Anterior ischaemic optic neuropathy Flashcards
What are the two types of AION?
Arteritic and non-arteritic
What is AION?
Ischaemia of the optic nerve resulting in disc swelling
What is AAION otherwise known as?
GCA/temporal arteritis
What is NAION
Non inflammatory disease of small blood vessels supplying the optic nerve - result of systemic disease such as CVD
Which form of AION has the better prognosis?
NAION
What are some risk factors for AAION?
Female
Age>50
PMH of polymyalgia rheumatica
What are some risk factors for NAION?
Age>50 but younger than AAION
CVD RF
Anaemia
Give the typical presenting complaint of someone with AAION?
Sudden painless loss of vision New onset headache around temporal region Jaw claudication Scalp tenderness Diplopia
Give the typical presenting complaint of someone with NAION
Painless loss of vision - blurring
Often wake up with it
What systemic symptoms may patients with AION have?
Fatigue, malaise, anorexia, weight loss and depression
What clinical signs may be seen in AAION?
Reduced VA, dyschromatopsia (reduced colour vision), fundoscopy showing pale swollen optic disc, pupil examination (RAPD), scalp tenderness, pulseless temporal artery
What clinical signs may be seen in NAION?
Reduced VA, dyschromatopsia, fundoscopy showing pale swollen optic disc with splinter haemorrhages, RAPD on pupil examination, altitudinal visual field defect
What investigations should be done for AAION
FBC - normochromic anaemia, increased platelets
ESR and CRP - elevated
LFT - increased ALT and ALP
Temporal artery biopsy
Duplex USS temporal artery - halo sign - oedema of the vessel
What investigations should be done for NAION?
BP
Vasculitis screen - anyone younger than 50
Lipid profile
Glucose and HbA1C
What is the management for AAION?
High dose steroids and ophthalmology referral
