Table 1.

Classification of Diseases of the Meibomian Gland

Reduced number of glands

Congenital deficiency

Replacement of glands

Distichiasis

Distichiasis lymphoedema syndrome

Metaplastic disease of the meibomian gland

Meibomian gland dysfunction

Hypersecretory*

Meibomian seborrhea

Hyposecretory†

Retinoid toxicity

Obstructive

Subclinical

Cicatricial or noncicatricial

Focal or diffuse

Primary, or secondary to:

Local disease

Anterior blepharitis;

Cicatricial conjunctivitis (e.g. Trachoma; Stevens-Johnson syndrome, pemphigoid; acne rosacea, atopy

Chemical burns

Systemic disease

Seborrheic dermatitis

Acne rosacea

Atopy

Ichthyosis

Psoriasis

Anhydrotic ectodermal dysplasia

Ectrodactyly

Fungal disease

Turner syndrome

Toxicity

PCB exposure; retinoids

Other (ocular)

Internal hordeolum

Chalazion

Concretions

Neoplasia

^*Although there is evidence for an accumulation of meibomian oil within the glands, there is none yet for overproduction, as opposed to excessive release on expression.

^†Hypothetical: Evidence is not available for a condition of primary hyposecretion.