Peripheral Microvascular Abnormalities Detected by Wide-Field Fluorescein Angiography in Eyes with Branch Retinal Vein Occlusion

Abstract

Purpose: To evaluate the location of microvascular abnormalities using wide-field fluorescein angiography (WFFA) and investigate the impact on visual outcome in eyes with branch retinal vein occlusion (BRVO). Methods: Forty eyes of 39 patients (24 males and 15 females with an average age of 71 years) were retrospectively reviewed. One patient had BRVO bilaterally. WFFA was performed in all patients to evaluate perfusion status and detect microvascular abnormalities. The WFFA images were divided into 3 zones: zone 1, posterior pole; zone 2, mid-periphery; zone 3, far periphery, in order to document the presence of microvascular abnormalities. Scatter retinal photocoagulation (PC) was performed for retinal neovascularization (NV) and/or widespread nonperfused areas (NPAs). Results: The incidence of microvascular abnormalities in zone 3 was significantly (p < 0.0001) less than in zones 1 and 2. The presence of larger NPAs in zone 1, but not in zone 3, was associated with the incidence of NV and vitreous hemorrhage. The presence of peripheral lesions and the application of PC did not affect the visual outcome. Conclusion: The presence of peripheral abnormalities or scatter PC for NPAs did not affect the visual outcome in eyes with BRVO.

<p>Ultra-Widefield Fluorescein Angiographic Patterns, Retinal Microvascular Anomalies and Retinal Ischemic Index in Branch Retinal Vein Occlusions with Established Retinal Neovascularization</p>

“…In the BRVO study by Yasuda et al 5 on 40 eyes, NVE was more commonly observed in eyes with larger nonperfused retina in the posterior pole than in mid-periphery, but not observed in the far-peripheral retina in their cohort. 5 However, our observations are consistent with Prasad et al 10 in reporting NVE development in untreated or under-treated nonperfusion retina at any location of retina. 10 In the present cohort, the location of NVE is primarily confined to an area of persistent (or residual) black-RI defined by the initial BRVO occlusion territory boundary, which may or may not affect the macula or the far-peripheral retina.…”

“… 6 – 9 In contrast, published data on ARI are very limited in BRVO, and the studies available had applied ARI of 5 DD or more as the arbitrary guide for NVE risk in ischemic BRVO. 1 , 5 …”

“…[6][7][8][9] In contrast, published data on ARI are very limited in BRVO, and the studies available had applied ARI of 5 DD or more as the arbitrary guide for NVE risk in ischemic BRVO. 1,5 To the best of our knowledge, we provide the first ARI analysis in ischemic BRVO eyes using UWF-FA. Our cohort shows that NVE development can arise from various ARI sizes, ranging from the smallest ARI of 5DD (in only two patients) to the largest 354DD (Table 2).…”

“…1 In recent years, advancement in imaging devices such as ultra-widefield fundus fluorescein angiogram (UWF-FA) has allowed the capture of a much wider retina view from a single image and greater visualization of other peripheral retinal pathology. 4,5 In addition, few studies had concentrated on re-defining the angiographic retinal ischemic index (ARI) and associating its importance with NVE development in central retinal vein occlusions (CRVO) but not in BRVO. [6][7][8] In our daily clinical practice of interpreting UWF-FA, we repeatedly observed a recurring theme of common angiographic features in BRVO eyes with evidence of vitreous hemorrhage from active NVE.…”

<p>Morphologic Classifications and Locations of Microaneurysms and Clinical Relevance in Branch Retinal Vein Occlusion</p>

“…Retinal neovascularization also developed at the borders between the nonperfused and perfused areas in eyes with BRVO. 29 It is well known that overexpression of vascular endothelial growth factor (VEGF) in eyes with ischemic retinal diseases causes retinal neovascularization. MAs also formed after intravitreal injection of VEGF proteins in nonhuman primates, 30 and blockage of VEGF suppressed MA formation in eyes with BRVO.…”