Dry Eye Syndrome: A Review

Dry eye syndrome is a recent discovery in the group of distinct treatable ocular diseases. This condition has been observed to be increasing wildly in the recent past due to civilizational changes. Dry eye is also referred to as tear film instability, a condition that typically develops from deficiencies of one or more components of the biologically complex pre-ocular tear film. Tears are composed of three layers: the outer oily lipid layer, the middle watery lacrimal layer, and the inner mucous or mucin layer. Each layer is produced by a different part of the eye, for example, the lacrimal gland produces the lacrimal layer. Therefore, a problem originating in any part of the eye can result in dry eyes. Clinically, dry eye cases represent a mixed picture of an allergy, an infection, and either drug or chemical toxicity. Therefore, dry eyes are often considered to be an accompaniment of Spring Catarrh, Follicular/ Trachomatous conjunctivitis, Glaucoma, Aphakia, and so on, in clinical practice. Dry eye conditions are classified into those with adequate aqueous tear production, and those with aqueous tear deficiency. Lacrimal gland tear production can be determined clinically by means of a Schirmer test without anaesthesia (Schirmer 1) or by other more sophisticated tests for the evaluation of aqueous tear production and turnover. Certain specific pathological tests can differentially diagnose cases with aqueous tear production and aqueous tear deficiency. The market availability of artificial tear solutions or ocular surface wetting/lubricating eye drops, have played a significant role in the management of dry eye.