Dry Eye Disease (DED) affects over340 million people globally, with prevalence increasing due to agingpopulations and digital device use. This multifactorial disorder of the ocularsurface involves tear film instability, hyperosmolarity,and ocular surface inflammation.
Classification & Pathophysiology
1. Aqueous-Deficient Dry Eye (ADDE)
- Sjögren's Syndrome-related (autoimmune)
- Non-Sjögren's (lacrimal gland dysfunction)
- Characteristics: Schirmer test <10mm/5min, low tear meniscus
2. Evaporative Dry Eye (EDE)
- Meibomian Gland Dysfunction (MGD) (85% of cases)
- Characteristics: TBUT <7sec, meibum quality score >2
- Subtypes: Obstructive vs hypersecretory
Diagnostic Workup
Clinical Tests
| Test | Normal Value | DED Indicator |
| Tear Break-Up Time (TBUT) | ≥10 sec | <7 sec |
| Ocular Surface Staining | 0-3 (NEI scale) | ≥4 |
| Schirmer (without anesthesia) | ≥15mm/5min | ≤10mm |
| Osmolarity | <308 mOsm/L | >316 mOsm/L |
| Meibography | ≤25% gland dropout | >30% dropout |
Treatment Algorithm
First-Line Therapies
- Artificial Tears:
- Preservative-free (≥4x/day)
- Hyaluronic acid-based (0.15-0.3%)
- Lipid-containing (for MGD)
- Lid Hygiene:
- Warm compresses (42°C, 10min BID)
- Lid scrubs (hypochlorous acid)
- Environmental Modifications:
- Humidity >40%
- Blink exercises (20-20-20 rule)
Advanced Treatments
Pharmacological Options
| Medication | Mechanism | Dosage | Efficacy |
| Cyclosporine 0.05% | T-cell inhibition | BID | 60% improvement at 3mo |
| Lifitegrast 5% | LFA-1 antagonist | BID | Faster onset (2 weeks) |
| Corticosteroids | Anti-inflammatory | Pulse therapy | Short-term use only |
Procedural Interventions
- Intense Pulsed Light (IPL): 3-4 sessions (67% MGD improvement)
- Meibomian Gland Probing: For obstructive MGD
- Punctal Plugs: Temporary → permanent occlusion
Emerging Therapies
Novel Approaches
- Nerve Stimulation:
- Nasal spray devices (varenicline)
- External stimulators (TrueTear)
- Biologic Agents:
- Topical interleukin-1 antagonists
- Stem cell-derived exosomes
- Device-Based:
- Electroceutical contact lenses
- Wearable humidification chambers
Patient Education Essentials
Self-Management Strategies
- Dietary Modifications:
- Omega-3 (2000mg EPA+DHA daily)
- Vitamin D (if deficient)
- Digital Device Use:
- Blue light filters (controversial)
- Position screens below eye level
- Sleep Optimization:
- Moisture chamber goggles
- Eyelid taping (nocturnal lagophthalmos)
Special Populations
Post-Refractive Surgery
- Prophylactic treatment pre-op
- Bandage contact lenses
- Steroid pulse therapy
Contact Lens Wearers
- Daily disposables recommended
- Low modulus materials
- Lubricant-compatible solutions
Monitoring Parameters
- Symptom Scores: OSDI, SPEED
- Objective Signs: Corneal staining, TBUT
- QoL Measures: IDEEL questionnaire
Future Directions
- Tear Biomarkers: MMP-9 point-of-care testing
- Gene Therapy: Lacrimal gland regeneration
- Smart Contact Lenses: Real-time osmolarity monitoring
Conclusion
Modern DED management requires personalized,multi-modal approaches addressing both symptoms and underlyingpathophysiology. With 70-80% of patients achieving significantimprovement through current therapies, early diagnosis and consistent treatmentremain crucial for preventing ocular surface damage.