COTW December 21st
Case history:
A 70 year old female the with a history of hypertension, DM, and known bilateral carotid artery stenosis presented with painless vision loss to the right eye. She is able to see shapes and colors from her right eye. Her left eye is normal. No other symptoms.
Vitals notable for hypertension.
Exam: Pupillary and eye exam normal. Decreased visual acuity to right eye, only able to see shapes.
No other focal deficits.
Ultrasound was obtained of the eye to evaluate for retinal detachment or vitreous hemorrhage.
This image was obtained using the high frequency L10-5 linear transducer. Notice the hyperechoic dot sitting behind the retina within the optic nerve sheath.
This is the same eye, but with the L20-5 high frequency linear transducer. Note the sharper image and the subtle vitreous hemorrhage not seen with the L10.
Here is another view where you can also see the hyperechoic dot as well as more vitreous hemorrhage.
The retrobulbar spot sign is a hyperechoic dot within the optic nerve sheath that is highly suggestive of central retinal artery occlusion (CRAO), which is what this patient had. This patient had painless monocular vision loss.
The retrobulbar spot sign is ~30-80% sensitive (not great), but 100% specific in most studies.
Another example why POCUS can be helpful in non-traumatic monocular vision loss. Other pathology may include vitreous hemorrhage, vitreous detachment, as well as retinal detachment.
Read more at:
Smith AT, Wilbert CD, Ferre RM. Using the Retrobulbar Spot Sign to Assist in Diagnosis and Management of Central Retinal Artery Occlusions. Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 2019; [pubmed]