16 Questions
What is a potential consequence of MGD?
Alteration of the tear film
What percentage of Americans over the age of 60 are estimated to have MGD?
70%
Which of the following is a risk factor for MGD?
Deficiency of sex hormones
What is the name of the syndrome associated with MGD that causes skin and mucous membrane problems?
Stevens-Johnson syndrome
What is the main difference between low delivery and high delivery categories of MGD?
Secretion status
What is the most common cause of hyposecretion in MGD?
Obstruction of meibomian glands
What is the name of the classification system proposed for MGD?
2011 International Workshop on MGD
What is a hormonal risk factor for MGD?
Androgen deficiency
What is the main function of the lipids secreted by Meibomian glands?
To protect evaporation of the aqueous phase of tear film
Who first described the Meibomian glands in detail?
Heinrich Meibom
What is the approximate length of Meibomian glands in the upper eyelid of Caucasian eyes?
5.5 mm
What is the term coined by Korb and Henriquez to describe the obstruction of Meibomian gland orifices?
Meibomian Gland Dysfunction (MGD)
What is the primary role of the orbicularis muscle in Meibomian gland function?
To contract and facilitate the secretion of meibum
What is the definition of Meibomian Gland Dysfunction (MGD) according to the International Workshop on MGD?
A chronic, diffuse abnormality of the meibomian glands
What is the approximate number of Meibomian glands in the human upper eyelid?
25-40
What is the composition of meibum?
Over 100 major individual complex mixtures of lipids and 90 proteins
Study Notes
Meibomian Gland Dysfunction (MGD)
- Recognized by ICD codes
- Meibomian glands, or glandulae tarsales, are large sebaceous glands present in eyelids that secrete lipids to protect evaporation of the aqueous phase of tear film
- There are about 25-40 glands in the human upper eyelid and about 20-30 in the lower eyelid
- Each gland consists of clusters of about 10-15 secretory acini that secrete lipid material through small ductules via a central duct at the lid margin
- Meibum contains over 100 major individual complex mixture of lipids, over 90 proteins, and electrolytes that contribute to the stability of tear film in health and disease
Characteristics of MGD
- Chronic, diffuse abnormality of the meibomian glands
- Commonly characterized by terminal duct obstruction and/or qualitative/quantitative changes in the glandular secretion
- May result in alteration of the tear film, symptoms of eye irritation, clinically apparent inflammation, and ocular surface disease
Epidemiology of MGD
- Underdiagnosed and undertreated disease
- Asymptomatic disease is far more common than symptomatic MGD
- Estimated that 70% of Americans over the age of 60 have MGD
- Prevalence is less among Caucasians when compared to Asians and ranges from 3.5-70% depending on the parameter looked at
Risk Factors of MGD
- Aging
- Deficiency of sex hormones (notably androgens)
- Systemic conditions (e.g. Sjogren's syndrome, Stevens-Johnson Syndrome, psoriasis, atopy, polycystic ovary syndrome, hypertension)
- Ophthalmic factors (e.g. aniridia, chronic blepharitis, contact lens wear, eyelid tattooing, trachoma, Demodex folliculorum infestation)
- Use of certain medications (e.g. antibiotics, Isotretinoin, antihistamines, antidepressants, hormone replacement therapy)
Classification of MGD
- Classified based on the final consequence of Dry Eye Diseases (DED) into low delivery and high delivery categories based on the secretion status
- Low delivery status further classified into hyposecretory and obstructive conditions
- Hyposecretion due to decreased Meibomian gland function from gland atrophy or medications
- Obstruction of meibomian glands due to hypertrophy of ductal epithelium and keratinization due to aging, or other factors
Learn about Meibomian Gland Dysfunction (MGD), its ICD codes, and the function of Meibomian glands in the eyelids.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
