Ultra-Wide-Field Fluorescein Angiography–Guided Normalization of Ischemic Index Calculation in Eyes With Retinal Vein Occlusion

Abstract

PURPOSE. The purpose of this study was to compare the use of central and montaged ultrawide-field fluorescein angiography (UWFFA) images for calculating the area of nonperfusion (NP) and ischemic index (ISI) in patients with retinal vein occlusion (RVO) and macular edema (ME) and to correlate these measurements with best-corrected visual acuity (BCVA) and central macular thickness (CMT).METHODS. Thirty eyes of 30 RVO patients with recurrent ME were enrolled. Baseline UWFA images were sent to the Doheny Image Reading Center for quantitative analysis by certified graders. The association between ISI from the various zones and BCVA and CMT was examined by Spearman rank correlation and compared. Generalized linear models (GLMs) were used to analyze associations between BCVA and disease status.RESULTS. The NP area and ISI for central and montaged images were not significantly different for any retinal zone. A modest but statistically significant negative linear correlation was observed between BCVA and ISI, ranging from r ¼ À0.3825 in the perimacular area (PMA) to r ¼ À0.584 in the far peripheral area (FPA). On GLM analysis, both PMA (b ¼ À1.059; 95% confidence interval: À1.74 to À0.378) and FPA (b ¼ À0.505; 95% confidence interval: À0.988 to À0.021) were significant independent predictors of BCVA. We found no correlation between ISI from the various zones and CMT in this cohort. CONCLUSIONS.Montaging of UWFFA images may not be required to adequately quantify and represent areas of NP in eyes with RVO. NP in both the PMA and peripheral retina appear relevant to visual function, highlighting the importance of evaluating the retinal periphery in these individuals.

Retinal Capillary Plexus Pattern and Density from Fovea to Periphery Measured in Healthy Eyes with Swept-Source Optical Coherence Tomography Angiography

“…Detecting and assessing the surface of capillary non-perfusion areas is a critical prognostic factor in many retinal vascular diseases, especially in diabetic retinopathy and retinal vein occlusion [10][11][12][13] . This objective has been partially met using ultra-widefield fluorescein angiography (FA), but its resolution in the periphery is insufficient to accurately measure capillary non-perfusion areas compared to WF-OCTA 14 .…”

Performance evaluation of two fundus oculi angiographic imaging system: Optos 200Tx and Heidelberg Spectralis

“…All of the angiographic images were captured by an experienced technician. UWFFA images from the Optos 200Tx were transformed to stereographic projection images using proprietary software available from the manufacturer (Doheny Eye Institute) before quantitative analysis (16).…”

“…The retina profiles of the FFA images captured by the two devices were then respectively depicted by using Adobe ® Photoshop CS6 (Adobe Inc.). Grading results were saved as binary masks and subsequently calculated in square millimeters by summing the size of all pixels that make up the mask using the manufacturer's (16) quantification software (Doheny Eye Institute). If the UWFA image was poor, the image quality was improved by adjusting the contrast and brightness, and subsequently, the contour of the image was accurately delineated and measured.…”

Automated vessel density detection in fluorescein angiography images correlates with vision in proliferative diabetic retinopathy

“…In clinical applications, as compared to OCT images, ultra-widefield fluorescein angiography (UWFFA) images are currently assessed qualitatively. For research studies, the quantification of UWFFA has been focused on manually measuring the absence of retinal vessels or retinal non-perfusion and calculating an ischemic or nonperfusion index [15][16][17][18]. However, limitations of this labor-intensive approach include the time required for manual…”