Rationale for Aggressive Management of MGD

It may be time to expand our thinking on MGD detection and treatment.

By Preeya K. Gupta, MD

In recent years, it has been increasingly recognized that meibomian gland dysfunction (MGD) may be the leading cause of dry eye disease.1 Meibomian gland obstruction and reduced meibum production play a central role in destabilizing the tear film, resulting in symptoms of eye dryness, irritation, inflammation, and ocular surface disease.2 Yet MGD remains an underdiagnosed entity. In part, this is because not all cases of MGD can be identified based on morphologic changes.3 Recognizing more subtle cases sometimes requires an understanding of the functionality of the glands themselves.4

Studies have reported a wide range of MGD prevalence, from as low as 3.5% to as high as 70%.5-10 Because these studies used different definitions and approaches to identifying MGD prevalence, there is not a clear picture of how many patients might have MGD requiring treatment. However, a number of ophthalmic, systemic, and therapeutic risk factors have been identified.

One intriguing question that has arisen regarding MGD risk factors is whether the increased use of digital devices is a causative factor. This may be one of the reasons behind an apparent epidemiologic shift in the characteristic types of patients affected by MGD, with younger patients now more likely to experience its effects.

The subtle morphology in many cases of MGD, the apparent increase in its prevalence, and the shifting demographics of the disease all argue for a more aggressive approach to treatment. My rationale for this statement is set forth in the remainder of this article.

CHANGING DEMOGRAPHICS

One obvious reason for what seems like a recent rise in MGD prevalence may be the availability of better diagnostics and better treatments. Our enhanced ability to detect MGD allows us to intervene early in its course. Access to better diagnostics has also led to increased awareness of MGD in the eye care community, with the result that more patients are being diagnosed and treated.

Greater awareness of MGD is undoubtedly needed. Its association with dry eye disease has been well documented, as noted.1 Beyond eye dryness, however, MGD is also an important cause of visual symptoms in its own right, including eyelid irritation, redness, swelling, and other symptoms.

One consequence of better MGD diagnostics is a greater realization of MGD prevalence in populations we previously thought were not much affected. This, coupled with an increase in the use of digital devices, is causing a shift in the demographic profile of the typical MGD patient. The classical thinking is that an elderly patient with a history of recent ocular surgery might be the most likely to experience MGD. In my practice, however, men and women in their 30s and 40s are now the most likely to have MGD. The role of digital devices in this shift has not been clearly or definitively elucidated, but it is my sense that staring at a digital device reduces the blink rate, which in turn yields less stimulation of secretion by the meibomian glands, leading over time to development of MGD.

The changing demographics of MGD presents a clinical challenge. Because the thinking has been to look for signs and symptoms in older individuals, the disease may be underreported and underdiagnosed among those outside the classic patient profile. The danger here is that, because MGD is progressive and chronic, failure to recognize it and intervene early may lead to worse outcomes.

In addition, because MGD can lead to instability in the tear film, and because the tear film is an important refracting surface, undetected MGD can affect the accuracy of keratometry and biometry readings. When MGD is missed, therefore, it may lead to suboptimal refractive outcomes after refractive or cataract surgery.

SCREENING AND ADVANCED DIAGNOSTICS

A questionnaire can be a useful adjunct to quickly screen and identify patients in need of additional evaluation for MGD. Expanding the pool of patients who fill out the Ocular Surface Disease Index or Standard Patient Evaluation of Eye Dryness questionnaires could help to identify unknown MGD in nonclassic patients, such as young patients and those with early symptoms of MGD.

Once MGD is identified, additional clinical tools can help to build the patient’s profile. I have a pretty low barrier to suggest additional workup for MGD if questionnaire responses are suggestive of disease. To that end, meibography with Dynamic Meibomian Imaging on the LipiView II (TearScience) has become an indispensible tool for diagnosis and patient education. The old adage that a picture is worth 1,000 words is definitely true. Imaging also helps to assess the severity of the MGD. Both of these factors can be important for educating young or seemingly asymptomatic patients that they have gland atrophy that must be treated. This is especially important if there is a disconnect between the patient’s signs and symptoms, which is often the case with dry eye disease, whatever the cause.

Watch it Now

Preeya K. Gupta, MD, speaks with Mark Kontos, MD, and Brandon Ayres, MD, about the challenges associated with ocular surface disease.

Meibography is performed at baseline assessment. Other tests may be performed during an initial encounter and then repeated over time to provide an index of the effectiveness of treatment. These include lipid layer analysis with the LipiView II, tear osmolarity testing (TearLab), and the InflammaDry point-of-care test (Rapid Pathogen Screening). There is often a lag time between when treatment is started and when patients start to feel relief from their symptoms, so these tests can help to reassure patients that treatment is in fact working.

THOUGHTS ON TREATMENT

Once MGD has been detected and quantified, our final goal is to provide the patient with a treatment approach that has been shown to be safe and effective. The LipiFlow Thermal Pulsation Device (TearScience) has been shown in multiple peer-reviewed reports and multicenter clinical trials to effectively clear obstruction in the meibomian glands.11 Removing the obstruction and returning the gland to normal function is key to treating the underlying problem and relieving symptoms.

There can be a lag time between initiation of treatment with thermal pulsation and the consequent normalization of the tear film (in my experience, between 2 and 4 months). Therefore, it is prudent to set expectations for patients so that they can be assured the treatment needs time to work.

The approach to MGD must be individualized for each patient. As with aqueous deficient dry eye disease, different factors on different days may have different effects on the health of the ocular surface in the patient with MGD. There is no one-size-fits-all strategy to address MGD, although it is safe to say that an aggressive approach to identifying it early and intervening appropriately is likely to achieve the outcomes our patients desire. n

1. Nichols KK, Foulks GN, Bron AJ, et al. The international workshop on meibomian gland dysfunction: executive summary. Invest Ophthalmol Vis Sci. 2011;52(4):1922-1929.

2. Nelson JD, Shimazaki J, Benitez-del-Castillo JM, et al. The international workshop on meibomian gland dysfunction: report of the definition and classification subcommittee. Invest Ophthalmol Vis Sci. 2011;52(4):1930-1937.

3. Foulks GN, Bron AJ. Meibomian gland dysfunction: a clinical scheme for description, diagnosis, classification, and grading. Ocul Surf. 2003;1(3):107-126.

4. Blackie CA, Korb DR, Knop E, et al. Nonobvious obstructive meibomian gland dysfunction. Cornea. 2010;29(12):1333-1245.

5. Schein OD, Munoz B, Tielsch JM, Bandeen-Roche K, West S. Prevalence of dry eye among the elderly. Am J Ophthalmol. 1997;124:723-728.

6. Lekhanont K, Rojanaporn D, Chuck RS, Vongthongsri A. Prevalence of dry eye in Bangkok, Thailand. Cornea. 2006;25:1162-1167.

7. Lin PY, Tsai SY, Cheng CY, et al. Prevalence of dry eye among an elderly Chinese population in Taiwan: The Shihpai Eye Study. Ophthalmology. 2003;110:1096-1101.

8. Uchino M, Dogru M, Yagi Y. The features of dry eye disease in a Japanese elderly population. Optom Vis Sci. 2006;83:797-802.

9. Jie Y, Xu L, Wu YY, Jonas JB. Prevalence of dry eye among adult Chinese in the Beijing Eye Study. Eye (Lond). 2009;23:688-693.

10. McCarty CA, Bansal AK, Livingston PM, et al. The epidemiology of dry eye in Melbourne, Australia. Ophthalmology. 1998;105:1114-1119.

11. Blackie CA, Carlson AN, Korb DR. Treatment for meibomian gland dysfunction and dry eye symptoms with a single-dose vectored thermal pulsation: a review. Curr Opin Ophthalmol. 2015;26(4):306-313.

Preeya K. Gupta, MD
• Assistant professor of ophthalmology, division of cornea and refractive surgery, Duke University Eye Center
• Clinical director, Duke Eye Center
• (919) 660-5071; preeya.gupta@duke.edu
• Financial disclosure: consultant to Allergan, Biotissue, Shire, and TearScience