To define the retinal and choroidal imaging findings of carotid cavernous fistula (CCF) including central foveal thickness, subfoveal choroidal thickness, choroidal vascularity index (CVI) parameters, and tortuosity indexes (TIs) as compared to a control group (CG).

Cross-sectional study.

The spectral domain enhanced-depth imaging optical coherence tomography images of 19 eyes of 19 consecutive patients with angiographically proven CCF and 19 eyes of 19 age- and sex-matched healthy control subjects were included. The patient group was divided according to CCF venous drainage pattern as anterior (A-CCF: draining into ophthalmic veins) and posterior (P-CCF: not draining into ophthalmic veins). The clinically affected eyes of the patient group, ipsilateral to the fistula, were included in the analysis.

There were 15 A-CCFs (78.9%) and 4 P-CCFs (21.1%). The mean SFCT of the A-CCF group (395.21 ± 111.69 μm) was significantly higher than those of the P-CCF (246.84 ± 94.12 μm) and CG groups (280.79 ± 111.36 μm) (P = .039 and P = .006, respectively). The mean CVI of the A-CCF group was significantly higher than that of the CG (68.97 ± 4.81 and 65.66 ± 3.37, respectively, P = .033). The A-CCF group had significantly higher inferior, superior, and total venous TI than the CG group (P = .001, P = .001, and P < .001, respectively).

In this first study investigating the CVI and TI in CCF patients, we demonstrated that SFCT, CVI, and TI could potentially be used to aid in the diagnosis of A-CCF.