Ultrasound diagnostic criteria of anterior ischemic optic neuropathy and optic neuritis

Abstract

Purpose: to determine objective echographic criteria for the differential diagnosis of anterior ischemic optic neuropathy (AION) and optic neuritis (ON).Material and methods. The research involved 60 patients aged 40 to 60 years, including 30 patients with suspected AION and 30 patients with suspected ON. The control group consisted of 40 healthy volunteers. In addition to the standard ophthalmological examination, all patients underwent ultrasound optic nerve s examination with measurement of the optic nerve thickness and acoustic density (AD) of the parenchyma and optic nerve sheets. Assessment of blood flow in retrobulbar vessels was carried out in the modes of Color Doppler Imaging and pulse dopplerography.Results. There were no statistically significant differences in average echographic parameters of the optic nerve s thickness between the groups of patients with AION and ON. In patients with ON there was a statistically significant decrease in the average AD index compared to that in patients with AION and in healthy volunteers (106.02 ± 5.40 y. e., 146.58 ± 9.70 y.e. and 135.3 ± 2.1 y. e., accordingly). The AD values in all patients with AION exceeded 133 y. e., in patients with ON this index was less than 132 y. e. Evaluation of hemodynamic parameters in the vessels of the eye demonstrated a statistically significant decrease in the peak systolic velocity (Vsyst) and end-diastolic velocity (Vdiast) blood flow in the central retinal artery and medial and lateral short posterior ciliary arteries in patients with AION (in 2-fold) compared with ON and normal indices (p < 0.001). There were no statistically significant differences between parameters of blood flow in patients with ON and in healthy volunteers. In addition, there were no significant intergroup differences of hemodynamic parameters of the ophthalmic artery (p > 0.05).Conclusions. AD of the optic nerve and parameters of blood flow velocities (Vsyst and Vdiast) in medial and lateral short posterior ciliary arteries can be attributed to the diagnostic criteria of the AION and ON.