Clinical Pathway

Dry Eye Workup

Evidence-based clinical pathway for comprehensive dry eye assessment and management in Singapore, developed in accordance with TFOS DEWS II guidelines.

Last updated: February 2026

OVERVIEW

Dry Eye Disease Clinical Workflow

Dry eye disease (DED) is a multifactorial disease of the ocular surface characterized by loss of homeostasis of the tear film, accompanied by ocular symptoms, with tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities playing etiological roles (TFOS DEWS II, 2017).

This workflow follows the TFOS DEWS II diagnostic methodology and treatment algorithm, adapted for optometric practice in Singapore with consideration for local climate, demographics, and available resources.

SECTION 1

Structured Intake & Patient History

1.1 Symptom Assessment

Utilize validated questionnaires for standardized symptom assessment:

OSDI (Ocular Surface Disease Index): 12-item questionnaire scoring 0–100. Normal (<13), Mild (13–22), Moderate (23–32), Severe (33–100)
DEQ-5 (Dry Eye Questionnaire-5): Simplified 5-item tool scoring 0–22. Score ≥6 suggests clinically significant dry eye
SPEED (Standard Patient Evaluation of Eye Dryness): 8-item assessment of frequency and severity

1.2 Risk Factor Identification

Category	Risk Factors
Environmental	Air conditioning, low humidity, wind exposure, screen time >6 hours/day, Singapore’s tropical climate with indoor air conditioning
Systemic	Sjögren’s syndrome, diabetes mellitus, thyroid disorders, rheumatoid arthritis, rosacea, hormonal changes (menopause)
Medications	Antihistamines, antidepressants, isotretinoin, beta-blockers, diuretics, oral contraceptives
Ocular	Contact lens wear, refractive surgery (LASIK/PRK), incomplete blink, blepharitis, meibomian gland dysfunction
Demographic	Age >50 years, female gender, Asian ethnicity (higher MGD prevalence)

1.3 Medical & Medication History

Document all systemic medications and supplements
Screen for autoimmune conditions (especially Sjögren’s syndrome)
Previous ocular surgeries or procedures
Contact lens history (type, wearing schedule, solution use)
Current topical medications and preservative exposure

SECTION 2

Clinical Examination Protocol

2.1 Examination Sequence (Least to Most Invasive)

Symptom Questionnaire

OSDI, DEQ-5, or SPEED before any examination

Non-Invasive Tear Break-Up Time (NIBUT)

Before any ocular surface contact. Normal: ≥10 seconds

Tear Meniscus Height (TMH)

Slit lamp assessment. Normal: 0.2–0.5 mm. <0.2 mm suggests aqueous deficiency

Lid & Meibomian Gland Assessment

Lid margin evaluation, gland expressibility, secretion quality

Blink Assessment

Frequency (normal: 12–15/min) and completeness during conversation and reading

Tear Film Break-Up Time (TBUT) with Fluorescein

Minimal volume instillation. Normal: ≥10 seconds. <5 seconds indicates severe instability

Ocular Surface Staining

Fluorescein (cornea), Lissamine Green (conjunctiva). Grade using Oxford or CCLRU scale

Schirmer Test (if indicated)

Without anesthesia: <5 mm/5 min severe, 5–10 mm moderate, >10 mm normal

2.2 Meibomian Gland Dysfunction (MGD) Assessment

MGD is present in 85% of evaporative dry eye cases. Systematic evaluation is essential:

Parameter	Assessment Method	Grading
Lid Margin	Slit lamp evaluation	Normal, irregular/thickened, vascular engorgement, plugging/pouting, displacement
Gland Expressibility	Firm pressure on 5 central lower lid glands	Grade 0: All glands expressible Grade 1: 3–4 glands expressible Grade 2: 1–2 glands expressible Grade 3: No glands expressible
Secretion Quality	Observe expressed meibum	Grade 0: Clear liquid Grade 1: Cloudy liquid Grade 2: Cloudy particulate Grade 3: Thick toothpaste-like
Gland Dropout	Meibography (if available)	Grade 0: No loss (0%) Grade 1: <25% loss Grade 2: 25–50% loss Grade 3: 51–75% loss Grade 4: >75% loss

SECTION 3

Classification & Severity Grading

3.1 TFOS DEWS II Classification

Aqueous Deficient Dry Eye (ADDE)

Primary Mechanism: Reduced tear production

Key Findings:

Reduced tear meniscus height (<0.2 mm)
Low Schirmer test (<5–10 mm/5 min)
May have normal TBUT initially
Associated with Sjögren’s syndrome or lacrimal gland dysfunction

Evaporative Dry Eye (EDE)

Primary Mechanism: Excessive tear evaporation

Key Findings:

Normal or near-normal tear volume
Reduced TBUT (<10 seconds)
MGD present in 85% of cases
Most common type in Asian populations

Note: Mixed mechanism dry eye (both ADDE and EDE) is common and requires addressing both components.

3.2 Severity Grading System

Severity	Symptoms	TBUT	Staining	Schirmer
Level 1 (Mild)	Episodic discomfort under stress	≥10 sec	Minimal (Grade 0–1)	>10 mm
Level 2 (Moderate)	Frequent symptoms with/without stress	5–10 sec	Variable (Grade 1–2)	5–10 mm
Level 3 (Severe)	Constant bothersome symptoms	<5 sec	Marked (Grade 2–3)	2–5 mm
Level 4 (Very Severe)	Disabling, impairs daily function	Immediate	Severe (Grade 3–4)	<2 mm

SECTION 4

Evidence-Based Treatment Ladder

Level 1: Mild Dry Eye

Patient Education & Lifestyle Modifications

Explain dry eye pathophysiology and chronic nature
Environmental modification: humidifiers, reduce air conditioning exposure, position away from direct airflow
Digital device usage: 20-20-20 rule (every 20 min, look 20 feet away for 20 sec)
Conscious blinking exercises, especially during screen use
Adequate hydration (8 glasses water/day), omega-3 rich diet
Protective eyewear outdoors (wrap-around sunglasses)

Artificial Tears

Preservative-free formulations preferred if using >4 times/day
Start with low-viscosity drops for daytime use
Gel or ointment for nighttime if needed
Frequency: Minimum 4 times/day, increase as needed

Lid Hygiene (if MGD present)

Warm compresses: 40–45°C for 5–10 minutes, twice daily
Lid massage: Gentle downward strokes on upper lid, upward on lower lid
Lid scrubs: Diluted baby shampoo or commercial lid wipes, once daily

Level 2: Moderate Dry Eye

Continue all Level 1 treatments and add:

Omega-3 Fatty Acid Supplementation

Dosage: EPA + DHA ≥2000 mg/day (EPA:DHA ratio 3:1 to 4:1 preferred)
Duration: Minimum 3–6 months for therapeutic effect
Evidence: Meta-analyses show improvement in TBUT, OSDI scores, and tear osmolarity
Particularly effective for MGD-related evaporative dry eye

Anti-Inflammatory Therapy

🏥 SINGAPORE PRACTICE NOTE

Anti-inflammatory medications require prescription. Refer to ophthalmologist or collaborate with general practitioner for medication management.

Cyclosporine A 0.05%: Twice daily. Onset 3–6 months. Reduces inflammation, increases tear production
Lifitegrast 5%: Twice daily. Faster onset (2 weeks). LFA-1 antagonist
Short-term topical corticosteroids (e.g., fluorometholone 0.1% QID for 2 weeks) for acute exacerbations

Tear Conservation

🏥 SINGAPORE PRACTICE NOTE

Punctal plug procedures are performed by ophthalmologists in Singapore. Refer appropriate candidates.

Punctal plugs: For aqueous deficient dry eye unresponsive to lubricants
Trial with temporary collagen plugs (dissolve in 7–10 days) before permanent silicone plugs
Insert lower puncta first; add upper if needed
Monitor for epiphora, increased discharge, or granuloma formation

Level 3: Severe Dry Eye

Continue all previous treatments. Most Level 3 interventions require ophthalmology referral in Singapore:

Advanced MGD Therapy

🏥 SINGAPORE PRACTICE NOTE

Advanced MGD procedures (thermal pulsation, IPL, meibomian gland probing) are performed by ophthalmologists. Refer candidates with severe MGD unresponsive to conservative therapy.

Thermal Pulsation (LipiFlow): Automated heating + pulsatile pressure. Single 12-minute treatment. Improvement lasts 6–12 months
Intense Pulsed Light (IPL): 3–4 sessions at 2–4 week intervals. Reduces lid inflammation, improves meibum quality
Meibomian gland probing: For obstructed glands unresponsive to conservative therapy

Autologous Serum Tears

🏥 SINGAPORE PRACTICE NOTE

Autologous serum preparation requires medical oversight and laboratory facilities. Refer to ophthalmology.

20–50% concentration in preservative-free saline
Contains growth factors, vitamins, immunoglobulins, fibronectin
Particularly effective for severe aqueous deficiency and neurotrophic keratopathy
Requires proper storage (refrigeration) and patient compliance

Systemic Therapy

🏥 SINGAPORE PRACTICE NOTE

Systemic antibiotics require prescription. Collaborate with ophthalmologist or general practitioner for medication management.

Oral tetracyclines: Doxycycline 50–100 mg daily or azithromycin 500 mg daily for 3 days, then 250–500 mg 3×/week
Anti-inflammatory and lipid-altering properties beneficial for MGD and rosacea-associated dry eye
Duration: 3–6 months minimum

Bandage Contact Lenses

✓ OPTOMETRIC SCOPE

Bandage contact lens fitting is within optometric scope in Singapore. Close monitoring essential.

Silicone hydrogel lenses for persistent epithelial defects
Scleral lenses create fluid reservoir, protect ocular surface
Requires careful monitoring for infection risk
Consider co-management with ophthalmology for complex cases

Level 4: Refractory / Very Severe Dry Eye

Referral to Ophthalmology

Refer for consideration of:

Surgical intervention: Permanent punctal occlusion, tarsorrhaphy, salivary gland transplantation
Immunosuppressive therapy: For severe autoimmune-related dry eye (Sjögren’s syndrome)
Amniotic membrane transplantation: For persistent epithelial defects or severe limbal stem cell deficiency
Investigation of systemic causes: Rheumatology referral if autoimmune disease suspected

⚠️ Red Flags Requiring Urgent Referral:

Corneal infiltrate or suspected microbial keratitis
Persistent epithelial defect >2 weeks despite treatment
Corneal ulceration or thinning
Significant visual impairment affecting daily activities
Suspected Stevens-Johnson syndrome or other severe ocular surface disease

SECTION 5

Follow-Up & Monitoring Protocol

Severity Level	Initial Follow-Up	Subsequent Monitoring	Key Parameters
Mild	4–6 weeks	3–6 months if stable	OSDI score, TBUT, symptom improvement
Moderate	2–4 weeks	1–3 months	All baseline tests, medication tolerance, MGD improvement
Severe	1–2 weeks	2–4 weeks initially, then monthly	Comprehensive examination, staining scores, medication compliance
Very Severe	3–7 days	Weekly until stabilized	Full workup, corneal integrity, vision assessment, coordinate with ophthalmology

Treatment Response Assessment

Criteria for Adequate Treatment Response:

✓≥20% improvement in OSDI or symptom score
✓Improvement in TBUT (≥2 seconds increase)
✓Reduction in ocular surface staining (≥1 grade improvement)
✓Patient-reported improvement in quality of life

If inadequate response after 4–6 weeks: Re-evaluate diagnosis, assess compliance, escalate treatment tier, or consider referral.

SECTION 6

Special Considerations for Singapore Practice

Contact Lens-Related Dry Eye

Highly prevalent: 50% of contact lens wearers experience symptoms
Management approach:
- Reduce wearing time, consider daily disposables
- Switch to high-water-content or silicone hydrogel materials
- Preservative-free rewetting drops during wear
- If severe: Contact lens holiday (1–2 weeks) with aggressive dry eye therapy
- Consider discontinuation if refractory despite optimal management

Post-Refractive Surgery Dry Eye

LASIK/PRK causes transient neurotrophic dry eye (3–6 months typical duration)
Pre-operative screening critical: Identify pre-existing dry eye, optimize before surgery
Post-operative protocol:
- Intensive preservative-free lubrication (hourly initially)
- Consider autologous serum for severe cases
- Punctal plugs if persistent >3 months
- Collaborate with operating surgeon for complex cases

Regulatory & Referral Pathways in Singapore

Optometrists and Opticians Act: Optometrists can diagnose and co-manage dry eye disease
Prescription medications: Cyclosporine, lifitegrast require medical prescription. Collaborate with ophthalmologist or general practitioner
Referral indications:
- Lack of improvement after 3 months optimal therapy
- Suspected systemic disease (rheumatology workup needed)
- Corneal complications (ulceration, thinning, scarring)
- Need for advanced procedures (IPL, thermal pulsation, surgical intervention)
Documentation: Detailed referral letter with baseline measurements, treatment history, severity grading essential for continuity of care

References

1. Craig JP, Nichols KK, Akpek EK, et al. TFOS DEWS II Definition and Classification Report. The Ocular Surface. 2017;15(3):276-283. doi:10.1016/j.jtos.2017.05.008
2. Wolffsohn JS, Arita R, Chalmers R, et al. TFOS DEWS II Diagnostic Methodology report. The Ocular Surface. 2017;15(3):539-574. doi:10.1016/j.jtos.2017.05.001
3. Jones L, Downie LE, Korb D, et al. TFOS DEWS II Management and Therapy Report. The Ocular Surface. 2017;15(3):575-628. doi:10.1016/j.jtos.2017.05.006
4. Stapleton F, Alves M, Bunya VY, et al. TFOS DEWS II Epidemiology Report. The Ocular Surface. 2017;15(3):334-365. doi:10.1016/j.jtos.2017.05.003
5. Tomlinson A, Bron AJ, Korb DR, et al. The international workshop on meibomian gland dysfunction: report of the diagnosis subcommittee. Investigative Ophthalmology & Visual Science. 2011;52(4):2006-2049. doi:10.1167/iovs.10-6997f
6. Schiffman RM, Christianson MD, Jacobsen G, Hirsch JD, Reis BL. Reliability and validity of the Ocular Surface Disease Index. Archives of Ophthalmology. 2000;118(5):615-621. doi:10.1001/archopht.118.5.615
7. Chalmers RL, Begley CG, Caffery B. Validation of the 5-Item Dry Eye Questionnaire (DEQ-5). Contact Lens and Anterior Eye. 2010;33(2):55-60. doi:10.1016/j.clae.2009.12.010
8. Asbell PA, Maguire MG, Pistilli M, et al. n-3 Fatty Acid Supplementation for the Treatment of Dry Eye Disease. New England Journal of Medicine. 2018;378(18):1681-1690. doi:10.1056/NEJMoa1709691
9. Liu Y, Kam WR, Sullivan DA. Influence of Omega 3 and 6 Fatty Acids on Human Meibomian Gland Epithelial Cells. Cornea. 2016;35(8):1122-1126. doi:10.1097/ICO.0000000000000874
10. Baudouin C, Irkeç M, Messmer EM, et al. Clinical impact of inflammation in dry eye disease. Acta Ophthalmologica. 2018;96(2):111-119. doi:10.1111/aos.13436
11. Donnenfeld ED, Perry HD, Nattis AS, Rosenberg ED. Lifitegrast for the treatment of dry eye disease in adults. Expert Opinion on Pharmacotherapy. 2017;18(14):1517-1524. doi:10.1080/14656566.2017.1372748
12. Geerling G, Tauber J, Baudouin C, et al. The international workshop on meibomian gland dysfunction: report of the subcommittee on management and treatment. Investigative Ophthalmology & Visual Science. 2011;52(4):2050-2064. doi:10.1167/iovs.10-6997g
13. Arita R, Fukuoka S, Morishige N. Therapeutic efficacy of intense pulsed light in patients with refractory meibomian gland dysfunction. The Ocular Surface. 2019;17(1):104-110. doi:10.1016/j.jtos.2018.11.004
14. Greiner JV, Glonek T, Korb DR, Leahy CD. Effect of a single vectored thermal pulsation treatment on meibomian gland function. Eye & Contact Lens. 2012;38(5):e1-e7. doi:10.1097/ICL.0b013e318268d2e0
15. Pan Q, Angelina A, Marrone M, Stark WJ, Akpek EK. Autologous serum eye drops for dry eye. Cochrane Database of Systematic Reviews. 2017;2(2):CD009327. doi:10.1002/14651858.CD009327.pub3
16. Doughty MJ, Fonn D, Richter D, et al. A patient questionnaire approach to estimating the prevalence of dry eye symptoms in patients presenting to optometric practices across Canada. Optometry and Vision Science. 1997;74(8):624-631. doi:10.1097/00006324-199708000-00023
17. Tong L, Chaurasia SS, Mehta JS, Beuerman RW. Screening for meibomian gland disease: its relation to dry eye subtypes and symptoms in a tertiary referral clinic in singapore. Investigative Ophthalmology & Visual Science. 2010;51(7):3449-3454. doi:10.1167/iovs.09-4445
18. Nichols JJ, Willcox MD, Bron AJ, et al. The TFOS International Workshop on Contact Lens Discomfort: executive summary. Investigative Ophthalmology & Visual Science. 2013;54(11):TFOS7-TFOS13. doi:10.1167/iovs.13-13212