34. Meibomian Gland Dysfunction and Seborrea

Question 1

How is the meibomian gland secretion altered by hormones

Answer 1

Increased by androgens

Decreased by estrogens and anti-androgens.

Question 2

Briefly name the 6 categories for chronic blepharitis by McCulley

Answer 2

1. Staphylococcal
2. Seborrheic
3. Mixed Seborrheic and staphylococcal
4. Seborrheic + Meibomian seborrhea (Hipersecretory MGD)
5. Seborrheic + secondary meibomitis (MGD with occlusion in a spotty distribution)
6. Primary meibomitis: occlusion of ALL MGs, in association with seborrheic dermatitis or acne rosacea.

Question 3

Name and describe the 4 types of meibomian gland dysfunction by Mathers et al.

Answer 3

1. Seborrheic: Hypersecretion, normal gland morphology and tear osmolarity.
2. Obstructive: Low meibum expresion/ high dropout, increased osmolarity, normal schirmer’s test.
3. Obstructive with sicca: obstructive, increased osmolarity and LOW schirmer’s test.
4. sicca: Normal glands, but with increased osmolarity and low schirmer’s test.

Question 4

What type of MGD is present in patients with Acne Rosacea, Seborrheic dermatitis, And Atopy?

(Low delivery vs high delivery)

Answer 4

All of the can present both, high or low delivery

Question 5

What percentage of patients with Sjogren’s-associated dry eye disease have MGD?

Answer 5

aprox 60%

Question 6

Is the effect of isotretinoin in low-delivery MGD permanent?

Answer 6

No, it is usually reversible when treatment is stopped.

Question 7

According to Krachmer’s, what specific type of lipid encourages bacterial growth in meibomian secretions?

Answer 7

Cholesterol esters (not universally present in meibum) stimulate coagulase-negative staph and S. Aureus.

Question 8

What happens with the meibum’s melting point if its triglyceride and free fatty acid concentration are increased?

Answer 8

The melting point increases

_{<em>And therefore, so does its viscosity. </em>}

Question 9

Which are the most common bacteria found in the adult lids?

Answer 9

• S. Epidermidis (94%)
• Propionebacterium Acnes (87%)
• Corinebacterium sp (64%)

_{<em><strong>Staph Aureus</strong> is acctually not that frequent in the normal lid (15%)</em>}

Question 10

Which of the “lid bacteria” can produce lipase?

Answer 10

• S. Aureus
• P. Acnes
• Corinebacterium Sp