At Réspa – Optometry & Dry Eye Wellness Centre, fluorescein biomicroscopy forms an important part of our dry eye assessment. Using a gentle fluorescein dye together with slit-lamp examination under cobalt blue light, our Hong Kong–registered optometrists evaluate how effectively your tear film coats and protects the ocular surface.

This assessment is quick, comfortable, and provides valuable insight into tear film stability and ocular surface condition.

What This Test Evaluates

1. Tear Film Break-Up Time (TBUT)

After a small amount of fluorescein dye is applied, you will be asked to blink and then gently keep your eyes open. Under cobalt blue light, we observe how long the tear film remains smooth and intact before break-up occurs.

• A longer break-up time generally indicates better tear film stability

• Shorter break-up times suggest tear instability, which is commonly associated with dry eye–related discomfort

2. Tear Break-Up Patterns

The way the tear film breaks up can offer insight into which component of the tear film may be affected — whether aqueous, lipid, or mucin-related.

Different patterns help us better understand the contributing factors behind your symptoms and guide personalised management recommendations.

3. Ocular Surface Staining

Fluorescein dye highlights areas of the ocular surface that may be stressed or insufficiently protected by the tear film. Under blue light, these areas appear bright green, allowing us to observe:

• Areas of surface dryness or irritation

• Localised ocular surface stress

• Patterns that may indicate increased vulnerability of the corneal surface

4. Tear Meniscus Height

The tear meniscus — the thin reservoir of tears along the lower eyelid — is assessed to estimate tear volume.

• A lower tear meniscus may suggest reduced tear availability

• A higher tear meniscus can be associated with reflex tearing or ocular surface irritation

Why This Matters for Your Care at Réspa

By understanding the stability, distribution, and quality of your tear film, our optometrists can gain a clearer picture of the factors contributing to your dry eye–related symptoms.

These findings help guide:

• Personalised dry eye management recommendations

• Appropriate eye wellness strategies and home-care guidance

• Selection of supportive in-office procedures, where suitable

• Objective monitoring of changes over time

Every detail contributes to a management plan designed to support eye comfort, ocular surface protection, and long-term visual well-being, in line with Réspa’s optometrist-led, patient-centred approach.