DISEASE
In otherwise healthy patients, the observance of a cotton wool spot (CWS) is not considered normal. A single cotton wool spot in one eye can be the earliest ophthalmoscopic finding in diabetic or hypertensive retinopathy.
In a series of patients who had (CWS) and no known medical history, diastolic blood pressure equal to or greater than 90 mmHg was detected in 50% of patients, and elevated blood sugar was found in 20% of patients.
Pathophysiology
Cotton wool spots are believed to occur secondary to ischemia from retinal arteriole obstruction. It is thought to represent nerve fiber layer infarct and pre-capillary arteriolar occlusion.
However,
factors responsible for focal interruption of axoplasmic flow in the retinal nerve fiber layer may result in similar intra-axonal organelle accumulations.
The histological hallmark of cotton wool spots is considered by many authors to be cytoid bodies. They are named cytoid bodies because they look like cells,
However,
they are eosinophilic segments of ganglion cell axons that are swollen because of defective axoplasmic flow. Cytoid bodies are usually packed with accumulations of mitochondria and other intracellular material.
Fundus Explorer Pro
Photograph the retinal findings described here with the phone already in your pocket — 22 D optics and built-in illumination in one handheld unit.
From Choroida — the team behind this siteMANAGEMENT
Workup and treatment are directed towards the underlying etiology. Cotton wool spots classically disappear in 6–12 weeks,
However, in diabetic retinopathy, they may persist for longer.
Initial work-up may include vitals (blood pressure, heart rate, etc.) and metabolic studies including HbA1c, CBC, CMP, and HIV.
Directed work-up may include ESR, CRP, EKG, echocardiogram, carotid ultrasound, hypercoagulable labs (protein C, protein S, Leiden, etc), PT/PTT, homocysteine, and more.
Document what you see
Two smartphone imaging tools built for everyday clinic use — one for the slit lamp, one for the fundus.
From Choroida — the team behind this siteREFERENCES
- Adam T. Gerstenblith, Michael P. Rabinowitz. Wills Eye Manual, The: office and emergency room diagnosis and treatment of eye disease, 6th edition. Lippincott Williams & Wilkins, 2012.
- Brown GC, Brown MM, Hiller T, Fischer D, Benson WE, Magargal LE. “Cotton-wool spots.” Retina. 5, no. 4 (Fall-Winter 1985): 206-14.
- Arroyo, Jorge G. “Cotton-Wool Spots May Challenge Diagnosis .” Review of ophthalmology, 2004: 111-114.
- Arroyo JG, Irvine AR. “Retinal distortion and cotton-wool spots associated with epiretinal membrane contraction.” Ophthalmology 102 (1995): 662-8.
- Purnima S. Patel, SriniVas R. Sadda. “Retinal Artery Obstructions.” In Retina (Fifth Edition), by Stephen J. Ryan, 1012-1025. Elsevier Inc., 2012.D. McLeod, D.
- McLeod, E. M. Kohner and A. C. Bird. “The role of axoplasmic transport in the pathogenesis of retinal cotton-wool spots.” Br J Ophthalmol 61 (1977): 177-191.
