Managing contagion in a clinical setting

May 1, 2014

Eye-care professionals can employ a variety of techniques and diagnostic technologies to identify infection, eliminate it, and improve outcomes for their patients.

 

Take-home

Eye-care professionals can employ a variety of techniques and diagnostic technologies to identify infection, eliminate it, and improve outcomes for their patients.

 

By Francis S. Mah, MD, Special to Ophthalmology Times

San Diego, CA-It is the responsibility of eye-care professionals (ECPs) to prioritize management of contagion in a clinical setting in order to avoid a potential ocular infectious epidemic. Progressive techniques and diagnostic technologies have made it possible to identify infection, eliminate it, and improve the outcomes of patients we treat.

Medical implications

The number of infectious, contagious patients I counsel per week varies as there is a season for infections that changes depending on the time of year. For example, over the past summer and fall in San Diego, CA, there was an epidemic of adenoviral conjunctivitis and epidemic keratoconjunctivitis (EKC).

During that time, I treated one to two infectious patients per day when, in general, I see two to three infectious patients per week. The medical implications of improper management of an infectious disease affects both local communities and clinics. If there is an epidemic, there is a greater number of people and a greater amount of health-care dollars being spent to care for these patients.

The ripple effect is that adults and children who are infected lose days from work and school. There are additional costs associated with providing a babysitter, nanny, or having a parent stay home from work to care for an ill child.

 

Reducing infection

Certain tactics and technologies can be employed to reduce infections and improve outcomes. For example, if an urgent or primary-care physician refers a person to my clinic, and my colleagues and I want to rule out or confirm if the patient has adenoviral conjunctivitis, then we follow a red eye protocol.

When the patient presents to the office, instead of having him or her sign in and sit in the waiting room where he or she can infect others or contaminate the waiting room, we send the patient directly to what we refer to as a “red eye room,” a reserved work-up room. We do this because the adenovirus is so hearty that it can live on inanimate objects for a long period. It can live on magazines, pens, or even a cloth for days or weeks, depending on how hard the object is. We don't want the patient to sit and converse with other people and touch things in the office because adenovirus spreads on contact.

Once the patient is in the red eye room, every caretaker who sees the patient first washes their hands and, unfortunately, does not shake the patient's hands. Right away, we administer a point-of-care, rapid diagnostic test (AdenoPlus, Nicox, Inc.) that helps differentiate adenovirus from other similarly presenting causes of red eye. We use the test in our urgent care and our pediatric offices. The test results only take a couple of minutes to appear, and during that time we take the patient’s history and conduct an examination. As is pretty well known, it's difficult even for a seasoned, experienced clinician to identify the cause of conjunctivitis-whether it's allergic, toxic, bacterial, viral, or otherwise infectious.

If the patient tests positive, we educate the patient on hygiene and ways to avoid contagion. We have the patient return in a couple of weeks to be examined for subepithelial infiltrates.

If the patient tests negative, then we know to consider other possibilities, but the diagnostic test is our key dividing point.

 

After ruling out infection

If a patient looks as if he or she may have allergic conjunctivitis, meaning the patient has tearing and redness with itching as a primary symptom, then it is possible to perform a pinprick test for allergic conjunctivitis (Allergy RX, Doctors RX). It is made with 40 plastic pinpricks of allergens that are found in a particular region.

For example, I reside in San Diego, so the test I might use contains the 40 most common environmental allergens found in the region, including specific trees, weeds, and grasses. The pinprick test can increase the identification of atopic individuals and therefore increase referrals to our allergy and immunology colleagues.

If a patient has inflammation on the ocular surface, it is possible the patient may have dry eye disease. To confirm, an in-office test (InflammaDry, Rapid Pathogen Screening Inc.) that detects MMP-9, an inflammatory marker that is consistently elevated in the tears of patients with dry eye disease can now be used. MMP-9 has been found to be a very specific marker for ocular surface inflammation.1

For example, in an eye with minimal symptoms-but possibly a foreign body sensation-the test can determine if there is inflammation on the ocular surface, which could point us in the direction of dry eyes. Using an ocular surface interferometer (LipiView, TearScience) to measure the absolute thickness of the tear film lipid layer by analyzing more than 1 billion data points of the interferometric image of the tear film can also assist in the diagnosis of ocular surface inflammation. It helps test for meibomian gland dysfunction, and a test to measure tear osmolarity (TearLab Osmolarity Test, TearLab) as osmolarity values above 308 msOsms/L are indicative of dry eye disease.2

More and more tests are becoming available that help delineate which direction the ECP should go as far as treatment is concerned. Additionally, a new diagnostic test (Sjö, Nicox Inc.) has recently been made available in the United States. This test can detect Sjögren’s syndrome in patients with dry eye at an earlier stage than traditional diagnostic methods.

 

Case study

A 41-year-old male machinist presented with foreign body sensation and redness OU, which he had been experiencing for 2 weeks (Figure 1).

He was treated with trifluorothymidine q1h, tobramycyin QID, and neomycin-bacitracin-polytrim QID. He also received tetracaine drops, topical steroids drops, and methylprednisolone acetate injectable suspension injections OU and penicillin intramuscular injections twice over the 2-week span. Upon examination, the patient had a visual acuity of 20/70 OD and 20/20 OS. Examination of his eyelids revealed swelling OU. His conjunctiva had follicles and erythema OU, and his cornea had early subepithelial infiltrates OU (Figure 2).

EKC and medicamentosa was diagnosed with the test for adenoviral conjunctivitis (AdenoPlus, Nicox Inc.) 10 days after presentation. Research has proven that conjunctivitis cases are misdiagnosed 50% of the time.3

Just as in this case, antibiotics were ineffective against the viral form of the infection, yet are prescribed in up to 95% of cases.4

Employing certain tactics and technologies helps to reduce infections and improve outcomes in patients. Diagnosing diseases accurately when they first present reduces costs and increases efficiency and patient satisfaction.

 

References

1. Chotikavanich S, de Paiva CS, Li de Q, et al. Production and activity of matrix metalloproteinase-9 on the ocular surface increase in dysfunctional tear syndrome. Invest Ophthalmol Vis Sci. 2009ul;50:3203-3209.

2. Sullivan BD, Crews LA, Sonmez B, et al. Clinical utility of objective tests for dry eye disease: variability over time and implications for clinical trials and disease management. Cornea. 2012;31:1000-1008.

3. O’Brien TP, Jeng BH, McDonald M, et al. Acute conjunctivitis: truth and misconceptions. Curr Med Res Opin. 2009;25:1953-1961.

4. Everitt H, Little P. How do GPs diagnose and manage acute conjunctivitis: a GP survey. Fam Prac. 2002;19:658-660.

 

Francis S. Mah, MD, is director of cornea and external disease and co-director of refractive surgery, Scripps Clinic, La Jolla, CA. He is a consultant to Nicox Inc. Readers may contact Dr. Mah at 858/554-7996 or mah.francis@scrippshealth.org.