Differential diagnosis and management of common dry eye subtypes

Abstract

Dry eye is a prevalent disease causing chronic eye irritation, ocular surface damage and increase risk of eye infection. Six dry eye case studies are presentted to illustrate differential diagnosis and management of dry eye subtypes commonly encountered in optometric practice: autoimmune and non‐autominnune aqueous tear deficiency (ATD), liqid anomally, lid surfacing anomaly, allergic dry eye and marginal dry eye. A two‐stage diagnostic process is described: (1) identification of dry eye using a preliminary test protocol of the McMonnies dry eye survey, fluorescein break‐up time (FBUT) and rose bengal of the McMonnies dry eye suryvey, fluroescein break‐up time (FEBUT) and rose bengal staining and (2) differential diagnosis using a battery of specific tests for diagnosing each dry eye subtype. Subtype‐specific tests included: the cotton thread tear test (CTTT) and Lactoplace® for ATD diagnosis; biomicroscopy of the precorneal lipid layer, lid margins, lashes, and meibomian excreta for lipid anomaly; biomicroscopy for evidence of lid surfacing anomalies such as incomplete blining, ectropion and pterygia; and positive history and slit‐lamp signs of allergy to diagnose allergic dry eye. Impression cytoglogy, a technique enabling the grading of conjunctival squamous metaplasia and goblet cell density, was useful in differenting autoimmune from non‐autoimmune ATD. Specific management strategic for each of the comom dry eye subtypes are described, with the severity of symptoms also influencing the nature of treatment. Correct classification of a patient's dry eye enable the practitioner to better comprehend the aetiology and therefore initiate appropriate, effective treatement form the outset. In the absence of a cure for dry eye, patient reiview is essential to promote compliance, monitor improvement and modify treatement accrodingly.

Key words:

• allergic dry eye
• aqueous tear decifiency
• conjunctival impression cytology
• dry eye
• lid surfacing anomaly
• lipid anomaly
• Sjõgren's syndrome
• squamous metaplasia