The tear film is composed of 3 layers-a superficial oily layer, a central water layer and a deep mucus layer. Abnormalities or deficiency of any component can lead to ‘dry eye’.
Disruption of the oil layer, usually due to blepharitis, leads to an adequate or increased volume of tears but instability causes symptoms of dryness.
The water layer is largely produced by the main lacrimal glands. Inflammation (eg Sjogren’s syndrome), tumour or trauma of these depletes production and leads to dry eyes.
Mucus production may be impaired due to generalise conjunctival diseases such as pemphigoid or from chemical trauma.
Clinical Features
Soreness, grittiness especially in hot or dry environments
Foreign body sensation
Itching/burning
Blurring of vision
Photophobia
Mucus discharge
Watering
Redness
Management
Regular artificial tears
Preservative-free preparation needed if more than 6-8 times per day or contact lenses worn
Treat blepharitis
See ophthalmologist if persistent symptoms, redness, swelling or impaired vision
