Observation of fundus and optical coherence tomography angiography manifestations in carotid cavernous fistula patients

Purpose This study aimed to investigate fundus and optical coherence tomography angiography (angio-OCT) manifestations in carotid cavernous fistula (CCF) patients. Methods Nine eyes of 7 CCF patients diagnosed with digital subtraction angiography (DSA) were included in this study. Best-corrected visual acuity (BCVA), intraocular pressure (IOP), slit lamp, fundus, spectral-domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (angio-OCT) examination in the CCF patients and 10 normal controls were conducted. Subfoveal choroidal thickness (SFCT) and macular vascular density (VD) were measured and compared with the control group. SFCT and VD were also compared before and after embolization therapy. Results Two male and 5 female CCF patients were included. The average age was 59.7 ±10.0 (years). Embolization therapy was conducted in 3 patients. Fundus manifestations included disc oedema and exudation, retinal venular dilation, and retinal haemorrhage. B-scan OCT examination revealed retinal and choroidal undulations, retinal-choroidal thickness, retinal cystoid oedema, and subretinal fluid. The SFCT of the affected eyes was thicker than that of the control group (412.3 ± 123.7 μm vs. 272.9 ± 62.9 μm; P = 0.006). Macular superficial capillary plexus (SCP) VD in affected eyes was lower than that in the control eyes (50.1 ±2.3 % vs. 52.7 ± 1.7 % ; P = 0.014). The SFCT was reduced, and the vessel density in the SCP was increased after embolization therapy. Conclusion We demonstrated decreased VD in CCF patients with specific fundus and OCT manifestations. The pathological changes were immediately reduced after embolization therapy. This preliminary observation provides a supplemental method for the diagnosis and pathophysiological examination of CCF patients.