Dry Eye Disease

What is Dry Eye Disease

Dry eye disease (DED) is one of the most common ocular conditions, affecting tens of millions of people worldwide. It occurs when the eye does not produce enough tears, or when tears evaporate too quickly, leaving the eye surface inadequately lubricated. Oculoplastic surgeons evaluate and treat dry eye, particularly when it relates to eyelid malposition, lagophthalmos, or previous eyelid surgery.

For a detailed illustrated guide, see the Anatomy Overview.

Anatomy of the Tear Film

Tears coat the ocular surface and are composed of three layers:

• Lipid layer (outermost) — secreted by the meibomian glands in the eyelid margins. Reduces evaporation and gives the tear film stability.
• Aqueous layer (middle) — produced by the lacrimal gland and accessory lacrimal glands. Provides moisture, oxygen, and immune factors.
• Mucin layer (innermost) — secreted by goblet cells in the conjunctiva. Anchors the tear film to the corneal surface.

Disruption of any layer can produce dry eye symptoms. The most common form is evaporative dry eye, due to meibomian gland dysfunction (MGD), accounting for over 80% of cases.

Causes of Dry Eye

Evaluation

A thorough dry eye evaluation includes:

• Symptom questionnaires (OSDI, SANDE) — standardized scoring of symptom severity and frequency.
• Slit lamp examination — evaluates lid margin, meibomian gland orifices, conjunctival goblet cells, and corneal staining.
• Tear break-up time (TBUT) — measures how quickly the tear film breaks between blinks. Normal ≥10 seconds.
• Schirmer's test — quantifies aqueous tear production. A strip of filter paper is placed at the lower lid margin.
• Meibography — infrared imaging of meibomian glands to assess dropout and morphology.
• Eyelid evaluation — checking for lagophthalmos, ectropion, trichiasis, or incomplete blink contributing to exposure.

Medical Treatment

The stepwise approach to dry eye treatment depends on disease severity:

Artificial Tears & Lubricants

Preservative-free artificial tears are the first-line treatment. Frequency depends on severity — from as-needed to every 1–2 hours. Gel formulations and ointments provide longer contact time, especially useful at night. Patients with evaporative dry eye benefit from lipid-supplementing drops.

Prescription Anti-inflammatory Drops

• Restasis® (cyclosporine 0.05%) — reduces inflammation and stimulates goblet cell proliferation. Full effect in 3–6 months.
• Xiidra® (lifitegrast 5%) — blocks LFA-1 to reduce T-cell-mediated surface inflammation. May provide faster symptom relief.
• Cequa® (cyclosporine 0.09%) — higher concentration cyclosporine with nanomicellar delivery.

Lid Hygiene & Warm Compresses

For meibomian gland dysfunction: warm compresses applied for 5–10 minutes to melt thickened meibum, followed by gentle lid massage. Lid scrubs with dilute baby shampoo or commercial lid wipes reduce bacterial load and improve gland function.

Punctal Occlusion (Punctal Plugs)

Punctal plugs are small devices inserted into the tear drainage openings (puncta) on the upper and lower eyelids to reduce tear drainage and increase tear film volume on the eye surface. They are a simple office procedure performed under topical anesthesia.

• Temporary plugs — made of collagen or other absorbable material; dissolve in days to weeks. Used to test response before permanent occlusion.
• Permanent plugs — silicone or acrylic devices; can be removed if needed. Placed in the horizontal canaliculus (intracanalicular) or at the punctal opening (punctal).

Plugs are appropriate when dry eye symptoms persist despite adequate lubrication therapy and anti-inflammatory treatment. They are contraindicated in active ocular surface inflammation or chronic dacryocystitis.

Surgical Treatment

When dry eye is related to eyelid malposition or incomplete closure, surgical correction addresses the root cause:

• Ectropion repair — restores the lower lid to its normal apposition against the globe, allowing the tear meniscus to form properly and the punctum to drain effectively.
• Gold weight implantation / tarsorrhaphy — for lagophthalmos from facial nerve palsy, reduces nocturnal and incomplete closure exposure.
• Orbital decompression — in thyroid eye disease with proptosis, reducing globe protrusion improves lid-globe apposition and exposure.
• Punctal cautery — permanent closure of the puncta by thermal cautery when plugs are insufficient or repeatedly expelled.

Dry Eye After LASIK / PRK

Refractive surgery consistently causes a transient reduction in corneal sensation and tear production due to severing of corneal nerves during flap creation or ablation. Most patients experience significant dry eye in the first 3–6 months after LASIK. PRK patients may also develop dry eye though the mechanism differs slightly. Management includes:

• Aggressive preservative-free lubrication starting immediately postoperatively
• Anti-inflammatory drops (cyclosporine, lifitegrast) if symptoms persist beyond 3 months
• Punctal plugs for patients with persistent aqueous deficiency
• Evaluation for underlying blepharitis or MGD that may have been unmasked by surgery

Patients with pre-existing dry eye should be counseled before LASIK about the risk of symptom worsening and should consider treatment optimization before undergoing refractive surgery.