Dry Eye Syndrome: Causes, Symptoms, Diagnosis, and Treatment

What Is Dry Eye Syndrome?

Every blink spreads a thin, multi-layered tear film across the ocular surface. This film provides lubrication, oxygen delivery, and a smooth optical surface for clear vision. Dry eye syndrome occurs when this film is either produced in insufficient quantity or is of poor quality — breaking up too quickly before the next blink.

The consequences range from mild discomfort and intermittent blur to significant pain, contact lens intolerance, and impaired quality of life. Dry eye is among the most common reasons Australians visit an eye specialist.

Two Main Types

Dry eye is broadly divided into two categories, though most patients have elements of both:

• Aqueous-deficient dry eye— the lacrimal glands produce an insufficient volume of tears. Associated with Sjögren’s syndrome, age-related lacrimal gland atrophy, radiation exposure, and certain medications.
• Evaporative dry eye (meibomian gland dysfunction, MGD) — the meibomian glands lining the eyelid margins secrete an inadequate or abnormal lipid (oil) layer. Without sufficient lipid, tears evaporate rapidly between blinks. This is the most common form, accounting for approximately 85% of dry eye cases.

Causes & Risk Factors

Dry eye is multifactorial. The most clinically important risk factors are:

• • Age — tear production and meibomian gland function both decline with age
• • Female sex — hormonal influences (particularly post-menopausal oestrogen decline) increase dry eye prevalence in women
• • Prolonged screen use — reduced blink rate and incomplete blinking accelerate evaporation
• • Contact lens wear — lenses disrupt the tear film and accelerate evaporation
• • Medications — antihistamines, antidepressants, beta-blockers, diuretics, isotretinoin, and hormone replacement therapy all reduce tear production or quality
• • Autoimmune disease — Sjögren’s syndrome, rheumatoid arthritis, lupus
• • Environment — dry climate, air conditioning, heating, and high altitude all increase evaporation
• • Post-surgical — dry eye commonly worsens or first appears after cataract surgery or LASIK, due to transected corneal nerves reducing the blink reflex

Symptoms

The symptom pattern of dry eye is distinctive, though it overlaps with other ocular surface conditions:

• • Grittiness or a foreign body sensation (“sand in the eye”)
• • Burning or stinging, particularly in the afternoon or evening
• • Intermittent blurring that clears momentarily with a full blink
• • Light sensitivity (photophobia)
• • Difficulty tolerating contact lenses
• • Watery or overflowing eyes (reflex tearing)
• • Worsening symptoms in air conditioning, wind, smoke, or low humidity environments
• • Morning crusting or stickiness of the lids (with MGD)

Diagnosis

Proper diagnosis of dry eye requires both subjective and objective assessment:

• OSDI questionnaire— the Ocular Surface Disease Index is a validated 12-item questionnaire quantifying symptom severity and impact on daily activities.
• Tear break-up time (TBUT)— fluorescein dye is instilled; the time from a complete blink to the first dry spot appearing is measured. Less than 10 seconds suggests tear film instability.
• Schirmer’s test— a strip of filter paper is placed in the lower lid for five minutes to measure reflex tear production. Less than 10 mm of wetting suggests aqueous deficiency.
• Vital staining— fluorescein and lissamine green dyes highlight areas of epithelial damage on the cornea and conjunctiva.
• Meibography— infrared imaging of the meibomian glands through the eyelids to assess gland morphology and degree of dropout (permanent gland loss).

Treatment

Treatment follows a stepwise approach, escalating based on severity and response:

• 1. Artificial tears— preservative-free lubricating drops are the foundation of dry eye management. Frequency is titrated to symptoms. Gels or ointments at night for more severe cases.
• 2. Lid hygiene— for MGD: warm compresses applied to closed lids for 10 minutes to melt thickened meibum, followed by gentle lid massage. Commercially available eyelid cleansers reduce bacterial load.
• 3. Omega-3 fatty acid supplements— high-dose marine omega-3s (EPA + DHA) improve meibomian gland secretion quality; evidence supports their benefit in MGD-predominant dry eye.
• 4. Punctal plugs— tiny silicone or collagen plugs occlude the puncta (tear drainage openings) in the inner corners of the lids, retaining tears on the ocular surface for longer.
• 5. Cyclosporine drops— topical cyclosporine (available as Ikervis or compounded formulations) reduces T-cell mediated inflammation of the lacrimal gland and ocular surface, improving aqueous tear production. Takes 3–6 months for full effect.
• 6. Autologous serum eye drops— drops prepared from the patient’s own blood serum contain growth factors and proteins that closely match natural tears. Used for moderate–severe dry eye not responding to conventional treatment.
• 7. Intense pulsed light (IPL)— a light-based treatment applied to the skin around the eyelids that liquefies inspissated meibum, reduces eyelid inflammation, and improves meibomian gland function. Requires a series of treatments; well supported for MGD-type dry eye.
• 8. Scleral contact lenses— for severe ocular surface disease, large-diameter rigid lenses create a fluid reservoir over the cornea, providing continuous lubrication regardless of tear film quality.

Frequently Asked Questions