Cotton Wool Spots in Giant Cell Arteritis

This is a case of cotton wool spots in a patient with temporal artery-biopsy proven temporal arteritis.; ; A 66-year-old woman presents with isolated painless vision loss related to a left optic neuropathy in her left eye. She denies systemic symptoms to suggest giant cell arteritis.; Her examination shows: visual acuity: 20/20 OD, 20/40 OS, pupils: 1+ left RAPD, color vision: 14/14 OU correct Ishihara plates. She has the following bloodwork: erythrocyte sedimentation rate 47 mm/hr (normal 1-30), c-reactive protein 2.79 mg/L (normal < 8), platelets 329 (normal 150-450). A MRI brain with and without contrast was normal.; The patient's vision loss was attributed to a posterior ischemic optic neuropathy of the left eye. The presence of cotton wool spots and ischemic optic neuropathy in an elderly patient raised concern for giant cell arteritis. A left temporal artery biopsy was positive for giant cell arteritis. The patient was treated with corticosteroids. Color fundus photographs taken following treatment showed resolution of her peripapillary cotton wool spots.

Cotton wool spots in giant cell arteritis Rahul A. Sharma, MD, MPH Valérie Biousse, MD A 66-year-old woman presents with isolated painless vision loss related to a left optic neuropathy in her left eye. She denies systemic symptoms to suggest giant cell arteritis. Her examination shows: • Visual acuity: 20/20 OD, 20/40 OS • Pupils: 1+ left RAPD • Color vision: 14/14 OU correct Ishihara plates She has the following bloodwork: • Erythrocyte sedimentation rate 47 mm/hr (normal 1-30) • C-reactive protein 2.79 mg/L (normal < 8) • Platelets 329 (normal 150-450) Figure 1 Right eye (OD) Left eye (OS) Color photographs of both eyes, centered on the optic nerves. Figure 1 Right eye (OD) Left eye (OS) Color photographs centered on the optic nerves, showing long-standing gliosis around the right optic nerve (green arrow) and peripapillary cotton wool spots around the left optic nerve (red arrows). Figure 2 Left eye Right eye Humphrey visual fields (HVF, 24-2 SITA Fast) were normal in the right eye and showed superior and inferior arcuate defects in the left eye consistent with a left optic neuropathy. • A MRI brain with and without contrast was normal. • The patient's vision loss was attributed to a posterior ischemic optic neuropathy of the left eye. • The presence of cotton wool spots and ischemic optic neuropathy in an elderly patient raised concern for giant cell arteritis. • A left temporal artery biopsy was positive for giant cell arteritis. Figure 3 Right eye (OD) The patient was treated with corticosteroids. Color fundus photographs taken following treatment showed resolution of her peripapillary cotton wool spots. Left eye (OS) At onset of vision loss Following steroid therapy Cotton Wool Spots • Typically superficial, white and one-fourth disc area or less in size; often multiple • Most often peripapillary, along the temporal retinal vascular arcades or in the macula • Occur due to infarction of the retinal nerve fiber layer • Usually fade in 5-7 weeks but may persist Cotton wool spots (red arrow) in a patient with central retinal vein occlusion Cotton wool spots in a patient with hypertensive retinopathy Cotton wool spots in a patient with diabetic retinopathy Summary point: ● Cotton wool spots (CWS) are thought to develop due to focal inner retinal ischemia. ● The most common cause of CWS is diabetes. CWS may also be seen in systemic arterial hypertension, collagen vascular diseases, cardiac valvular disease, retinal vein occlusions, HIV-associated retinopathy, radiation retinopathy, sickle cell retinopathy, carotid artery obstructive disease, vasculitis (such as giant cell arteritis) and other conditions. ● Though CWS are non-specific, their presence should arouse particular suspicion for giant cell arteritis in older patients without a history of hypertension or diabetes.