Microvascular Changes in the Cystic Lesion of Branch Retinal Vein Occlusion Imaged by Swept-Source Optical Coherence Tomography Angiography.

Introduction: This study aimed to describe the quantitative features of the microvasculature in the cystic lesions of branch retinal vein occlusion (BRVO). Methods: A total of 43 eyes with BRVO, treated with anti-vascular endothelial growth factor therapy, were analyzed. Using wide-field swept-source optical coherence tomography angiography (OCTA), en face OCT images were obtained by depth-integrated reflectivity of the retina, and vascular density (VD), vascular length (VL), vascular lacunarity, and fractal dimension (FD) were evaluated in a 12 × 12-mm area of retinal nonperfusion. Results: The mean area of affected lesions was 38.7 ± 19.8 mm2, and cystic lesions were 8.5 ± 10.1 mm2. VD, VL, and FD were significantly decreased in the cystic lesions compared to other affected lesions in the same eyes (p = 0.0010, p = 0.0001, and p = 0.0003, respectively) and in all eyes (p = 0.0281, p = 0.0050, and p < 0.0001, respectively). VD in cystic lesions within the vascular arcade (25 eyes) correlated with best-corrected visual acuity on OCTA (r = -0.433, and p = 0.0492). Conclusions: Vascular structure in the cystic lesions was unpreserved compared to the other lesions in BRVO. These findings may help in understanding the pathophysiology of retinal edema in BRVO.

Analysis of optic disc tilt angle in intrapapillary hemorrhage adjacent to peripapillary subretinal hemorrhage using swept-source optical coherence tomography.

Purpose: To report findings on the tilt angle of optic nerve heads (ONHs) that developed intrapapillary hemorrhage with adjacent peripapillary subretinal hemorrhage (IHAPSH) using swept-source optical coherence tomography (SS-OCT). Observations: Five consecutive patients who presented with IHAPSH were reviewed retrospectively. We reviewed five consecutive eyes from the five patients, analyzed the optic tilt angle obtained from SS-OCT B-scans, and compared the results and other clinical characteristics. All patients had larger optic disc tilt angles in the eyes with IHAPSH than in the contralateral, unaffected eye. The mean ratio of the tilt angle in the eyes with IHAPSH to that in the contralateral eye was 1.37 (95% confidence interval 1.15-1.58). Conclusions and Importance: The ONH of IHAPSH was evaluated quantitatively with SS-OCT for the first time in this study. Larger angle tilted discs in IHAPSH-affected eyes are anatomically and histologically more vulnerable and may explain why IHAPSH develops monocularly.

Association of disorganization of retinal inner layers with optical coherence tomography angiography features in branch retinal vein occlusion.

PURPOSE: To examine the associations between the disorganization of the retinal inner layers (DRIL) and optical coherence tomography angiography characteristics and visual acuity (VA) outcomes in eyes with macular edema secondary to branch retinal vein occlusion (BRVO). METHODS: In this single-center cross-sectional cohort study, the data of 43 patients with macular edema secondary to BRVO that received pro re nata anti-vascular endothelial growth factor therapy were analyzed. B-scan and en face angiographic images were obtained by swept-source-based wide-field optical coherence tomography angiography performed at a single visit 1 month after the anti-vascular endothelial growth factor therapy session and evaluated. Correlations between the vascular indices in macula-centered 3 × 3 and 12 × 12 mm2 areas and B-scan parameters, such as DRIL length and VA, were examined. RESULTS: The mean DRIL length (Rs = 0.588, p < 0.001) and the proportion of scans with DRIL out of five scans (Rs = 0.507, p = 0.001) were significantly correlated with the final best-corrected VA in patients with BRVO. DRIL length was associated with vascular density (VD) and vascular length in the macula (Rs = - 0.425, p = 0.006 and Rs = - 0.382, p = 0.013, respectively), but not with VD and vascular length in the larger areas (12 × 12 mm2). Multilinear regression analysis revealed that the extent of macular edema (p = 0.0016) and VD in the 3 × 3 mm2 area (p = 0.004) was significantly associated with the DRIL development. CONCLUSION: DRIL severity was correlated with VA and associated with the peri-macular perfusion status in eyes with BRVO. Macular edema and macular perfusion affected DRIL severity. These findings would help understand the pathogenesis of DRIL in eyes with BRVO.

Observation of treated iris neovascularization by swept-source-based en-face anterior-segment optical coherence tomography angiography.

We evaluated regression of iris neovascularization (INV) using en-face anterior-segment optical coherence tomography angiography (AS-OCTA) after anti-vascular endothelial growth factor (VEGF) therapy. Seven consecutive eyes with INV were examined before and after anti-VEGF therapy, and all AS-OCTA scans were obtained using a swept-source OCTA system with an anterior-segment lens adapter. Slit-lamp microscopy photography and anterior indocyanine green angiography also were performed. Quantitative analyses of the vascular density, vascular lacunarity, and fractal dimension on AS-OCTA images were performed. AS-OCTA visualized the INV as signals around the pupillary margin, which corresponded to the vasculature confirmed by slit-lamp microscopy. After anti-VEGF drug injection, regression of INV was observed by AS-OCTA in all eyes (100%). The vascular density decreased and vascular lacunarity increased significantly after anti-VEGF therapy. This pilot study demonstrated the ability of AS-OCTA not only to detect but also to evaluate INV. Further study is warranted to improve the algorithm for delineating the iris vasculature to decrease artifacts.