Definitions
- •
Keratoconjunctivitis sicca (KCS): eye with some degree of dryness.
- •
Xerophthalmia: dry eye associated with vitamin A deficiency.
- •
Xerosis: extreme dryness with keratinization occurring secondary to severe conjunctival cicatrization.
- •
Sjögren syndrome: autoimmune inflammatory disease of which KCS is a typical feature (see below).
Classification of keratoconjunctivitis sicca
- •
Aqueous layer deficiency: (a) Sjögren syndrome, (b) non-Sjögren age-related hyposecretion, (c) absence or damage to lacrimal tissue, (d) conjunctival scarring with obstruction of lacrimal gland ductules, (e) neurological lesions with sensory or motor reflex loss, and (f) vitamin A deficiency.
- •
Evaporative: (a) meibomian gland disease, (b) exposure keratopathy, (c) defective blinking, (d) contact lens-associated, and (e) environmental factors.
Sjögren syndrome
Pathogenesis: autoimmune inflammation and destruction of lacrimal and salivary glands occurring in isolation (primary) or in association with other diseases such as rheumatoid arthritis and systemic lupus erythematosus (secondary); affects females more commonly than males.
Diagnosis
- •
Presentation: adult life with grittiness of the eyes and dryness of the mouth (xerostomia).
- •
Signs: (a) enlarged salivary and occasionally lacrimal glands, (b) xerostomia with a fissured tongue, (c) dry nasal passages, (d) diminished vaginal secretions, (e) Raynaud phenomenon, and (f) arthralgia, myalgia, and fatigue.
- •
Complications: (a) dental caries, (b) reflux oesophagitis and gastritis, (c) malabsorption due to pancreatic failure, and (d) pulmonary disease.
- •
Investigations: (a) serum autoantibodies, (b) Schirmer test ( Fig. 4.1 ), and (c) biopsy of minor salivary glands.
Fig 4.1
- •
Treatment: symptomatic (see below), salivary stimulants, and immunosuppression.
Diagnosis
Symptoms
- •
Dryness, grittiness, and burning, characteristically worse during the day.
- •
Stringy discharge, transient blurring of vision, redness and crusting of the lids are common.
- •
Signs
- •
Marginal tear meniscus is thinned ( Fig. 4.2 ) or absent (normal height 1 mm).
- •
