case_images: PMC11182162_01
case_images: Relative volume flow (RFV) waveforms in CCF cases. RFV waveforms for arteriole and venule pairs in each CCF case are shown at presentation in the middle column. For unilateral cases, the unaffected fellow eye is shown in the first column to the left. For cases with follow-up recordings after thrombosis of the fistula, post-thrombosis scans are shown in the last column on the right. There is some degree of reduced venule blood flow velocity (blue) during peak arterial flow (red, corresponding to systole) in all cases of CCF. This was not observed in unaffected fellow eyes, nor after thrombosis of the fistula.
case_images: fopht-03-1301410-g002.jpg
case_images: PMC11182162_01_fopht-03-1301410-g002.jpg
case_images: f2
case_images: CCFs from a single university neuro-ophthalmology practice (the RFV waveforms for each case are shown in  Figure 2 ).
case_images: Representative relative volume flow (RFV) waveforms for each subject group. RFV waveforms show blood flow velocity changes over time within a single cardiac cycle. Representative waveforms measured within paired arterioles (red) and venules (blue) are shown for each patient group for reference and qualitative comparison. Note that the y-axis RFV scales are not matched between groups in order to accentuate the waveform shape. The A-V delay and increased venous pulsatility are not present in conditions without an A-V fistula, such as normal eyes, acute NAION eyes, papilledema, venous stasis retinopathy (CRVO), or glaucoma.
case_images: fopht-03-1301410-g003.jpg
case_images: PMC11182162_01_fopht-03-1301410-g003.jpg
case_images: f3
case_images: Representative waveforms of each patient group are shown in  Figure 3 .