Meibomian Gland Dysfunction (MGD)

Meibomian Gland Dysfunction and Dry Eye Disease

Dry eye disease is a common condition that occurs when the eyes do not produce enough tears or when the tears evaporate too quickly. Meibomian gland dysfunction (MGD) is a condition that affects the meibomian glands, which are small oil glands located on the eyelids. When the meibomian glands are not functioning properly, they can produce less oil, which can lead to dry eye disease.

Understanding the Meibomian Glands 

Before we delve into MGD, let's first understand the crucial role of the meibomian glands. These tiny glands are located in the eyelids and produce an oily substance called meibum. Meibum forms the outer layer of the tear film, which helps keep the tears from evaporating too quickly and ensures a smooth distribution of tears over the surface of the eye.

Pathophysiology of MGD

The pathophysiology of MGD is complex and not fully understood. However, it is thought to be caused by a combination of factors, including:

• Epithelial hyperkeratinisation: This is the thickening and hardening of the cells that line the meibomian glands. This can lead to duct obstruction and meibum stasis, which is the build-up of oil in the glands.
• Meibum stasis: This is the build-up of oil in the meibomian glands. This can lead to cystic dilation, which is the enlargement of the glands.
• Acinar atrophy and gland dropout: This is the shrinking and loss of the meibomian glands. This can occur due to chronic inflammation or other factors.

There are many risk factors for MGD, including contact lens wear, hormonal changes, age, makeup use, and skin diseases.

How Common is MGD?

Meibomian gland dysfunction manifests in various degrees, posing a growing concern for optometrists. With our increasing reliance on technology and screen time in both home and work environments, the incidence of MGD is anticipated to rise. Research highlights the prevalence of MGD:

• Up to 86% of patients with dry eye
• Up to 39% of asymptomatic patients
• Afflicting 80% of glaucoma patients on long-term anti-glaucoma medications
• Affecting 63% of pre-cataract surgical patients

Meibomian gland dysfunction is a condition steadily rising in prevalence among our patients. Yet, detecting it can pose a significant challenge. Rather than waiting for patients to voice complaints, optometrists should adopt a proactive approach, conducting thorough tests to identify MGD promptly. Addressing this condition early can prevent complications and ensure optimal eye health.

Common Symptoms of MGD 

In my clinical practice, I've observed that individuals often perceive dry eye symptoms in various ways. Patients with MGD often present with an array of findings, such as abnormal meibum secretions, meibomian orifice plugging and gland dropout, a frothy tear film, and telangiectasias.

When discussing their reported discomfort, many patients attribute their symptoms to allergies, insufficient sleep, extended contact lens wear, or exposure to soap. 

The symptoms of MGD can vary from person to person but often include:

1. Dryness and irritation in the eyes
2. Redness and swelling of the eyelids
3. Grittiness or a foreign body sensation in the eyes
4. Excessive tearing
5. Blurred or fluctuating vision
6. Eye fatigue, especially during prolonged visual tasks

Frequently, I find myself clarifying to patients that although their symptoms may seem temporary, they are likely rooted in underlying issues such as meibomian gland dysfunction and dry eye disease. Unfortunately, these conditions persist and worsen despite various attempts with conventional palliative treatments. It becomes imperative to enlighten our patients about advanced treatment alternatives that go beyond the temporary relief provided by artificial tears.

Causes and Risk Factors of MGD

Several factors contribute to the development of Meibomian Gland Dysfunction, including:

• Age
• MGD becomes more common as we age, as the meibomian glands tend to deteriorate over time.
• Hormonal changes
• Fluctuations in hormones, particularly in women during menopause, can affect the quality of meibum.
• Environmental factors
• Prolonged exposure to environmental conditions like dry air, wind, and air pollution can contribute to MGD.
• Systemic diseases
• Certain conditions like rosacea, blepharitis, and autoimmune disorders may increase the risk of developing MGD.
• Lifestyle factors
• Poor eyelid hygiene, excessive digital device usage, and prolonged contact lens wear can also contribute to MGD.

Diagnosis of MGD

Screening methods for dry eyes include dry eye questionnaires, vital stains to check for corneal or conjunctival damage, tear breakup time (TBUT), MMP-9 testing for inflammation, and meibography for gland integrity.

Meibomian Gland Dysfunction Treatment

Traditionally, individuals experiencing symptoms such as redness, dryness, and burning often resorted to over-the-counter eye drops as a standard remedy. However, with our current understanding of meibomian gland dysfunction and dry eye disease, there is a need for a paradigm shift in the approach to treatment.

Early intervention by optometrists is essential, urging them to recommend in-office treatments when conventional remedies fail to adequately manage these symptoms.

There are a variety of treatments for MGD, depending on the severity of the condition. Mild cases may be treated with over-the-counter eye drops or ointments. More severe cases may require prescription medications or in-office procedures.

1. MGD is associated with altered meibomian secretions and there is no telangiectatic vessel formation (non-telangiectatic MGD):
1. Our treatment pathway primarily targets alleviating meibomian gland obstruction and improving meibum expression.
2. MGD is associated with ocular surface inflammation
1. Blocking the inflammatory cascade using either corticosteroids or other immunomodulating ophthalmic agents, is often necessary before prescribing MGD treatment and blepharoexfoliation to rehabilitate the tear film.
3. Those with obstructive MGD with telangiectatic vessel formation 
1. Intense pulsed light (IPL) may serve as an effective adjuvant therapy to photocoagulate the telangiectatic vessels.

Over-the-counter treatments

• Warm compresses
• Applying a warm compress to the eyelids can help soften the hardened meibum, making it easier to express. 
• Lid hygiene
• Regular and gentle cleaning of the eyelids can help remove debris and unclog the meibomian glands.
• Lubricants
• Lubricating eye drops can provide temporary relief from dryness and discomfort.

Prescription medications

• Antibiotics
• These can help to treat any infection that may be contributing to MGD.
• Steroids
• These can help to reduce inflammation and swelling.
• Cyclosporine
• This medication can help to improve the function of the oil glands.

In-office procedures

• Intense Pulsed Light (IPL)
• This procedure uses light to kill bacteria and improve the function of the oil glands.
• Thermal Pulsation Devices
• Lipiflow
• An FDA-approved treatment. It uses heat and pressure to improve gland function, with one 12-minute treatment equivalent to three months of warm compresses. Results can last up to 12 months, and it also enhances soft contact lens tolerance by four hours in patients with both MGD and DED.
• TearCare
• It offers controlled heat via disposable wearable elements attached to a portable hub, allowing patients to keep their eyes open during the 15-minute treatment. Meibum clearance follows, conducted individually for each eyelid section.
• Clinical studies show TearCare's superiority over conventional warm compresses, with improved tear break-up time and symptom relief. In a trial against LipiFlow, TearCare showed better symptom improvement after one month for female participants.
• Systane iLux
• An FDA-approved device for Meibomian Gland Dysfunction. It applies LED heat and pressure to eyelids, improving gland expression. With a disposable tip and 8-12 minute treatment time, it enhances tear break-up time and gland expressibility in 4 weeks.
• Clinical studies confirm its efficacy, comparable to the Lipiflow System.
• Mibo ThermaFlo
• It applies heat to the eyelids at 42.5°C, softening meibum and improving gland function. The device has adjustable settings for patient comfort and uses ultrasound gel for a gentle massage. Treatment lasts 12 minutes, and both eyes can be treated simultaneously. Patients experience immediate relief, but multiple sessions, typically three treatments spaced two weeks apart, are recommended for optimal results, often followed by manual gland evacuation.
• Thermal 1-Touch 
• The Thermal 1-Touch device provides consistent heat and mild pressure to the outer eyelids, with customizable settings for temperature (39-44°C) and treatment duration (10-30 minutes). It heats all four eyelids at once. After treatment, manual gland evacuation using the included Mastrota meibomian paddle is necessary.
• EyeXpress
• This procedure uses a small probe to remove oil buildup from the glands.
• Blephex
• This procedure uses a brush to remove oil buildup and debris from the eyelids.
• NuLids
• This device uses a combination of heat and suction to remove oil build-up and debris from the eyelids.

Image above illustrates lower eyelid manual gland expression post-IPL

The best treatment for MGD will vary depending on the individual patient. It is important to see an optometrist to determine the best course of treatment.

Since MGD can be asymptomatic, expressing glands and checking gland morphology is recommended during routine eyecare visits.

Advice For Optometrists!

• Proactive identification of MGD is crucial in addressing Dry Eye Disease. Rather than relying on patients to report symptoms as the condition progresses, optometrists must take a more active role in early detection.
• Encouraging patients to consider in-office treatments is key for both symptomatic relief and preventive care.
• In my clinic, utilizing meibography images has been eye-opening for many patients who are often unaware of the connection between their symptoms and blockages in their oil glands.
• Despite initial hesitation from some patients, presenting a comprehensive evaluation of their oil glands, along with meibography results and symptom review, has proven to be enlightening.
• Many individuals readily accept in-office treatments, while others, even if not immediately convinced, recall our conversation and revisit the option even a year later.
• It's essential to shift the paradigm from mere palliative treatments to a more active approach involving regular screening and early intervention for MGD. Recognizing the first signs of compromise, such as lid swelling and inflammation, is paramount for effective management.
• Delaying diagnosis until late-stage symptoms occur should be avoided, as early treatment yields the best results in managing MGD.

Closing Thoughts 

In our increasingly digital world, early and regular diagnosis of MGD and dry eye disease plays a pivotal role in preserving ocular health. It's important to acknowledge that, by the time a patient reaches 50, much of the opportunity for reversing the disease has passed, leaving us with the task of primarily slowing its progression. Therefore, it's imperative to consider dry eye screening during a patient's 20s and 30s as a critical step in safeguarding their long-term eye health.

While we've made significant strides in diagnosing and treating MGD and dry eye disease, there remain areas that warrant deeper exploration. The journey of diagnosing and managing these conditions is an ongoing process, and we continue to work towards a more comprehensive understanding and improved treatment approaches.

Frequently Asked Questions: 

How long does meibomian gland dysfunction last?

The duration of meibomian gland dysfunction (MGD) can vary from person to person. Some people may experience only mild symptoms that go away on their own, while others may have more severe symptoms that require treatment. In general, MGD is a chronic condition that can last for months or even years.

There are a number of things that can affect the duration of MGD, including:

• The severity of the condition
• The underlying cause of MGD
• The patient's age and overall health
• The effectiveness of treatment

If you are diagnosed with MGD, it is important to work with your doctor to develop a treatment plan that is right for you. This may include eyelid hygiene, medications, or other therapies. With proper treatment, most people with MGD can manage their symptoms and prevent the condition from getting worse.