Dry eye

3 layers

Lipid- spread by surface tension. Prevents evaporation

Aqueous - spread by blinking

Mucous

Dry eye ( new/ pre-existing)

Px complains of symptoms

Medications

All CL px

Any anterior segment pathology ( pterygium/ pinguecula )

• Itchy sore, gritty, scratchy, burning, FB sensation (sand)

• Redness

• Stringy mucus

• Epiphora

• Blurred vision

• Photophobia

• Difficultly wearing CL

Non invasive

1. Optic section + specular ( look for debris, lipid) - qualitative

2. Keratometry mires/ keratometry mires ( look when mires wobble, break)

3. Measuring tear meniscus ( quantitative)

Invasive - fluorescien

1. TBUT- quantitative

2. tear volume

3. Tear meniscus height ( ~0.3mm) - quantitative

4. Schirmer strip - quantitative

5. Phenol red thread test- quantitative

1. NaFl- absorbed by TF and fills in gaps caused by epi cells loss

   • Pharmacy med

   • Not true dye

   • Used with DES, FB, CL, Goldmann

   • Used with cobalt blue + Wratten filter

2. Rose Bengal- taken up by dead cells and mucus

   • Pharmacy med

   • Used with green light

   • Stings on instillation

   • Takes long to drain

3. Lissamine green- stains dead cells

   • Reversible and can be washed out

   • Viewed with red filter

   • Lodge wiper epitheliopathy