6 - Corneal & Conjunctival Infections

Question 1

What is the conjunctiva?

Answer 1

= transparent mucous membrane lining the inner surface of the eyelids & anterior surface of the globe, terminating at the corneoscleral limbus

Question 2

What are the 3 types of conjunctiva?

Answer 2

1. Palpebral - (more hidden side) starts at mucocutaneoux junction of lid margins & is firmly attached to posterior tarsal plates. Tarsal bld vessels are oriented vertically
2. Forniceal - loose & redundant
3. Bulbar

Question 3

Describe the epithelium of the conjunctiva.

Answer 3

• non-keratinised *, 5 layers
• basal cuboidal cells evolve into flattened polyhedral cells
• mucous secreting goblet cells *

Question 4

Describe the stroma of the conjunctiva.

Answer 4

• richly vascularised loose CT
• accessory lacrimal glands of Krause & Wolfring deep in the stroma
  (their secretions = essential components of tear film)
• lymphoid tissue assoc w/ conjunctiva –> imp to consider in diagnosing lymphoma

Question 5

What is CALT?

Answer 5

conjunctiva-associated lymphoid tissue
- regulation of ocular surface immune responses

Consists of:

1. lymphocytes * in epithelium,
2. lymphatics * & associated bld vessels
3. stromal cell component of lymphocytes & plasma cells

Question 6

What are the different conjunctival reactions?

Answer 6

1. Hyperemia
2. Hemorrhgaes
3. Chemosis (conjunctival edema)

Question 7

Conjunctival hyperaemia = ?

Answer 7

= conjunctival reaction that appears as dilation and redness of the conjunctival vessels.

• diffuse, beefy-red & more intense AWAY from the limbus (typical of bacterial infection)
• distinguished from ciliary injection of iridocyclitis

Question 8

What is a ciliary injection?

Answer 8

involves branches of the anterior ciliary arteries and indicates inflammation of the cornea, iris, or ciliary body. Conjunctival injection mainly affects the posterior conjunctival blood vessels

Question 9

What are the 2 types of conjunctival hyperaemia?

Answer 9

1. Diffuse: when all of the conjunctiva is homogenously involved –> indicates inflammation of the conjunctiva.
2. Peri-keratic (around limbus/cornea): Where the cornea is principal tissue involved –> conjunctiva becomes hyperaemic in a peri-keratic way all around the cornea.

Question 10

When may haemorrhages of the conjunctiva occur?

Answer 10

1. VIRAL conjunctivitis –> when
   they are frequently multiple, small
   and discrete, and severe.
2. BACTERIAL “ –> when they are larger and diffuse.

Question 11

What is chemosis?

Answer 11

= CONJUNCTIVAL EDEMA

seen as a translucent swelling, which may protrude through the eyelids

Question 12

What are the different types of conjunctivitis?

Answer 12

1. Acute bacterial
2. Viral (pink eye)
3. Adenoviral
4. Bacterial
5. Hyperacute bacterial
6. Chlamydial

Question 13

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