Evaluation of ocular blood flow characteristics in patients with dysthyroid ophthalmopathy by optical coherence tomography angiography

The aim of this cross-sectional prospective study was to compare the Optical Cohorence Tomography Angiography (OCT-A) findings of patients with active, inactive dysthyroid ophthalmopathy (DO) with the findings of healthy volunteers with the same demographic characteristics, as well as to compare the OCT-A findings of patients with active DO before and after pulse steroid treatment. Forty eyes of 20 active DO patients, 40 eyes of 20 inactive patients and 40 eyes of 20 healthy volunteers were included in the study. OCT-A was performed after comprehensive eye examination in all groups. While the superficial capillary plexus (SCP) and deep capillary plexus (DCP) vascular density (VD) were found to be lower in the inactive and active patient groups compared to the healthy control group, the whole area, superior hemisphere and parafoveal inferior VD in the inactive group was significantly lower than the healthy control group ( P<0.05). The DCP VD was significantly lower in the whole area, superior hemisphere, parafoveal region and parafoveal nasal side in active and inactive groups compared to the control group (P<0. 05). Peripapillary whole area and inferior hemisphere VD were significantly lower in active patients compared to inactive and control groups. There was no difference between the groups in terms of central macular thickness (CMC), foveal avascular zone (FAZ) area, outer retinal capillary blood flow area (ORCBFA), choriocapillaris blood flow area (CBFA) and peripapillary retinal nerve fiber layer (RNFL) thickness (P> 0.05). In active DO patients, the CMT, SCP whole area, superior hemisphere and parafoveal VD were significantly lower after treatment than before treatment (P<0.05). In active DO patients, the peripapillary RNFL, superior hemisphere, inferior hemisphere, nasal-superior, nasal-inferior and inferior-nasal quadrants RNFL thickness were significantly lower after treatment than before treatment (P<0.05). There was no signficant differences before and after treatment in terms of peripapillary capillary and DCP VD, ORCBFA, CBFA, FAZ area, and tone (P>0.05). Hertel exophthalmometry value and CAS were found to be significantly lower after treatment than before treatment (P<0.05). The OCT-A has a high potential for use in the diagnosis and follow-up of DO. Therefore, more work can be done on this subject.