OPH - Lens, Pupil, Eyelid Disorders

Question 1

Cataracts

Pathophysiology
Risk Factors/Causes
Clinical Features
Management

Answer 1

1.) Pathophysiology - lens becomes cloudy and opaque which reduces the amount of light that enters the eye

2. ) Risk Factors/Causes
   - ↑age (most common), smoking, alcohol
   - trauma: direct or blunt trauma, infection (uveitis)
   - systemic disease: DM, myotonic dystrophy, neurofibromatosis type 2, hypocalcaemia
   - drugs: long term corticosteroid use, allopurinol, amiodarone, phenothiazines
   - down’s syndrome
   - congenital cataracts are screened for using the red reflex during the neonatal examination
3. ) Clinical Features - sx usually asymmetrical
   - gradual generalised reduction in visual acuity and progressive blurring of vision
   - faded colour vision: appear more brown or yellow
   - ‘starbursts’ appear around lights, esp at night
   - loss of the red reflex: lens appears grey/white
   - in children, can present w/ a squint or leukocoria
4. ) Management
   - do nothing: If the symptoms are manageable then no intervention may be necessary
   - cataract surgery: replace lens with an artificial one, should be offered regardless of visual acuity
   - screen for AMD or DR as cataracts can prevent the detection of other pathology

Question 2

Cataracts Surgery (Pseudophakia)

Phaecoemulsification
Endophthalmitis
Posterior Lens Capsule Opacification
Other Rare Complications

Answer 2

1. ) Phaecoemulsification - breaking down the existing lens with ultrasound waves before replacing it
   - simple day case procedure which can be carried out under topical anaesthetic, GA for special circumstances
2. ) Endophthalmitis - rare but serious complication
   - infection/inflammation of the intraocular fluids
   - treated w/ intravitreal antibiotic injections
   - can lead to loss of vision and loss of the eye itself
   - patient presents within days of surgery with severe pain, loss of vision and hyperaemia, eye discharge
3. ) Posterior Lens Capsule Opacification
   - common complication
   - patients presents within weeks of surgery with blurry vision and a white opacity may be visible on inspection
   - treated with a simple laser procedure
4. ) Other Rare Complications
   - posterior lens capsular ruptures allowing vitreous humour to flow into the anterior chamber
   - retinal detachment, glaucoma
   - corneal or macular oedema

Question 3

Eyelid Disorders

Entropion
Ectropion
Trichiasis

Answer 3

1. ) Entropion - eyelid turns inwards with the lashes against the eyeball –> corneal damage and ulceration
   - initial tx: tape down eyelid to prevent it turning in, use regular lubricating eye drops to prevent dryness
   - definitive: surgical intervention
   - urgent referral to ophthalmology if there’s a sight risk
2. ) Ectropion - eyelid turns outwards exposing the inner aspect of the eyelid, usually affects the bottom lid
   - causes exposure keratopathy as the eyeball is exposed and not adequately lubricated and protected
   - eye drops used to protect the surface of the eye
   - significant cases may need surgical intervention
   - urgent referral to ophthalmology if there’s a sight risk
3. ) Trichiasis - inward growth of the eyelashes causing pain and can result in corneal damage and ulceration
   - management is epilation (remove lashes)
   - recurrent cases may require electrolysis, cryotherapy or laser treatment to prevent the lash from regrowing
   - urgent referral to ophthalmology if there’s a sight risk