Current Dry Eye Technology
Dry Eye Technology Update
A look at current diagnostic and management tools for dry eye.
|Dr. Gaume Giannoni is a clinical associate professor at the University of Houston College of Optometry and the Co-Director/Co-Founder of the Dry Eye Center at the University Eye Institute. She also sees patients in a private practice setting and has received authorship honoraria from Bausch + Lomb.|
Amber Gaume Giannoni, OD, FAAO
Properly diagnosing and successfully managing dry eye disease (DED) is challenging. If the underlying mechanism is incorrectly or poorly understood, your recommended treatment regimen will likely be ineffective. Keeping abreast of technological advances is one potential way to improve your ability to properly diagnose and treat your patients, regardless of the condition they have.
Following is a review of some of the current technology being used to diagnose and manage dry eye patients.
Rapid Diagnostic Devices (“Detectors”)
Osmolarity We’ve known for years that DED is associated with a concentrated tear film, and studies show that osmolarity is a potential marker of disease severity (Sullivan et al, 2010; Suzuki et al, 2010). Until recently, there hasn’t been an easy and quick in-office method to obtain and analyze tear samples. The TearLab Osmolarity System (TearLab Corp.) is an in-office lab test that can provide this information in seconds. It is extremely easy to use and poses no discomfort for patients (Figure 1). Combined with other diagnostic testing, tear osmolarity can be instrumental for initial diagnosis, disease staging, or to follow the efficacy of your treatment recommendations.
Figure 1. TearLab Osmolarity System.
Inflammation By definition, DED is associated with inflammation (Lemp et al, 2007). Significant research is currently being conducted worldwide to determine which inflammatory biomarkers are present in the tear films of dry eye sufferers.
One of these markers, matrix metalloproteinase-9, is thought to be associated with damage to the ocular surface. The RPS InflammaDry Detector Kit (Rapid Pathogen Screening) identifies levels of matrix metalloproteinase-9 in the tear film in an easy process, similar to that of the AdenoPlus RPS detector for adenovirus. If results are high, initial therapy should be aimed at controlling inflammation via steroids, cyclosporine, or other means.
InflammaDry is currently in clinical trials and is not commercially available in the United States, but it is available in Canada as well as internationally.
Meibomian gland assessments are imperative to conduct in every dry eye sufferer, especially for those who have symptoms but no obvious meibomian gland disease. A lid margin and tear film evaluation doesn’t provide enough information to adequately gauge the quality or quantity of meibomian gland secretions.
One quick and inexpensive way to investigate meibomian gland content is to perform gland expression. Numerous “expressors” are available on the market, including the Mastrota Meibomian Gland Paddle (Ocusoft), which basically functions as a back-stop when placed behind the lid, so external pressure can be applied without stressing the globe. Collins Expressor Forceps (Bruder Healthcare) provide simultaneous force to the anterior and posterior lid with one instrument, and other variations include expressors with roller-tips such as the Maskin Meibum Expressor (Rhein Medical) and the MG Expressor Kit (Gulden Ophthalmics).
Of course, it is impossible to standardize expression results with these instruments, as differing techniques allow examiners to apply varying forces. In an attempt to normalize results, The Meibomian Gland Evaluator (TearScience) was developed, which allows for the application of a constant force to the lid, irrespective of the examiner using it.
If you were to utilize one of the meibomian gland expression techniques discussed above and nothing materializes from the gland, is it an obstructive condition or an atrophic one? You can’t really answer this question without viewing the glands, unless you’d prefer to suffer with your patients through months of treatment failure before reaching the same conclusion.
A patient who has significant meibomian gland atrophy has little chance of achieving adequate symptom reduction with warm compresses alone—your recommended dry eye treatment protocol is only as good as your diagnosis. Traditional contact meibography involves retroilluminating the lower lid by everting it with a transilluminator head and viewing the glands through slit lamp oculars.
This works well with a little practice, and this information can ultimately impact patient management. For example, in the case of gland atrophy, you may still decide to prescribe lid therapy to aid in the preservation of remaining gland function, but it likely won’t address your patient’s symptoms. Knowing this in advance, you can employ concurrent therapy to manage your patient’s symptoms and reduce overall frustration during the management process.
Unfortunately, contact meibography is not very comfortable for patients, nor does it produce a visual for patient education. Infrared, non-contact meibomian gland imaging, obtained by instruments such as the Oculus Keratograph 5M (Oculus Inc.), or by coupling a long-wavelength video camera with a slit lamp, can be excellent diagnostic tools and teaching aids.
Many patients don’t easily understand the concept of these glands, let alone the notion of gland atrophy. I often show them an image of normal meibomian glands (Figure 2) followed by one that demonstrates significant gland atrophy (Figure 3). By the time they view their own image, they have a much better understanding of basic morphology, which can significantly improve compliance. In this case, a picture truly is worth a thousand words.
Figure 2. Infrared Meibography showing relatively normal meibomian glands. Slight shortening of a few of the nasal glands can be observed.
Figure 3. Infrared Meibography showing severe meibomian gland atrophy. Only a single gland is observed.
Photos courtesy of Dr. Kelly Nichols
The Oculus Keratograph 5M (Figure 4) also offers other objective measures for dry eye testing, including tear meniscus height, computerized classification of limbal and bulbar redness, and high-definition photos and video. It can also provide non-invasive computer-controlled testing of non-fluorescein tear breakup time (TBUT), which essentially removes two of the most common sources of TBUT testing error: differences in NaFl volume/concentration and practitioner-induced error.
Figure 4. Oculus Keratograph 5M.
In two distinct steps, the LipiView/LipiFlow Thermal Pulsation System (TearScience) analyzes blink patterns, quantifies lipid layer thickness, and expresses both the upper and lower meibomian glands. LipiView is performed as a first step, using white light interferometry.
An assessment of a patient’s blink and lipid layer is calculated to determine whether therapy with the LipiFlow device is appropriate. An innovative method to express meibomian gland contents, LipiFlow uses an eyepiece to heat the lids from the globe-side, while massaging the lids using inflatable bladders (Figure 5). One study indicates that a single treatment can improve meibomian gland function for up to 12 months (Greiner, 2011).
Figure 5. Lipiflow Thermal Pulsation System.
Although some feel that Lipiflow is unsuitable if partial meibomian gland atrophy exists, it could be argued that this is exactly the type of patient who could benefit the most from the treatment to preserve remaining meibomian gland function. It’s important to note that the LipiFlow system is not covered by insurance. It is relatively expensive, so as always, setting appropriate patient expectations and educating patients properly will go a long way to ensuring patient satisfaction.
One of the possible causes of meibomian gland obstruction is the formation of fibrovascular tissue within the gland. The Maskin Meibomian Gland Intraductal Probing System (Rhein Medical) was developed by Dr. Steve Maskin to address this issue. Stainless steel filaments are inserted into the meibomian gland opening to penetrate this fibrous tissue and restore normal gland function. It has been reported that patients often note immediate relief, and a single treatment can last anywhere from 12 to 18 months (Maskin, 2010). Moderate discomfort and mild bleeding are not uncommon.
Patient Management Tip
Although gland expression can be performed with a saline-soaked (to keep fibers at bay) cotton-tipped applicator, here is something to consider: many of our patients have already had unsuccessful visits with other practitioners for their dry eye complaints. In fact, believe it or not, most already have a lack of confidence in your ability to solve their problem before they walk in your office. That may decline further when you grab that same old cottontipped applicator that has been used on them 10 times before. “New” technology, even something as simple and inexpensive as an expressor paddle, can go a long way in earning some of that confidence back. It demonstrates to your patients that you are current with emerging technology, and that you don’t mind spending a little extra money on the front end to take better care of them.
Intense Pulsed Light Therapy
Intense pulsed light therapy (IPL) uses modified skin rejuvenation light (normally used to treat dermatological conditions such as rosacea and acne) to heat the meibomian glands and thin secretions, thus normalizing the gland over time.
Very little peer-reviewed data is available on IPL, but an abstract was recently presented on a small research study (Toyos, 2013) using IPL at the annual Association for Research in Vision and Ophthalmology meeting in Seattle. The 90-subject study was conducted over a 30-month period, and results indicated that 93 percent of patients were satisfied with their symptoms post-therapy. Examiners determined that improvement was found clinically in 87 percent of the patients after approximately seven treatment sessions and four maintenance visits. Dr. Toyos recommends maintenance visits for patients every six to 12 months (Kent, 2013).
As professionals, it is vital to at least be aware of new technology in eye care, whatever our particular specialty. Patients have asked me about my thoughts on specific, revolutionary dry eye treatments, often before many of my colleagues have heard of them. When I ask where they’ve learned this information, nearly all have responded, “through dry eye blogs and forums.” In the age of fingertip information, our patients are more knowledgeable than ever and they share their experiences via the internet with others across the world. In the words of a colleague, “We constantly need to educate ourselves on new and emerging technology in all aspects of eye care. As the experts, it’s a tough pill to swallow when you are introduced to cutting-edge technology by your patient.” CLS
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