L5: Opaque eye pt 1

what are some causes of red/pink neovascularisation of the cornea

• Mechanical irritation

• Chronic disease

• Corneal ulceration (ulcerative keratitis)

• Scleritis/episcleritis

• Granulation tissue

• Neoplasia

what are some mechanical irritation methods that cause neovascularisation

• Eyelid abnormalities

  • Entropion, ectropion

  • Trichiasis

  • Districhiasis

  • Ectopic cilia

• Chemical burn

What are some chronic diseases that cause neovascularisation

• Chronic superficial keratitis “pannus”

• Eosinophilic keratitis

• Keratoconjunctivitis sicca (dry eye)

• Immune mediated keratitis

What are some causes of white/yellow (deposit/infiltrate) corneas

• Lipids

• calcium

• Abscess/infiltrate

• scar/fibrosis

• fluorescein

What are some causes of blue (oedema) corneas

• Corneal ulcer

• vascularisation (leaky vessels)

• Intraocular disease

  • Uveitis

  • Glaucoma

  • Lens luxation

What are some causes brown/black (pigment) corneas

• Mechanical irritation

• sequestrum (bottom left)

• Pigmentary keratitis

• Melanoma

• Foreign body

• Corneal perforation with entrapped iris (bottom right)

What is the anatomy/physiology of the cornea

• Epithelium

• stroma

• Descements membrane

• Endothelium

why is the healthy cornea transparent

• No blood vessels

• No myelinated nerves

• No pigment

• Relatively dehydrated

What are some clinical signs of corneal disease

Loss of transparency

• Red/pink

• White/yellow

• Blue

• Brown/black

Other

• Epiphora/discharge

• Blepharospasm

• Photophobia

• Self trauma/rubbing

What are some diagnostic tests to determine the health/opacity of the cornea

• Schirmer tear test 1 (STT-1)

• Fluorescein

• Seidel

• Cytology. culture and sensitivity

What areas of the cornea can heal (and in what order?)

• Epithelium

• Stromal

• Endothelium

• Vascularisation

How does the corneal epithelium heal

• Enlargement and sliding of epithelial cells together (1-2 hours)

• Mitosis of epithelial cells

• Completely healed in 1-2 weeks

How does the stroma heal

• New collagen fibres and lamellae

• weeks to months

Describe endothelium healing in the cornea

• Limited capacity for mitosis

• Endothelial cells enlarge in size, reduce in number and lose their hexagonal appearance

How fast/ vascularisation of cornea healing occur

• 0.5 mm per day

What are some ulcerative diseases that cause corneal opacity

• KCS

• SCCED

• Superficial ulcer

• Deep ulcer

• Descemetocoele

• corneal perforation

• Melting (malacic) ulcer

• foreign body

• immune mediated superficial punctate keratitis

• FHV-1

Which is the only corneal ulcerative disease that can be debrided

• Spontaneous chronic corneal epithelial defect (SCCED)

What does this show

KCS

What does this show

Spontaneous chronic corneal epithelial defect

What does this show

Superficial ulcer

What does this show

Deep ulcer

What does this show

Descemetocoele

What does this show

corneal perforation

what does this show

Melting (malacic) ulcer

What does this show

Foreign body

What does this show

immune mediated superficial punctate keratitis

what does this show

Feline herpesvirus

Dendritic-top

Geographic- bottom

What topicals can you apply to manage ulcerative keratitis

• Topical antibiotic, antiviral, antifungal

  • chloramphenicol, ofloxacin

• Topical mydriatic/cycloplegic

  • atropine

• Topical anti-collagenase

  • Serum, EDTA

• Systemic analgesic

  • Oral, NSAID

• ± topical immunomodulator

  • Cyclosporine ointment

• ± topical anti-inflammatory

  • Risk of delayed corneal healing

What are the ways of managing ulcerative keratitis

• Medical

• Corneal collagen cross linking

• Surgical grafting

• Tarsorrhaphy vs 3rd eyelid flap vs contact lens

When does ulcerative disease become non-healing

Longer than 2 weeks on appropriate treatment

What are some causes of non healing ulcerative disease

• mechanical irritation

• Infection

• Malacia

• SCCED

• neoplasia (rare)

What are some non ulcerative diseases

• Eosinophilic keratitis

• Chronic superficial keratitis (pannus)

• Corneal sequestrum

• Acute bullous keratopathy

• Pigmentary keratitis

• Mineral deposition

• Scar/fibrosis

What does this show

Eosinophilic keratitis

ulcerative in up to 25% of cases

What does this show

Chronic superficial keratitis (pannus)

What does this show

Corneal sequestrum

May be ulcerative around the edge or have started as an ulcer

What does this show

Acute bullous keratopathy

what does this show

pigmentary keratitis

What does this show

mineral deposition

• Calcium/lipid

What does this show

Scar/fibrosis

What are some causes of corneal oedema

• Endothelial degeneration

• Uveitis

• Lens luxation

• Glaucoma

What does this show

Endothelial degeneration

What does this show

Uveitis

What does this show

Lens luxation

What does this show

Glaucoma

What cases should third eyelid flaps be reserved for

• Globe proptosis

• Bullous keratopathy