Aqueous Deficient Dry Eye

Aqueous deficient dry eye (ADDE) results from reduced tear production by the lacrimal glands despite a normal lipid layer.

• Sjogren syndrome related: lymphocytic infiltration of lacrimal and salivary glands with acinar destruction, anti-Ro (SS-A) and anti-La (SS-B) antibodies.
• Non-Sjogren: age related lacrimal gland dysfunction, lacrimal duct obstruction (trachoma, cicatricial pemphigoid, Stevens-Johnson syndrome, chemical injury), reflex hyposecretion (neurotrophic cornea, contact lens wear, refractive surgery, V and VII cranial nerve lesions), drugs (antihistamines, antidepressants, diuretics, isotretinoin, beta blockers), graft versus host disease, sarcoidosis, HIV, hepatitis C, and radiotherapy.
• Tear hyperosmolarity and inflammation damage the ocular surface and create a vicious cycle.

• Dryness, burning, grittiness, foreign body sensation, photophobia, fluctuating vision that clears with blinking, worse late in the day and in low humidity.
• Paradoxical epiphora from reflex tearing.
• Reduced tear meniscus height (under 0.2 mm), debris in tears, filamentary keratitis, punctate epithelial erosions, conjunctival staining (lissamine green).
• Sjogren: dry mouth, parotid swelling, arthralgia, Raynaud, dental caries, dry skin and vaginal dryness, fatigue.
• Complications: corneal ulceration, perforation, scarring, infection.

• Schirmer test without anaesthesia: under 5 mm in 5 minutes strongly suggests ADDE (under 10 mm borderline). Schirmer with anaesthesia assesses basal secretion.
• Tear break up time (fluorescein, under 10 seconds abnormal); tear osmolarity (over 308 mOsm/L, or interocular difference over 8 mOsm/L); corneal and conjunctival staining grading (Oxford scale).
• Matrix metalloproteinase-9 point-of-care testing for inflammation.
• Sjogren screen: anti-Ro/SSA, anti-La/SSB, ANA, rheumatoid factor, immunoglobulins (raised IgG), complement C4 (low C4 suggests lymphoma risk); minor salivary gland biopsy showing focus score of 1 or more per 4 mm2; salivary flow rate (under 0.1 mL/min unstimulated).
• Cranial nerve examination and drug review. Check serum ACE and chest imaging if sarcoid suspected.

• Stepwise approach, tailored to severity.
• Step 1: education, environment modification (humidifier, blink training, screen breaks every 20 minutes), stop causative drugs, preservative free artificial tears (carboxymethylcellulose 0.5 to 1 percent, hyaluronate 0.1 to 0.3 percent) 4 to 8 times daily, night gel or ointment.
• Step 2: anti-inflammatory therapy:
  • Cyclosporine 0.05 percent twice daily or 0.1 percent once daily (effect over 3 to 6 months), or lifitegrast 5 percent twice daily.
  • Short course topical corticosteroid (fluorometholone 0.1 percent or loteprednol 0.5 percent four times daily for 2 to 4 weeks, then taper).
  • Punctal occlusion with plugs (silicone, collagen) or cautery.
• Step 3: autologous serum eye drops 20 to 50 percent, 4 to 6 times daily; bandage and scleral contact lenses (PROSE); oral secretagogues in Sjogren (pilocarpine 5 mg four times daily or cevimeline 30 mg three times daily); oral omega-3 fatty acids (about 2 g daily EPA and DHA).
• Step 4: topical corticosteroid long term in selected cases, amniotic membrane (self-retained), tarsorrhaphy, salivary gland autograft for severe cases.
• Treat Sjogren with rheumatology: hydroxychloroquine 200 to 400 mg daily for arthralgia, and monitor for lymphoma.
• Corneal ulcer or melt needs urgent ophthalmic care.