Skyler Sloane & Andre Velazquez
A 73-year-old male presented to our emergency department with a chief complaint of new intermittent double vision for the past two weeks. The patient noticed that he saw double when looking at signs on the freeway. These were new symptoms he had not experienced in the past. The patient reported a history of hypertension, hyperlipidemia, and recently diagnosed prostate cancer. The patient also confirmed a history of ocular migraine. The patient denied current headaches, new floaters or flashes, curtains, or clouds in his vision.
Upon arrival, vital signs were: BP 131/91 | Pulse 107 | Temp 97.8 °F (36.6 °C) | SpO2 98%
Visual acuity: OD 20/20 and OS) 20/20. Pupil light reaction from 3 mm to 2 mm bilaterally. Extraocular movement was full and normal in both eyes. Finger counting was normal in both eyes. The right eye had an intraocular pressure of 13 mmHg and the left eye had an intraocular pressure of 14 mmHg. The bedside anterior segment exam was normal.
We performed a bedside ultrasound while waiting for an ophthalmology consult and obtained the following images of the left eye.
Figure 1: Ultrasound of the left eye.
Figure 2: Labeled ultrasound of the left eye showing asteroid hyalosis (hyperechoic free-floating particles in the vitreous chamber).
In the obtained images, we see hyperechoic free-floating particles in the vitreous chamber as we scan through the eye. From these images, we reached a diagnosis of asteroid hyalosis. This was later confirmed by ophthalmology through a dilated fundus exam.
Asteroid hyalosis (AH) is an uncommon degenerative condition that is characterized by the formation of asteroid bodies (AB), comprised of calcium and phospholipids within the vitreous chamber (1). The greatest prominent risk factor is age (2).
Asteroid hyalosis is benign and asymptomatic in most cases and is not a viable cause for the diplopia that our patient presented with (1). Ophthalmology reported no evidence of strabismus or nystagmus. Additionally, the optic nerve was observed to be sharp and perfused. They postulated that the complaints could be explained by superior oblique myokymia vs retinal hemifield slide. Given the patient’s history of recently diagnosed prostate cancer, brain imaging was recommended to rule out intracranial pathology. Brain imaging revealed no evidence of acute infarct, hemorrhage, or mass. A follow-up with ophthalmology revealed ocular misalignment with a small esotropia in the left eye and a left abduction deficit. The ophthalmologist postulated that this could be due to minor six nerve palsy. This esotropia was found to be the cause of the ocular diplopia.
Asteroid hyalosis can mimic vitreous hemorrhage on ultrasound. Both conditions may show hyperechoic echogenicities swirling in the vitreous chamber in a washing machine or snow globe motion (3). Asteroid particles are composed of calcium linked to phospholipids and often take on an intensely hyperechoic appearance on ultrasound due to their density (2). Conversely, vitreous hemorrhage often appears less hyperechoic than asteroid particles and can have a less granular appearance (4). Differentiating between asteroid hyalosis, a benign and largely asymptomatic condition, and vitreous hemorrhage, a more serious condition that may require emergent intervention is critical.
Figure 3: Vitreous Hemorrhage: diffuse mobile opacity often referred to as a “snow globe” appearance that is made apparent by side-to-side movement of the eye.
We presented this case to raise awareness of the utility of point-of-care ultrasound in rapidly diagnosing rare ocular diseases. Furthermore, this case is significant because asteroid hyalinosis is a relatively rare disease that is infrequently observed in the emergency department.
References:
- Scott, D. A. R., Møller-Lorentzen, T. B., Faber, C., Wied, J., Grauslund, J., & Subhi, Y. (2021). Spotlight on Asteroid Hyalosis: A Clinical Perspective. Clinical Ophthalmology, 15, 2537–2544. https://doi.org/10.2147/OPTH.S272333
- Duong R, Abou-Samra A, Bogaard JD, Shildkrot Y. Asteroid Hyalosis: An Update on Prevalence, Risk Factors, Emerging Clinical Impact and Management Strategies. Clin Ophthalmol. 2023 Jun 20;17:1739-1754. doi: 10.2147/OPTH.S389111.
- Gros EC, Mccafferty LR. Asteroid Hyalosis: A Mimicker of Vitreous Hemorrhage on Point of Care Ultrasound: A Case Report. POCUS J. 2023 Nov 27;8(2):113-115. doi: 10.24908/pocus.v8i2.16391.
- De La Hoz Polo M, Torramilans Lluís A, Pozuelo Segura O, Anguera Bosque A, Esmerado Appiani C, Caminal Mitjana JM. Ocular ultrasonography focused on the posterior eye segment: what radiologists should know. (2016) Insights into imaging. 7 (3): 351-64. doi:10.1007/s13244-016-0471-z