Prevalence of dry eye subtypes in clinical optometry practice

Background: Dry eye conditions are now recognized as having multiple causes. A subtype-based dry eye diagnostic protocol was developed to determine the prevalence of dry eye and dry eye subtypes, and the effects of age and gender, in subjects presenting to clinical optometry practice. Methods: Dry eye diagnostic criteria were: presence of one or more McMonnies dry eye survey primary symptoms, fluorescein tear break time <10 s and rose bengal ocular surface staining. Dry eye subtype differential diagnosis was made predominantly on the basis of biomicroscopic signs. Subtype categories were: lipid anomaly dry eye (LADE), aqueous tear deficiency (ATD), primary mucin anomalies, allergic/toxic dry eye (ADE), primary epitheliopathies and lid surfacing/blinking anomalies (LSADE). Results: Dry eye prevalence was 10.8% for n = 1584 subjects. Dry eye was significantly more prevalent in subjects 40 years or older (18.1%) compared with those <40 years (7.3%) (p = 0.001). LADE was the most prevalent subtype (4.0%), followed by ADE at 3.1%, LSADE at 1.8%, and ATD at 1.7%. ATD was the only subtype with a significant gender prevalence difference, being more prevalent in women (p = 0.0023). The prevalence of LADE and ATD were significantly greater in those 40 years or older (p = 0.001 and p = 0.0023 respectively). Conclusions: The results of this study support a subtype-based approach to dry eye diagnosis and management in clinical practice.