Optical Coherence Tomography Angiography in Multiple Sclerosis: A Prospective Study

Purpose : To evaluate retinal axonal density and retina and choriocapillaris vascular flow density in patients affected by multiple sclerosis (MS) with spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). Methods : A prospective comparative study evaluating imaging technology (Optovue RTVue XR, Optovue Inc., Fremont, CA, USA; and Zeiss Cirrus-HD-OCT) in patient with multiple sclerosis (MS) and in normal individuals, was performed at the Eye Clinic, San Giovanni di Dio Hospital, University of Cagliari, Italy. Macular, choriocapillaris and radial peripapillary capillary (RPC) capillary flow densities (CFD) were measured and compared with controls, and their relationships with optic neuritis episodes were analysed. CFD of MS patients and healthy controls was correlated with peripapillary RFNL thickness and ganglion cell density, as detected by SD-OCT with Optovue and Zeiss Device, respectively. Mean and standard deviation were calculated for each OCT-A parameter. Data distribution was evaluated by Shapiro-Wilk test and Kolmogorov-Smirnov test with Lilliefors correction. Results : 111 eyes from 56 patients with MS (48 females: mean age 43.525±14.390; and 8 males: mean age 48.585±16.721) ( 28 eyes right eyes; 27 left eyes) and 80 eyes from 40 healthy controls (HC) (32 females, 18 males; average age: 42.07± ±14.97) were included in the study. Patients with MS were subdivided in two groups: 23 patients with previous optic neuritis (ON) (MS NO+) and 33 patients had a negative history for ON (MS NO-). Significant differences between cases and controls were found in superficial capillary plexus, deep capillary plexus, choriocapillary layer and RPC flow densities among the three groups (p>0.05). The average of CFD of NH in MSON+ group was significantly lower than the HC and MSON- groups (p=0.0221). A significant difference was found between cases and controls in terms of ganglion cells analysis with Optovue OCT (p=0.000) and Cirrus OCT (p=0.000). A significant correlation was found between CFS of SCP and ganglion cells analysis obtained with Optovue device (p=0.013). A weak correlation was found between CFD of ONH and RFLN analyzed with Optovue OCT (p=0.066) or with Zeiss device (p=1) Conclusions : OCTA with the SSADA algorithm is highly repeatable and reproducible for CFD measurement of the ONH and macular regions in MS patients with or without a history of ON.