2-22 - Conj. Inflammation

Question 1

Describe lymphatic drainage of conj.

Answer 1

Lymph vessels at superficial and deep plexus of substantia propria.
Two groups of lymphatics:
- Lateral lymphatics – Drains to pre-auricular/parotide lymph nodes (in front of ear)
- Medial lymphatics – Drains to Submandibular lymph nodes (under jaw bone)

Question 2

Follicles vs Papillae

Answer 2

Follicles:
- Subepithelial foci of hyperplastic lymphoid tissue in conj. Stroma.
- Made of central germinal cells surrounded by mature lymphocytes
- Multi discrete, slightly elevated, yellow-white nodules (like small rice grains)
- Avascular, w/ accessory vascularization (BVs run around it)
Papillae:
- Conjunctival epithelium hyperplasia
- Excessive growth causes folds/projections
- Vascular core w/ diffuse stromal infiltrate of variable inflammatory cells
- Appears red velvety, fine mosaic-like pattern of elevated red dots surrounded by paler channels
- Less specific diagnoses as can also be from different types of mechanical damage…
- Horner-trantas dots are gelantinous appearance at limbus
- Can coalesce into giant papillae if severe

Question 3

Membranes

Answer 3

• Excreted inflammatory exudates from conj. or microbe at conj.
  True membranes:
• Infiltrate superficial layers of conjunctival epithelium
• Very integrated w/ tissue so removal leads to tearing + bleed
  Pseudomembranes:
• Coagulated exudate adherent to inflamed conjunctival epithelium
• Peeling away will leave underlying epithelium intact

Question 4

Bacteria conjunctivitis

Answer 4

• Common, self-limiting, topical antibiotic can be given
• Lots of different species can cause it
• Characteristic muco/purulent discharge = Eyes often glued together when waking. Px often rubs off in morning so we often don’t see this gunk and have to rely on their description of symptom.
• Characteristic Papillae
• Pseudomembrane if severe
• Injection also present
• Gritty sensation + mild irritation
• Unilateral, but can become bilateral due to hygiene

Question 5

Viral conjunctivitis
(include time course, treatment)

Answer 5

Adenoviral keratoconjunctivitis
- Due to adenovirus most of the time
- Common + contagious
- Unilateral, often self-inoculate to bilateral
- Pharyngoconjunctival fever (PCF) seortypes 3, 4, 7 or Epidemic keratoconjunctivitis (EKC) serotypes 8, 19, 37
- Often systemic systems first before eye
- Watery discharge + follicles + lymphadenopathy
- Gritty sensation + mild irritation
- Often lead to keratitis (hence the name), which can affect vision

Question 6

Desribe histology/layers of conj.

Answer 6

Epithelium
- 2-7 cells thick
- Has goblet cells
- Cuboidal/columnar at bottom but more squamous at surface
- Melanocytes at basal layer
Substantia propria = 2 parts.
- Adenoidal layer = lymphoid tissue
- Fibrous layer = Nerves, BVs, glands of Krause and Wolfring.

Question 7

List non-specific signs and symptoms of conjuncitivitis

Answer 7

Signs:
- Conjunctival reaction
- Discharge
- Chemosis (swelling of conj.)
- Follicles and papillae
- Membranes (+ pseudomembranes).
Can lead to cornea involvement, but conjunctivitis by itself doesn’t affect vision usually.

Symptoms:
- Discomfort
- Lacrimation

Question 8

Describe conj. reaction
Describe discharge

Answer 8

Both are more diffuse as oppose to focal, helps differentiate from other conditions.
Hyperemia:
- More redness due to BVs more red
Injection:
- BVs vasodilate
- More red going away from limbus (as oppose to ciliary injection)

Exudate filtering through dilated BVs of conjunctival epithelium
- Variable quantity and quality.
Either:
- Watery (serous)
- Mucoid (stringy, ropy)
- Muco-purulent
- Moderate/severe purulent

Question 9

Describe chemosis

Answer 9

Small but noticeable severe conjunctival swelling (oedema)
- Due to BVs leaking protein-rich fluid
- Appears as translucent blister or fluid-filled “sac”
- Folds may form in fornices
- Can protrude closed eyes if severe.