Retinal Detachment (RD)
A retinal detachment is defined by a separation of the sensory retina from the underlying retinal pigment epithelium. This cuts off the blood supply to the rods and cones in the eye and can cause permanent vision loss. A retinal detachment is an ocular emergency that must be referred immediately to an ophthalmologist (Ghazi & Green).
A patient with a detached retina typically presents with painless, fixed visual field loss, new floaters, or flashes (photopsia) with the perception of a curtain coming down (inferior detachment) or up (superior detachment). Unfortunately, fundoscopy using a direct ophthalmoscope is limited and can miss retinal detachments.
There are three major types of retinal detachment (rhegmatogenous, traction, and exudative):
Ocular ultrasound is both sensitive and specific for diagnosing retinal detachments. While distinguishing between the 3 types of retinal detachment is important from a treatment standpoint, ocular ultrasound should not focus on distinguishing between them. The primary purpose of POCUS is to be able to diagnose a retinal detachment and then allow the ophthalmologist to help definitively diagnose the retinal detachment type and treatment option.
Retinal Detachment Ultrasound Findings
On B scan (B mode), ocular ultrasound retinal detachment is best visualized in normal and often low gain settings. A retinal detachment looks like a thick/hyperechoic membrane lifted off of the posterior surface of the globe that floats and moves with the patient’s eye movement.
If the retinal detachment is large, the hyperechoic membrane will be tethered to the optic nerve. However, if the retinal detachment is small or not near the optic nerve, the hyperechoic membrane will be tethered closely to the back wall of the eye and will not move much with eye movement. It is important to scan the eye in multiple axes (transverse and sagittal) to detect small retinal detachments.
See below for an ocular ultrasound retinal detachment image and video. Notice how the retinal detachment is tethered to the optic nerve as the patient moves their eye.
