Staging Meibomian Gland Disease
Staging Meibomian Gland Disease
The MGD Workshop has given us an objective means to evaluate our patients.
By Kelly K. Nichols, OD, MPH, PhD
Our profession has increased its focus on ocular surface disease in recent years — how it affects quality of life, vision, ocular health and surgical outcomes. Any acknowledgement of a medical problem comes with a desire for objective definitions and criteria, and the International Workshop on Meibomian Gland Dysfuction (MGD Workshop) has provided just such an algorithm for this critical element of dry eye. Based on test results, it allows you to stage the disease and identify the recommended treatment for your patient.
Testing and Treatment
MGD staging is based on three key features:
2. lid appearance and meibomian gland secretions
3. ocular surface staining.
When you express the meibomian glands, you rate the clarity and consistency of the secretions, from 0, clear and thin, to 4, opaque white and thick. You'll also rate the glands' expressibility — consider a 4-3-2-1 scale where you assess the number of glands from the central inferior 8 that express. If ≥4 glands express, that is “normal,” 3 is “mildly reduced,” 2 is “moderately reduced,” and ≤1 is “significantly reduced.”
Recommended dyes include fluorescein for the cornea and lissamine green for the conjunctiva. Staining scores follow standard Oxford and DEWS scales.
Based on these factors, the MGD workshop recommends treatments for each stage of MGD. The evidence-based recommendations are compiled from retrospective study of various modalities, as well as an examination of what is commonly prescribed in practice.
Treatments for mild MGD start out benign, and as the disease stage increases, treatment evolves into more of a therapeutic approach. Treatments for each stage are additions to those listed for lower stages.
The Tear Film & Ocular Surface Society offers the algorithm online for free (tearfilm.org/pdfs/TFOS_Mgd_Report_Overview.pdf).
At Stage 1, patients are asymptomatic. Secretion clarity is ≥2 to <4 when a sum of each gland is taken, or has an overall slight cloudiness, with an expressibility of 1 (easy). There is no ocular surface staining. At this point, the patient may or may not have a problem. Explain what MGD is and how diet, environment and medications may affect the condition. If you think it would benefit the patient, recommend warm compresses, hygiene and massage once or twice a day.
Patients with Stage 2 MGD have a few mild discomfort issues, itching or photophobia. You see scattered lid margin features, and secretions show some cloudiness (rate ≥4 to <8 when a sum of each gland is taken) with an expressibility of 1 (easy). They might have limited staining — DEWS 0 to 7 (diffuse), Oxford 0 to 3 — or none at all. In addition to Stage 1 treatments, talk about dry environments, lifestyle changes like workstations, and omega-3 supplements. Implement the lid hygiene, compresses and massage. Recommend artificial lubricants, a topical emollient lubricant or liposomal spray, and consider topical azithromycin, and oral tetracycline (especially for rosacea patients).
Stage 3 patients have moderate symptoms that limit their activities. In addition to scattered lid margin features, patients have plugging and vascularity. Secretions are graded ≥8 to <13 (sum score, generally cloudy, possibly granular) with an expressibility of 2 (some difficulty). Conjunctival and peripheral corneal staining, often inferior, is mild to moderate (DEWS 8 to 23, Oxford 4 to 10). Additional treatments include oral tetracycline, nighttime lubricant ointment, and anti-inflammatory dry eye therapy (cyclosporine emulsion, Restasis, Allergan) should be considered.
Finally, patients with Stage 4 MGD have significant discomfort, itching or photophobia with noticeable limitation of activities. You see dropout or posterior displacement (dragging) of the meibomian orifices on the lids. Secretions are severely altered, rating >13 (granular to opaque) with an expressibility of 3 (very difficult). Central staining is visible in addition to diffuse, multi-region staining (DEWS 24 to 33, Oxford 11 to 15). Signs of inflammation, such as moderate conjunctival hyperemia or phlyctenules, also can be apparent. Add anti-inflammatory treatment for dry eye, if not prescribed previously. Topical steroids also may be a short-term adjunctive therapy.
Why Use the Algorithm?
The MGD Workshop has given us something that's not always easy to find: objectivity. Whether you're planning to participate in ocular surface disease studies, looking for baseline data for treatment, or simply looking for the best evidence-based treatment for your patients, it's an excellent guideline.
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.
Nichols KK, Foulks GN, Bron AJ, et al. The International Workshop on Meibomian Gland Dysfunction: Executive summary. Invest Ophthalmol Vis Sci. 2011;52(4):1922-1999.
Optometric Management, Issue: September 2011