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Fulfilling the Fundamental Goal:
Education as the Key in Prevention and Treatment of
Microbial Keratitis
CLCS STUDENT RESEARCH AWARD
SPONSORED BY: ALLERGAN
TOPIC:
COMBATING MICROBIAL KERATITIS IN OUR CONTACT LENS PATIENTS:
PREVENTION AND TREATMENT
By
Renee Phipps, BS
Illinois College of Optometry
Class of 2008
1
TABLE OF CONTENTS
Page
Abstract
3
Introduction
4
Method
5
Participants
5
Results
5
Survey
6
Discussion: Prevention & Treatment
8
Conclusion
13
References
14
2
ABSTRACT
The presentation of a red painful eye behind the biomicroscope carries with it a
number of potential diagnoses. When a contact lens is introduced as a modifying factor in
the case, the possibility of microbial keratitis becomes a very likely etiology. This ocular
condition, may be associated with significant visual and corneal devastation.1 As
optometrists, the loss of vision and alteration in vital tissue is of great concern and in this
condition, great question. With the introduction of new more ‘healthy’ lens materials and
lens solutions, how are the numbers still continuing to rise? Perhaps, there is a link
between education, prevention and treatment, and more importantly patient
understanding of contact lenses. This research paper will explore the patient’s knowledge
and care of contact lenses, by means of a randomized survey. Prevention and treatment of
microbial keratitis will also be addressed as key components in managing this public
health condition.
3
INTRODUCTION
As Optometrists, our goal is to provide superior vision, while maintaining good
ocular health. Since the genesis of soft contact lens extended wear in 19811 we
continue to strive for this goal; however with various obstacles placed in our path. Of
the many factors that obstruct our course, microbial keratitis (MK) in contact lens
wearers has proven to be among the most encumbering. Recognized as potentially
the most visually devastating complication of contact lens wear 3, it’s prevalence is
questioned, when new lens materials and cleaning solutions continue to promise
decreased contamination and facility for microbial nesting. Where does the
accountability fall and why does this pathology continue to slip into our solution?
Perhaps derisory patient compliance, overshadowed by media applause for new found
convenience and versatility is to blame. Or is it possibly the ever growing perception
of contact lenses as an accessory or cosmetic device which lies at the foundation of
this ever growing impediment? Irregardless to the possible etiology of this contact
lens problem, the goal continues to be the convergence of first-class health and
vision. With this considered it is important to understand what the patient knows
about their contact lenses and the care of these optical devices. And secondly, it is
imperative to implement an educational campaign centered on the patient’s
knowledge of contact lenses, their current perception and understanding of their use.
First, in effort to appreciate the patient’s awareness of his/ her lenses a survey was
conducted.
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METHOD
The understanding a patient has for his/ her contact lens was ascertained in a 16
question randomized survey. Permission was requested and granted by all individuals
surveyed.
PARTICIPANTS
A total of 60 individuals participated. The data was collected between February
10 2008 and March 1, 2008. Participants resided in either the United States of America or
Canada. Only 50 surveys were used, as 10 of the participants were not contact lens
wearers. Demographics such age and race were excluded. The sex of the participants was
included, as recent research has shown that 63.6% of MK cases in a 291 sample were
male.4
RESULTS
The survey results give us an idea of what patients understand about their contact
lenses. The main points to highlight are the fact that only 46% of surveyed contact lens
wearers are disposing of their cases after 1 month or less; 26% are re-using old contact
lens solution; only 79% of patients are washing hands when handling lenses; less than
half were trained to use contact lenses by doctors (23/50); 26 individuals reports wearing
extended wear contact lenses; however 32 report sleeping in the lenses. Also, the survey
revealed that only 26% of make-up wearers discard of their make up after 3-4 months as
recommended by University of Illinois Eye & Ear Infirmary.
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SURVEY
Please see Table 1.0, to continue to Discuss please see page 6
Table 1.0
Question
#
1
2
3
4
5
6
7
8
9
10
Question posed and Responses of participants
Q: Do you wear contact lenses?
A: 50 people /60 survey, group total adjusted to 50 people
Q: Male or Female?
A: 30 female 60%, 20 male 40%
Q: Do you know what solution you use for your contact lenses (CL)?
A: Yes 66%; No 34 %
Q: Have you ever used a solution other than a designated CL solution to store or clean your lenses?
A: Yes 36%; No 64%
Q: Do you wear your CL everyday?
A: Yes 54%; No 46%
Q: Do you sleep in your CL?
A: Yes 64%; No 36%
Q: Do you sleep in your CL for
i) 0 nights
ii) 1-5 days
iii) 5-7 days
iv) 7-14 days
v) 15-30 days
vi) Greater than 30 days.?
A: the numbering corresponds to the option provided in the questions.
i) 36%
ii) 30%
iii) 16%
iv) 8%
v) 6%
vi) 4%
Q: How frequently do you reuse CL solution in your case?
i) 0 days
ii) 1-2days
iii) 3 days
iv) Greater than 3 days?
A: the numbering corresponds to the option provided in the questions
i) 74%
ii) 20%
iii) 4%
iv) 2%
Q: Do you rub your lenses to clean them?
A: Yes 60%, No 40%
Q: How frequently do you change your CL case?
i) every 6 months
ii) every 3 months
iii) every 1 month
iv) every 2 weeks
v) every week
vi) no case?
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A: the numbering corresponds to the option provided in the questions.
i) 0%
ii) 38%
iii) 34%
iv) 10%
v) 2%
vi) 16 %
Q: Do you wash your hands before taking out CL?
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A: Yes 76%; No 24%
Q: Do you wash your hands before inserting (putting on) your CL?
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A: Yes 82%; No 18%
Q: What kind of CL do you wear?
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i) Dailies
ii) Extended wear
iii) RGP
iv) 1 month disposable
v) Don’t know?
A: the numbering corresponds to the option provided in the questions.
i) 16%
ii) 52%
iii) 2%
iv) 26%
v) 4%
Q: Do you wear make up with your contact lenses?
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A: 60% Yes, 40% No
Q: How frequently do you throw out the eye make up?
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i) Don’t wear eye make up
ii) 1 month,
iii) 2 months
iv) 3-4 months
v) 6 months,
vi) 1 year or greater
A: the numbering corresponds to the option provided in the questions.
i) 40%
ii) 4%
iii) 8%
iv) 16%
v) 32%
Q: Who taught you how to care for your contact lenses and insert and remove them?
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i) Front desk assistant
ii) Doctor
iii) Optician
iv) I was never taught
A: the numbering corresponds to the option provided in the questions.
i) 12%
ii) 44%
iii) 34%
iv) 10%
Q: Have you ever had an eye problem related to CL wear?
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A: Yes 20%; No 80%
Key: Q- Question; A- Answer
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DISCUSSION
Prevention
From the results obtained it is clear that patients need to be properly educated
about their lenses. Much of the data highlighted in the results section, draws attention to
areas where patients may leave themselves susceptible to microbial keratitis. Two
campaigns that may be implemented to prevent MK are:
1- Don’t put it in your eye: promote hygiene, clean hands, new cases and
rubbing lenses clean.
Proper hygiene is a key component in preventing microbial keratitis. It is estimated that
we have between 2 and 10 million bacteria between our fingertip and elbow and that
germs can stay alive on hands for up to three hours.5 As doctor’s facing ocular
complications related to hygiene, it is important to address this public health concern and
reinforce the guidelines and recommendations set forth by the Center for Disease Control
and Prevention. Hand washing with soap and water remains a sensible strategy for hand
hygiene in non-health care settings.6 Also, with the outbreak of various forms of keratitis,
namely fungal (Fusarium) and Acanthamoeba, there has been an in increased awareness
of lens case hygiene. In May 2006 the FDA recommended to keep the contact lens case
clean and replace every 3-6 months. More strict guidelines are currently implemented by
the American Optometric Association that advises patients to replace contact lens cases at
least every 3 months. 7 The importance of changing contact lenses has also penetrated the
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medical device industry. This is best recognized with the invention of LensAlert!. This
device alerts the patient as to when he/ she should change their contact case and lenses.8
Additionally, each doctor must stress the importance of changing contact lens solution
and rubbing lenses clean, for the purpose of cleaning the lens. With this campaign put
into practice, sending a message of hygiene, patients are sure to begin to understand their
responsibility as contact lens wearers and participants in sustaining their personal health.
2- Cosmetic Medicine: Despite their cosmetic appeal, contact lenses are
primarily a medical appliance that dynamically interacts with the
outermost surface of the eye and surrounding a mucous membrane; and
typically serves to correct refractive error.
Under this campaign Doctors of Optometry will be encouraged to educate their patients
on insertion and removal, the possibility of MK and the risks of frequent contact with this
highly sensitive organ. The patients will learn of the importance of contact lens solution
and that because the use of this medical device is controlled by laws and limited by
research findings, they must adhere to use guidelines outlined by their primary eye care
provider. Also, under this initiative patients will be coached about correct lens wear
schedules. This is especially important since from the introductory survey we see that
64% of patients report sleeping in lenses, while only 52% of patients are wearing lenses
approved for overnight wear. Additional research shows that hypoxia caused by
overnight soft contact lens wear, seems to enhance the vulnerability of the cornea to
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microorganism infection. It is also noted that the propensity for Pseudomonas aeruginosa
to adhere to hydrogel lenses is increased with the presences of surface deposits.3
Implementing these two educational campaigns may help to inform patients about
proper contact lens care and decrease the statistics which show that with the growth of
contact lens use in recent years there is has been a parallel increase in contact lens
associated MK to include 50% of all cases in the US and up to 35% in Europe.9
Understanding and treating
Microbial keratitis presents acutely with significant pain. The cornea is marked
with stromal inflammation with an overlying epithelial defect due to replicating
microorganisms.1,4 MK associated with contact lenses is an ever growing concern, not
only because of its potentially devastating visual outcome, but also because of the large
number of lens wearers around the globe.10 Contact lenses function as the conduit in the
chain of events that lead to MK, by introducing the microbe to the eye and anchoring it
on the ocular surface for hours or even days. It is this role that makes contact lenses one
of the most common risk factors associated with MK.10,11 Ocular trauma is also a known
risk factor, as are the following less common associations: preexisting ocular disease,
cocaine use, ocular surgery, lid misalignment, diabetes, and smoking.1,10,11 With this
considered, contact lenses could also be the culprits behind varying levels of ocular
trauma. Whether in the form of a corneal abrasion or simply a mild disruption of the
epithelium, the lens may leave the cornea vulnerable to microbes that aim to excavate the
top and penetrate other layers. 10
10
Current treatment of MK is dictated by a number of factors: depth, size and
location of the lesion within the cornea.11 A treating doctor should also consider the type
of bacteria causing the problem, which is typically ascertained by a culture. Pseudomonas
aeruginosa for example was found to be the most common cultured Gram negative
organism among CL wearers. This is a significant finding primarily because of the ability
of this microorganism to penetrate the cornea. Information obtained from cultures can
direct treatment and were once the corner stone of treatment prior to broad spectrum
fluoroquinolones. 11 In years past bacterial MK was most commonly treated with fortified
aminoglycosides, which have especially good coverage against many gram negative and
some gram positive microbes. Fortified formulations include compounded medications
like vancomycin and cephalosporines or tobramycin and gemtamicin. 11 According to
Wills Eye Manual, treatment of bacterial MK follows an algorithm based on risk of
visual loss. All treatments outlined involve fluoroquinolone therapy, namely,
ciprofloxacin, ofloxacin, moxifloxacin or gatifloxacin. In a case with low visual risk,
these medications are dosed every two to four hours. Borderline risk of vision loss,
defined as a peripheral infiltrate with epithelial defect, requires administration of the
aforementioned fluoroquinolones every hour around the clock. With the presence of
bacterial MK, there may be an anterior chamber reaction noted and/or pain reported by
patients which can be managed with cycloplegic drops (the administration of a steroid is
reserved until after the epithelium has healed). Also noted in the Wills Eye Manual are
treatment guidelines for vision threatening lesions, which require fortified tobramycin or
gentamicin 15mg/mL every 30-60 minutes; alternating between either fortified cefazolin
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(50mg/mL) or vancomycin (25mg/mL). In the presence of MK, stress the importance of
no contact lens wear.
In addition to bacterial MK, the treatment of Acanthamoeba corneal lesions is of
great importance. This class of MK is typically found in a patient with a recent history of
swimming in contact lenses or using non-sterile liquids to store or clean contact lenses. It
is conservatively estimated that about 1.65 to 2.01 cases of Acanthamoebic keratitis occur
per million contact lens wearers in the United States.8 Though appearing with relatively
low incidence, Acanthomoebic MK is difficult to treat. The current therapies
implemented to combat this protozoan include a combination of Brolene ( propamidine
isethionate) coupled with an antimicrobial agent and PHMB ( polyhexamethylene
biguanide). Treatment of Acanthamoeba may last up to three or four months, beginning
with dosing every one to two hours with eventual reduced administration with
improvement.11
Fungal keratitis and viral keratitis are two other kinds of MK. Fungal Keratitis, in
recent years has had a fair amount of media exposure. Linked to poor hygiene and
unclean lens cases, this order of MK is best known for its connection to vegetative
contact or trauma. Fungal keratitis is typically treated with natamycin 5% or
amphotericin B 0.15%. Due to the poor corneal penetration of these two medications,
consider corneal scraping to improve therapy efficacy. 11 On the other side of the coin, is
viral keratitis, which follows a well established treatment regime involving trifluridine up
to nine times per day with taper. Other treatment options include oral acyclovir and
corneal debridement.
12
The current treatment guidelines, as outlined above of quite effective in the
treatment of all the respective types of MK. There are still new developments being made
every day, ranging from Australian studies by a company called ‘Biosignal’ to create the
first extended wear contact lens permanently infused with an antibacterial substance, to
new technologies in the lens material and solution compounds.8
CONCLUSION
As optometrists, it is imperative to understand that ultimately, contact lenses, as a class of
device are quite safe, but they are associated with some risk not encountered with
spectacle use.2 Research confirms that microbial keratitis is as an important ocular
morbidity and names contact lens wear as a significant risk for this condition 1,4 Thus,
when the statistical results of the introductory survey are taken into account, along with
our primary goal and ever changing understanding of contact lenses and potential ocular
effects, the public health issue and goal for resolution are unmistakable. The solution lies
in aggressive prevention and treatment. Education has a crucial role in prevention, as an
essential element of the proposed campaigns. And proper treatment is recognized as an
integral part of preserving vision. When these two mainstays are coupled, optometrists
can attain the fundamental goal to provide superior vision, while maintaining good ocular
health.
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M, O’Day D, Shovlin J. The Incidence of microbial keratitis among wearers of a
30-day silicone hydrogel extended wear contact lens. Ophthalmology, 2005; 112
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Principle and Practice of Ophthalmology, Third Edition. Philadelphia: Saunders
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Week. Available at: http://www.bristol-city.gov.uk/ccm/content/pressreleases/2005/06/Press-Release-10687LH05.en;jsessionid=21AA436D8BB16331EBA781742B3E7F96. Accessed:
March
1,2008.
6. Centers for Disease Control and Prevention (CDC). Hand hygiene guidelines fact
sheet. Available at: http://www.cdc.gov/od/oc/media/pressrel/fs021025.htm.
Accessed: March 1, 2008
7. American Optometric Association. Contact Lens. Available at:
http://www.aoa.org/x5230.xml. Accessed: March 1, 2008
8. Barr JT et al. All About Vision: What’s New in Contact Lenses and Solutions.
Available at: http://www.allaboutvision.com/whatsnew/contacts.htm Accessed:
March 1, 2008
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Care; 2007; 152-165
10. Willcox M. Which is more important to the initiation of contact lens related
microbial keratitis, trauma to the ocular surface or bacterial pathogenic factors?.
Clin Exp Optom; 2006; 89:5: 277-279
11. Black, G. A look at microbial keratitis today; Review of Optometry 2007 April,
63-68
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12. Kunimoto DY, Kanitkar KD, Makar M, Friedberg MA. Wills Eye Manual:
Office and Emergency Room Diagnosis and Treatment of Eye Disease, Forth
Edition. Philadelphia: Lippincott Williams & Wilkins 2004; 52-56
13. Mita A, Tsesmetzoglou, McElvanney A. Corneal deposits and topical ofloxacin:
the effect of polypharmacy in the management of microbial keratitis. Eye. 2007
Mar; 21(3):410-2.
14. Dahlgren MA, Lingappan A, Wilhelmus KR. The clinical diagnosis of microbial
keratitis. Am J Ophthalmol. 2007 Jun; 143(6):940-944.
15. Lim L, Loughnan MS, Sullivan LJ. Microbial keratitis associated with extended
wear silicone hydrogel contact lenses. Br J Ophthalmology 2002 March, 86(3):
355-357
16. University of Illinois Eye & Ear Infirmary. Cosmetics. Available at:
http://www.agingeye.net/otheragingeye/cosmetics.php Accessed: March 1, 2008
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