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खुला एक्सेस

अमूर्त

Fractal Analysis of Peripapillary Vasculature in Eyes with Papilledema Using Optical Coherence Tomography Angiography

Ravneet Rai, Bing Chiu, Soshian Sarrafpour, Akash Gupta, Edmund Tsui, David Fell, Sherief Raouf, Nicole K Scripsema, Sarwar Zahid, Sarita Dave, Patricia Garcia, Toco Chui, Richard B Rosen, Rudrani Banik and Joshua A Young

Background: Papilledema is swelling of the optic nerve secondary to increased intracranial pressure. Optical coherence tomography angiography (OCTA) is a technique that allows for fast and non-invasive imaging of the peripapillary microvasculature. Here, we evaluate a novel way of analyzing OCTA images of eyes with papilledema through the use of fractals to estimate vascular complexity through fractal dimension.

Methods: A retrospective clinical chart review of papilledema patients imaged with OCTA was performed. En face OCT angiograms identifying peripapillary vessels were obtained using a spectral-domain OCT system. Default automated peripapillary scans of 4.5 mm × 4.5 mm diameter were processed with ImageJ. Fractal analysis was performed with Fractalyse software.

Results: Fifty-six eyes with papilledema and 40 eyes from healthy controls were analyzed. The fractal dimension of eyes with papilledema (1.677, SD=0.075) was significantly higher than that of control eyes (1.630, SD=0.062; P=0.002). Subgroup analysis demonstrated significantly higher fractal dimension in Grade 0 papilledema (1.707, SD=0.047) as compared to controls.

Conclusion: Increases in fractal dimension of peripapillary vasculature for papilledema may reflect potential increases in microvasculature, particularly during early stages. OCTA fractal dimension analysis has potential to establish quantitative parameters for peripapillary microvascular pathology in papilledema.