Prospective Analysis of Retrobulbar Vessels in Sudden Visual Loss by Orbital Ultrasound Detection of Retrobulbar Embolic Plaques

Abstract

 

Purpose:

 

Sudden loss of vision is often caused by vascular processes such as embolic artery occlusion or anterior ischaemic optic neuropathy (AION) due to giant cell arteritis. These two entities require different acute therapy managements as in an embolic event the protective anticoagulation is most important while in giant cell arteritis a quick high dose substitution of steroids is essential. Thus a prompt differentiation in diagnostics is most important but often difficult and in the end dependent to an invasive biopsy of the Arteria temporalis. Sonographic detection of a retrobulbar embolic plaque can therefore be an important additive diagnostic tool.

 

Methods:

 

In a prospective study 15 eyes of 15 consecutive patients with sudden visual loss due to either central retinal artery occlusion (CRAO) or AION as found in indirect funduscopy were included. Apart from the usual diagnostics including laboratory parameters, anamnesis, visual acuity test, perimetry, and when indicated fluorescein angiography and biopsy they underwent evaluation by orbital color Doppler imaging in search for retrobulbar hyperechoic embolic plaques within two days after initial symptoms.

 

Results:

 

Overall seven of 15 patients (47%) showed a hyperechoic retrobulbar plaque. All of those seven patients demonstrated CRAO in the usual neuroophthalmic examination. Two further patients with funduscopically CRAO did not show any hyperechoic plaque. Overall seven of nine patients (78%) with CRAO had a positive sonographic correlate. All of these had visual acuity of counting fingers or worse. Of the remaining six patients with AION three were after biopsy diagnosed as arteritic AION due to giant cell arteritis. None of them demonstrated any hyperechoic retrobulbar plaques in ultrasound imaging.

 

Conclusions:

 

Ultrasound imaging as presented seems to be a suitable diagnostic tool in patients with sudden visual loss due to CRAO and AION. By this noninvasive examination quick differentiation of embolic events from arteritic or other causes is possible. As this discrimination results in different therapy managements for the patient the practically risk-free technology should be considered for a broad application in these disease patterns.

 

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • clinical (human) or epidemiologic studies: systems/equipment/techniques • blood supply