The Critical Importance of Looking for MGD in Dry Eye Disease
By: Paul M. Karpecki, OD, FAAO
Clinical Director – PECAA
Are you specifically looking for MGD? You should be. Here’s why.
One key event that has dramatically changed the ability to effectively manage dry eye disease is the greater understanding of meibomian gland dysfunction (MGD) in the last decade. When I started my first dedicated dry eye clinic, it wasn’t a condition that was identified regularly and perhaps that is why patients weren’t achieving high success with management of dry eye disease. And even if we knew to look for and grade MGD, there were few effective treatments at that time. Uncovering the presence of MGD in all patients, looking at the components of the disease and then choosing effective treatments is the key to today’s success in the management of this most common cause of dry eye disease.
Identifying MGD
Every exam should include an examination of the meibomian glands and their expression characteristics. For example, it appears that MGD may be a leading cause of contact lens drop-out, whether by affecting blink rates or adding stress the meibomian gland output required. If clinicians are not looking for it, they can’t take measures to prevent patients from abandoning contact lens use or seeking another eye doctor. Likewise it can contribute to inaccurate biometry measurements for IOL calculations and of course result in significant and progress dry eye disease that can in turn lead to severe atrophy of the meibomian glands.
In examining the lower eyelid in particular, which is responsible for the majority of oil in the tear film, look for notching which is a sign of gland atrophy, froth in the tear film which is an indication of MGD, telangiectasia, tylosis or thickening of the eyelids, hyperemia and even the location of the meibomian glands which appear to migrate posteriorly or become displaced in the presence of chronic MGD. Next, by using a wet q-tip or better yet the Meibomian gland evaluator (TearScience) or an expression paddle such as the Mastrota Paddle (OcuSoft) express the area of the nasal to central glands and note how many glands express and the quality of the meibum. Healthy meibum is clear like olive oil and easily expresses and rolls off the eyelid barely noticeable. A turbid expression, paste-like or non-expressive glands are indicative of further progression of the disease. Other tests that are effective in helping with a diagnosis include osmolarity testing, patient questionnaires such as the SPEED or OSDI questionnaire, blink analysis and especially meibography. Meibography can reveal the effects on the structure of the gland and show areas of atrophy, thus aiding in the diagnosis and severity of the disease.
The Four Components of MGD and Effective Management
MGD begins with obstruction of the meibomian glands and this leads to further sequelae that all must be effectively managed. The other sequelae include inflammation, biofilm development and tear film disruption or instability.
Obstruction
MGD begins with obstruction of the meibomian glands and this leads to further sequelae that all must be effectively managed. When obstruction begins, it appears to cause the other glands to up-regulate or over-work to make up for the ones that are not functioning. This leads to further stress and eventually gland atrophy. If a gland is non-functional for a period of time, it may also get a covering of keratin over it that further prevents its ability to produce oils for the tear film. So obstruction must be managed as a priority. Treatment options may include scaling the lower eyelid to remove keratin, but the key to removing obstruction is thermal treatments that can soften the meibum over time and even proper gland expression. One very novel technology that combines both is the LipiFlow thermal-pulsation system. By providing heat through the back surface of the eyelid a more direct thermal effect occurs and by avoiding the external eyelid, you can get a significant effect in a relatively short treatment time. When combined with pulsation this may further improve the meibum consistency. Other thermal systems that may benefit patients with MGD obstruction include MeiboFlo and IPL lasers. Keep in mind that previous MGD treatments such as ‘rice-in-a-sock’ simply do not allow adequate penetration of heat because of the limits through the external skin from dry heat. There are also limitations to a wet wash cloth compress as a patient would have a messy situation while exchanging the wash cloths while at a sink for 8-10 minutes or longer to maintain adequate heat levels. But warm compresses increase the tear film lipid layer if penetrating heat and compliance is in place. One such novel innovation that has improved MGD management is the Bruder Eye Hydrating Compress. This daily use compress uses a small angstrom opening within their patented medi-beads that upon microwaving for 15-20 seconds releases hydration that is obtained from the environment. It is reusable, durable, can be washed and provides adequate heat and hydration for approximately 12-14 minutes. The hydration aids in transfer of heat to the glands. Other commercial compresses available to patients include ThermalEyes and TheraPearls. One thing that has changed in the use of compresses is that patients are no longer instructed to massage their eyelids afterwards. That component is now left to thermal pulsation systems. These technologies are compatible and an analogy would be to the dental model where thermal pulsation systems work similar to dental cleaning and the commercial compresses are similar to daily brushing or flossing.
Inflammation
Studies have shown that inflammation is present in cases of MGD and also in cases of dry eye disease. Therefore it is important to treat the inflammation associated with this disease. Anti-inflammatory medications known to work include cyclosporine, corticosteroids and corticosteroid-combination agents , oral doxycycline, topical azithromycin and omega fatty acids. Because of the constant stress of a poor tear film, friction from the eyelid moving across the ocular surface and obstruction of glands inflammation plays a key role in further damage and progression of the disease. It must be well managed to effectively control the disease.
Biofilm formation
Lid hygiene may also play a key role in the management of MGD as biofilms have been known to develop in this disease. Lid hygiene products may play a key role as studies have shown. This includes the use of eyelid cleansers and evening mechanical cleaning devices such as BlephEx.
Tear Film Alterations/Hyperosmolarity
Without an adequate lipid component to the tear film, the result is evaporation. This in turn causes increased meibocyte production that is greater than the oil production, further obstruction of the glands and tear film instability. Thus patients have a dry eye and require adequate artificial tears to supplement the tear film.
MGD is a critical disease that results in chronic dry eye, and progression of the disease finally resulting in complete MG atrophy. It likely plays a key role in contact lens drop-out, unexpected post surgical results and overall quality of vision. By looking at the components of the disease including obstruction, inflammation, biofilm formation and tear film instability one can effectively manage these patients and provide adequate treatment and symptomatic relief to patients and a higher quality of life.
Disclosures:
Consultant: AcuFocus, AMO, Alcon Labs, Allergan, Akorn, Bausch + Lomb/Valeant, BioTissue, Bruder Healthcare, Cambium Pharmaceuticals, Eyemaginations, Essilor, Focus Laboratories, iCare USA, Ocusoft, Freedom Meditech, iCare USA, Konan Medical, Beaver-Visitech, Eye Solutions, Reichert, Shire Pharmaceuticals, RySurg, Science Based Health, SightRisk, TearLab, TearScience, TLC Vision, Topcon, Vmax
Research Grant: Rigel Pharma, Eleven Biotherapeutics, Akorn, Bausch + Lomb, Allergan, Fera Pharmaceuticals, Shire Pharmaceuticals
Speakers Bureau: Glaukos
