Clinical features

The condition usually affects both eyes. Symptoms are worse in the morning; there may be several exacerbations and remissions (1).

• If contact dermatitis is the cause there is generally a history of atopy or there may be other areas of the dermatitis due to the application of the cosmetics.

Symptoms include:

• anterior blepharitis
  • may be asymptomatic
  • ocular discomfort, soreness, burning, itching, mild photophobia
  • symptoms of dry eyes - blurred vision, poor tolerance of contact lenses
• posterior blepharitis
  • may be asymptomatic
  • ocular discomfort, soreness, burning, stinging
  • symptoms of dry eyes - blurred vision, poor tolerance of contact lenses

Signs include:

• staphylococcal blepharitis (anterior blepharitis)
  • erythema, oedema and telangiectasiae of the lid margin
  • crusting of anterior lid margin (scales at bases of lashes) which may form collarettes which encircle the lashes
  • recurrent styes and chalazia (rarely)
  • aqueous tear deficiency
  • conjunctival hyperaemia
  • in severe and long standing disease there can be
    • trichiasis - misdirection of eyelashes towards the eye
    • poliosis - depigmentation of the eyelashes
    • madarosis - loss of eyelashes
    • eyelid ulceration and eyelid and corneal scarring may occur
• seborrhoeic blepharitis (anterior blepharitis)
  • erythema, edema, and telangiectasia of the lid margins (changes are less marked than in staphylococcal blepharitis)
  • oily scale and greasy crusting on the lashes
  • conjunctival hyperaemia
  • aqueous tear deficiency
• Demodex folliculorum mite infestation (anterior blepharitis)
  • lid margin erythema
  • “cylindrical dandruff” - characteristic clear sleeve (collarette) covers base of lash, extending further up the lash than flat staphylococcal rosettes
  • misalignment, trichiasis or madarosis could occur due to persistent infestation of the lash follicles
• MGD (posterior blepharitis)
  • thick and/or opaque secretion at Meibomian gland orifices (which is difficult or impossible to express by finger pressure)
  • dilated gland and formation of microliths and chalazia - due to plugging of the ducts
  • telangiectasias and lid scarring may be present
  • excess lipid, foamy discharge (1)
  • conjunctival hyperaemia

Reference:

• (1) Lindsley K et al. Interventions for chronic blepharitis. Cochrane Database of Systematic Reviews 2012, Issue 5. Art. No.: CD005556. DOI: 10.1002/14651858.CD005556.pub2. Accessed 11 March 2022.
• (2) The College of Optometrists (2021). Blepharitis (Lid Margin Disease)