Possibilities of OCT Angiography for Diagnosis of Anterior Ischemic Optic Neuropathy: Parameters of the Ganglion Cell Complex, Optic Disc and Peripapillary Retina

Abstract

Purpose. Study the thickness of periapillary retina, ganglion cell complex and optic disc parameters in patients with nonarteritised anterior ischemic optic neuropathy using the spectral OCT angiography. Material and Methods. We examined 17 people (17 eyes) with unilateral non-arteritised anterior ischemic optic neuropathy (no more than 30 days from the appearance of complaints), the average age was 64.1±8.1 years. The control group consisted of 37 volunteers. All the subjects were treated with spectral OCT angiography on RTVue XR Avanti device (Optovue Inc., USA). Results. In patients with non-arteritised anterior ischemic optic neuropathy, compared to the control group, there was a statistically significant increase in the average thickness of periapillary retina nerve fiber layer from 136 to 403 µm, an increase in optic disc area and neuroretinal belt (p < 0.0001) and the absence of cupping (Cup Volume = 0). A decrease in average thickness of ganglion cell complex was found in 8 out of 17 patients, while all patients showed increases in FLV (p=0.008) and GLV (p=0.036). A direct correlation relationship between FLV (r=0.64; p<0.05) and GLV (r=0.51; p<0.05) was found, as well as a moderate negative correlation relationship between uncorrected visual acuity (r=-0.58; p<0,05), moderate direct correlation relationship between average thickness of periapillary retina nerve fiber layer and thickness of ganglion cell complex (r=0.68; p<0,05), and high inverse correlation relationship between FLV (r=-0.77; p<0,05) and GLV (r=-0.76; p<0,05). Conclusion. A comprehensive analysis of thickness of periapillary retina nerve fiber layer and parameters of ganglion cell complex using spectral OCT angiography may allow for a more accurate detection of early retinal structural abnormalities and the timely commencement of conservative therapy to preserve functional parameters. Key words: spectral OCT angiography, anterior ischemic optic neuropathy, ganglion cell complex, optic disc.