeruginosa (36, 49.3%) and Staphylococcus spp . (16, 21.9%) were most commonly identified. Six (4.3%) cases were polymicrobial. Most (97.0%) patients were successfully treated with topical antibiotics alone, with 80.6% achieving good final corrected-distance-visual-acuity (CDVA) of ≥ 0.30 logMAR. Poor visual outcome (final CDVA < 0.30 logMAR) was significantly associated with presenting CDVA < 0.6 logMAR ( p = 0.002) and central ulcer ( p = 0.004). Poor corneal healing (complete healing of > 30 days from initial presentation) was significantly associated with age > 50 years ( p = 0.028), female gender ( p = 0.020), and infiltrate size >3 mm ( p = 0.031). Conclusions Poor CL wear behaviour/hygiene is commonly observed in CLBK, highlighting the importance of improved counselling and awareness regarding CL use and hygiene. When presented early and managed appropriately, most patients are able to achieve good clinical outcomes with medical treatment alone.
Article
Purpose The purpose of this study was to assess trends in microbiology profiles and antibiotic susceptibility among pediatric infectious keratitis cases in Southern California, United States. Methods This is a retrospective chart review of patients aged 18 years or younger diagnosed with infectious keratitis with a positive microbiology culture between 2006 and 2019 at a tertiary academic institution. Patient demographics, microbiology results, and antibiotic susceptibilities were analyzed. Results There were 23 patients included in the study period. The mean age (±SD) was 11 ± 7 years, with 60% 10 years and older. 75% were female, and 45% were of Hispanic or Latino descent. A total of 14 patients (61%) presented between June and November. A total of 30 microorganisms were identified from 24 corneal cultures of 23 eyes, and 92% were bacterial. The most common gram-positive and gram-negative isolates were Staphylococcus spp. (5/13, 38%) and Pseudomonas spp. (9/15, 60%), respectively. 92.3% gram-positive isolates were susceptible to vancomycin, but only 7.7% were susceptible to erythromycin. Gram-negative isolates were susceptible to gentamicin (86%), ciprofloxacin (79%), and ceftazidime (55%). Pseudomonas spp. was highly susceptible to gentamicin (100%) and ciprofloxacin (83%), and it was moderately susceptible to tobramycin (44%) and ceftazidime (67%). Conclusions Pediatric microbial keratitis cases in Southern California were predominantly bacterial infections, with gram-positive isolates highly susceptible to vancomycin and gram-negative isolates, particularly Pseudomonas spp., showing high susceptibility to gentamicin and ciprofloxacin.
Article
The increased usage of nonrefractive cosmetic contact lenses in Asia and a trend toward increased online purchasing of both refractive and cosmetic contact lenses poses unique challenges in the management of contact lens–related complications. However, regulations have lagged behind this increased uptake in the community. This paper reviews regulations surrounding the manufacturing, import, and distribution of contact lenses in the Asia Pacific region and compares them with international regulations from the European Union and United States. It found a need for more specific regulations and closer surveillance targeted at new trends in contact lens purchasing and usage. This paper also found a need for more effective enforcement of current regulations.
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Fungal keratitis is regarded as the main culprit for the globally prevalent blindness and visual impairment, with contact lenses and traumatic injury being the chief contributors to the disease in developing countries. The incorporation of the function of noncoding RNAs ( ncRNAs ) into the genomic investigations of fungal keratitis disease can pave the way for the development of novel diagnostic markers and disease-modifying treatments. During the last decade, the expression and function of eukaryotic genomes are proved to be predominantly regulated by ∼20–30 nucleotide RNA molecules. Functioning in both somatic and germline line-ages in a vast array of eukaryotic species, two major categories of these small RNAs- short interfering RNAs ( siRNAs ) and microRNAs ( miRNAs )-modulate endogenous genes and safeguard the genome against invasive nucleic acids. Recent progress has lifted the veil of a stunning diversity in their biogenesis pathways and the regulatory mechanisms at their disposal. Fundamental biology, as well as disease etiology and treatment, can reap the rewards of our precise perception of siRNA and miRNA based regulation. The current review strives to shed light on recent advances made in the realm of pathogenesis, risk factors, and the role of ncRNAs in fungal keratitis.
Article
Purpose To assess risk factors for contact lens (CL)-related bacterial keratitis, cases and high-risk controls were enrolled. Using high-risk controls can help elucidate whether certain CL types or modalities are attributable to disease burden if risky wear patterns are similar between the cases and controls. This analysis identified whether such CL factors were associated with the occurrence of bacterial keratitis. In addition, a case-only analysis determined CL factors associated with severe disease. Methods From 2018 to 2021, 158 controls were enrolled at University Hospitals of Cleveland Eye Institute, and 153 bacterial keratitis cases were enrolled across 14 sites in the United States. Cases were soft CL wearers with either culture-proven bacterial keratitis or a corneal infiltrate with an overlying epithelial defect within the central 4 mm of the cornea, uveitis, or significant pain. Fungal, protozoan, or nonsoft CL wear-related microbial keratitis cases were excluded. Controls were recruited from high-risk CL wearers with no history of disease. All participants completed a questionnaire related to demographics, type of CL used, wearing schedule, lens handling practices, and storage case handling. Cases with ulcer/infiltrate size ≥2 mm in size, presence of hypopyon, or had fortified antibiotics prescribed were classified as severe keratitis. Univariate and multivariable logistic regression was used to assess association of CL variables with the occurrence of bacterial keratitis as well as occurrence of severe disease among the cases only. Results Compared with the control cohort, cases were older (mean age 45.6 vs. 38.9 years), had more males (42.5% vs. 23.6%), and had more current or former smokers (41.7% vs. 12.9%). There were no significant associations between CL material (silicone hydrogel vs. not) or CL type (daily disposable vs. reusable) and occurrence of bacterial keratitis. More than two-thirds (67.3%) of cases were classified as severe. Among cases only, univariate analyses found current smokers to have increased risk of severe disease (OR=2.87; 95% CI 1.13–7.26, P =0.03). Adjusting for age, sex, and smoking among the cases only, daily disposable lenses were protective against severe disease (OR=0.32; 95% CI 0.11–0.89, P =0.03). Reusable lenses increased risk of severe microbial keratitis between 3.0- and 4.4-fold compared with compliant daily disposability. Discussion/Conclusion Compared with a high-risk control cohort, no specific lens factors were associated with occurrence of CL-associated bacterial keratitis. Among cases only, current smokers and patients wearing reusable lenses are at increased risk of severe keratitis. Daily disposable lenses were protective even when noncompliance to daily disposability was considered.
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Purpose: To understand soft contact lens (SCL) and gas-permeable (GP) lens wearers' behaviors and knowledge regarding exposure of lenses to water. Methods: The Contact Lens Risk Survey (CLRS) and health behavior questions were completed online by a convenience sample of 1056 SCL and 85 GP lens wearers aged 20 to 76 years. Participants were asked about exposing their lenses to water and their understanding of risks associated with these behaviors. Chi-square analyses examined relationships between patient behaviors and perceptions. Results: GP lens wearers were more likely than SCL wearers to ever rinse or store lenses in water (rinsing: 91% GP, 31% SCL, P < 0.001; storing: 33% GP, 15% SCL P < 0.001). Among SCL wearers, men were more likely to store (24% vs. 13%, P = 0.003) or rinse (41% vs. 29%, P = 0.012) their lenses in water. Showering while wearing lenses was more common in SCL wearers (86%) than GP lens wearers (67%) (P < 0.0001). Swimming while wearing lenses was reported by 62% of SCL wearers and 48% of GP lens wearers (P = 0.027). Wearers who rinsed (SCL; P < 0.0001, GP; P = 0.11) or stored lenses in water (SCL; P < 0.0001, GP P = 0.007) reported that this behavior had little or no effect on their infection risk, compared with those who did not. Both SCL (P < 0.0001) and GP lens wearers (P < 0.0001) perceived that distilled water was safer than tap water for storing or rinsing lenses. Conclusions: Despite previously published evidence of Acanthamoeba keratitis' association with water exposure, most SCL, and nearly all GP lens wearers, regularly expose their lenses to water, with many unaware of the risk.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.
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In the United States, approximately 900,000 youths smoke their first cigarette each year (1). Health communication interventions are evidence-based strategies for preventing the initiation of tobacco use, promoting and facilitating cessation, and changing beliefs and attitudes about tobacco use (2,3). This report describes the association between the Food and Drug Administration's (FDA's) first national tobacco public education campaign, The Real Cost, and rates of smoking initiation among youths in the United States from 2014 to 2016. A nationally representative cohort study of youths (N = 5,185) was conducted during November 2013-March 2016. Results from a discrete-time survival model indicate that, among youths who reported never having smoked a cigarette in the baseline survey, the odds of reporting smoking initiation at follow-up were lower among youths with frequent exposure to campaign advertisements than among those with little or no exposure (adjusted odds ratio [aOR] = 0.70, 95% confidence interval [CI] = 0.55-0.91). Based on the results of the model, The Real Cost is associated with an estimated 348,398 U.S. youths aged 11-18 years who did not initiate smoking during February 2014-March 2016. Sustained youth-focused tobacco education campaigns, such as The Real Cost, can help speed progress toward preventing tobacco use among youths in the United States.
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Contact lenses provide safe and effective vision correction for many Americans. However, contact lens wearers risk infection if they fail to wear, clean, disinfect, and store their contact lenses as directed. Over the past decade, CDC has investigated several multistate outbreaks of serious eye infections among contact lens wearers, including Acanthamoeba keratitis. Each investigation identified frequent contact lens hygiene-related risk behaviors among patients. To guide prevention efforts, a population-based survey was used to estimate the number of contact lens wearers aged ≥18 years in the United States. A separate online survey of contact lens wearers assessed the prevalence of contact lens hygiene-related risk behaviors. Approximately 99% of wearers reported at least one contact lens hygiene risk behavior. Nearly one third of contact lens wearers reported having experienced a previous contact lens-related red or painful eye requiring a doctor's visit. An estimated 40.9 million U.S. adults wear contact lenses, and many could be at risk for serious eye infections because of poor contact lens wear and care behaviors. These findings have informed the creation of targeted prevention messages aimed at contact lens wearers such as keeping all water away from contact lenses, discarding used disinfecting solution from the case and cleaning with fresh solution each day, and replacing their contact lens case every 3 months.
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To describe age and other risk factors for corneal infiltrative and inflammatory events (CIEs) in young, soft contact lens (SCL) wearers and to model the age-related risk. A multicenter, retrospective chart review of 3549 SCL wearers (8-33 years at first observed visit, +8.00 to -12.00D, oversampling <18 years) captured CIEs from January 2006 to September 2009. The review noted age, sex, SCL worn, use of lens care products, and SCL wearing history. Event diagnoses were adjudicated to consensus by reviewers masked to wearer identity, age, and SCL parameters. Significant univariate risk factors for CIEs were subsequently tested in multivariate generalized estimating equations. Charts from 14,305 visits observing 4,663 SCL years yielded 187 CIEs in 168 wearers. Age was a significant nonlinear risk factor, peaking between 15 and 25 years (P < 0.008). Less than 1 year of SCL use was protective versus longer years of wear (P < 0.0003). Use of multipurpose care products (2.86×), silicone hydrogels (1.85×), and extended wear (2.37×) were significantly associated with CIEs in the multivariate model (P < 0.0001 each). Patient age, years of lens wear, use of multipurpose care products, silicone hydrogels, and extended wear were all significantly associated with CIEs with SCL wear. Use of SCLs in young patients aged 8 to 15 years was associated with a lower risk of infiltrative events compared with teens and young adults. In terms of safety outcomes, SCLs appear to be an acceptable method of delivering optics designed to manage myopia progression in children and young teens in the future.
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An outbreak of Acanthamoeba keratitis, a rare, potentially blinding, corneal infection, was detected in the United States in 2007; cases had been increasing since 2004. A case-control study was conducted to investigate the outbreak. We interviewed 105 case-patients from 30 states and 184 controls matched geographically and by contact lens use. Available contact lenses, cases, solutions, and corneal specimens from case-patients were cultured and tested by molecular methods. In multivariate analyses, case-patients had significantly greater odds of having used Advanced Medical Optics Complete Moisture Plus (AMOCMP) solution (odds ratio 16.9, 95% confidence interval 4.8-59.5). AMOCMP manufacturing lot information was available for 22 case-patients, but none of the lots were identical. Three unopened bottles of AMOCMP tested negative for Acanthamoeba spp. Our findings suggest that the solution was not intrinsically contaminated and that its anti-Acanthamoeba efficacy was likely insufficient. Premarket standardized testing of contact lens solutions for activity against Acanthamoeba spp. is warranted.
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Fusarium keratitis is a serious corneal infection, most commonly associated with corneal injury. Beginning in March 2006, the Centers for Disease Control and Prevention received multiple reports of Fusarium keratitis among contact lens wearers. To define the specific activities, contact lens hygiene practices, or products associated with this outbreak. Epidemiological investigation of Fusarium keratitis occurring in the United States. A confirmed case was defined as keratitis with illness onset after June 1, 2005, with no history of recent ocular trauma and a corneal culture growing Fusarium species. Data were obtained by patient and ophthalmologist interviews for case patients and neighborhood-matched controls by trained personnel. Available Fusarium isolates from patients' clinical and environmental specimens were genotyped by multilocus sequence typing. Environmental sampling for Fusarium was conducted at a contact lens solution manufacturing plant. Keratitis infection with Fusarium species. As of June 30, 2006, we identified 164 confirmed case patients in 33 states and 1 US territory. Median age was 41 years (range, 12-83 years). Corneal transplantation was required or planned in 55 (34%). One hundred fifty-four (94%) of the confirmed case patients wore soft contact lenses. Forty-five case patients and 78 controls were included in the case-control study. Case patients were significantly more likely than controls to report using a specific contact lens solution, ReNu with MoistureLoc (69% vs 15%; odds ratio, 13.3; 95% confidence interval, 3.1-119.5). The prevalence of reported use of ReNu MultiPlus solution was similar between case patients and controls (18% vs 20%; odds ratio, 0.7; 95% confidence interval, 0.2-2.8). Fusarium was not recovered from the factory, warehouse, solution filtrate, or unopened solution bottles; production of implicated lots was not clustered in time. Among 39 isolates tested, at least 10 different Fusarium species were identified, comprising 19 unique multilocus genotypes. The findings from this investigation indicate that this outbreak of Fusarium keratitis was associated with use of ReNu with MoistureLoc contact lens solution. Contact lens users should not use ReNu with MoistureLoc.
Article
Previous studies have reported that the risk of corneal infectious and inflammatory events (CIEs) with soft contact lens (SCL) wear is highest in late adolescence and early adulthood. This study assesses the associations between patient age and other factors that may contribute to CIEs in young SCL wearers. After ethics approvals and informed consent, a nonclinical population of young SCL wearers was surveyed in five US cities. Data from 542 SCL wearers aged 12-33 years were collected electronically. Responses were analyzed by age bins (12-14, 15-17, 18-21, 22-25, 26-29, and 30-33 years) using chi-square test. The cohort was 34% male and balanced across age bins. There were several significant associations between survey response and age (in bins). Wearers aged 18-21 years reported more recent nights with less than 6 hours of sleep (p < 0.001), more colds/flu (p = 0.049), and higher stress levels (p < 0.001). Wearers 18-21 and those 22-25 years were more likely to wear SCLs when showering (p < 0.001) and also reported more frequent naps with SCLs (p < 0.001). They reported sleeping in SCLs after alcohol use (p = 0.031), when traveling (p = 0.001), and when away from home (p = 0.024). Lower rates of regular hand washing before lens application (p = 0.054) was also associated with these groups. In addition, the relationship between reactive replacement and recommended replacement was dependent on age (p < 0.0001). Patient age influences lens wearing behaviors, environmental exposures, and other determinants of health that may contribute to increased CIEs in younger wearers. Targeted, age-specific education should be considered for both new and established SCL wearers.
Article
To establish risk factors for moderate and severe microbial keratitis among daily contact lens (CL) wearers in Australia. A prospective, 12-month, population-based, case-control study. New cases of moderate and severe microbial keratitis in daily wear CL users presenting in Australia over a 12-month period were identified through surveillance of all ophthalmic practitioners. Case detection was augmented by record audits at major ophthalmic centers. Controls were users of daily wear CLs in the community identified using a national telephone survey. Cases and controls were interviewed by telephone to determine subject demographics and CL wear history. Multiple binary logistic regression was used to determine independent risk factors and univariate population attributable risk percentage (PAR%) was estimated for each risk factor. Independent risk factors, relative risk (with 95% confidence intervals [CIs]), and PAR%. There were 90 eligible moderate and severe cases related to daily wear of CLs reported during the study period. We identified 1090 community controls using daily wear CLs. Independent risk factors for moderate and severe keratitis while adjusting for age, gender, and lens material type included poor storage case hygiene 6.4× (95% CI, 1.9-21.8; PAR, 49%), infrequent storage case replacement 5.4× (95% CI, 1.5-18.9; PAR, 27%), solution type 7.2× (95% CI, 2.3-22.5; PAR, 35%), occasional overnight lens use (<1 night per week) 6.5× (95% CI, 1.3-31.7; PAR, 23%), high socioeconomic status 4.1× (95% CI, 1.2-14.4; PAR, 31%), and smoking 3.7× (95% CI, 1.1-12.8; PAR, 31%). Moderate and severe microbial keratitis associated with daily use of CLs was independently associated with factors likely to cause contamination of CL storage cases (frequency of storage case replacement, hygiene, and solution type). Other factors included occasional overnight use of CLs, smoking, and socioeconomic class. Disease load may be considerably reduced by attention to modifiable risk factors related to CL storage case practice.
Article
To evaluate the relationship between compliance with replacement frequency (RF) and contact lens (CL)-related problems in silicone hydrogel (SiHy) wearers. 501 SiHy wearers from seven optometry offices completed surveys regarding their lens wear and any CL related problems which they may have experienced in the preceding 12 months. File review was subsequently conducted at their optometry offices to confirm the information provided. 49% of respondents were wearing 2-week replacement (2WR) and 51% 1-month replacement (1MR) SiHy lenses. 67% wore their lenses for longer than the manufacturers' recommended RF (MRRF) and 60% for longer than their optometrist's recommended RF (ORRF). The mean RF was 2.6× the MRRF for 2WR and 1.5× for 1MR wearers (p<0.001) with median values of 31 and 37 days, respectively. Twenty-three percent reported signs or symptoms consistent with potential complications relating to CL wear. This rate was significantly higher for wearers who were non-compliant with the ORRF than compliant wearers (26% versus 18%, p=0.028). It was also higher for those multipurpose solution users who reported never/almost never rubbing and rinsing their lenses when compared with those who did this every night (29% versus 17%, p=0.007). Two thirds of the SiHy wearers did not comply with the MRRF and 2WR wearers stretched the replacement interval of their lenses to a greater degree than 1MR wearers. Failing to replace lenses when recommended and failing to rub and rinse lenses were associated with a higher rate of patient-reported CL problems.
Article
Non-compliance is a significant factor in contact lens related microbial keratitis and includes solution reuse and failure to recap the lens storage case resulting in evaporation effects. To address this, impact of partial evaporation on the antimicrobial efficacy of multipurpose contact lens care solutions was investigated. Solutions were evaporated under a stream of air to 2× and 4× concentration and challenged with Fusarium solani (ATCC 36031), Candida albicans (ATCC 10231) and Acanthamoeba castellanii (ATCC 50370). The level of organism kill at 6h was compared to the non-evaporated product. ReNu with MoistureLoc(®) (RML) lost 90-100% of biocidal activity against C. albicans on evaporation, 75-99% for F. solani and 29-33% with A. castellanii at 2× or 4× concentration, respectively. OPTI-FREE(®) RepleniSH(®) lost 72-90% efficacy against C. albicans and F. solani, and 61% at 2× and 10% at 4× concentration with A. castellanii. ReNu(®) MultiPlus, AQuify(®) Multi-Purpose and Biotrue™ showed only loss in efficacy with C. albicans at 4× concentration giving 79%, 34.5% and 48% reduction, respectively. No loss in biocidal activity on evaporation was obtained with Complete(®) Revitalens for all organisms. Partial evaporation can affect biocidal efficacy of multi-purpose solutions and may have been a significant factor in an outbreak of Fusarium keratitis cases associated with RML. Evaporation results in increased binding of cationic disinfectants to counter-ions in the formulation, reducing ability to attach and rupture anionic microbial cell walls. Interaction may also occur between the biocidal ingredient and other components, such as surfactants, resulting in sequestration of activity through micelle formation.