Dry Eye

Question 1

Define dry eye.

Answer 1

Dry eye occurs when there is inadequate tear volume or function, resulting in an unstable tear film and ocular surface disease.

Question 2

What are the three layers of the tear film?

Answer 2

Lipid layer (meibomian glands), aqueous layer (lacrimal glands), mucous layer (conjunctival goblet cells).

Question 3

What is Keratoconjunctivitis sicca (KCS)?

Answer 3

Any eye with some degree of dryness.

Question 4

What does Xerophthalmia describe?

Answer 4

Dry eye associated with vitamin A deficiency.

Question 5

What is Xerosis?

Answer 5

Extreme ocular dryness and keratinization from severe conjunctival cicatrization.

Question 6

Which autoimmune syndrome features dry eyes?

Answer 6

Sjogren syndrome.

Question 7

Main function of lipid layer in tear film?

Answer 7

Prevents evaporation of aqueous layer and maintains tear film thickness.

Question 8

Functions of aqueous layer?

Answer 8

Provides oxygen, antibacterial activity, washes debris, optically enhances corneal surface.

Question 9

Key composition of mucous layer?

Answer 9

Mucins, produced mainly by conjunctival goblet cells.

Question 10

Main hormones regulating tear film lipids?

Answer 10

Androgens.

Question 11

Four core mechanisms of dry eye disease?

Answer 11

Tear instability, tear hyperosmolarity, inflammation, ocular surface damage.

Question 12

Two main types of dry eye per DEWS?

Answer 12

Aqueous-deficient and evaporative types.

Question 13

Examples of aqueous-deficient dry eye causes?

Answer 13

Sjogren syndrome, lacrimal gland deficiency, duct obstruction, reflex hyposecretion.

Question 14

Examples of evaporative dry eye causes?

Answer 14

Meibomian gland deficiency, lid aperture disorders, low blink rate, drug action, vitamin A deficiency, contact lens wear.

Question 15

Classic triad of Sjogren syndrome?

Answer 15

Dry eyes, dry mouth, parotid gland enlargement.

Question 16

Most common ocular symptoms of dry eye?

Answer 16

Dryness, grittiness, burning, worsening throughout the day.

Question 17

One sign of conjunctival involvement in dry eye?

Answer 17

Redness and staining with rose Bengal or lissamine green.

Question 18

What is punctate epithelial erosion?

Answer 18

Small erosions in corneal epithelium, visible with fluorescein staining.

Question 19

Name a key dry eye investigation.

Answer 19

Schirmer test for tear production.

Question 20

What does a Schirmer test measure?

Answer 20

Amount of wetting of filter paper in lower lid after 5 minutes.

Question 21

What value is abnormal in Schirmer test (without anesthesia)?

Answer 21

Less than 10 mm wetting after 5 minutes.

Question 22

Which dyes are used for ocular surface staining?

Answer 22

Fluorescein, rose Bengal, lissamine green.

Question 23

Accepted osmolarity threshold for dry eye diagnosis?

Answer 23

308 mOsml or 316 mOsml for moderate-severe.

Question 24

First-line management level for dry eye?

Answer 24

Education and environmental/dietary modifications.

Question 25

Name two artificial tear substitute categories.

Answer 25

Gels and ointments.

Question 26

Function of punctal occlusion in dry eye?

Answer 26

Reduces drainage, preserving natural tears and prolonging effect of artificial tears.

Question 27

Which topical medication should be minimized if possible in dry eye?

Answer 27

Preservative-containing eye drops.

Question 28

Name a drug class effective as anti-inflammatory in dry eye.

Answer 28

Topical steroids or omega fatty acids.

Question 29

Why use lissamine green over rose Bengal?

Answer 29

Lissamine green stains like rose Bengal but causes less irritation.

Question 30

Key complications of severe dry eye?

Answer 30

Epithelial breakdown, melting, perforation, bacterial keratitis.

Question 31

Name two surgical treatments for severe dry eye.

Answer 31

Eyelid surgery (tarsorrhaphy), salivary gland auto-transplantation.

Question 32

Give an example of an advanced therapy for severe dry eye.

Answer 32

Serum eye drops (autologous or umbilical cord serum), photobiomodulation.