Comparison between Spectral-Domain and Swept-Source OCT Angiography for the Measurement of Persistent Hypertransmission Defects in Age-Related Macular Degeneration.

Purpose: Spectral-domain OCT angiography (SD-OCTA) scans were tested in an algorithm developed for use with swept-source OCT angiography (SS-OCTA) scans to determine if SD-OCTA scans yielded similar results for the detection and measurement of persistent choroidal hypertransmission defects (hyperTDs). Design: Retrospective study. Participants: Forty pairs of scans from 32 patients with late-stage nonexudative age-related macular degeneration (AMD). Methods: Patients underwent both SD-OCTA and SS-OCTA imaging at the same visit using the 6 × 6 mm OCTA scan patterns. Using a semiautomatic algorithm that helped with outlining the hyperTDs, 2 graders independently validated persistent hyperTDs, which are defined as having a greatest linear dimension ≥250 µm on the en face images generated using a slab extending from 64 to 400 µm beneath Bruch's membrane. The number of lesions and square root (sqrt) total area of the hyperTDs were obtained from the algorithm using each imaging method. Main Outcome Measures: The mean sqrt area measurements and the number of hyperTDs were compared. Results: The number of lesions and sqrt total area of the hyperTDs were highly concordant between the 2 instruments (rc = 0.969 and rc = 0.999, respectively). The mean number of hyperTDs was 4.3 ± 3.1 for SD-OCTA scans and 4.5 ± 3.3 for SS-OCTA scans (P = 0.06). The mean sqrt total area measurements were 1.16 ± 0.64 mm for the SD-OCTA scans and 1.17 ± 0.65 mm for the SS-OCTA scans (P < 0.001). Because of the small standard error of the differences, the mean difference between the scans was statistically significant but not clinically significant. Conclusions: Spectral-domain OCTA scans provide similar results to SS-OCTA scans when used to obtain the number and area measurements of persistent hyperTDs through a semiautomated algorithm previously developed for SS-OCTA. This facilitates the detection of atrophy with a more widely available scan pattern and the longitudinal study of early to late-stage AMD. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Detection of macular neovascularization in eyes presenting with macular edema using optical coherence tomography angiography and a deep-learning model.

PURPOSE: To test the diagnostic performance of an artificial intelligence algorithm for detecting and segmenting macular neovascularization (MNV) with optical coherence tomography (OCT) and OCT angiography(OCTA) in eyes with macular edema from various diagnoses. DESIGN: Prospective cross-sectional study. PARTICIPANTS: Study participants with macular edema due to either treatment-naïve exudative age-related macular degeneration (AMD), diabetic macular edema (DME), or retinal vein occlusion (RVO). METHODS: Study participants were imaged with macular 3x3-mm and 6x6-mm spectral-domain OCTA. Eyes with exudative AMD were required to have MNV in the central 3x3-mm area. A previously developed hybrid multi-task convolutional neural network for MNV detection (aiMNV) and segmentation was applied to all images, regardless of image quality. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of detecting MNV; and intersection over union(IoU) score and F1 score for segmentation. RESULTS: Of 114 eyes from 112 study participants, 56 eyes had MNV due to exudative AMD and 58 eyes with macular edema due to either DME or RVO. 3x3-mm OCTA scans with aiMNV detected MNV with 96.4% sensitivity, 98.3% specificity, 98.2% PPV, and 96.6% NPV. For segmentation, the average IoU score was 0.947 and the F1 score was 0.973. 6x6-mm scans performed well; however, sensitivity for MNV detection was lower than 3x3-mm scans due to lower scan sampling density. CONCLUSION: This novel aiMNV algorithm can accurately detect and segment MNV in eyes with exudative AMD from a control group of eyes that present with macular edema from either DME or RVO. Higher scan sampling density improved the aiMNV sensitivity for MNV detection.

Factors Associated with Retinal Microvasculature Dropout Induced by Elevation of Intraocular Pressure in Primary Open-Angle Glaucoma.

PURPOSE: To investigate the risk factors related to decrease in vessel density (VD) observed in primary open-angle glaucoma (POAG), due to acute increase in intraocular pressure (IOP) by an ophthalmodynamometer (OPD). METHODS: This cross-sectional study involved 42 eyes of participants (22 Controls and 20 POAG patients) that underwent optical coherence tomography angiography (OCT-A) to assess VD in the peripapillary region in three examination sets: primary gaze position (1), 25-degree adduction (2) and 25-degree adduction with OPD compression (3). Individual relationships between IOP levels and changes in the superficial complex VD were evaluated after image processing and exclusion of large retinal vessels. Multivariable regression analysis was used to verify factors associated with differences in VD induced by IOP elevation. RESULTS: A significant increase in IOP was induced by OPD compression during adduction (mean ± SD, Control: + 13.8 ± 2.8; POAG: + 13.4 ± 2.1 mmHg). Only during IOP elevation (set 3), a significant VD decrease was observed both in POAG eyes (p = 0.008) and controls (p = 0.022). Baseline IOP (p = 0.022), maximum IOP (p = 0.003), and scleral rigidity (p = 0.029) were significantly associated with VD decreases in eyes with POAG. No changes were observed in VD during adduction gaze exclusively. CONCLUSION: Acute IOP elevation induced with OPD, but not adduction gaze, decreased peripapillary VD measured with OCT-A imaging. IOP levels and scleral rigidity significantly affected VD reduction in POAG patients. Thus, high scleral rigidity may decrease the ability of the globe to dampen the well-known effects of IOP fluctuation on glaucoma onset and progression. KEY MESSAGES: What is known Decrease vascular density in the peripapillary retina was associated with POAG, but factors related to the vascular response to elevated IOP are unexplored. What is new OCT-A quantification shows decreases in vascular density of the superficial layers of the peripapillary retina during an acute elevation in IOP. High IOP levels and scleral rigidity significantly affected vascular density reduction in POAG patients.

Resistive index of central retinal artery, aortic arterial stiffness and OCTA correlated parameters in the early stage of fabry disease.

This study aimed to evaluate the impact of Fabry disease (FD) on retinal microvasculature using optical coherence tomography angiography (OCTA), arterial stiffness, and the resistive index (RI) of the central retinal artery (CRA) in early disease stages. Twenty-nine genetically confirmed FD patients and twenty-six healthy controls were enrolled. Vessel density (VD) values of the superficial, deep, and choriocapillaris plexuses (SCP, DCP, and CC) were measured via OCTA. CRA RI was studied using color Doppler and grayscale sonography, and aortic pulse wave velocity (PWV) was assessed with the Complior method. CRA RI was significantly lower in the control group compared to the Fabry group (p < 0.001). Central VD was found to be significantly higher in the control group compared to the Fabry group in all the retinal layers (SCP (p < 0.001), DCP (p < 0.005), CC (p < 0.001)). PWV was significantly higher in the Fabry group than in the control group (p = 0.03). Fabry disease patients demonstrate elevated arterial stiffness, increased CRA RI, and diminished retinal microvascular density compared to healthy controls, indicating early ocular damage. Continuous monitoring and targeted screening for organ impairment are crucial in FD management. Identifying biomarkers for assessing ocular vascular involvement and treatment response is imperative. Further research is needed.

The Current and Novel Imaging Modalities for Ocular Vasculitis in Behcet's Disease: A Review.

Behcet's syndrome is a multisystem inflammatory disorder characterized by a chronic relapsing course and diverse clinical manifestations, prominently affecting young adults along the ancient Silk Road and beyond. The disease pathogenesis involves complex interactions between genetic predisposition, environmental triggers, and dysregulated immune responses, leading to systemic vasculitis and tissue damage. Ocular involvement, a hallmark of Behcet's Disease (BD), significantly impacts morbidity, with uveitis as a common initial presentation that can progress to severe vision-threatening complications like retinal vasculitis and occlusive disease. This review consolidates current knowledge on ocular manifestations in BD, emphasizing the pivotal role of multimodal imaging in diagnostic evaluation and management. Fundus photography serves as a baseline tool for documenting intraocular lesions and monitoring treatment responses. Fluorescein angiography remains the gold standard for detecting acute inflammatory changes and vascular leakage patterns essential for disease staging and prognostication. Recent advancements in imaging, such as ultra-wide field imaging (UWF), indocyanine green angiography (ICGA), Doppler ultrasonography, Optical Coherence Tomography (OCT), OCT angiography (OCTA), adaptive optics (AO), and retinal function imaging (RFI), provide unprecedented insights into microvascular dynamics, structural changes, and functional impairments associated with ocular BD. Integration of these advanced imaging modalities enhances early detection of subclinical disease, facilitates precise localization of inflammatory lesions, guides therapeutic interventions, and monitors treatment efficacy. OCT and OCTA, in particular, offer non-invasive, high-resolution assessments of macular edema, vascular perfusion abnormalities, and choroidal thickness alterations critical for optimizing patient care. In conclusion, multimodal imaging represents the cornerstone in the comprehensive management of ocular manifestations in Behcet's Disease, offering clinicians invaluable tools for accurate diagnosis, treatment planning, and long-term monitoring of disease progression and treatment outcomes.

Internal Limiting Membrane Peeling for Large Macular Holes Induces Only Structural Remodeling without Functional Impairment Over 12 Years.

PURPOSE: To evaluate the very long-term functional and structural outcomes of internal limiting membrane (ILM) peeling for full-thickness macular holes (FTMH). DESIGN: Observational case series nested within a multicenter, randomized, controlled clinical trial (RCT) (ClinicalTrials.gov: NCT00190190). SUBJECTS: Patients who underwent vitrectomy with or without ILM peeling for an idiopathic large FTMH in a tertiary ophthalmology center, with a minimum follow-up of 10 years after surgery. METHODS: Review of charts, spectral-domain OCT (SD-OCT) scans, OCT angiography (OCTA) scans, and microperimetry of patients originally enrolled in the RCT. MAIN OUTCOME MEASURES: Primary outcome was functional assessment in both groups (ILM peeling or not) including the retinal sensitivity (RS), distance and near best-corrected visual acuity (BCVA), and number of eyes achieving ≥0.3 logarithm of the minimum angle of resolution >10 years after surgery. Secondary outcomes were structural assessment in the entire 3 × 3-mm and 6 × 6-mm areas, and regionally in the different areas of the ETDRS grid: OCT and OCTA biomarkers in both groups and fellow eyes. RESULTS: Thirteen eyes of 13 patients with a mean follow-up of 12 ± 0.73 years were included. The mean RS and BCVA, or visual improvement did not differ between ILM peeling (n = 8) and no peeling (n = 5) (all P > 0.05). The dissociated optic nerve fiber layers on en face OCT were only observed in eyes with ILM peeling, predominantly in temporal parafoveal (20%) and perifoveal (19%) rings. The mean total retinal thickness and inner retinal thickness in the parafoveal ring were significantly lower in peeled eyes (309 ± 11 µm and 94 ± 9 µm respectively) versus nonpeeled eyes (330 ± 21 µm and 108 ± 11 µm respectively; P = 0.037 and P = 0.040), without significant difference in ganglion cell or retinal nerve fiber layers. Accordingly, the mean superficial capillary plexus density in the parafoveal ring was significantly lower in eyes with peeling versus without (39.65 ± 3.76 % versus 47.22 ± 4.00; P = 0.005). The mean foveal avascular zone area was smaller in eyes with peeling versus without (0.24 ± 0.05 mm2 vs. 0.42 ± 0.13 mm2, respectively, P = 0.005). CONCLUSIONS: Despite persistent structural changes especially in the parafoveal ring, ILM peeling for idiopathic large FTMH did not seem to impact long-term RS or BCVA over 12 years. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Optical coherence tomography angiography for microaneurysms in anti-vascular endothelial growth factor treated diabetic macular edema.

BACKGROUND: We aimed to evaluate microaneurysms (MAs) after treatment with anti-vascular endothelial growth factor (anti-VEGF) therapy to understand causes of chronic edema and anti-VEGF resistance. METHODS: Patients with non-proliferative diabetic retinopathy, with or without macular edema were recruited. Optical coherence tomography angiography (OCTA) MAs-related parameters were observed, including the maximum diameter of overall dimensions, material presence, and flow signal within the lumen. OCTA parameters also included central macular thickness (CMT), foveal avascular zone, superficial and deep capillary plexuses, and non-flow area measurements on the superficial retinal slab. RESULTS: Overall, 48 eyes from 43 patients were evaluated. CMT differed significantly between the diabetic macular edema (DME ) and non-DME (NDME) groups at 1st, 2nd, 3rd, and 6th months of follow-up (P < 0.001; <0.001; 0.003; <0.001, respectively). A total of 55 and 59 MAs were observed in the DME (mean = 99.40 ± 3.18 µm) and NDME (mean maximum diameter = 74.70 ± 2.86 µm) groups at baseline, respectively (significant between-group difference: P < 0.001). Blood flow signal was measurable for 46 (83.6%) and 34 (59.3%) eyes in the DME and NDME groups, respectively (significant between-group difference: P < 0.001). CONCLUSIONS: Compared to the NDME group, the DME group had larger MAs and a higher blood-flow signal ratio. Following anti-VEGF therapy, changes in the diameter of MAs were observed before changes in CMT thickness.

Quantitative Volumetric Analysis of Retinal Ischemia with an Oxygen Diffusion Model and OCT Angiography.

Purpose: Retinal ischemia is a major feature of diabetic retinopathy (DR). Traditional nonperfused areas measured by OCT angiography (OCTA) measure blood supply but not ischemia. We propose a novel 3-dimensional (3D) quantitative method to derive ischemia measurements from OCTA data. Design: Cross-sectional study. Participants: We acquired 223 macular OCTA volumes from 33 healthy eyes, 33 diabetic eyes without retinopathy, 7 eyes with nonreferable DR, 17 eyes with referable but nonvision-threatening DR, and 133 eyes with vision-threatening DR. Methods: Each eye was scanned using a spectral-domain OCTA system (Avanti RTVue-XR, Visionix/Optovue, Inc) with 1.6-mm scan depth in a 3 × 3-mm region (640 × 304 × 304 voxels) centered on the fovea. For each scanned OCTA volume, a custom algorithm removed flow projection artifacts. We then enhanced, binarized, and skeletonized the vasculature in each OCTA volume and generated a 3D oxygen tension map using a zero-order kinetics oxygen diffusion model. Each volume was scaled to the average retina thickness in healthy controls after foveal registration and flattening of the Bruch's membrane. Finally, we extracted 3D ischemia maps by comparison with a reference map established from scans of healthy eyes using the same processing. To assess the ability of the ischemia maps to grade DR severity, we constructed receiver operating characteristic curves for diagnosing diabetes, referable DR, and vision-threatening DR. Main Outcome Measures: Spearman correlation coefficient and area under receiver operating characteristic curve (AUC) were used to quantify the ability of the ischemia maps to DR. Results: The ischemia maps showed that the ischemic tissues were at or near pathologically nonperfused areas, but not the normally nonvascular tissue, such as the foveal avascular zone. We found multiple novel metrics, including inferred 3D-oxygen tension, ischemia index, and ischemic volume ratio, were strongly correlated with DR severity. The AUCs of ischemia index measured were 0.94 for diabetes, 0.89 for DR, 0.88 for referable DR, and 0.85 for vision-threatening DR. Conclusions: A quantitative method to infer 3D oxygen tension and ischemia using OCTA in diabetic eyes can identify ischemic tissue that are more specific to pathologic changes in DR. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Prediction of Functional and Anatomic Progression in Lamellar Macular Holes.

Purpose: To use artificial intelligence to identify imaging biomarkers for anatomic and functional progression of lamellar macular hole (LMH) and elaborate a deep learning (DL) model based on OCT and OCT angiography (OCTA) for prediction of visual acuity (VA) loss in untreated LMHs. Design: Multicentric retrospective observational study. Participants: Patients aged >18 years diagnosed with idiopathic LMHs with availability of good quality OCT and OCTA acquisitions at baseline and a follow-up >2 years were recruited. Methods: A DL model based on soft voting of 2 separate models (OCT and OCTA-based respectively) was trained for identification of cases with VA loss >5 ETDRS letters (attributable to LMH progression only) during a 2-year follow-up. Biomarkers of anatomic and functional progression of LMH were evaluated with regression analysis, feature learning (support vector machine [SVM] model), and visualization maps. Main Outcome Measures: Ellipsoid zone (EZ) damage, volumetric tissue loss (TL), vitreopapillary adhesion (VPA), epiretinal proliferation, central macular thickness (CMT), parafoveal vessel density (VD) and vessel length density (VLD) of retinal capillary plexuses, choriocapillaris (CC), and flow deficit density (FDD). Results: Functionally progressing LMHs (VA-PROG group, 41/139 eyes [29.5%]) showed higher prevalence of EZ damage, higher volumetric TL, higher prevalence of VPA, lower superficial capillary plexus (SCP), VD and VLD, and higher CC FDD compared with functionally stable LMHs (VA-STABLE group, 98/139 eyes [70.5%]). The DL and SVM models showed 92.5% and 90.5% accuracy, respectively. The best-performing features in the SVM were EZ damage, TL, CC FDD, and parafoveal SCP VD. Epiretinal proliferation and lower CMT were risk factors for anatomic progression only. Conclusions: Deep learning can accurately predict functional progression of untreated LMHs over 2 years. The use of AI might improve our understanding of the natural course of retinal diseases. The integrity of CC and SCP might play an important role in the progression of LMHs. Financial Disclosures: The authors have no proprietary or commercial interest in any materials discussed in this article.

Benefit of Optical Coherence Tomography-Angiography in Patients Undergoing Transsphenoidal Pituitary Adenoma Surgery: A Prospective Controlled Study.

BACKGROUND: Although visual field (VF) defects are common in compressive pituitary adenoma (CPA), their pathophysiology has not been fully elucidated. The mechanical theory (i.e., direct compression of the optic chiasm by the CPA) and the vascular theory (i.e., compression of the vessels supplying the visual path by the CPA) or their association could explain the visual impairment. The aim of this study was to determine whether the vascular density (VD) improved after surgical decompression of the optic chiasm in CPA patients and whether OCT-A could help to identify predictive factors for postoperative visual recovery. METHODS: A prospective controlled study was conducted in patients who underwent transsphenoidal pituitary adenoma surgery. Patients were divided into two groups: with CPA and without CPA (NCPA). All patients underwent a neuro-ophthalmological examination, VF testing, macular and optic disc structural OCT [retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thicknesses] and OCT-A before and then 1 and 6 months after surgery. RESULTS: Twenty-four eyes and fourteen eyes were included, respectively, in the CPA and NCPA groups. None of the VD parameters assessed by OCT-A were significantly improved after surgery in the CPA group. In the CPA group, the mean macular superficial VD was significantly decreased at 6 months. The multivariate analysis failed to identify any preoperative parameters predictive of postoperative VF improvement. CONCLUSIONS: Our preliminary findings suggest that the visual impairment observed in CPA patients could not be explained by the vascular theory. None of the preoperative OCT-A parameters allowed a postoperative VF recovery assessment. Trial registration number NCT04074642, ID-RCB 2019-A01186-51 date of registration 30 July 2019.

Association of Microvasculature Changes with Visual Outcomes in Idiopathic Epiretinal Membrane Surgery: A Clinical Trial.

Purpose: The purpose of this paper is to evaluate macular microvascular changes and their correlation with visual outcomes after idiopathic epiretinal membrane (iERM) surgery. Methods: Forty-seven eyes operated for iERM were included in this retrospective case series. The foveal avascular zone (FAZ) area, and the vessel density (VD) in the superficial and the deep capillary plexus (SCP and DCP) were evaluated using optical coherence tomography angiography (OCTA). The association between the OCTA parameters and best-corrected visual acuity (BCVA) was examined preoperatively and postoperatively. Regression analyses were conducted to determine the potential predictive factors for visual recovery. Results: At baseline, the FAZ area in iERM eyes was significantly smaller than that in the control eyes (p < 0.001). iERM eyes also had a lower macular VD in both the SCP and the DCP (p < 0.001). Preoperative BCVA was negatively correlated with the FAZ area (r = -0.499, p < 0.001) and macular VD in the DCP (r = -0.422, p = 0.003). A negative correlation was also found between postoperative BCVA and macular VD in both the SCP (r = -0.394, p = 0.006) and the DCP (r = -0.569, p < 0.001). In the bivariate analyses, age, preoperative BCVA, iERM stage, and baseline macular VD in the SCP were significantly associated with BCVA at 6 months post-surgery. Multivariate regression analysis revealed that the preoperative BCVA was the only predictor of visual outcomes in iERM eyes (p < 0.001). Conclusions: Idiopathic epiretinal membrane (iERM) causes microvascular changes, including foveal avascular zone (FAZ) contraction and decreased macular vessel density (VD) in both the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). These changes were significantly correlated with pre- and/or postoperative best-corrected visual acuity (BCVA). However, none of these alterations appeared to have prognostic value for visual outcomes in patients with iERM.

A gender-based analysis of retinal microvascular alterations in patients with diabetes mellitus using OCT angiography.

PURPOSE: To assess the difference in microvascular changes between males and females with diabetes mellitus (DM) without diabetic retinopathy (NoDR) and with mild-to-moderate non-proliferative diabetic retinopathy (NPDR) using Optical Coherence Tomography Angiography (OCT-A). DESIGN: Retrospective cross-sectional study. METHODS: 267 DM patients, 133 females (49.81 %), 111 with NoDR (41.57 %) and 156 NPDR (58.43 %) were included. Foveal-centered 3 × 3 mm OCT-A images corresponding to the superficial (SCP), intermediate (ICP) and deep capillary plexus (DCP), and full retinal (RET) slab were used for analysis. For each slab, FAZ area, perimeter, and circularity index (CI) were determined, following manual delineation of the FAZ; perfusion (PD) and vessel density (VD), fractal dimension (FD), vessel length density (VLD), geometric perfusion deficits (GPD) were also computed. Flow voids (FV) were determined in the choriocapillaris plexus; and perfused capillary density (PCD) in the RET slab. RESULTS: Females showed larger FAZ CI in SCP and greater FAZ area and perimeter than males in NPDR group. Males had higher central macular thickness than females in NPDR group. All density metrics at the level of ICP and DCP were affected in the NPDR group with no gender differences. Of note, the same significant findings were found in type 1 DM patients, and not in type 2 DM patients. CONCLUSIONS: Our OCT-A findings suggest significant microvascular changes in females with NPDR compared to males, but no such differences in patients without DR. Therefore, gender-related vascular alterations might be present in early stages of DR with potential role.

Clinical utility of swept-source optical coherence tomography angiography for the diagnosis of exudative maculopathy.

PURPOSE: To assess the feasibility of swept-source optical coherence tomography angiography (SS-OCTA) to differentiate macular diseases, including nonpolypoidal macular neovascularization (MNV), polypoidal choroidal vasculopathy (PCV), type 3 MNV, and chronic central serous chorioretinopathy (CSC) without indocyanine green angiography (ICGA). STUDY DESIGN: Retrospective observational study. METHODS: This study examined 63 eyes of 63 patients with treatment-naive neovascular age-related macular degeneration (AMD), including 23 eyes with nonpolypoidal MNV, 17 eyes with PCV, and 1 eye with type 3 MNV and 22 eyes with chronic CSC. Two independent retina specialists, blinded to the clinical diagnosis, assessed each case of neovascular AMD and chronic CSC using only B-scan and en face images of SS-OCTA without referring to other examination outcomes. RESULTS: By SS-OCTA alone, 19 eyes were diagnosed with nonpolypoidal MNV, 17 eyes with PCV, 2 eyes with type 3 MNV, and 22 eyes with chronic CSC, indicating high sensitivity (82.6%, 94.1%, 100%, and 100%, respectively) and specificity (100%, 97.8%, 98.4%, and 100%, respectively); however, three eyes could not be diagnosed because of obscure images. The agreement of diagnosis with SS-OCTA alone was high between the two specialists (κ = 0.82). CONCLUSION: SS-OCTA showed high sensitivity and specificity in the differentiation of nonpolypoidal MNV, PCV, type 3 MNV, and chronic CSC. The differential criteria based on SS-OCTA could be a substitute for the ICGA-based diagnoses.

Quantitative optical coherence tomography angiography assessments in the fellow eyes of those with central serous chorioretinopathy.

BACKGROUND: To analyze the vessel density (VD) of the retina and choriocapillaris (CC) layer and the structure of the foveal avascular zone (FAZ) in the fellow eyes of central serous chorioretinopathy (CSC) patients by using optical coherence tomography angiography (OCTA). METHODS: This was a case-control study. Unilateral CSC patients and age-matched healthy subjects were recruited from the Affiliated Eye Hospital of Wenzhou Medical University between July 2016 and July 2021. All eyes were divided into three groups: acute CSC (aCSC), chronic CSC (cCSC), and healthy controls. Both aCSC and cCSC were again divided into two subgroups: the affected eyes and the fellow eyes. In this study, all parameters of VD and FAZ were measured by self-software of OCTA. RESULTS: A total of 231 eyes of 137 subjects were included, with 47 aCSC patients, 47 cCSC patients, and 43 healthy controls. In the fellow eyes of CSC, the retinal VD was significantly lower (all P < 0.05), and the FAZ was significantly larger (all P < 0.05) in the cCSC group than in healthy controls, while no difference was detected in the CC layer. There was no significant difference between the aCSC group and healthy controls in all OCTA parameters. In the affected eyes of CSC, the superficial retinal vessel density (SRVD) was significantly higher (all P < 0.05) in healthy controls than in the aCSC and cCSC groups, while the deep retinal vessel density (DRVD) was significantly lower (all P < 0.05) and the FAZ was larger (all P < 0.05) in the cCSC group than in the aCSC group and healthy controls. A liner regression equation was established: Y (BCVA, best corrected visual acuity) = 3.692-0.036✱X1 (DRVD-Fovea)-0.031✱X2 (FD-300, vessel density around the 300 µm width of the FAZ), R2 = 0.427. CONCLUSION: Based on OCTA measurements, this study revealed that the retinal microvascular network was impaired even in the fellow eyes of those with cCSC, which should arouse attention to the observation of unilateral CSC.

Impact of preocular and ocular circulatory dynamics on the vascular density of retinal capillary plexuses and choriocapillaris.

PURPOSE: To highlight the influence of preocular and ocular vascular circulatory dynamics on the vascular density (VD) of retinal capillary plexuses (RCPs) and choriocapillaris (CC) in patients with and without cardiovascular risk (CVR) factors. METHODS: A retrospective observational study in patients with and without CVR factors (type 1 and 2 diabetes, arterial hypertension, and hypercholesterolemia). Fluorescein (FA) and indocyanine (ICGA) angiography circulatory times were arterial time (FAAT), start (FAstartLF) and end (FAendLF) of laminar flow, and arterial time (ICGAAT), respectively. OCT angiography VDs were superficial (VDSCP) and deep (VDDCP) RCPs and CC (VDCC) VDs. Correlation and regression analysis were performed after adjusting for confounding factors. RESULTS: 177 eyes of 177 patients (mean age: 65.2 ± 15.9 years, n = 92 with and 85 without CVR) were included. VDSCP and VDDCP were significantly inversely correlated with FAAT, FAstartLF and FAendLF likewise VDCC with ICGAAT. Correlations were stronger in patients without CVR than with CVR. CVR, FAAT, FAstartLF and FAendLF were more strongly correlated with VDDCP than VDSCP. FAAT, FAstartLF and FAendLF significantly impacted VDSCP and VDDCP, likewise ICGAAT impacted VDDCP. VDDCP was most strongly impacted by FAAT and FAstartLF. CONCLUSION: Ocular and pre-ocular circulatory dynamics significantly impacted RCPs and CC VDs, especially deep RCP.

[OCT biomarkers in diabetic maculopathy and artificial intelligence]. / OCT-Biomarker bei diabetischer Makulopathie und künstliche Intelligenz.

Diabetes mellitus is a chronic disease the microvascular complications of which include diabetic retinopathy and maculopathy. Diabetic macular edema, proliferative diabetic retinopathy, and diabetic macular ischemia pose a threat to visual acuity. Artificial intelligence can play an increasingly more important role in making the diagnosis and the treatment regimen of maculopathies in everyday clinical practice in the future. It can be used to automatically detect and quantify pathological parameters of the retina. The aim is to improve patient care in the clinical routine using so-called clinical decision support systems with personalized treatment algorithms. This review article outlines the current research regarding new biomarkers in diabetic maculopathy using optical coherence tomography (OCT) and OCT angiography (OCT-A).

OCT Angiography of the Retina and the Choroid in the Macula in Patients with Normal Tension Glaucoma and Primary Open Angle Glaucoma.

The aim of this study was to compare vessel density (VD) in the retina and choroid in eyes with primary open angle glaucoma (POAG), normal tension glaucoma (NTG) and controls. Patients with POAG, NTG and controls underwent OCT scanning of the macula and the disc followed by 6 × 6 mm macula OCT angiography (OCTA) imaging. Global and hemifield VD were recorded for the superficial (SVP) and deep (DVP) vascular plexus and the choriocapillaris (CC). The OCT thickness of the nerve fiber layer (NFL) and ganglion cell layer (GCC) was also measured. Data from 65 POAG, 33 NTG and 40 control eyes matched for age were analyzed. Mean SVP VD was lower in NTG and POAG eyes compared to controls (38.8 ± 5.3, 40.7 ± 6.8 and 48.5 ± 4.0%, p < 0.001). Mean DVP VD was lower in NTG and POAG eyes compared to controls (43.1 ± 6.1, 44.5 ± 7.6 and 48.6 ± 5.8%, p = 0.002). There was no difference in SVP VD or DVP VD between the glaucoma groups (p > 0.050). No difference was noted in CC VD between the groups (68.3 ± 2.3, 67.6 ± 3.7 and 68.5 ± 2.6%, p = 0.287). Lower SVP and DVP VD was seen in eyes with glaucoma compared to normal eyes. NTG and POAG eyes had similar VD loss. Eyes with glaucoma manifested similar CC VD compared to controls.

Branch retinal artery occlusion in a 49-year-Old woman taking phentermine.

Purpose: This report describes the presentation of a 49-year-old woman with a branch retinal artery occlusion of the right eye in the setting of taking phentermine, a commonly used weight loss medication. Observations: A 49-year-old woman presented with acute painless vision loss in her right eye and was found to have a branch retinal artery occlusion after taking prescribed dosages of phentermine for weight loss therapy. Fundus examination revealed retinal whitening in the distribution of the superior temporal branch retinal artery, and spectral domain optical coherence tomography demonstrated macular edema. Systemic evaluation was negative for cardiovascular, infectious, or autoimmune etiologies. Based on the retinal findings, the patient was diagnosed with phentermine associated branch retinal artery occlusion. She was followed for nine years with no further complications and her vision remained stable in the right eye. Conclusions and Importance: This case highlights that phentermine, a commonly used weight loss medication, could be associated with ischemic retinopathies. Thus, clinicians should be aware that retinal vascular occlusions may not only occur in those who use recreational amphetamines but also in patients taking the prescribed dosages of a weight loss medication like phentermine.

Macular Ischemia Changes in Patients with Diabetic Macular Edema Treated with Aflibercept and Ranibizumab.

Τhis study aims to assess changes in the fovea avascular zone (FAZ) in treatment naïve patients receiving aflibercept or ranibizumab injections for diabetic macular edema (DME). Best corrected visual acuity (BCVA) testing, OCT, and OCT-angiography imaging were performed at baseline and 1 month after each injection. Injections of either aflibercept or ranibizumab were administered monthly for 6 consecutive months. FAZ in the superficial (SCP) and the deep capillary plexus (DCP) using OCT angiography was recorded for each visit. Fifty eyes from fifty patients with a mean age of 67.0 ± 10.7 years were included in the study. Twenty-five patients received aflibercept and twenty-five received ranibizumab. BCVA was 40.8 ± 10.0 and increased to 52.1 ± 7.9 ETDRS letters at the last visit (p < 0.001). CRT was 295.6 ± 34.0 at baseline and 247.9 ± 29.7 at the last study visit (p < 0.001). SCP FAZ was 350.6 ± 79.5 µm2 at baseline and 339.0 ± 71.3 µm2 after sox monthly injections (p = 0.132). DCP FAZ was 558.6 ± 199.0 µm2 at baseline and 459.5 ± 156.1 µm2 after six monthly injections (p < 0.001). There was no effect of the choice of ranibizumab or aflibercept on DCP FAZ change (p = 0.277). In conclusion, treatment with 6 monthly injections of ranibizumab and aflibercept led to an increase in BCVA and a decrease in CRT and DCP FAZ area. Both drugs led to an improvement in DCP ischemia.

Superficial ocular vascular changes after orbital decompression in patients with thyroid ophthalmopathy measured by anterior segment OCT angiography; an observational study.

Thyroid eye disease (TED) is a common ophthalmologic manifestation of thyroid dysfunction. Despite various imaging techniques available, there hasn't been a widely adopted method for assessing the anterior segment vasculature in TED patients. Our study aimed to evaluate alterations in ocular surface circulation following orbital decompression surgery in TED patients and investigate factors influencing these changes. Using anterior segment optical coherence tomography-angiography (AS-OCTA), we measured ocular surface vascularity features, including vessel density (VD), vessel diameter index (VDI), and vessel length density (VLD), both before and after decompression surgery, alongside standard ophthalmic examinations. Our AS-OCTA analysis revealed a significant decrease in most of the temporal vasculature measurements six weeks post-surgery (p < 0.05). However, differences in the nasal region were not statistically significant. These findings indicate notable changes in ocular surface circulation following orbital decompression in TED patients, which may have implications for intraocular pressure (IOP) control and ocular surface symptoms management. AS-OCTA holds promise as a tool for evaluating the effectiveness of decompression surgery and assessing the need for further interventions.