Winter 2006 Winter 14 14 Issue Issue A Quick Guide to Dry Eye Chronic dry eye and associated eye, dry mouth, autoimmune and soreness, scratchiness, dryness, ocular surface irritation can cause connective tissue disorders. grittiness, burning, stinging and blurred vision, contact lens blurry vision. Patients often intolerance, increased risk of Diabetes is a primary cause of report a sandy gritty irritation infection and, in severe cases, tear deficient dry eye. Diabetes that becomes worse as the day progressive ocular surface disease causes significant loss of corneal progresses. This is because the and corneal morbidity. sensitivity reducing both reflex corneal surface recovers with lid Appropriate diagnosis and tearing and the blink rate closure but evaporation of tears management is important. Dry associated with good quality and during the day causes increased eye can be classified into two adequate tears. tear film osmolarity and categories; evaporative and tear subsequent irritation. Symptoms deficient dry eye. Contact lens wear can cause tear may persist for many months. deficient dry eye, as can refractive Meibomitis is also described using surgery. a gritty sandy sensation, usually Evaporative dry eye. worse in the mornings due to the Meibomium gland dysfunction is inflamed lids releasing the prevalent cause of evaporative Common medications affecting inflammatory mediators next to dry eye causing an unstable tear the aqueous tear film include the cornea and decreased tear film and increased evaporation. topical and systemic secretion due to eye closure. Meibomitis is another cause and antihistamines, tricyclic is associated with acne rosacea antidepressants, topical and Secondary dry eye symptoms are and seborrhoeic dermatitis. systemic beta blockers, oral caused by environmental and Incomplete lid closure and contraceptive pills, systemic dietary factors including cigarette abnormal blink patterns due to topical non-steroidal anti- smoke, smog, air-conditioning, ectropion, entropion, pterygia, inflammatory agents among central heating, dehydrating facial palsies, nocturnal others. Preservative build-up from temperature controlled lagophthalmos, proptosis, and eyedrops may affect the aqueous environments, weather conditions lower lid laxity may also be tear film, particularly as well as alcohol and caffeine. contributing factors . Evaporative benzalkonium chloride. dry eye is worsened with exposure to irritants including air- Dry eye diagnosis Te s t s f o r d r y e y e conditioning, dry heat, low History based on known risk Specific evaluation of dry eye humidity, wind and intense factors and associations is the includes medication history, a concentration associated with most useful tool for dry eye validated dry eye questionnaire, close work and computer use. diagnosis. Signs may not correlate environmental evaluation, with symptoms and different general health history and, when signs are present as severity required, a test of tear secretion. Tear deficient dry eye Slit lamp evaluation will assess Aqueous tear deficiency is more increases. The history will tear film meniscus, mucous and prevalent in females possibly distinguish dry eye from other particles in the tear film, associated with menopausal ocular conditions with similar meibomium gland dysfunction, factors. Sjogren’s syndrome also descriptive signs and symptoms. allergic ocular irritation, punctal causes severe aqueous tear Primary dry eye symptoms are position, lid margin defects and deficiency having a prevalence of not specific. Symptoms include 0.4-1%, the majority being female (80-95%). It is associated with dry “Your local optometrist is available to work with you for better eye health in the community” Dry eye conditions affect a significant number of people positioning. Corneal staining using fluorescein, rose bengal or lissamine green aids this assessment. The staining location and pattern can indicate the cause of dry eye with reasonable sensitivity and good predictive value. Dry eye treatment The primary goals of dry eye treatment are reducing and improving symptoms by management of environmental factors affecting tear quantity and quality. Newer treatments are aimed at reducing tear osmolarity, improving tear film stability and reversing and improving ocular surface damage as opposed to simply providing more tears. If drops are used frequently then non-preserved drops are more appropriate. Preserved drops may exacerbate ocular surface damage due to compromised epithelial barrier function or inhibited tear clearance increasing Punctal occlusion will improve objective signs of tear ocular surface-preservative exposure. deficient dry eye. Punctal occlusion can be a permanent or temporary measure, reversible as symptoms improve Lubricating gels and ointments are thicker than eyedrops and remain on the corneal surface longer. Meibomium gland dysfunction is mainly treated using Due to visual disturbances, ointments are best used at lid hygiene methods. Oral tetracyclines are effective in night and are useful for people who sleep with their longstanding chronic meibomitis improving the eyes slightly open. consistency of meibomium gland oil production, promoting tear film stability and reducing tear Omega-3 and omega-6 essential fatty-acids are evaporation. relevant to both dry eye and meibomitis. Omega 3 fatty-acids are provided mostly by fish oils, castor oil, flaxseed oil and walnuts Omega 6 fatty-acids produce Summary inflammatory submetabolites. Excessive amounts may Dry eye conditions affect a significant number of people. exacerbate inflammation in the body. A diet rich in Differential diagnosis of dry eye is best achieved by a omega-6 may worsen dry eye disease for people prone thorough history and slitlamp evaluation with corneal to meibomitis and blepharitis. Omega 3 fatty acids staining. Diagnosis, treatment and management can be provide a balancing anti-inflammatory effect to omega performed by an optometrist. Successful treatment and 6 fatty acid intake. Omega 3 fatty acids also affect the management of dry eye and meibomium lid disease meibomium gland lipid production. prevents chronic corneal changes which may affect vision. WELLINGTON WELLINGTON PO Box 1978 1978 Box PO NZ Association of Optometrists Optometrists of Association NZ EYE EYE CARE CARE PRIMARY PRIMARY PRIMARY.