How new tests help sort out OSD

They can make the diagnosis of ocular surface disease quicker, more accurate and affordable.

By Jodi Luchs, MD

Jodi Luchs, MD, is a member of the Cornea Service at Long Island Jewish/North Shore University Medical Center, and an assistant clinical professor at Hofstra University School of Medicine. Disclosure: Dr. Luchs disclosed relationships with Allergan, Alcon, Bausch + Lomb, InSite Vision, EyeGate and Optimedica.

All too often, busy ophthalmology practices have dismissed ocular surface disease (OSD) as a nuisance. It is a nuisance, of course — difficult to diagnose, with signs and symptoms similar to those of other diseases and thus difficult to treat. Given its prevalence, however, it’s our duty as clinicians to get to the bottom of this malady and provide relief.

Fortunately, some new tests offer quick, easy, accurate diagnosis. Here is a review of some that have greatly helped me help my patients with OSD.

TEARLAB OSMOLARITY SYSTEM

My practice began using this device, made by TearLab Corporation (San Diego, Calif.) in 2011, when we participated in a clinical trial. We were so pleased with its performance that we purchased it at the end of the trial.

Initially, I restricted its use to patients who complained specifically of dry eyes, but soon broadened its application. Now, I use it for anyone who presents with symptoms of grittiness, burning in the eyes, or foreign-body sensation.

The test consists of a hand-held device with a disposable sample collection card at the tip that picks up approximately 50 nL of tear film at the tear meniscus, which is then placed in a portable, counter top system reader (Figure 1). In seconds, the reader converts the tear fluid to an osmolarity score expressed in mOsm/L, which is displayed on an LCD panel.

1 TearLab’s Tear Osmolarity System

My technicians have become so proficient at administering the test that I have the results by the time the patient returns to the examination room. Your technicians should perform the TearLab test first because some of the other tests may require the patient to produce reflexive tears. Likewise, I do not instill any drops into the eyes or touch the eyes before performing the TearLab test, because sometimes just the process of measuring visual acuity slows the blink rate, which affects tear production.

2 TearScience’s LipiView

ONE PIECE OF A TOUGH PUZZLE

The TearLab is not the only test we use to diagnose dry eye. We also look at tear break-up times, fluorescein- and lissamine-green-staining patterns and Schirmer testing. We can talk for hours about the relative merits of these tests, but the bottom line is, we use all of them along with the patient-reported symptoms to put together a diagnosis of OSD.

A big disconnect can exist between symptoms and clinical signs in dry eye and OSD generally. Patients often have a symptom of dry eye disease with very few signs or vice versa. Patients may have significant signs of OSD and few symptoms, or significantly fewer symptoms than we would expect.

We are often surprised by what we see or what we hear from our patients as well as what we don’t see. The TearLab Osmolarity System is one additional instrument we have that can give us insight and help us treat our patients appropriately, sooner.

Cost/benefit analysis #1

Like most diagnostic tests, The TearLab test does cost money, but the good news is the cost per test decreases as the volume increases. The disposable tips for the device that processes the tear film cost $10 to $12 per unit. Insurance does cover the test, which helps offset the price. Some carriers pay less than the cost of the disposable tip, some pay more. On average, your practice should realize a few dollars per procedure, but you certainly won’t lose money.

The TearLab Osmolarity test can grow your practice in other ways. By using this test, you may diagnose and treat someone for dry eye earlier than you might have otherwise. Patients will be grateful for the relief and they will consider you an expert in this area. Grateful patients may bring in their relatives and friends, some of whom are sure to need other services you provide, such as cataract or refractive surgery. Further, you will see your dry eye patients more often to monitor their disease.

LIPIFLOW/LIPIVIEW SYSTEM

TearScience’s (Morrisville, N.C.) system for care of patients with meibomian gland dysfunction (MGD), or evaporative dry eye, uses tear interferometry to visualize and measure the thickness of the tear film lipid layer and then expresses the meibomian glands with a “thermal pulsation system.”

The system treats posterior blepharitis, by applying the heat and pressure required to open the blocked glands and get secretions to flow into the tears. Theoretically, using this therapy significantly improves the ocular surface and stabilizes the tear film. We can reduce evaporative dry eye and improve our patients’ symptoms.

With the LipiView, we can visualize the lipid layer of the tear film, which is helpful diagnostically and also post-treatment to monitor the response of the lipid layer to the therapy (Figure 2). It is a procedure I reserve and suggest for patients with posterior blepharitis.

Role in tear-film management

By definition, patients who have meibomian gland disease and posterior blepharitis have an abnormal tear film, which irritates the ocular surface. In the long term, tear film insufficiency can set them up for developing a secondary aqueous deficiency dry eye if the evaporative dry eye continues to irritate the ocular surface enough.

When I observe a patient is not responding to conventional treatment with warm compresses and topical azithromycin or oral doxycyline, I recommend treatment with the LipiFlow/LipiView system. I believe it can play a critical role in diagnosing and managing the abnormal tear film to keep the patient’s condition from worsening.

Cost/benefit analysis #2

Insurance does not cover the LipiView and LipiFlow, both the diagnostic and therapeutic applications. Not every patient is willing to pay out of pocket for the diagnostic test as well as the treatment. The associated costs are about $350 per eye for just the disposable activator for the LipiFlow treatment.

Administering the treatment is not inexpensive from the physician’s point of view, but given the cost of the device and disposables, I would be surprised, at least in the near term, if insurance companies cover it.

A significant advantage of this treatment — and something that you can educate your patients about — is the duration of its effect. It’s not as if the patients experience a few days of relief and then the effect is gone. The procedure offers some significant long-term relief.

Patients may experience months of improvement after the LipiFLow treatment, which can even be extended by continuing the conventional therapy for blepharitis after the treatment. Warm compresses, lid massage, topical treatment with azithromycin and oral doxycyline will help prolong the effect. With this in mind, a patient experiencing significant discomfort may be willing to pay for LipiFlow/LipiView.

3 The RPS AdenoPlus Detector

ADENOPLUS DETECTOR

Made by RPS (Sarasota, Fla.) and distributed by Nicox (Sophia Antipolis, France), the AdenoPlus is a point-of-care diagnostic test that takes a sample of the tear film from the conjunctival cul de sac (Figure 3).

In 10 minutes or less, the AdenoPlus Detector indicates whether the patient has adenovirus, the leading cause of pink eye. Most pink eye or conjunctivitis is caused by a virus, specifically the adenovirus, rather than bacteria. I have found this device provides an accurate answer within a few minutes. Usually the response time is even faster.

AdenoPlus is as easy to read as a pregnancy test — one line is negative and two lines is positive — with better than 90% sensitivity and specificity if the patient has adenovirus.

When I started using this test a couple years ago, I typically administered it to confirm adenovirus. Also, it’s an effective way to monitor if patients still are infectious when they return for their follow-up visits. I since started using the test more routinely whenever a patient presents with an acute red eye. I was surprised by the results.

A more precise diagnosis

As cornea specialists, we think we are pretty good at differentiating bacterial from viral conjunctivitis. However, a study published a number of years ago showed that even corneal specialists got it right only about 50% of the time.

I’m embarrassed to admit that my track record really is no better than that. About 50% of the time, I’m right. I didn’t know that until I had the AdenoPlus Detector to help me make more accurate diagnoses.

The AdenoPlus Detector has helped my patients because it tells us whether we need to treat them with antibiotics in the case of bacterial conjunctivitis, or if we need to consider other therapy if the infection is viral.

An accurate diagnosis is also important from a public-health standpoint: Adenovirus is extremely contagious, and the virus persists for up to two weeks. We need to make that diagnosis accurately so we can better counsel and treat our patients, and thus help limit the spread of the virus in the workplace or in school.

Cost/benefit analysis #3

Happily, payers reimburse for this test. The AdenoPlus test costs about $10. Like the TearLab Osmolarity System, reimbursement can vary: some pay more, some pay less. Generally, you will net a few dollars per test.

The test requires a small time investment. My technicians can do it while they work up the patient with red eye. I’ll have the results waiting when the patient arrives in the examination room.

Patients are certainly happy to see that I am using a new, modern tool to help make the diagnosis. It’s no different from like the rapid strep test or flu test that they see in the children’s pediatrician’s office.

Offering the AdenoPlus test in your practice makes you a better clinician, enables you to give better patient care and helps limit the spread of infectious disease — and it’s reimburseable.

DEMAND CREATING A GROWING SUPPLY

In addition to the tests I’ve discussed, the Tear Microassay System (Advanced Tear Diagnostics, Birmingham, Ala.) is another option. It takes a small sample of the tear film and looks at lactoferrin levels, a protein associated with dry eye. Low lactoferrin means the patient has dry eye, while higher levels indicate a more normal tear film. The same test can look for IgE in the tears as well for allergy. Both indications are reimbursable.

RPS has additional tests that it may introduce in the near future. One looks for herpes simplex virus, a dry eye test checks the levels of MMP9 — an inflammatory mediator in the tear film associated with dry eye — and even detect IgE in the tears, which is associated with allergy. These point-of-care diagnostic tests expanded to other ocular surface diseases should only make it easier for us to diagnose and manage red eye.

More of these point-of-care diagnostic tests are becoming available, both because ocular surface disease is so prevalent, creating a market for them, and because of the difficulty in diagnosing OSD due to the similar signs and symptoms and overlapping clinical findings of many of the diseases.

Fortunately for us and our patients, ophthalmic manufacturers are making diagnosis of OSD and other ocular conditions much easier. OM