Assessment of retinal and choroidal microvasculature in night shift medical workers by OCT angiography.

This study evaluated retinal and choroidal microvascular changes in night shift medical workers and its correlation with melatonin level. Night shift medical workers (group A, 25 workers) and non-night shift workers (group B, 25 workers) were recruited. The images of macula and optic nerve head were obtained by swept-source OCT-angiography. Vessel density of retina, choriocapillaris (CC), choriocapillaris flow deficit (CC FD), choroidal thickness (CT) and choroidal vascularity index (CVI) were measured. 6-sulfatoxymelatonin concentration was analyzed from the morning urine. CC FD and CVI were significantly decreased and CT was significantly increased in group A (all P < 0.05). 6-sulfatoxymelatonin concentration was significantly lower in group A (P < 0.05), which was significantly positively correlated with CC FD size (r = 0.318, P = 0.024) and CVI of the most regions (maximum r-value was 0.482, P < 0.001), and was significantly negatively associated with CT of all regions (maximum r-value was - 0.477, P < 0.001). In night shift medical workers, the reduction of melatonin was significantly correlated with CT thickening, CVI reduction and CC FD reduction, which suggested that they might have a higher risk of eye diseases. CC FD could be a sensitive and accurate indicator to reflect CC perfusion.

Quantitative assessment of choroidal parameters and retinal thickness in central serous chorioretinopathy using ultra-widefield swept-source optical coherence tomography: a cross-sectional study.

OBJECTIVE: In this study, we used ultra-wide field swept-source optical coherence tomography angiography (UWF SS-OCTA) to assess changes in retinal thickness (RT) and choroidal parameters in individuals who had received a diagnosis of central serous chorioretinopathy (CSC). METHODS: The study encompassed the evaluation of 59 eyes from 47 patients with a diagnosis of CSC, alongside 33 fellow eyes and 31 eyes from healthy individuals (controls). The parameters assessed included RT, choroidal thickness (CT), choriocapillaris density, vascular density of the large choroidal vessel layer, three-dimensional choroidal vascularity index (3D-CVI), choroidal vessel volume per unit area (mCVV/a), and choroidal stroma volume per unit area (mCSV/a). RESULTS: Metrics including mCVV/a, mCSV/a, 3D-CVI, CT, and RT exhibited significantly elevated values in the eyes affected by CSC compared to those of the control group across nine subfields. Moreover, a substantial number of the subfields in both CSC-affected and fellow eyes exhibited increased values for mCVV/a, mCSV/a, 3D-CVI, CT, and RT when compared with the control group. Additionally, acute and chronic CSC subfields demonstrated significantly elevated values for mCVV/a, mCSV/a, 3D-CVI, CT, and RT in comparison to healthy control eyes. Notably, specific subfields associated with complex and atypical forms of CSC revealed higher metrics compared to those of the control group. CONCLUSION: In conclusion, the UWF SS-OCTA proved to be a valuable tool for exploring the anatomical etiology and clinical classification and diagnosis of CSC.

Quantitative assessment of retinochoroidal microvasculature in patients with carotid artery stenosis using OCT angiography.

PURPOSE: To investigate the alterations in retinochoroidal parameters measured by optical coherence tomography (OCT) and OCT angiography (OCTA) in patients with carotid artery stenosis (CAS) and assess their associations with digital subtraction angiography (DSA) data. METHOD: This study enrolled patients diagnosed with CAS and age-matched healthy controls. Both groups underwent OCT and OCTA examinations. DSA and assessment of carotid artery stenosis were performed only in the CAS group. The study evaluated various retinochoroidal parameters from OCT and OCTA, including linear vessel density (LVD), foveal avascular zone (FAZ), choroidal thickness (ChT), and retinal nerve fiber layer (RNFL) thickness. DSA-derived measures included cervical segment (C1) diameter, cavernous segment (C4) diameter, stenosis percentage, ophthalmic artery (OA) filling time, C1-OA filling time, and residual stenosis. RESULTS: A total of 42 eyes from 30 CAS patients and 60 eyes from 30 healthy controls were included. Patients with CAS displayed significantly decreased LVD compared to controls (p < 0.001). Additionally, the CAS group had thinner choroid and RNFL (p = 0.047 and p < 0.001, respectively). Macular LVD negatively correlated with both stenosis percentage and C1-OA filling time (p = 0.010 and p = 0.014, respectively). In patients who underwent carotid artery stenting, preoperative ChT significantly correlated with residual stenosis (Pearson r = -0.480, p = 0.020). CONCLUSION: OCT and OCTA provide a quantitative assessment of retinochoroidal microstructural changes associated with CAS, suggesting potential for noninvasive evaluation of the disease. This might contribute to the prevention of irreversible ocular complications and early detection of CAS. Furthermore, ChT may not only aid in diagnosing CAS more reliably but also offer prognostic information.

Optical coherence tomography angiography assessment of retinochoroidal microcirculation differences in preeclampsia.

BACKGROUND: To investigate microvascular changes in pregnant women with preeclampsia using optical coherence tomography angiography (OCTA) and compare the results with healthy pregnant and non-pregnant subjects. METHODS: Superficial capillary plexus (SCP), deep capillary plexus (DCP) choriocapillaris (CC) vessel density (VD) and foveal avascular zone area (FAZ), retina, retinal nerve fiber layer (RNFL), the ganglion cell layer (GCL) and the choroidal thickness were examined and compared in preeclamptic pregnant (group 1), healthy pregnant women (group 2) and non-pregnant, age-matched female controls (group 3). The correlations of the parameters with each other and with blood pressure were evaluated. RESULTS: No significant difference was found between the groups when retinal, RNFL and GCL thickness values (p> 0.05). The choroidal thickness values were significantly lower in group 1 than in group 2 (p = 0.029). The central foveal VD of the SCP and DCP was significantly lower in group 1 compared to groups 2 and 3 (p = 0.03, p< 0.01 respectively). The mean VD of the SCP was significantly higher in groups 1 and 2 than in group 3 (p = 0.01). The FAZ area was statistically significantly lower in group 3 than in group 2 (p = 0.032). The CC VD was lower in group 3 compared to the other groups in all measurements (p < 0.01).The FAZ area was positively correlated with systolic blood pressure in group 1. CONCLUSION: The use of OCTA, a non-invasive imaging technique, to assess the retinal microcirculation appears to have the potential to in the early diagnosis or follow up in preeclampsia before signs of hypertensive retinopathy.

Assessment of choriocapillaris and choroidal vascular changes in posterior uveitis using swept-source wide-field optical coherence tomography angiography.

PURPOSE: To evaluate choriocapillaris (CC) and choroidal vascular changes in patients with posterior uveitis using swept-source (SS) wide-field optical coherence tomography angiography (OCTA). METHOD: Consecutive patients with posterior uveitis were evaluated using 3×3 mm and 12×12 mm OCTA scan patterns and montage images of 5×12×12 mm or 2×15×9 mm, covering approximately 70°-90° of the retina. The images were quantitatively and qualitatively analysed and compared with healthy controls. RESULTS: Eighty-six eyes of 56 patients with posterior uveitis (mean age 45.2±19.9 years; 58.9% female), and 38 eyes of 19 age-matched healthy controls (57.9% female) were included. The mean perfusion density (PD) in 3×3 mm and 12×12 mm CC scans was significantly lower in eyes with posterior uveitis compared with those of healthy controls. However, no significant difference in the mean PD of choroidal scans was found comparing eyes with posterior uveitis and healthy controls. The mean PD in eyes with active disease was significantly higher compared with the inactive eyes on 12×12 mm choroidal scans (55.61% vs 51.25%, p=0.02), while no difference was found in the CC slabs. CONCLUSION: CC and choroidal assessment using OCTA provides useful information in patients with posterior uveitis. SS-OCTA metrics of the CC and choroidal slabs are promising tools in uveitis patients in the future. TRIAL REGISTRATION NUMBER: NCT02811536.

Assessment of retinal and choroidal microcirculation after unilateral recession-resection surgery for horizontal strabismus by swept-source optical coherence tomography angiography.

This study explored the possible hemodynamic changes of the retina and choroid after horizontal strabismus surgery using swept-source optical coherence tomography angiography (SS-OCTA). 32 eyes of 32 patients who underwent unilateral horizontal rectus muscle recession-resection surgery were included. SS-OCTA examinations were performed preoperatively and one week postoperatively. Several OCTA measurements were used, including vessel density (VD) of the superficial vascular complex (SVC), VD of the deep vascular complex (DVC), VD of the choriocapillaris (CC), choroidal vascular index (CVI) and choroidal thickness (CT). No significant change in VD of SVC, DVC, and CC was observed whereas CT increased significantly with CVI unchanged. Recession-resection surgery for horizontal strabismus seemed not to significantly influence the microcirculation of the retina and CC in the early postoperative period. However, choroidal thickening happened with a constant CVI probably due to the postoperative inflammation. Further studies are needed to investigate the long-term effects of unilateral recession-resection surgery for horizontal strabismus on the microcirculation of the retina and choroid.

Quantitative Assessment of Retinal and Choroidal Microvasculature in Asymptomatic Patients with Carotid Artery Stenosis.

SIGNIFICANCE: Carotid disease contributes to 15 to 20% of all ischemic strokes, one of the leading causes of permanent disabilities and mortality globally. With its growing prevalence and the inflicted disability rates, screening for anomalies that precede the onset of its serious complications is of crucial global significance. PURPOSE: This study aimed to assess the relationship between retinal and choroidal perfusion changes with the degree of stenosis using quantitative swept-source optical coherence tomography angiography in patients with internal carotid artery stenosis. METHODS: A retrospective cohort study was conducted in 72 eyes with carotid stenosis. According to the degree of stenosis, the participants were divided into a healthy group (group 1: 34 eyes), a mild-moderate stenosis group (group 2: 22 eyes), and a severe stenosis group (group 3: 16 eyes). Swept-source optical coherence tomography angiography was performed to scan macular fovea. Capillary density values in the different retinal and choroidal layers were the major measurements for our study. RESULTS: Mean vessel density in the midchoroid layer was significantly higher in groups 2 and 3 compared with group 1. Deep choroid disclosed significantly superior vascular density values in group 3 compared with groups 2 and 1. Superficial and deep capillary plexus showed decreased vascular density values when comparing group 3 with groups 1 and 2, although they were not significant. CONCLUSIONS: Our report provides the first evidence that choroidal microvascular changes were correlated with severity of carotid artery stenosis. Optical coherence tomography angiography can sensitively detect subtle, early changes in the ocular blood in carotid disease representing a useful, noninvasive, and objective approach to the retinal microvasculature.

Comparative assessment of choroidal thickness and choroidal vascularity index in patients with restless legs syndrome.

BACKGROUND: Increased sympathetic activity has been emphasized in the pathophysiology of restless legs syndrome (RLS). This study aims to evaluate the choroidal thickness (CT) and choroidal vascularity index (CVI) values of individuals with RLS. METHODS: A total of 60 volunteers, 30 individuals with RLS and 30 healthy individuals, were included in the study. The central macular thickness, subfoveal CT, and the CTs 1000 µm away from the fovea in the temporal and nasal regions were measured by optical coherence tomography. Total choroidal area (TCA), luminal area (LA) and stromal area (SA) were calculated using the binarization method. CVI was calculated as the ratio of lumen area to total choroidal area (LA/TCA). RESULTS: There was no significant difference between the participants in terms of age, gender, spherical equivalent, intraocular pressure, and axial length (p>0.05). The mean LA/SA was 1.56%±0.05 in RLS group and 1.99%±0.28 in the control group. The mean CVI was 0.64%±0.02% in RLS group and 0.66%±0.03 in the control group. There was no significant difference between the groups in terms of CT, TCA and LA values. There were significant differences between the groups in SA, LA/SA and CVI values (p = 0.017, p<0.001, and p = 0.004, respectively). CONCLUSION: SA values were significantly higher in RLS group than in control group. The LA/SA and CVI values were significantly lower in RLS group than in control group. These findings suggests that there is vascular narrowing due to sympathetic overactivity in RLS patients.

Quantitative assessment of choriocapillaris flow deficits and type 1 macular neovascularization growth in age-related macular degeneration.

During the past 15 years, new treatment paradigms for neovascular age-related macular degeneration (nvAMD) have evolved due to the advent of intravitreal anti-vascular endothelial growth factor (VEGF) therapy and rapid advances in retinal imaging. Recent publications describe eyes with type 1 macular neovascularization (MNV) as showing more resistance to macular atrophy than eyes with other lesion types. We sought to explore whether the perfusion status of the native choriocapillaris (CC) surrounding type 1 MNV influences its pattern of growth. To evaluate this effect, we analyzed a case series of 22 eyes from 19 nvAMD patients with type 1 MNV exhibiting growth on swept-source optical coherence tomography angiography (SS-OCTA) over a minimum follow-up of 12 months. We observed an overall weak correlation between type 1 MNV growth and CC flow deficits (FDs) average size (τ = 0.17, 95% CI [- 0.20, 0.62]) and a moderate correlation with CC FD % (τ = 0.21, 95% CI [- 0.16, 0.68]). Type 1 MNV was located beneath the fovea in most of the eyes (86%) and median visual acuity was 20/35 Snellen equivalent. Our results support that type 1 MNV recapitulates areas of CC blood flow impairment while serving to preserve foveal function.

Deep learning based diagnostic quality assessment of choroidal OCT features with expert-evaluated explainability.

Various vision-threatening eye diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR) are caused due to the dysfunctions manifested in the highly vascular choroid layer of the posterior segment of the eye. In the current clinical practice, screening choroidal structural changes is widely based on optical coherence tomography (OCT) images. Accordingly, to assist clinicians, several automated choroidal biomarker detection methods using OCT images are developed. However, the performance of these algorithms is largely constrained by the quality of the OCT scan. Consequently, determining the quality of choroidal features in OCT scans is significant in building standardized quantification tools and hence constitutes our main objective. This study includes a dataset of 1593 good and 2581 bad quality Spectralis OCT images graded by an expert. Noting the efficacy of deep-learning (DL) in medical image analysis, we propose to train three state-of-the-art DL models: ResNet18, EfficientNet-B0 and EfficientNet-B3 to detect the quality of OCT images. The choice of these models was inspired by their ability to preserve the salient features across all the layers without information loss. To evaluate the attention of DL models on the choroid, we introduced color transparency maps (CTMs) based on GradCAM explanations. Further, we proposed two subjective grading scores: overall choroid coverage (OCC) and choroid coverage in the visible region(CCVR) based on CTMs to objectively correlate visual explanations vis-à-vis DL model attentions. We observed that the average accuracy and F-scores for the three DL models are greater than 96%. Further, the OCC and CCVR scores achieved for the three DL models under consideration substantiate that they mostly focus on the choroid layer in making the decision. In particular, of the three DL models, EfficientNet-B3 is in close agreement with the clinician's inference. The proposed DL-based framework demonstrated high detection accuracy as well as attention on the choroid layer, where EfficientNet-B3 reported superior performance. Our work assumes significance in bench-marking the automated choroid biomarker detection tools and facilitating high-throughput screening. Further, the methods proposed in this work can be adopted for evaluating the attention of DL-based approaches developed for other region-specific quality assessment tasks.

Choroidal vascularity index (CVI)-Net-based automatic assessment of diabetic retinopathy severity using CVI in optical coherence tomography images.

A deep learning model called choroidal vascularity index (CVI)-Net is proposed to automatically segment the choroid layer and its vessels in overall optical coherence tomography (OCT) scans. Clinical parameters are then automatically quantified to determine structural and vascular changes in the choroid with the progression of diabetic retinopathy (DR) severity. The study includes 65 eyes consisting of 34 with proliferative DR (PDR), 17 with nonproliferative DR (NPDR), and 14 healthy controls from two OCT systems. On a dataset of 396 OCT B-scan images with manually annotated ground truths, overall Dice coefficients of 96.6 ± 1.5 and 89.1 ± 3.1 are obtained by CVI-Net for the choroid layer and vessel segmentation, respectively. The mean CVI values among the normal, NPDR, and PDR groups are consistent with reported outcomes. Statistical results indicate that CVI shows a significant negative correlation with DR severity level, and this correlation is independent of changes in other physiological parameters.

Assessment of Choroidal Vasculature and Innate Immune Cells in the Eyes of Albino and Pigmented Mice.

The visualization of choroidal vasculature and innate immune cells in the eyes of pigmented mice has been challenging due to the presence of a retinal pigment epithelium (RPE) layer separating the choroid and retina. Here, we established methods for visualizing the choroidal macrophages, mast cells, and vasculature in eyes of albino and pigmented mice using cell type-specific staining. We were able to visualize the choroidal arterial and venous systems. An arterial circle around the optic nerve was found in mice similar to the Zinn-Haller arterial circle that exists in humans and primates. Three different structural patterns of choriocapillaris were observed throughout the whole choroid: honeycomb-like, maze-like, and finger-like patterns. Choroidal mast cells were relatively few but dense around the optic nerve. Mast cell distribution in the middle and periphery was different among strains. Macrophages were found in all layers of the choroid. Thus, utilizing the simple and reliable methods described herein will allow the evaluation of transgenic and preclinical mouse models of ocular diseases that affect the choroid, including age-related macular degeneration (AMD), diabetic choroidopathy, and retinopathy of prematurity. These studies will advance our understanding of the pathophysiology, and molecular and cellular mechanisms that can be targeted therapeutically, in these diseases.

The assessment of acute chorioretinal changes due to intensive physical exercise in young adults.

PURPOSE: There is abundant evidence on the benefits of physical activity on cardiovascular health. However, there are only few data on the acute effects of physical exercise on the retina and choroid. Our aim was the in vivo examination of chorioretinal alterations following short intense physical activity by spectral domain optical coherence tomography (SD-OCT). METHODS: Twenty-one eyes of 21 healthy, young subjects (mean age 22.5 ± 4.1 years, 15 males and 6 females) were recruited. Macular scanning with a SD-OCT was performed before and following a vita maxima-type physical strain exercise on a rowing ergometer until complete fatigue. Follow-up OCT scans were performed 1, 5, 15, 30 and 60 minutes following the exercise. The OCT images were exported and analyzed using our custom-built OCTRIMA 3D software and the thickness of 7 retinal layers was calculated, along with semi-automated measurement of the choroidal thickness. One-way ANOVA analysis was performed followed by Dunnett post hoc test for the thickness change compared to baseline and the correlation between performance and thickness change has also been calculated. The level of significance was set at 0.001. RESULTS: We observed a significant thinning of the total retina 1 minute post-exercise (-7.3 ± 0.6 µm, p < 0.001) which was followed by a significant thickening by 5 and 15 minutes (+3.6 ± 0.6 µm and +4.0 ± 0.6 µm, respectively, both p <0.001). Post-exercise retinal thickness returned to baseline by 30 minutes. This trend was present throughout the most layers of the retina, with significant changes in the ganglion cell-inner plexiform layer complex, (-1.3 ± 0.1 µm, +0.6 ± 0.1 µm and +0.7 ± 0.1 µm, respectively, p <0.001 for all), in the inner nuclear layer at 1 and 5 minutes (-0.8 ± 0.1 µm and +0.8 ± 0.1 µm, respectively, p <0.001 for both), in the outer nuclear layer-photoreceptor inner segment complex at 5 minute (+2.3 ± 0.4 µm, p <0.001 for all) and in the interdigitation zone-retinal pigment epithelium complex at 1 and 15 minutes (-3.3 ± 0.4 µm and +1.8 ± 0.4 µm, respectively, p <0.001 for both). There was no significant change in choroidal thickness; however, we could detect a tendency towards thinning at 1, 15, and 30 minutes following exercise. The observed changes in thickness change did not correlate with performance. Similar trends were observed in both professional and amateur sportsmen (n = 15 and n = 6, respectively). The absolute changes in choroidal thickness did not show any correlation with the thickness changes of the intraretinal layers. CONCLUSIONS: Our study implies that in young adults, intense physical exercise has an acute effect on the granular layers of the retina, resulting in thinning followed by rebound thickening before normalization. We could not identify any clear correlation with either choroidal changes or performance that might explain our observations, and hence the exact mechanism warrants further clarification. We believe that a combination of vascular and mechanic changes is behind the observed trends.

Assessment of choroidal structural changes in patients with pre- and early-stage clinical diabetic retinopathy using wide-field SS-OCTA.

Purpose: To investigate the micro-vascular changes in choroidal structures in patients with pre- and early-stage clinical diabetic retinopathy (DR) using wide-field Swept-Source Optical Coherence Tomography Angiography (SS-OCTA). Method: This observational cross-sectional study included 131 eyes of 68 subjects that were divided into healthy controls (group 1, n = 46), pre-DR (group 2, n = 43), early-stage DR (group 3, n = 42) cohorts. All participants that underwent SS-OCTA examination were inpatients in the department of Ophthalmology and the department of Endocrinology, Qilu Hospital, Shandong University, and Department of Ophthalmology, Aier Eye Hospital, Jinan, from July 11, 2021 to March 17, 2022. The choroidal vascularity index (CVI), choroidal thickness (ChT) and central macular thickness (CMT) in the whole area (diameter of 12 mm) and concentric rings with different ranges (0-3, 3-6, 6-9, and 9-12 mm) were recorded and analyzed from the OCTA image. Result: Compared with healthy eyes, decreases in CVI and ChT were found in the eyes of patients with pre-or early-stage DR. The changes were more significant in the peripheral choroid, with the most prominent abnormalities in the 9-12mm area (P < 0.001). However, there was no obvious difference in the average CMT value. Furthermore, CVI and ChT were significantly correlated with the duration of diabetes in the range of 6-9 and 9-12 mm (Ps < 0.05; Correlation coefficient = -0.549, -0.395, respectively), with the strongest correlation (Ps < 0.01; Correlation coefficient = -0.597, -0.413, respectively) observed at 9-12 mm. Conclusion: The CVI and ChT values of diabetic patients are significantly lower than in healthy controls, especially in patients with early-stage DR. In addition, the peripheral choroidal capillaries are more susceptible to early DM-induced injury than in the central area.

Occurrence of Macular Neovascularization after Retinal Pigment Epithelium-Choroid Translocation Surgery to Treat Complicated Age-Related Macular Degeneration: Incidence, Management, and Outcome.

INTRODUCTION: This study investigates the incidence, clinical characteristics, and treatment response of macular neovascularization (MNV) occurring after retinal pigment epithelium (RPE) and choroid graft translocation surgery (RPE-choroid TS). METHODS: Retrospective analysis of 36 eyes of 36 consecutive patients who underwent RPE-choroid TS. Longer term follow-up of graft survival focusing on the occurrence of MNV was performed using multimodal imaging. RESULTS: Indications for RPE-choroid TS included complications of neovascular age-related macular degeneration in 34 patients and drusenoid pigment epithelial detachment in 2 patients. With a mean follow-up of 30 months, 8 patients out of 36 developed signs of MNV. Of these 8 patients, 4 presented with a drop in visual acuity (VA) due to centrally located type 3 MNV. Early diagnosis and treatment prevented significant functional consequences. Four patients developed type 2 MNV at the border of the graft, which did not tend to affect the VA. CONCLUSION: We report a high incidence of MNV after RPE-choroid TS. Early diagnosis and treatment may preserve function in these patients. The type of MNV and location can be used to guide the management.

Assessment of Choroidal Vascularity and Choriocapillaris Blood Perfusion in Anisomyopic Adults by SS-OCT/OCTA.

Purpose: To explore the association of choroidal vascularity and choriocapillaris blood perfusion with myopic severity in anisomyopes. Methods: Refractive error, axial length (AL), and other biometric parameters were measured in 34 anisomyopic young adults. Macular choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI), were determined from swept-source optical coherence tomography (SS-OCT) vertical and horizontal B-scans. The percentage of choriocapillaris flow voids (FV%) was obtained from en face SS-OCT-angiography. Results: The spherical equivalent refraction (SER) was -3.35 ± 1.25 diopters in the more myopic eyes and -1.25 ± 1.17 diopters in the less myopic eyes (P < 0.001). The interocular difference in SER was highly correlated with that in AL (P < 0.001). The macular ChT, TCA, LA, and SA were smaller in the more myopic eyes than in the less myopic eyes in both vertical and horizontal scans (all P < 0.001). Importantly, the CVIs in vertical and horizontal scans were smaller and the FV% was greater in the more myopic eyes (P < 0.05). In vertical scans, the interocular difference in CVIs was correlated with that in the SER, AL, and ChT (all P < 0.05). The interocular difference in FV% was correlated with that in SER, AL, and vertical and horizontal ChTs (all P < 0.05). Conclusions: Choroidal vascularity and choriocapillaris blood perfusion were lower in the more myopic eyes of anisomyopic adults. These changes were correlated with the severity of myopia and choroidal thinning, indicating that choroidal blood flow is disturbed in human myopia.

THE INCIDENCE, CHARACTERISTICS, MANAGEMENT, PROGNOSIS, AND CLASSIFICATION OF BREAKTHROUGH VITREOUS HEMORRHAGE SECONDARY TO POLYPOIDAL CHOROIDAL VASCULOPATHY.

PURPOSE: To describe breakthrough vitreous hemorrhage secondary to polypoidal choroidal vasculopathy (PCV). METHODS: Patients with the diagnosis of PCV from January 2005 to March 2020 at Peking Union Medical College Hospital were retrospectively reviewed, cases with breakthrough vitreous hemorrhage were analyzed. Subgroup analysis was conducted regarding pachychoroid PCV and nonpachychoroid PCV. RESULTS: Among 722 PCV patients (834 eyes), 103 eyes with breakthrough vitreous hemorrhage (12.4%) were included. Pars plana vitrectomy and proper further interventions could significantly improve the best-corrected visual acuity from logMAR 2.15 ± 0.48 (Snellen 20/2825) to 1.65 ± 0.67 (20/893). Hemorrhagic retinal detachment, baseline central macular thickness, and best-corrected visual acuity were factors associated with final best-corrected visual acuity (P < 0.05). In the pachychoroid PCV group, patients were younger, all had hemorrhagic pigment epithelial detachment, with a higher prevalence of choroidal vascular hyperpermeability and hemorrhagic retinal detachment, thicker subfoveal choroidal thickness, and thinner central macular thickness; besides, the initial pars plana vitrectomy were more complicated, more additional surgeries had to be performed. More eyes in the nonpachychoroid PCV group had received anti-vascular endothelial growth factor or photodynamic therapy, mostly fibrovascular pigment epithelial detachment, the best-corrected visual acuity and the status of the fellow eye were significantly worse. For the final ocular status, more eyes in nonpachychoroid PCV group were taking anti-vascular endothelial growth factor monotherapy, whereas more eyes in pachychoroid PCV group were stable. The choroidal parameters of these two groups were all significantly different. CONCLUSION: Breakthrough vitreous hemorrhage is a troublesome complication of PCV. Pars plana vitrectomy and additional interventions are required for better prognosis. Vitreous hemorrhage secondary to pachychoroid PCV or nonpachychoroid PCV have different characteristics and prognosis.

Quantitative assessment of choriocapillaris flow deficits in diabetic retinopathy: A swept-source optical coherence tomography angiography study.

PURPOSE: To quantitatively assess choriocapillaris (CC) flow deficits in eyes with diabetic retinopathy (DR) using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: Diabetic subjects with different stages of DR and age-matched healthy subjects were recruited and imaged with SS-OCTA. The en face CC blood flow images were generated using previously published and validated algorithms. The percentage of CC flow deficits (FD%) and the mean CC flow deficit size were calculated in a 5-mm-diameter circle centered on the fovea from the 6×6-mm scans. RESULTS: Forty-five diabetic subjects and 27 control subjects were included in the study. The CC FD% in diabetic eyes was on average 1.4-fold greater than in control eyes (12.34±4.14% vs 8.82±2.61%, P < 0.001). The mean CC FD size in diabetic eyes was on average 1.4-fold larger than in control eyes (2151.3± 650.8µm2 vs 1574.4±255.0 µm2, P < 0.001). No significant difference in CC FD% or mean CC FD size was observed between eyes with nonproliferative DR and eyes with proliferative DR (P = 1.000 and P = 1.000, respectively). CONCLUSIONS: CC perfusion in DR can be objectively and quantitatively assessed with FD% and FD size. In the macular region, both CC FD% and CC FD size are increased in eyes with DR. SS-OCTA provides new insights for the investigations of CC perfusion status in diabetes in vivo.

Quantitative Assessment of Asymmetric Choroidal Outflow in Pachychoroid Eyes on Ultra-Widefield Indocyanine Green Angiography.

Purpose: To quantitatively demonstrate asymmetric choroidal outflow in pachychoroid (central serous chorioretinopathy [CSC]/pachychoroid pigment epitheliopathy [PPE]) eyes using mid-phase, ultra-widefield indocyanine green angiography (UWF ICGA) images. Methods: Eyes with a clinical diagnosis of CSC/PPE were imaged with multimodal imaging including UWF ICGA (Optos California). Quadrant brightness was measured by manually segmenting based on vortex vein location, calculating the brightness "max-min" value to assess nonuniformity between quadrants, and comparing between CSC/PPE and control eyes. A multivariate linear regression was performed to determine, across individual eyes, which specific quadrants have the greatest brightness in pachychoroid eyes, after taking into account patient-eye-specific variability. Results: Thirty-three eyes (18 patients) with CSC/PPE along with 16 eyes of 9 controls had a mean age of 51.94 ± 9.72 vs. 53.78 ± 17.92 years (P = 0.731), respectively. Max-min analysis showed significantly increased likelihood of nonuniform drainage between vortex veins in both CSC/PPE and control eyes. Multivariate linear regression in control eyes showed that on average, the inferotemporal quadrant was significantly brighter than the superonasal quadrant (9.72 units, P < 0.001). Among CSC/PPE eyes, adjusting for the preferential, nonuniform drainage in control eyes, the inferonasal and inferotemporal quadrants in CSC/PPE eyes remained significantly brighter than the reference quadrant by 5.36 units (P = 0.034) and 7.51 units (P = 0.008), respectively. Conclusions: Asymmetric choroidal venous outflow occurs in both control and CSC/PPE eyes based on UWF ICGA quantitative brightness levels in each quadrant. Increased brightness levels along inferior quadrants in mid-phase ICGA images suggest venous outflow congestion among eyes with CSC or PPE.

QUANTITATIVE ASSESSMENT OF CHORIOCAPILLARIS FLOW DEFICITS SURROUNDING CHOROIDAL NEOVASCULAR MEMBRANES.

PURPOSE: To quantify the regional variation in choriocapillaris (CC) flow deficits percentage (FD%) surrounding treatment-naïve Type 1 choroidal neovascularization (CNV) associated with age-related macular degeneration. METHODS: Patients were imaged with swept-source optical coherence tomography angiography system (Carl Zeiss PLEX Elite 9000; Carl Zeiss Meditec AG, Jena, Germany). Two 6 × 6-mm volume scans were acquired. Boundary-specific segmentation was used to isolate the Type 1 CNV. For CC assessment, both structural and optical coherence tomography angiography CC slabs (10-µm thick, starting 21 µm below the retinal pigment epithelium fit reference) were exported for signal compensation and averaging using ImageJ. The resultant CC image was binarized to calculate the FD%, for para-CNV and peri-CNV rings (each 500-µm wide). In a subgroup of 20 eyes, the FD% was compared with similar regions of age-matched controls. The FD% was also analyzed in small 500 × 500-µm squares equidistant from the fovea to compensate for regional variation of CC FD% as a potential confounding factor. RESULTS: Thirty-two eyes from 27 subjects were enrolled in this study. The CC FD% in the para-CNV ring was 26.58 ± 7.36, which was significantly higher than the peri-CNV ring (21.94 ± 6.31); P < 0.001. The FD% in para-CNV and peri-CNV rings was significantly greater than that of healthy controls (15.82 ± 1.29% and 15.53 ± 1.32%, respectively); P < 0.001. The FD% computed in the 500-µm squares equidistant from the fovea was also greater in the para-CNV ring (26.14 ± 7.11) than that in the peri-CNV ring (22.31 ± 6.21); P < 0.001. CONCLUSION: Choriocapillaris FD% is the highest in the region immediately surrounding the CNV.