Cornea II Hypersensitivity , corneal damage

What are Hypersensitivity reactions ?

• overreaction of immune system to allergen or antigen which wouldn't normally trigger an immune response

• immune system responds abnormally

• Allergies are immune reactions to exogenous substances → antigens or allergens

• Autoimmune disease arise from abnormal response to endogenous substances → autoantigens

What is the Aetiology of Marginal Keratitis ?

• Toxic or hypersensitivity reaction to bacterial exotoxins

What are the predisposing factors of Marginal Keratitis ?

• Blepharitis (staphylococcal)

• Current/recent upper respiratory tract infection

• phlyctenulosis

What are the symptoms of Marginal keratitis

• Discomfort, irritation , FB sensation

• Lacrimation

• Red eye

What are the signs of Marginal Keratitis ?

• shallow ulcer

• Round, arcuate , single or multiple

• usually parallel to limbus but separated by clear corneal zone

• stains with fluorescein

• Hyperaemia + oedema of adjacent bulbar conjunctiva

• NO AC involvement

What is the management of Marginal Keratitis?

• Self-limiting

• May scar

• treat underlying blepharitis

• ocular lubricants → symptomatic relief

• pain killers

• refer routinely if persistent or recurrent

• CL wearer → consider acanethoemba or CL related

What is mx of an opthalmologist for Microbial Keratitis?

• Microbiological cultures of lesion and lid margins

• Antibiotic tx for blepharitis

• topical steroid to calm inflammation

What is the Aetiology for CL associated Keratitis ?

• inflammatory response to bacterial antigens in hydrogel CL wearers

What are the predisposing factors to CL keratitis?

• Bacterial bioburden → poor hygiene CL, or case

• Smoking

What are the symptoms of CL keratitis

• may be asymptomatic

• moderately red, watery eye

• mild FB sensation

• mild photophobia

• symptoms improve after lens removed

What are the signs of CL associated keratitis ?

• single or multiple peripheral anterior stromal infiltrates , round , usually stain

• mild conjunctival hyperaemia, mild epiphora

• Quiet AC - no lid oedema

• usually unilateral

What is the mx of CL associated Keratitis?

• temporarily discontinue CL wear

• Tends to resolve quickly - 48 hours to 2-3 weeks

• refit with daily disposable CLs

• Address associated factors → hands hygiene, CL care

• Px education -risk factors

Allergic Keratoconjunctivits

Phylctenulosis

• Type 4 hypersensitivity reaction

• Associated with systemic disorders → Bechets disease, TB, rosacea

• Phylcten in cornea or conjunctiva

• conjunctival → inflamed nodules

• Cornea → grey nodules

• TX = topical steroids

Rosacea

• redness and cutaneous telangiectasia

• common

• 40-60 yr olds

• facial flushing/chronic hyperaemia of nose, forehead and upper cheeks

• bulbous nose in sever cases → rhinophyma

Ocular rosacea symptoms?

• Discomfort

• burning

• itching sensation

• photophobia

• blurred vision

• dry eye

What are the signs of ocular rosacea?

• Hyperaemic thickened lids

• telangiectasia of lid margins

• Chronic blepharitis

• recurrent chalazion/horedolum

• Punctate corneal staining lower

• Corneal ulcers and thinning

• peripheral neovascularisation and scarring

Tx of ocular rosacea?

• advice on avoiding triggers → spicy foods, alcohol, heat,cosmetics

• omega 3 fatty acid supplementation

• mx of blepharitis,chalazion etc

• ocular lubricants

Mx of ocular rosacea ophthalmologist

• oral antibiotics → tetracylcine

• topcial steroid for severe corneal disease

• in very severe cases systemic immunosuppression

What is Photokeratitis?

• Exposure to UVB or UVC

• Welding arc sun

• delay of 6-12 hours

symptoms fo photokeratitis

• mild cases → irritation & foreign body sensation

• severe → Pain, redness, photophobia, blurring of vision

Signs of photkeratitis

• bilateral lid chemosis + redness

• conjunctival hyperaemia

• epiphora

• Blepharospasm

• lacrimation

• blurry vision

what is neurotrophic keratopathy?

• impairment in corneal sensation + epithelial repair

• predisposition to trauma + reduced healing

• delayed clinical presentation

• HSK,HZO, CL wear, trauma to trigeminal nerve , diabetes, drugs → systemic beta blockers

What are the causes of corneal abrasion ?

• Trauma to eye surface

• dust, sand , CL , fingernail, tree branch

• usually recovers in 3 days

Symptoms of corneal abrasion

• PAINFUL, red watery eye

• Photophobia

• FB sensation

SIGNS → epithelial defect which stains with fluroescein

Management of corneal abrasion

• rule out FB

• Antibiotic ointment

• cease CL wear

• paracetamol for pain relief

• DO NOT PATCH

• complete epithelial basement repair takes 3 months

Recurrent corneal epithelial erosion

• recurrent epithelial breakdown

• follows episode of superficial trauma

• epithelial dystrophies

What are the symptoms of recurrent corneal epithelial erosion?

• sudden onset, unilateral SHARP PAIN on eye opening during the night or waking up

• Photophobia and lacrimation

• may recur over weeks,months or yrs

What are the signs of recurrent corneal epithelial erosion

• epithelial erosion , stains with fluoroescein → loose edges , slipped rug appearance

What is the management of recurrent corneal epithelial erosion ?

• Optometric mx

• ocular lubricants ++

• Ointment at night for at least 3/12 after last episode

• refer routinely if persistent or large defect

mx secondary care → lubricants, cycloplegia

antibiotic ointment

Foreign bodies symptoms and signs

• symptoms→ FB sensation, pain, red, watery and blurry , unilateral

Signs → rust ring , FB adherent to ocular surface

Linear corneal scratches - evert lids

seidel test to check for perforation

Management of FB

• Careful history → cause + prognosis

• Superficial FB → flush out with saline, normally no referral

• Depper → remove with needle or Alger brush

• SAME DAY REFERRAL TO EYE CLINIC