Definition:

Dry eye disease (also called keratoconjunctivitis sicca) is multifactorial disease of the tears, lids, and ocular surface which can result in symptoms of discomfort and/or visual disturbance and/or tear film instability with the potential for damage to the ocular surface. It is accompanied by increased osmolarity of the tear film and subacute inflammation of the ocular surface. Dry eye disease is subdivided into two forms, aqueous insufficiency (tear deficiency) and hyperevaporative (increased evaporation). However, mixed forms are common. Aqueous insufficiency is divided into two main groups: Sjogren's syndrome-related dry eye and non-Sjogren's syndrome-related dry eye. Dry eye in Sjogren's syndrome (an autoimmune disease) [DS:H01502] is often severe and requires more aggressive treatment. Evapourative dry eye is most commonly a result of meibomian gland dysfunction. Tests used to diagnose dry eye disease and to assess efficacy of treatments in clinical trials include the following: measurement of tear film break-up time (the interval between the individual's last complete blink and the break up of the tear film) using fluorescein (shortened in dry eye disease), evaluation of tear quantity with Schirmer's test (using a strip of filter paper placed under the lower eyelid), assessment of corneal and conjunctival epithelium integrity using stains and dyes, and evaluation of meibomian glands. Artificial tears of various kinds are recommended if the symptoms are mild. Lid hygiene is helpful in the treatment of hyperevaporative dry eye, while collagen or silicon plugs can be used for partial occlusion of the efferent lacrimal ducts to treat severe hyposecretory dry eye. The benefit of long-term topical anti-inflammatory treatment of moderate or severe dry eye disease with corticosteroids or cyclosporine A eye drops has been documented in clinical trials on a high evidence level. Orally administered tetracycline derivatives and omega-3 or omega-6 fatty acids are also used.