How can I differentiate between dry eye syndrome and other ocular surface disorders during a routine examination?

Differentiating between dry eye syndrome (DES) and other ocular surface disorders during a routine examination in general practice primarily involves identifying clinical features and symptoms that warrant specialist referral for definitive diagnosis ¹. There is no single test adequate to formally diagnose dry eye disease or assess for underlying conditions, and specialist assessment typically requires equipment and expertise not available in primary care ¹.

During a routine examination, an Admin should be aware of the following indicators that may suggest DES or other ocular surface disorders, prompting a referral:

• Clinical Features of Suspected Dry Eye Disease: While definitive diagnosis requires specialist tests, persistent or severe symptoms that do not respond to primary care management after 4–12 weeks should prompt referral ¹. Eye signs that may be observed by a specialist include punctate epithelial erosions in exposed areas of the cornea and bulbar conjunctiva, increased mucus strands, filaments, and other tear film debris, and reduced corneal sensitivity ¹.
• Red Flag Symptoms or Signs: Any red flag symptoms or signs that may indicate a serious or sight-threatening cause for symptoms, or a suspected serious complication, necessitate an urgent ophthalmology same-day assessment ¹.
• Suspected Serious Underlying Causes: If a serious underlying cause is suspected, such as Stevens-Johnson syndrome or ocular cicatricial pemphigoid, an urgent referral to ophthalmology is required ¹.
• Uncertain Diagnosis: An uncertain diagnosis, particularly if a child has unexplained symptoms or suspected corneal changes, warrants referral to ophthalmology or an appropriate specialist ¹.
• Suspected Underlying Systemic Conditions: If an underlying systemic condition, such as Sjögren’s syndrome, is suspected, referral to ophthalmology or an appropriate specialist is indicated ¹. For Sjögren's syndrome, diagnostics are advancing to include biomarkers and biomolecules beyond clinical symptoms, which are assessed by specialists (Wu et al., 2024).
• Abnormal Lid Anatomy or Function: Abnormal lid anatomy or function also warrants referral, as surgical correction may be needed ¹.

Specialist assessment for differentiation may include a slit lamp examination of the conjunctiva, tear film, cornea, eyelashes, and meibomian glands ¹. Additional specialist investigations can include the Schirmer test, assessment of tear break-up time, tear osmolarity testing, ocular surface dye staining, and tests of lacrimal gland function ¹. These comprehensive tests are crucial for distinguishing DES from other conditions and identifying underlying causes (Wolffsohn, 2017; Akpek, 2019; College of Optometrists, 2022) ¹.