What is the recommended treatment approach for a patient with dry eye syndrome considering slit therapy?

Slit-Lamp Biomicroscopy in Dry Eye Syndrome

Slit-lamp biomicroscopy is an essential diagnostic tool—not a treatment—used to document signs of dry eye, assess tear film quality and stability, and identify other causes of ocular irritation. 1

Purpose of Slit-Lamp Examination

The slit-lamp examination serves three critical diagnostic functions in dry eye evaluation:

• Document objective signs of dry eye disease to correlate with patient symptoms and guide treatment decisions 1
• Assess tear film characteristics including quality, quantity, and stability to determine the underlying pathophysiology 1
• Identify alternative or contributing causes of ocular surface irritation that may complicate diagnosis and management 1

Specific Slit-Lamp Findings to Evaluate

Tear Film Assessment

• Measure tear meniscus height along the inferior eyelid margin, which reflects aqueous tear volume 1
• Evaluate tear film composition for debris, increased viscosity, mucous strands, and foamy discharge on the lid margin 1
• Perform tear break-up time (TBUT) testing, with values less than 10 seconds indicating tear film instability 1, 2
• Assess break-up pattern to distinguish between aqueous deficiency and evaporative dry eye 1

Eyelid Margin Examination

• Inspect meibomian gland orifices for metaplasia, reduced expressible meibum, or atrophy 1
• Characterize meibomian gland secretions as turbid, thickened, foamy, or deficient 1
• Identify lid margin abnormalities including vascularization crossing the mucocutaneous junction, keratinization, scarring, and hyperemia 1
• Examine eyelashes for trichiasis, distichiasis, madarosis, collarettes, and deposits 1

Ocular Surface Staining

• Apply fluorescein dye to assess corneal epithelial damage, particularly localized interpalpebral drying and punctate epithelial erosions 1, 2
• Use lissamine green for conjunctival assessment, as it provides higher yield in the conjunctiva than other dyes 1
• Evaluate all four quadrants of the bulbar conjunctiva for punctate staining, hyperemia, conjunctivochalasis, localized drying, and keratinization 1
• Examine inferior fornix and tarsal conjunctiva for mucous threads, scarring, erythema, papillary reaction, follicle enlargement, and subepithelial fibrosis 1

Additional Structural Assessment

• Check punctal patency and position, noting presence and position of any plugs 1
• Assess for corneal complications including filamentary keratitis, scarring, thinning, neovascularization, or ulceration in severe cases 2

Clinical Context

A common pitfall is confusing slit-lamp examination with treatment. The slit-lamp is purely diagnostic—it allows visualization and documentation of dry eye pathology but does not treat the condition. 1

After completing slit-lamp biomicroscopy to establish diagnosis and severity, treatment should follow the American Academy of Ophthalmology's stepwise approach:

• Start with preservative-free artificial tears containing methylcellulose or hyaluronate at least twice daily, escalating to hourly if needed 3
• Advance to anti-inflammatory agents (cyclosporine 0.05% or lifitegrast 5%) when artificial tears fail to control symptoms 3
• Consider punctal occlusion using temporary silicone plugs initially, with permanent thermal or laser cautery reserved for severe cases after optimizing topical therapy 3

The slit-lamp examination should be repeated at follow-up visits to assess response to therapy and monitor for ocular surface damage, with frequency depending on disease severity. 1