Meibomian gland imaging clearly has a role, yet most practitioners aren’t looking at meibomian glands at all.
Optometrists have considered meibomian gland dysfunction (MGD) as an age-related disease; however, meibomian gland dropout is now being noted in the younger population, especially in females for unknown reasons.5 Every day we see MGD patients in our practices. Dry eye and ocular irritation are common reasons that patients seek eye care.6
Meibomian gland imaging was first described in 1977, using a transillumination technique. Meibography allows evaluation of the gland structure and may help in the diagnosis and treatment of MGD. Thanks to advances in technology, we now have access to high quality imaging in everyday practice.
Meibomian gland imaging clearly has a role, yet most practitioners aren’t looking at meibomian glands at all.7 Possible reasons for this may include lack of time, MGD is not sight threatening, patients may not comply unless overtly symptomatic, and they may not see it as a profitable endeavor.
Previously from Dr. Schachter: Dry eye checklist may help ODs treat patients more efficiently
Dry eye disease overall affects an increasing number of Americans and is expected to affect approximately 29 million by 2022.1 The Beaver Dam Offspring Study showed dry eye prevalence of 14.5 percent,2 of which, studies have shown meibomian gland dysfunction (MGD) prevalence of 78 percent to 86 percent.3,4
Meibomian gland dysfunction has many untoward effects. Studies have shown increased ocular symptoms such as itching, burning, watering and redness, thickened meibum, increased superficial punctate keratitis, and decreased tear film break-up time.8
Not only are patients uncomfortable, vison is adversely affected.9 When a tear film breaks up uniformly, the most power change possible across the ocular surface is 0.10 D. When it breaks up irregularly, power changes of up to 1.30 D can occur, causing higher order aberrations.10 This can cause blurred, fluctuating vision and can also result in inaccurate preoperative measurements prior to refractive and cataract surgery.
In addition, two recent studies have shown a correlation between cardiovascular disease and MGD, underscoring its potential significance to overall patient health.10,11
Meibomian glands are sebaceous glands of the eyelid that secrete meibum, which prevents evaporation of the tear film. The upper lid has between 25 and 40 glands that are about 5.5 mm long, and the lower lid has 20 to 30 glands that are approximately 2.5 mm long. A gland consists of a central duct and ductules connecting to acini. Each gland has 10 to 15 acini. The orifice opens onto the eyelid, just anterior to the Line of Marx. The longer upper glands may appear more tortuous, while the lower glands tend to be wider. Their appearance has been compared to a chain of onions.
Meibum is produced in acini by meibocytes and consists of a multitude of compounds, including lipids containing wax and cholesterol esters. The meibum moves through small ductules to the central duct, then toward the orifice. Constant secretion and blinking push meibum to the lid surface by the orbicularis oculi and Riolan’s muscle, located at the duct terminus.
Of significance, meibum in MGD patients contains fewer terpenoids and more proteins which can lead to thicker secretions, possibly plugging the gland. Terpenoids have antimycobacterial properties and are precursors to cholesterol esters, which can lead to decreased surface stability.12 Interestingly, the terpene Terpinen-4-ol is toxic to demodex.13 Perhaps fewer terpenes can lead to demodex brevis infestation in meibomian glands.
Related: How digital device usage is affecting youth
Several commercially available devices offer in-office imaging of meibomian glands. TearScience offers LipiView II and LipiScan, Oculus offers Keratograph 5M, and the newest device available is Meibox by Box Medical Systems. All three utilize infrared light for imaging. Imaging both lower lids takes a skilled tech approximately two minutes, including entering patient information.
Unique to LipiView, launched in 2014, is differing illumination to better view meibomian glands (Figure 4A-C).
• Dynamic illumination features surface lighting originating from multiple light sources to minimize reflection
• Adaptive transillumination changes the light intensity across the surface of the illuminator to compensate for lid thickness variations between patients
• Dual mode illumination is a combination of dynamic illumination and adaptive transillumination. It offers a multidimensional view of meibomian gland structure, resulting in the clearest gland imaging of current devices
In addition to imaging gland structure, the device measures lipid layer thickness to the sub-micron level and allows visualization of blink quantity and quality. When staring at devices, not only does blink quantity suffer, so does blink completeness.14 This feature can help to educate patients about the importance of blinking completely and taking breaks from excessive device use. Measuring lipid layer thickness is useful after treating patients, in particular with LipiFlow. Expect to see a thicker lipid layer after treatment.
Proprietary algorithms measure the extent of lid closure during each blink. These parameters are useful in patient education, counseling patients, and monitoring effectiveness of therapy.
Related: Understanding and defining MGD
In 2015, Tear Science released LipiScan, the first dedicated rapid high definition imager. It has a smaller footprint and lower price point than LipiView II. Image quality is excellent, although not quite as sharp as LipiView II.
According to the company, pricing for LipiScan Dynamic Meibomian Imaging (stand alone, fully contained) is $19,950, which includes installation, training, 1-year warranty, ongoing live support by phone and in-field sales/support team.
LipiView II with Dynamic Meibomian Imaging, Interferometry, Blink Dynamics (stand alone, fully contained) is $36,950, which includes installation, training, 1-year warranty, ongoing live support by phone and in-field sales/support team.
Keratograph 5M is a corneal topographer with a dry eye module. In addition to imaging meibomian glands, it can measure tear film break-up time, conjunctival redness, and tear meniscus (Figure 5).
Unique to Oculus is its JENVIS report, a pentagon-shaped report of five parameters:
Non-invasive tear film break-up time
• Conjunctival folds
• Tear meniscus.
This report allows practitioners to follow treatment success through the use of these analytics. Recent updates to the software include a 0-3 comparison scale to help grade atrophy level.
Image acquisition, especially of the upper lids, can be tricky. Better images are obtained if two people get the image-one holding the lids, the other capturing the image.
Keratograph 5M is a stand-alone device with its own computer and table. Image quality is good, but less sharp than the Tear Science devices.
According to the company, pricing for Keratograph 5M is $24,995, which includes PC, table, device, installation, training, 1-year warranty, lifetime updates, and online and phone support.
Related: Pros and cons of available MGD treatments
The newest addition to meibomian gland imaging is Meibox from Box Medical Solutions, which launched earlier this year.
This high-definition camera is portable, cloud based, and mounted on the slit lamp. Meibox features a versatile meibographer that can be moved room to room as a technician or doctor works up a patient for dry eye.
For clinics with a smaller footprint, Meibox allows smaller offices to enter the dry eye arena without huge space requirements and financial investments. For larger clinics with multiple doctors, a centralized location may make more sense depending on patient flow.
With cloud-based imaging, images can be pulled from any PC computer (Figures 6 and 7). For larger clinics with multiple doctors, an optional central imaging platform allows doctors to have a central testing station for patients. HD resolution is especially impressive when images are pulled up on a large flat screen TV.
Currently, Meibox offers only a streamlined imaging solution; however, according to the company, tear meniscus measurements, data plotting, and analytics are scheduled to be released in the next six months. Image quality is similar to that of LipiScan.
According to the company, pricing is $8,950, which includes Meibox, USB extender, remote installation and training, 1-year warranty, meibography updates, business plan guide, implementation guide, and access to clinical support documents.
Related: How MGD can work for your practice
Meiboscore and Meiboscale are two commonly used grading scales for MGD morphology.
Arita developed the Meiboscore system in 2008.15 It is based on area of the lid that is affected by gland dropout; scores range from 0 to 6.
0: Lid has no partial or missing glands
1: Involved lid area is <33 percent
2: Involved lid area is 33 to 66 percent
3: Involved lid area is >66 percent
Meiboscores for the upper and lower eyelids are summed by side to derive a total meiboscore from 0 through 6 per eye.
Meiboscale was proposed by Heiko Pult, OD, and validated in 2012. The five-grade pictorial scale is based on area of loss. Intra-observer and inter-observer agreement was better than a four-grade scale. Pult found, however, that computerized grading was superior to both. Expect to see this commercially available in the near future.16
Aside from gland dropout, we also see tortuosity and dilation. As the meibum thickens, the gland becomes dilated and tortuous. Halleran et al found that glands of the upper lid showed more tortuosity than those of the lower lids, emphasizing the need to image both upper and lower lids.17
Related: A stepwise approach to diagnosing MGD
Incorporating imaging into clinical practice has many advantages.
Being able to show patients what their glands look like is very useful in making patients part of the process. Engaging patients in this manner can increase treatment compliance.
Imaging also is very useful in making the correct diagnosis. Stage the level of disease by using one of the available grading scales. Pick one you like and stick with it. This apples-to apples-comparison is necessary to monitor disease progression and the effectiveness of your treatment.
Embracing this new technology can be a practice differentiator, and you will be seen as a resource for dry eye patients.
Once the diagnosis is made, can intervene and help these patients. Standard treatments for MGD include warm compresses, omega-3s, artificial tears, and gentle expression. LipiFlow can be very effective for patients with thickened meibum or obstructed glands. A lesser known procedure is debriding scale, which can improve signs and symptoms one month post-treatment and can be performed in-office.
Keep in mind that MGD does not mean the absence of inflammation. A recent study showed that an MGD group with hyperosmolarity exhibited high levels of the proinflammatory cytokine IFN-Î³ 15, which programs cell death for goblet cells.18 Anti-inflammatories should be part of the treatment plan if inflammation is suspected.
Some practitioners support intense pulsed light (IPL) as a treatment for meibomian gland dysfunction. Dell and colleagues showed improved signs and symptoms at 15 weeks following a series of treatments.19
Related: Understanding the link between MGD and OSD
Without question, time is of the essence in day-to-day practice. Carefully choose where to spend time with patients. Certain tests are standard of care-beyond that, we must look at clinical value and time spent obtaining information.
MGD is a common condition seen in practices daily. There is value in obtaining baseline images on your dry eye patients. In the same way we need to see progressive nerve atrophy to diagnose glaucoma, we may need to see progressive meibomian gland atrophy to help diagnose MGD.
We are seeing what appears to be abnormal glands in kids as young as age 10. The question is, what did the glands look like at age 8? Were they ever normal in that patient? Is the gland appearance congenital?
Following are several ways to put meibomian gland imaging into place:
• Make gland imaging part of pre-testing. For most devices, it takes about 2 minutes to enter data and capture the lower lids. For pre-test image capture, it may be best to obtain a baseline image at comprehensive exams, and re-image as symptoms warrant
• Screen and image as needed. Use a dry eye survey, such as Standard Patient Evaluation of Eye Dryness (SPEED) or Ocular Surface Disease Index (OSDI), and image patients who have symptoms. Another option is to screen with a transilluminator, which takes seconds, and image abnormal gland appearance is seen
• Bring patients back for a dry eye workup visit. In this scenario, ask patients with signs or symptoms to return for further evaluation
Related: Incorporating meibomian gland imaging
In the same way optometrists follow changes in the nerve fiber layer in glaucoma patients, I propose we obtain baseline meibomian gland imaging on all dry eye patients in order to follow for progression. Databases need to be established so practitioners know what is “normal.”
There is still much to learn about MGD. In-office imaging is a step in the right direction.
1. The Gallup Organization, Inc. The 2012 Gallup Study of Dry Eye Sufferers, 2012.
2. Paulsen AJ, Cruickshanks KJ, Fischer ME, Huang GH, Klein BE, Klein R, Dalton DS. Dry eye in the beaver dam offspring study: prevalence, risk factors, and health-related quality of life. Am J Ophthalmol. 2014 Apr;157(4):799-806.
3. Horwath-Winter J, Berghold A, Schmut O, Floegel I, Solhdju V, Bodner E, Schwantzer G, Haller-Schober EM. Evaluation of the clinical course of dry eye syndrome. Arch Ophthalmol. 2003 Oct; 121(10):1364-8.
4. Lemp MA, Crews LA, Bron AJ, Foulks GN, Sullivan BD. Distribution of aqueous-deficient and evaporative dry eye in a clinic-based patient cohort: a retrospective study. Cornea. 2012 May;31:472-8.
5. Schachter S, Schachter A, Kwan J, Hom M. Gender differences of meibomian gland atrophy in a younger population. Poster presented at American Academy of Optometry annual meeting: November 9-12, 2016; Anaheim, CA.
6 Schein OD, MuÃ±oz B, Tielsch JM, Bandeen-Roche K, West S. Prevalence of dry eye among the elderly. Am J Ophthalmol. 1997 Dec;124(6):723-8.
7. Schacter S, Schachter A, O’Dell L, Hom M. A dry eye survey of practicing optometrists. Poster presented at American Academy of Optometry annual meeting: November 9-12, 2016; Anaheim, CA.
8. Arita R, Itoh K, Maeda S, Maeda K, Furuta A, Fukuoka S, Tomidokoro A, Amano S. Proposed diagnostic criteria for obstructive meibomian gland dysfunction. Ophthalmology. 2009 Nov;116(11):2058-63.e1
9. Kaido M, Matsumoto Y, Shigeno Y, Ishida R, Dogru M, Tsubota K. Corneal fluorescein staining correlates with visual function in dry eye patients. Invest Ophthalmol Vis Sci. 2011 Dec 16;52(13):9516-22.
10. Viso E, RodrÃguez-Ares MT, Abelenda D, OubiÃ±a B, Gude F. Prevalence of asymptomatic and symptomatic meibomian gland dysfunction in the general population of Spain. Invest Ophthalmol Vis Sci. 2012 May 4;53(6):2601-6.
11. Chen HC, Chen CT, Chen HT, Hwang YS, Lin HS, Ma D. Relationships of meibomian gland dysfunction and cardiovascular disease risk factors in a middle-aged population. Invest Ophthalmol Vis Sci. 2013 June;54(15):5431.
12. Borchman D, Foulks GN, Yappert MC, Milliner SE. Differences in human meibum lipid composition with meibomian gland dysfunction using NMR and principal component analysis. Invest Ophthalmol Vis Sci. 2012 Jan 25;53(1):337-47.
13. Gao YY, Tseng S. Method for treating ocular demodex. U.S. Patent No. 8,865,232. 21 Oct 2014. Available at: patentimages.storage.googleapis.com/pdfs/US8865232.pdf. Accessed 8/8/17.
14. ArgilÃ©s M, Cardona G, PÃ©rez-CabrÃ© E, RodrÃguez M. Rate and Incomplete Blinks in Six Different Controlled Hard-Copy and Electronic Reading Conditions. Invest Ophthalmol Vis Sci. 2015 Oct;56(11):6679-85.
15. Arita R, Itoh K, Inoue K, Amano S. Noncontact infrared meibography to document age-related changes of the meibomian glands in a normal population. Ophthalmology. 2008 May;115(5):911-5.
16. Pult H, Riede-Pult BH, Nichols JJ. Relation between upper and lower lids' meibomian gland morphology, tear film, and dry eye. Optom Vis Sci. 2012 Mar;89(3):E310-5.
17. Halleran CC, Kwan J, Hom MM, Harthan J. Agreement in Reading Centre Grading of Meibomian Gland Tortuosity and Atrophy. Poster presented at American Academy of Optometry annual meeting: November 9-12, 2016; Anaheim, CA.
18. Jackson DC, Zeng W, Wong CY, Mifsud EJ, Williamson NA, Ang CS, Vingrys AJ, Downie LE. Tear Interferon-Gamma as a Biomarker for Evaporative Dry Eye DiseaseTear Interferon-Gamma in Dry Eye Disease. Invest Ophthalmol Vis Sci. 2016 Sep 1;57(11):4824-4830.
19. Dell SJ, Gaster RN, Barbarino SC, Cunningham DN. Prospective evaluation of intense pulsed light and meibomian gland expression efficacy on relieving signs and symptoms of dry eye disease due to meibomian gland dysfunction. Clin Ophthalmol. 2017 May 2;11:817-827.