Diurnal Stability Of Peripapillary Vessel Density And Nerve Fiber Layer Thickness On Optical Coherence Tomography Angiography In Healthy, Ocular Hypertension And Glaucoma Eyes

Sara Bochicchio,1 Paolo Milani,1 Lara Enrica Urbini,1 Ennio Bulone,1 Luciana Carmassi,1 Elena Fratantonio,1 Giacomo Castegna,1 Lorenza Scotti,2 Antonella Zambon,2 Fulvio Bergamini1 1Ophthalmology Department, Istituto Auxologico Italiano, Milan, Italy; 2Statistics and Quantitative Methods Department, University of Milano-Bicocca, Milan, ItalyCorrespondence: Paolo MilaniIstituto Auxologico Italiano, Via Mercalli 30, Milan, ItalyTel +39 2 3385840232Fax +39 2 20422262Email dottpaolomilani@hotmail.comPurpose: By using optical coherence tomography angiography (OCTA), to evaluate diurnal changes of the following parameters: vessel density in the peripapillary area (PP-VD) and in the optic nerve head (ONH-VD); thickness of retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC).Methods: All prospectively enrolled participants were imaged on the same day at 8 am and 7 pm by means of the XR Avanti device with AngioVue and AngioAnalytics software (Optovue Inc., Fremont, CA, USA). Only eyes with correct automatic segmentation and good-quality images (scan quality > 7/10) were included.Results: Forty-six eyes from 28 patients with glaucoma, 53 from 31 patients with ocular hypertension, and 62 from 38 controls were assessed. The mean measurements of all parameters investigated were significantly different in the morning and in the evening values in all three groups, with lower values in glaucomatous eyes (p0.1).Conclusion: Vessel density, GCC and RNFL were stable during daytime thus corroborating the clinical relevance of OCTA regardless the time of acquisition.Keywords: glaucoma, optical coherence tomography angiography, vessel density, daily fluctuations, retinal fiber layer