Dry eye disease: The scale of the problem

Dry eye disease, or keratoconjunctivitis sicca, is among the most frequentl y established diagnoses in ophthalmology; in Germany, one in four patients consulting an ophthalmologist complains of the symptoms of dry eye. Althoug h epidemiological studies investigating the prevalence of dry eye disease a re rare, published studies indicate that up to 20% of adults aged 45 years or more experience dry eye symptoms. Recent studies have shown that immunol ogic changes play a role in the pathogenesis of dry eye, not only in Sjogre n's syndrome, but also in postinfectious and age-related conditions. Despit e increasing understanding of the pathogenic factors involved in dry eye di sease, there has been a lack of consensus on diagnostic criteria, classific ation of disease states, and the aims and interpretation of specific diagno stic tests. There is a need, therefore, for standardization of disease term inology and diagnostic tests in order to improve the use fulness of epidemi ological and clinical investigation of this important ocular disorder. (Sur v Ophthalmol 45(Suppl 2):S199-202, 2001. (C) 2001 by Elsevier Science Inc. All rights reserved).