Evidence for Pro-angiogenic Functions of VEGF-Ax.

The VEGF-A isoforms play a crucial role in vascular development, and the VEGF signaling pathway is a clinically validated therapeutic target for several pathological conditions. Alternative mRNA splicing leads to the generation of multiple VEGF-A isoforms, including VEGF165. A recent study reported the presence of another isoform, VEGF-Ax, arising from programmed readthrough translation. Compared to VEGF165, VEGF-Ax has a 22-amino-acid extension in the COOH terminus and has been reported to function as a negative regulator of VEGF signaling in endothelial cells, with potent anti-angiogenic effects. Here, we show that, contrary to the earlier report, VEGF-Ax stimulates endothelial cell mitogenesis, angiogenesis, as well as vascular permeability. Accordingly, VEGF-Ax induces phosphorylation of key tyrosine residues in VEGFR-2. Notably, VEGF-Ax was less potent than VEGF165, consistent with its impaired binding to the VEGF co-receptor neuropilin-1.

Mild Hypoxia Accelerates Cerebral Cavernous Malformation Disease Through CX3CR1-CX3CL1 Signaling.

BACKGROUND: Heterogeneity in the severity of cerebral cavernous malformations (CCMs) disease, including brain bleedings and thrombosis that cause neurological disabilities in patients, suggests that environmental, genetic, or biological factors act as disease modifiers. Still, the underlying mechanisms are not entirely understood. Here, we report that mild hypoxia accelerates CCM disease by promoting angiogenesis, neuroinflammation, and vascular thrombosis in the brains of CCM mouse models. METHODS: We used genetic studies, RNA sequencing, spatial transcriptome, micro-computed tomography, fluorescence-activated cell sorting, multiplex immunofluorescence, coculture studies, and imaging techniques to reveal that sustained mild hypoxia via the CX3CR1-CX3CL1 (CX3C motif chemokine receptor 1/chemokine [CX3C motif] ligand 1) signaling pathway influences cell-specific neuroinflammatory interactions, contributing to heterogeneity in CCM severity. RESULTS: Histological and expression profiles of CCM neurovascular lesions (Slco1c1-iCreERT2;Pdcd10fl/fl; Pdcd10BECKO) in male and female mice found that sustained mild hypoxia (12% O2, 7 days) accelerates CCM disease. Our findings indicate that a small reduction in oxygen levels can significantly increase angiogenesis, neuroinflammation, and thrombosis in CCM disease by enhancing the interactions between endothelium, astrocytes, and immune cells. Our study indicates that the interactions between CX3CR1 and CX3CL1 are crucial in the maturation of CCM lesions and propensity to CCM immunothrombosis. In particular, this pathway regulates the recruitment and activation of microglia and other immune cells in CCM lesions, which leads to lesion growth and thrombosis. We found that human CX3CR1 variants are linked to lower lesion burden in familial CCMs, proving it is a genetic modifier in human disease and a potential marker for aggressiveness. Moreover, monoclonal blocking antibody against CX3CL1 or reducing 1 copy of the Cx3cr1 gene significantly reduces hypoxia-induced CCM immunothrombosis. CONCLUSIONS: Our study reveals that interactions between CX3CR1 and CX3CL1 can modify CCM neuropathology when lesions are accelerated by environmental hypoxia. Moreover, a hypoxic environment or hypoxia signaling caused by CCM disease influences the balance between neuroinflammation and neuroprotection mediated by CX3CR1-CX3CL1 signaling. These results establish CX3CR1 as a genetic marker for patient stratification and a potential predictor of CCM aggressiveness.

Heparin-binding VEGFR1 variants as long-acting VEGF inhibitors for treatment of intraocular neovascular disorders.

Neovascularization is a key feature of ischemic retinal diseases and the wet form of age-related macular degeneration (AMD), all leading causes of severe vision loss. Vascular endothelial growth factor (VEGF) inhibitors have transformed the treatment of these disorders. Millions of patients have been treated with these drugs worldwide. However, in real-life clinical settings, many patients do not experience the same degree of benefit observed in clinical trials, in part because they receive fewer anti-VEGF injections. Therefore, there is an urgent need to discover and identify novel long-acting VEGF inhibitors. We hypothesized that binding to heparan-sulfate proteoglycans (HSPG) in the vitreous, and possibly other ocular structures, may be a strategy to promote intraocular retention, ultimately leading to a reduced burden of intravitreal injections. We designed a series of VEGF receptor 1 variants and identified some with strong heparin-binding characteristics and ability to bind to vitreous matrix. Our data indicate that some of our variants have longer duration and greater efficacy in animal models of intraocular neovascularization than current standard of care. Our study represents a systematic attempt to exploit the functional diversity associated with heparin affinity of a VEGF receptor.

PENTOSAN POLYSULFATE SODIUM (ELMIRON) MACULOPATHY: A Genetic Perspective.

PURPOSE: To assess genetic associations for pentosan polysufate sodium maculopathy. METHODS: Genetic testing for inherited retinal dystrophy genes using exome testing and for 14 age-related macular degeneration-associated single nucleotide polymorphisms (SNPs) using panel testing were performed. In addition, full-field electroretinograms (ffERG) were obtained to identify any cone-rod dystrophy. RESULTS: Eleven of 15 patients were women, with a mean age of 69 (range 46-85). Inherited retinal dystrophy exome testing in five patients revealed six pathogenic variants, but failed to confirm inherited retinal dystrophy in any patient genetically. FfERG performed in 12 patients demonstrated only nonspecific a- and b-wave abnormalities in 11 cases and was normal in one case. For age-related macular degeneration single nucleotide polymorphisms, CFH rs3766405 ( P = 0.003) and CETP ( P = 0.027) were found to be statistically significantly associated with pentosan polysulfate maculopathy phenotype compared with the control population. CONCLUSION: Pentosan polysulfate maculopathy is not associated with Mendelian inherited retinal dystrophy genes. However, several age-related macular degeneration risk alleles were identified to be associated with maculopathy compared with their frequency in the normal population. This suggests a role for genes in disease pathology, particularly the alternative complement pathway. These findings would benefit from further investigation to understand the risk of developing maculopathy in taking pentosan polysulfate.

Barriers to Implementation of Teleretinal Diabetic Retinopathy Screening Programs Across the University of California.

Aim: To describe barriers to implementation of diabetic retinopathy (DR) teleretinal screening programs and artificial intelligence (AI) integration at the University of California (UC). Methods: Institutional representatives from UC Los Angeles, San Diego, San Francisco, Irvine, and Davis were surveyed for the year of their program's initiation, active status at the time of survey (December 2021), number of primary care clinics involved, screening image quality, types of eye providers, image interpretation turnaround time, and billing codes used. Representatives were asked to rate perceptions toward barriers to teleretinal DR screening and AI implementation using a 5-point Likert scale. Results: Four UC campuses had active DR teleretinal screening programs at the time of survey and screened between 246 and 2,123 patients at 1-6 clinics per campus. Sites reported variation between poor-quality photos (<5% to 15%) and average image interpretation time (1-5 days). Patient education, resource availability, and infrastructural support were identified as barriers to DR teleretinal screening. Cost and integration into existing technology infrastructures were identified as barriers to AI integration in DR screening. Conclusions: Despite the potential to increase access to care, there remain several barriers to widespread implementation of DR teleretinal screening. More research is needed to develop best practices to overcome these barriers.

Artificial Intelligence for Retinopathy of Prematurity: Validation of a Vascular Severity Scale against International Expert Diagnosis.

PURPOSE: To validate a vascular severity score as an appropriate output for artificial intelligence (AI) Software as a Medical Device (SaMD) for retinopathy of prematurity (ROP) through comparison with ordinal disease severity labels for stage and plus disease assigned by the International Classification of Retinopathy of Prematurity, Third Edition (ICROP3), committee. DESIGN: Validation study of an AI-based ROP vascular severity score. PARTICIPANTS: A total of 34 ROP experts from the ICROP3 committee. METHODS: Two separate datasets of 30 fundus photographs each for stage (0-5) and plus disease (plus, preplus, neither) were labeled by members of the ICROP3 committee using an open-source platform. Averaging these results produced a continuous label for plus (1-9) and stage (1-3) for each image. Experts were also asked to compare each image to each other in terms of relative severity for plus disease. Each image was also labeled with a vascular severity score from the Imaging and Informatics in ROP deep learning system, which was compared with each grader's diagnostic labels for correlation, as well as the ophthalmoscopic diagnosis of stage. MAIN OUTCOME MEASURES: Weighted kappa and Pearson correlation coefficients (CCs) were calculated between each pair of grader classification labels for stage and plus disease. The Elo algorithm was also used to convert pairwise comparisons for each expert into an ordered set of images from least to most severe. RESULTS: The mean weighted kappa and CC for all interobserver pairs for plus disease image comparison were 0.67 and 0.88, respectively. The vascular severity score was found to be highly correlated with both the average plus disease classification (CC = 0.90, P < 0.001) and the ophthalmoscopic diagnosis of stage (P < 0.001 by analysis of variance) among all experts. CONCLUSIONS: The ROP vascular severity score correlates well with the International Classification of Retinopathy of Prematurity committee member's labels for plus disease and stage, which had significant intergrader variability. Generation of a consensus for a validated scoring system for ROP SaMD can facilitate global innovation and regulatory authorization of these technologies.

Interleukin-22 promotes tumor angiogenesis.

TH17 cells play important yet complex roles in cancer development and progression. We previously reported that TH17 cells and IL-17 mediate resistance to anti-VEGF therapy by inducing recruitment of immunosuppressive and proangiogenic myeloid cells to the tumor microenvironment. Here, we demonstrate that IL-22, a key effector cytokine expressed by TH17 cells, directly acts on endothelial cells to promote tumor angiogenesis. IL-22 induces endothelial cell proliferation, survival, and chemotaxis in vitro and neovascularization in an ex vivo mouse choroid explant model. Blockade of IL-22, with a neutralizing antibody, significantly inhibits tumor growth associated with reduced microvascular density. No synergistic effect of IL-22 with VEGF was observed. These results identify IL-22 as a potential therapeutic target for blocking tumor angiogenesis.

Emerging Insights and Interventions for Diabetic Retinopathy.

PURPOSE OF REVIEW: To introduce recent advances in the understanding of diabetic retinopathy and to summarize current and emerging strategies to treat this common and complex cause of vision loss. RECENT FINDINGS: Advances in retinal imaging and functional analysis indicate that retinal vascular and neural pathologies exist long before the development of clinically visible retinopathy. Such diagnostics could facilitate risk stratification and selective early intervention in high-risk patients. Antagonists of the vascular endothelial growth factor pathway effectively reduce vision loss in diabetes and promote regression of disease severity. Promising new strategies to treat diabetic retinopathy involve novel systemic diabetes therapy and ocular therapies that antagonize angiogenic growth factor signaling, improve blood-retina barrier function and neurovascular coupling, modulate neuroretinal metabolism, or provide neuroprotection. Long considered a pure microvasculopathy, diabetic retinopathy in fact affects the neural and vascular retina as well as neurovascular communication. Emerging therapies include those that target neuroretinal dysfunction in addition to those modulating vascular biology.

COMPARISON OF 3 MM × 3 MM VERSUS 6 MM × 6 MM OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY SCAN SIZES IN THE EVALUATION OF NON-PROLIFERATIVE DIABETIC RETINOPATHY.

PURPOSE: To evaluate the utility of different optical coherence tomography angiography scan protocols in evaluating retinal changes in non-proliferative diabetic retinopathy. METHODS: Patients were imaged with the RTVue XR Avanti OCT 3 mm × 3 mm and 6 mm × 6 mm "Angio Retina" scan protocols. Ability to clearly delineate the foveal avascular zone (FAZ), FAZ remodeling, microaneurysms, capillary nonperfusion, motion, and doubling artifacts were evaluated. RESULTS: Forty-six eyes from 27 patients were enrolled. Eighty-nine percent of 3 mm × 3 mm versus 59% of 6 mm × 6 mm scans clearly delineated the FAZ (P = 0.001). Eighty percent of 3 mm × 3 mm versus 43% of 6 mm × 6 mm scans demonstrated FAZ remodeling (P = 0.0002). Microaneurysms were detected by 57% of 6 mm × 6 mm and 35% of 3 mm × 3 mm scans (P = 0.003). Capillary nonperfusion was detected in 87% of 3 mm × 3 mm scans versus 89% of 6 mm × 6 mm scans (P = 0.99). No significant differences were noted in the incidence of artifacts between the scan sizes (motion artifact P = 0.29 and doubling artifact P = 0.29). CONCLUSION: 3 mm × 3 mm scan delineated FAZ and remodeling better than 6 mm × 6 mm scan, likely because of its higher scan density. 6 mm × 6 mm scans detected microaneurysms more readily than 3 mm × 3 mm, likely because of its larger scan area. There were utility for both 3 mm × 3 mm and 6 mm × 6 mm scans when evaluating these patients.

IDENTIFICATION OF FACTORS RELATED TO SUBFOVEAL DETACHMENT SECONDARY TO EPIRETINAL MEMBRANE.

PURPOSE: To demonstrate factors related to the presence of subfoveal detachment (SD) secondary to epiretinal membrane (ERM) and to characterize the predictors for the resolution of SD after membrane peeling. METHODS: A retrospective chart review was conducted for the patients who underwent pars plana vitrectomy for the idiopathic ERM peeling. Preoperative spectral domain optical coherence tomography characteristics of the eyes including central foveal thickness, foveal center point thickness, presence of intraretinal cyst, continuity of the membrane, area of the membrane within fovea (1 mm), and entire macula (6 mm) were evaluated to find the best predictors for the presence of SD. These predictors as well as perioperative parameters including use of internal tamponade and volume of SD were considered for time of resolution of SD. RESULTS: Of 158 included eyes, 20.2% eyes (32 eyes) had SD, and the presence of SD was significantly related to involvement of the membrane within the macula. After surgery, SD completely resolved in 90.6% of eyes (29 eyes) at a median of 2.97 months (range: 0.03-12.0 months). The area of the membrane within fovea was the only significant predictor for time to resolution of SD (hazard ratio = 1.20, 95% confidence interval = 1.100-1.324, P = 0.021). A small percent of eyes showed some further changes including fluctuation (6.2%) or persistence (3.1%) of fluid. CONCLUSION: A larger extension of ERM over the macula is related to higher likelihood of the presence of SD. Time for resolution of subfoveal detachment does not seem to be affected by the preoperative and perioperative factors except the extent of membrane within 1,000 µm of the fovea.

COMPARISON OF RETINAL PATHOLOGY VISUALIZATION IN MULTISPECTRAL SCANNING LASER IMAGING.

PURPOSE: To compare retinal pathology visualization in multispectral scanning laser ophthalmoscope imaging between the Spectralis and Optos devices. METHODS: This retrospective cross-sectional study included 42 eyes from 30 patients with age-related macular degeneration (19 eyes), diabetic retinopathy (10 eyes), and epiretinal membrane (13 eyes). All patients underwent retinal imaging with a color fundus camera (broad-spectrum white light), the Spectralis HRA-2 system (3-color monochromatic lasers), and the Optos P200 system (2-color monochromatic lasers). The Optos image was cropped to a similar size as the Spectralis image. Seven masked graders marked retinal pathologies in each image within a 5 × 5 grid that included the macula. RESULTS: The average area with detected retinal pathology in all eyes was larger in the Spectralis images compared with Optos images (32.4% larger, P < 0.0001), mainly because of better visualization of epiretinal membrane and retinal hemorrhage. The average detection rate of age-related macular degeneration and diabetic retinopathy pathologies was similar across the three modalities, whereas epiretinal membrane detection rate was significantly higher in the Spectralis images. CONCLUSION: Spectralis tricolor multispectral scanning laser ophthalmoscope imaging had higher rate of pathology detection primarily because of better epiretinal membrane and retinal hemorrhage visualization compared with Optos bicolor multispectral scanning laser ophthalmoscope imaging.

RESOLUTION, DEPTH OF FIELD, AND PHYSICIAN SATISFACTION DURING DIGITALLY ASSISTED VITREORETINAL SURGERY.

PURPOSE: To evaluate depth of field, lateral resolution, and image quality of a heads-up 3D visualization system for vitreoretinal surgery using physician survey and optical measurement outcomes. METHODS: Depth of field and lateral resolution were compared between the standard ocular viewing system and the digital 3D system at ×5, ×13, and ×18 magnification by 6 retinal surgeons. Optical techniques were used as well as a survey of surgeon impression. Surgeon impression surveys were performed after 6 weeks of surgical use of the device. RESULTS: Physician questionnaire survey scores for depth of field at high magnification were better for the digital 3D system and equivalent for all other categories. Measured lateral resolution was 36.7 mm and 16.6 mm at ×5 magnification (P < 0.001), 14.3 mm and 6.4 mm at ×13 magnification (P < 0.001), and 9.8 mm and 4.2 mm (P < 0.001) at ×18 magnification for the digital 3D and oculars, respectively. Measured depth of field was 4.00 mm and 6.78 mm at ×5 magnification (P = 0.027), 0.72 mm and 0.86 mm at ×13 (P = 0.311), and 0.28 mm and 0.40 mm at ×18 magnification (P = 0.235) for the oculars and digital 3D, respectively. CONCLUSION: Lateral resolution of the digital 3D system was half that of the ocular viewing system and there was some improvement in depth of field with the digital system. Surgeon impression suggested that the digital system was superior when evaluating depth of field at high magnification.

ANATOMICAL AND FUNCTIONAL TESTING IN DIABETIC PATIENTS WITHOUT RETINOPATHY: Results of Optical Coherence Tomography Angiography and Visual Acuity Under Varying Contrast and Luminance Conditions.

PURPOSE: To assess early retinal microvascular and functional changes in diabetic patients without clinical evidence of diabetic retinopathy with optical coherence tomography angiography and central visual analyzer. METHODS: This was an observational case-control study of diabetic patients without diabetic retinopathy and nondiabetic controls. Patients underwent optical coherence tomography angiography imaging and visual acuity testing using the central visual analyzer. The foveal avascular zone area and the capillary density in the superficial and deep capillary plexuses were measured manually by a masked grader. RESULTS: Sixty eyes from 35 diabetic patients were included in the study group, and 45 eyes from 31 nondiabetic patients were included in the control group. The foveal avascular zone area was not significantly different between the diabetic group and controls (both P > 0.05). The mean capillary density in the deep capillary plexus was significantly lower in diabetic eyes compared with control eyes (P = 0.04). The mean visual acuity in all central visual analyzer modules was significantly decreased in diabetic patients compared with controls (all P < 0.05). CONCLUSION: Optical coherence tomography angiography was able to detect retinal microvascular changes in the deep capillary plexus, and the central visual analyzer showed signs of decreased visual acuity under conditions simulating suboptimal contrast and glare in diabetic patients without diabetic retinopathy.

Glaucoma after Lens-Sparing Vitrectomy for Advanced Retinopathy of Prematurity.

PURPOSE: To report the incidence of, and factors related to, glaucoma after lens-sparing vitrectomy (LSV) surgery in advanced retinopathy of prematurity (ROP). DESIGN: Retrospective case series at a single tertiary referral pediatric vitreoretinal practice. PARTICIPANTS: Four hundred and one eyes from 270 patients were included. METHODS: The medical records of patients who underwent LSV for stage 4A, 4B, and 5 ROP were retrospectively reviewed. Data were collected from patient charts including gender, gestational age at birth, birthweight, stage of ROP at presentation, prior treatment (laser or cryotherapy), subsequent retinal surgeries, presence of glaucoma, time to glaucoma (interval between LSV and the onset of glaucoma), date of lensectomy (if performed), and retinal attachment status at last visit. Lensectomy was considered as a time-dependent covariate in the analysis. MAIN OUTCOME MEASURES: Incidence of glaucoma and potential risk factors for time to glaucoma. RESULTS: Among 401 eyes with advanced ROP, 40 eyes (10.0%) had glaucoma during a mean of 3.06±4.11 years of follow-up. The incidence of glaucoma was 6.9% (17/247) in stage 4A, 12.0% (16/133) in stage 4B, and 33.3% (7/21) in stage 5 ROP. Twenty-one percent of eyes (87/401) required lensectomy at a mean of 1.23±2.19 years after LSV. In univariate analysis, having stage 5 ROP (vs. stage 4 ROP) and presence of lensectomy were found to be significantly associated with time to glaucoma (hazard ratio = 6.76, 95% confidence interval = 2.19-20.88, P = 0.001; hazard ratio = 3.06, 95% confidence interval = 1.56-6.0, P = 0.001, respectively). In multivariate analysis, lensectomy was the only significant independent factor associated with time to glaucoma (hazard ratio = 2.76, 95% confidence interval = 1.371-5.581, P = 0.004). CONCLUSIONS: Patients with more severe ROP had a higher incidence of glaucoma after lens-sparing vitrectomy. If a patient required lensectomy owing to progression of ROP and/or presence of lens opacity, then the hazard of having glaucoma significantly increased compared with those without lensectomy.

WNT7A/B promote choroidal neovascularization.

Perturbations in WNT signaling are associated with congenital eye disorders, including familial exudative vitreoretinopathy and Norrie disease. More recently, activation of the WNT pathway has also been shown to be associated with age-related macular degeneration (AMD). In this study, we identified that in choroidal neovascular membranes from AMD patients, ß-catenin is activated specifically in the vascular endothelium, suggesting that WNT promotes pathologic angiogenesis by directly affecting vascular endothelial cells. WNT7B has been shown to be important during eye development for regression of the fetal hyaloid vasculature. However, it has not yet been established whether WNT7A and/or WNT7B are involved in neovascular AMD pathogenesis. Here, we show that WNT7A and WNT7B increase the proliferation of human dermal microvascular endothelial cells in a dose-dependent manner. Both WNT7A and WNT7B also stimulated vascular sprouting from mouse choroidal explants in vitro. To evaluate in vivo relevance, we generated mice systemically deficient in Wnt7a and/or Wnt7b. Genetic deletion of both Wnt7a and Wnt7b decreased the severity of laser injury-induced choroidal neovascularization (CNV), while individual deletion of either Wnt7a or Wnt7b did not have a significant effect on CNV, suggesting that WNT7A and WNT7B have redundant pro-angiogenic roles in vivo. Cumulatively, these findings identify specific WNT isoforms that may play a pathologic role in CNV as observed in patients with neovascular AMD. Although the source of increased WNT7A and/or WNT7B in CNV requires further investigation, WNT signaling may be a potential target for therapeutic intervention if these results are demonstrated to be relevant in human disease.

Sutureless transscleral fixation of secondary intraocular lenses.

PURPOSE OF REVIEW: The surgical approach to eyes needing a secondary intraocular lens have evolved rapidly in recent years. Here, we will focus on techniques for scleral-fixation of intraocular lenses (IOLs), and will review the evidence for their safety and efficacy. RECENT FINDINGS: Transscleral fixation of IOLs refers the placement of lens haptics within scleral tunnels to stabilize the lens in eyes that lack adequate capsular support. Various surgical techniques have been reported recently to accomplish this goal. These include the use of a trocar, microvitreoretinal blade, or hypodermic needle to create the scleral tunnels, as well as several methods for placing the haptics through the tunnels. Although long-term data is lacking, each technique has been shown to have good visual outcomes without significant side effects. SUMMARY: Surgical approaches for the transscleral fixation of secondary IOLs provide a safe and effective technique for the management of eyes with insufficient capsular support.

Terson Syndrome Before Induction Chemotherapy for Acute Lymphoblastic Leukemia.

A previously healthy 2-year-old female infant presented with pancytopenia and was diagnosed with acute lymphoblastic leukemia. Before the initiation of treatment, she developed symptoms concerning for increased intracranial pressure. Head imaging revealed left parietal hemorrhage, in addition to a right vitreous hemorrhage, which was confirmed on ophthalmology examination later. Terson syndrome, in which intraocular hemorrhage is associated with intracranial hemorrhage, is more commonly reported in adults, although ocular manifestations of leukemia have been reported at presentation and are typically asymptomatic.

Animal Models of Proliferative Vitreoretinopathy and Their Use in Pharmaceutical Investigations.

Animal models are indispensable for pharmaceutical investigations. However, investigators often have difficulty choosing the appropriate modal for their research. To provide a comprehensive and convenient source of information about animal models of proliferative vitreoretinopathy (PVR), the current review sorted and analyzed representative animal models for pharmacotherapy of PVR since 1976.

REPRODUCIBILITY OF VESSEL DENSITY MEASUREMENT WITH OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN EYES WITH AND WITHOUT RETINOPATHY.

PURPOSE: To determine the intravisit and intervisit reproducibility of optical coherence tomography angiography measurements of macular vessel density in eyes with and without retinal diseases. METHODS: Fifteen healthy volunteers and 22 patients with retinal diseases underwent repeated optical coherence tomography angiography (Angiovue Imaging System, Optovue Inc) scans after pupil dilation on 2 separate visit days. For each visit day, the eyes were scanned twice. Vessel density defined as the proportion of vessel area with flowing blood over the total measurement area was calculated using Angiovue software. Intravisit and intervisit reproducibility were summarized as coefficient of variations and intraclass correlation coefficients were calculated from variance component models. RESULTS: The coefficient of variations representing the intravisit reproducibility of the superficial macular vessel density measurements for different quadrants on 3 mm × 3-mm scans varied from 2.1% to 4.9% and 3.4% to 6.8% for healthy and diseased eyes, respectively, and for the intervisit it was 2.9% to 5.1% and 4.0% to 6.8%, respectively. The coefficient of variations were lower in healthy eyes than in diseased eyes, lower for intravisit than for intervisit, lower on 3 mm × 3-mm scans than on 6 mm × 6-mm scans, and lower for paracentral subfields than for central subfield. CONCLUSION: The evidence presented here demonstrates good reproducibility of optical coherence tomography angiography for measurement of superficial macula vessel density in both healthy eyes and eyes with diabetic retinopathy without diabetic macular edema.