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Abstract
Dry eye is quite common disease in the population today. The condition greatly influences the patient’s quality of life by causing significant ocular discomfort. Dry eye is an ocular condition affecting approximately 10% to 20% of the population. Its prevalence increases with age, and the majority of those affected are women, particularly among postmenopausal women.
Dry eye is defined as a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tears film instability with potential damage to the ocular surface. It is accompanied by increased osmolarity of the tear film and inflammation of the ocular surface.
Dry eye is classified into Aqueous-deficient dry eye and Evaporative dry eye. Aqueous tear-deficient dry eye implies that dry eye is due to a failure of lacrimal tear secretion as Sjogren Syndrome Dry Eye and Non-Sjogren Dry Eye. Evaporative dry eye is due to excessive water loss from the exposed ocular surfaceas as in meibomian gland dysfunction.
The causative mechanisms of dry eye are tear hyperosmolarity and tear film instability.
The diagnosis dry eye depends on the clinical picture and investigations. Patients with dry eye complain of sandy/gritty irritation, dryness, or a burning sensation of the eye. Symptoms worsen as the day goes on.
The investigations of dry eye include many tests. The most important Schirmer test (≤ 5 mm severe dry eye) , Tear clearance rate (TCR), Tear film break-up time (TFBUT) (≤ 5 mm severe dry eye), meniscotometery, Fluorophotometry, Evaporimetry, Impression cytology, Semi-quantitative tear film interference test, Interferometry, Meibometry, Meibography, Tears Osmolarity, Tear ferning, Grading staining(≥4 according to van Bijsterveld’s scoring system), Tear function index (TFI), and Ocular protection index ( < 1).
Management of dry eye is directed towards providing symptomatic relief and preserving the integrity of the ocular surface. Management of dry eye is based on psychological, medical, non-surgical, and surgical treatments. Medical teartment include tear supplementation as Lubricants (artificial tears). The ideal artificial lubricant should be preservative-free.
It also includes Secretogogues such as diquafosol, biological tear substitutes such as autoloug serum, antinflammatory therapy such as Cyclosporine (CsA), Corticosteroids, tetracyclines, and essential fatty acids such as omega-6 and omega-3 fatty acids.
Non- surgical treatment includes punctal plugs, humidifiers, moist chamber, contact lens, and collagen shields.
Surgical treatment includes many operation such as cisternoplasty, blepharorraphy, punctal patches technique, transposition of the parotid duct, the dacro reservoir technique (abdominal lacrimal reservoirs), surgical moving of the lacrimal punctum to dry dock, amniotic membrane transplantation, and stem cell transplantation.
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