Table of contents

Eyelash Disorders

Eyelash disorders are typically caused by underlying eyelid diseases. This section will discuss the 3 important conditions related to lash dysfunction.

Blepharitis

Blepharitis is chronic inflammation of the eyelid of any cause. It is typically associated with Staphylococcus aureus infection.

Classification

Anterior

Affects the base of the eyelashes
2 further subtypes:
- Seborrhoeic (excessive secretions)
- Staphylococcal (direct infection)

Posterior

Affects the Meibomian glands

Anterior blepharitis has a better response to treatment because it occurs at the surface level.

Presentation

The lashes of a patient with anterior blepharitis. By Imran kabirhossain, CC BY-SA 4.0 .

Bilateral crusting of the lids and lashes
Foamy tear film and meibomian cysts are seen specifically with posterior blepharitis.
The lashes can appear normal in posterior blepharitis

Recurrent unilateral blepharitis should be investigated for sebaceous cell carcinoma. This is notoriously overlooked in primary care.

Associated conditions

Associated Condition	Blepharitis Type
Atopic dermatitis	Staphylococcal
Seborrheic dermatitis	Seborrheic
Acne rosacea	Posterior

Management

Lid hygiene
Warm compress
Topical lubrication and tetracyclines

Tetracyclines limit fatty acid production which can decrease the inflammatory secretions

Meibomian Gland Dysfunction (MGD)

MGD is a chronic disorder of the meibomian glands that overlaps with posterior blepharitis. It is characterised by duct obstruction and abnormal glandular secretions, which result in a characteristically foamy tear film.

Pathology

The meibomian glands secrete a lipid layer which contributes to the tear film.
The function of this layer is to help keep the tear film stable.
In MGD:
- the secretion of the meibomian oil is obstructed → stagnation within glands → inflammation →staphylococcal colonisation → chronic inflammation and scarring

Meibomianitis is a type of MGD where inflammation is marked. It is associated with acne rosacea and worse in the mornings with thick secretions and duct inflammation

Diagnostics

Presentation

Foamy tear film
Crusty eyelashes
Gritty irritated eyes

Investigations

Tear film breakup time of <5 seconds is a sign of tear film instability
Fluorescein staining of the cornea shows corneal epithelial damage

Management

Clinical classification determines the appropriate treatment.

Classification	Management
ONLY altered secretions	Diet (increase omega 3 index) Lid hygiene and warm expression of secretions
Mild discomfort and minimal ocular surface staining	Topical lubricants Increase humidity (wrap around glasses, avoid wind) Lysosomal sprays
Symptoms limit activity and there are inflammatory changes at the lid margin	Oral tetracycline derivatives
Meibomian gland dropout/displacement, central corneal staining, TFBUT <5s	Anti-inflammatory therapy for dry eye. Discussed further in the lacrimal chapter

MGD can lead to other diseases such as MG cysts, trichiasis, blepharitis, and keratitis.

Trichiasis

Trichiasis is the inward misdirection of the eyelashes. This can lead to corneal irritation and ulceration.

Type	Description
Distichiasis	A congenital abnormality where there are 2 rows of eyelashes. Can be associated with Meige syndrome
Acquired metaplastic lashes	Abnormally positioned lashes due to inflammation such as meibomitis and scarring
Pseudotrichiasis	Inwardly projecting lashes due to entropion

Management

Epilation - Recurrence is common so this is a temporising measure
Lash destruction by electrolysis/laser/cryotherapy - typically used when there is only a limited collection of abnormal lashes. Scarring and inflammation can be worsened.
Surgery - A pentagon excision can be used to remove focal groups of lashes.