Ophthalmology - Red Eyes (Acute Closed Angle Glaucoma, Anterior Uveitis, episcleritis and scleritis) Flashcards

1
Q

What is the pathophysiology of acute closed angle glaucoma?

A

-Glaucoma: optic nerve damage caused by significant rise in intraocular pressure -Occurs when iris bulges forwards and seals off trabecular meshwork - prevents aqueous humour drainage -Leads to build up of pressure in posterior chamber -Ophthalmological emergency

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2
Q

Name some risk factors for acute angle glaucoma

A
  • Age -F 4x > M
  • FHx: must screen people (annual, > 40 ya) with 1st degree affected relative
  • Chinese/East Asian origin
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3
Q

Name some medications which can precipitate AAG

A

-Adrenergic medication: noradrenalin -Anticholinergics: oxybutynin -TCAs: amitryptaline (anticholinergic effect)

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4
Q

What is the presentation (sx) of AAG?

A
  • Pt unwell, headache, N+V
  • V painful eye
  • Blurred vision
  • Halos around light (due to corneal swelling)
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5
Q

What will you see on examination in a patient with AAG?

A
  • Red, teary eye
  • Hazy cornea
  • Decreased visual acuity
  • Dilatation of affected pupil + fixed pupil size
  • Firm eyeball on palpation
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6
Q

What investigations should you perform in suspected AAG?

A
  • Automated perimetry: assesses visual fields
  • Slip lamp examination to look at fundus
  • Goldmann applanation tonometry: measures IOP
  • Corneal thickness measurement (used to calibrate tonometry)
  • Gonioscopy: assesses peripheral anterior chamber configuration and depth
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7
Q

How would you manage AAG in GP waiting for an ambulance?

A

Patient needs same day assessment by ophthalmology

Immediate Mx waiting for ambulance:

  • pilocarpine eye drops: muscarinic agonist - causes constriction of pupil and ciliary constriction, encourages flow of humour from ciliary body
  • acetazolamide 500mg PO: carbonic anhydrase inhibitor, reduces production of aqueous humour
  • analgesia + antiemetic
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8
Q

Apart from pilocarpine and acetazolamide, what other drugs can you give to reduce IOP?

A
  • Hyperosmotic agents: glycerol/mannitol - increase osmotic gradient between blood and fluid in eye
  • Timolol: beta locker - reduces production of aqueous humour
  • Dorzolamide: carbonic anhydrase inhibitor - reduces production of aqueous humour
  • Brimonidine: sympathomimetic - reduces production of aqueous humour and increases uveoscleral outflow
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9
Q

What is the definitive treatment for AAG if drug treatment fails?

A

-Laser iridotomy: laser made hole in iris to allow aqueous humour to flow into anterior chamber - relieves pressure that was pushing iris against cornea and humour can drain

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10
Q

What is anterior uveitis?

A
  • Inflammation of the anterior part of the uvea (includes iris, ciliary body and choroid)
  • Inflammation and immune cells (neutrophils, lymphocytes, macrophages) infiltrate the anterior chamber of eye.
  • Causes: autoimmune (main cause), infection, trauma, ischaemia or malignancy
  • Can be acute or chronic (>3/12)
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11
Q

Name some important associations of acute anterior uveitis

A

Associated with HLA B27 conditions

  • Ankylosing spondylitis
  • IBD
  • Reactive arthritis
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12
Q

What are the symptoms of anterior uveitis?

A
  • Usually unilateral with spontaneous onset
  • Floaters and flashes
  • Ciliary flush: ring of red spreading from cornea outwards
  • Reduced visual acuity
  • Miosis (shincter muscle contraction) and abnormal shaped pupil (posterior adhesions pull the iris into a weird shape)
  • Photophobia: due to ciliary spasm
  • Pain of movement
  • Excessive lacrimation
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13
Q

How do you manage a patient with suspected anterior uveitis?

A

-Must refer patients with potentially sight threatening causes of red eye for same day ophthalmology assessment.
-Full slit lamp assessment
-Tonometry (Goldmann applanation): assesses IOP pressure Management
-Steroids: topical/PO/IV (ophthalmologist’s choice) -
Cycloplegic medication: cyclopentolate or atropine (paralysis ciliary muscles to cause dilatation and stop pain of ciliary spasm)
-Laser therapy in extreme cases

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14
Q

What is episcleritis?

A
  • Benign and self limiting inflammation of the episclera (outermost layer of the sclera, which is just underneath clear conjunctiva)
  • Common in young/middle aged adults and not usually caused by infection.
  • Linked to RA and IBD
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15
Q

Outline the PC of someone with episcleritis

A
  • Typically not painful
  • Segmental redness (instead of diffuse) -eg patch of redness in lateral sclera
  • Foreign body sensation
  • Dilated episcleral vessels: mobile vessels when gentle pressure is applied vs in scleritis where vessels are deeper and do not move
  • Watery eye but no discharge
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16
Q

How do you manage episcleritis?

A
  • If in doubt, refer to ophthalmology
  • Usually self limiting (1-4 weeks)
  • Lubricating eye drops can help with sx
  • Analgesia, cold compress and safety net
17
Q

Describe a way of distinguishing between scleritis and episcleritis

A

-Phenylephrine: blanches conjunctival and episcleral vessels but not scleral vessels - if redness improves with it then it is more likely to be episcleritis than scleritis

18
Q

What is this?

A

Episcleritis: localised redness on lateral aspect of eye

19
Q

What is scleritis?

A

-Inflammation of the full thickness of sclera (serious)
-Not usually caused by infection -
Necrotising scleritis: v serious, can lead to perforation of sclera

20
Q

Name some conditions associated with scleritis

A

-RA
-SLE
-IBD
-Sarcoidosis
-Granulomatosis with polyangiitis
*Association in 50% of patients with scleritis

21
Q

How does scleritis present?

A
  • Severe pain
  • Pain with eye movement
  • Photophobia
  • Watery eye
  • Reduced/gradually reducing visual acuity
  • Abnormal pupil response to light
  • Tenderness on palpation
22
Q

How would you manage scleritis?

A
  • Refer pt with potentially sigh threatening causes of red eye to same day ophthalmology assessment
  • Consider underlying condition
  • NSAIDs
  • Steroids
  • Immunosuppression
23
Q

What is this?

A

Episcleritis: signs of deeper infection