Reduced light exposure mitigates streptozotocin-induced vascular changes and gliosis in diabetic retina by an anti-inflammatory effect and increased retinal cholesterol turnover.

Diabetic retinopathy is not cured efficiently and changes of lifestyle measures may delay early retinal injury in diabetes. The aim of our study was to investigate the effects of reduced daily light exposure on retinal vascular changes in streptozotocin (STZ)-induced model of DM with emphasis on inflammation, Aqp4 expression, visual cycle and cholesterol metabolism-related gene expression in rat retina and RPE. Male Wistar rats were divided into the following groups: 1. control; 2. diabetic group (DM) treated with streptozotocin (100 mg/kg); 3. group exposed to light/dark cycle 6/18 h (6/18); 4. diabetic group exposed to light/dark cycle 6/18 h (DM+6/18). Retinal vascular abnormalities were estimated based on lectin staining, while the expression of genes involved in the visual cycle, cholesterol metabolism, and inflammation was determined by qRT-PCR. Reduced light exposure alleviated vasculopathy, gliosis and the expression of IL-1 and TNF-α in the retina with increased perivascular Aqp4 expression. The expression of genes involved in visual cycle and cholesterol metabolism was significantly up-regulated in RPE in DM+6/18 vs. DM group. In the retina only the expression of APOE was significantly higher in DM+6/18 vs. DM group. Reduced light exposure mitigates vascular changes and gliosis in DM via its anti-inflammatory effect, increased retinal cholesterol turnover and perivascular Aqp4 expression.

Hemoglobin levels are associated with retinal vascular caliber in a middle-aged birth cohort.

Vascular and neural structures of the retina can be visualized non-invasively and used to predict ocular and systemic pathologies. We set out to evaluate the association of hemoglobin (Hb) levels within the national reference interval with retinal vascular caliber, optical coherence tomography (OCT) and visual field (VF) parameters in the Northern Finland 1966 Birth Cohort (n = 2319, 42.1% male, average age 47 years). The studied parameters were evaluated in Hb quintiles and multivariable linear regression models. The lowest Hb quintile of both sexes presented the narrowest central retinal vein equivalent (CRVE) and the healthiest cardiometabolic profile compared to the other Hb quintiles. In the regression models, CRVE associated positively with Hb levels in both sexes, (Bmales = 0.068 [0.001; 0.135], Bfemales = 0.087 [0.033; 0.140]), after being adjusted for key cardiometabolic and inflammatory parameters, smoking status, and fellow vessel caliber. No statistically significant associations of Hb levels with central retinal artery equivalent, OCT or VF parameters were detected. In conclusion, Hb levels were positively and specifically associated with CRVE, indicating that Hb levels are an independent factor affecting CRVE and the effect is in parallel with established risk factors for cardiometabolic diseases.

The long-term influence of perinatal factors on macular morphology and vessel density in preterm children.

BACKGROUND: Increased survival rate of extremely preterm children is associated with a higher risk of retinopathy of prematurity (ROP) and long-term sequelae, which implicate retinal changes. PURPOSE: To assess an influence of perinatal characteristics on morphology and retinal vascularity of the macula in preterm children. METHODS: A cohort of 123 preterm children at the age of 10.5 years (IQR: 8.12-12.77) was prospectively assessed. Optical coherence tomography angiography (OCTA) was performed using RTVueXR Avanti. Foveal thickness, parafoveal thickness, size of foveal avascular zone (FAZ), superficial and deep vessel density, central choroidal thickness (CCT) were analyzed. The associations between OCTA results and perinatal factors, including the presence of ROP and therapy requirements were assessed in preterm children. RESULTS: Significantly smaller FAZ, higher foveal thickness and vessel density were noted in children with ROP, Respiratory Distress Syndrome, Bronchopulmonary Dysplasia, required erythropoietin, transfusion or steroids. Foveal thickness was increased in children with ROP (p < 0.001) and following laser treatment (p < 0.05). Thinner CCT was noted in children with a history of sepsis (p < 0.05) and ROP required treatment (p < 0.05). Pregnancy bleeding was associated with higher superficial foveal vessel density (p < 0.05) and smaller FAZ (p < 0.05). CONCLUSION: Neonatal factors have a huge impact on retinal development, but the role of prenatal factors should not be neglected in preterm children.

Optical coherence tomography angiography analysis of choroidal microvasculature in various forms of diabetic macular edema.

INTRODUCTION: Optical coherence tomography angiography (OCTA) research in diabetic macular edema (DME) has focused on the retinal microvasculature with little attention to the choroid. The goal of this study was to analyze the association between quantitative choroidal OCTA parameters and various forms of DME observed on optical coherence tomography. METHODS: We conducted a retrospective study of 61 eyes of 53 patients with DME. DME was classified as early or advanced, and as sponge-like diffuse retinal thickening (DRT), cystoid macular edema (CME) or serous retinal detachment (SRD). Quantitative OCTA parameters (vessel density [VD] in the superficial capillary plexus [SCP], middle capillary plexus [MCP], deep capillary plexus [DCP] and choriocapillaris [CC]) were recorded. RESULTS: The VD in the CC and SCP was significantly higher in patients with early DME compared to patients with advanced DME (P value<0.01). CC VD was lower in subjects with SRD compared to DRT and CME (P value<0.001). Moreover, it was lower in CME compared to DRT (P value<0.05). No statistical differences were found between VD in the MCP and DCP (P value>0.05). Furthermore, CC VD was lower in patients with increased retinal thickness, disruption of the ellipsoid zone (EZ) or external limiting membrane (ELM), and disorganization of the inner retinal layers (DRIL) (P value<0.05). CONCLUSION: CC ischemia plays an important role in the pathogenesis of DME. We demonstrated a decrease in CC VD in patients with severe DME, SRD, retinal thickening, EZ and/or ELM disruption and DRIL.

Quantitative microvascular alterations in butterfly-shaped pattern dystrophy and adult-onset foveomacular vitelliform dystrophy.

PURPOSE: To study retinal microvascular parameters in patients with butterfly-shaped pattern dystrophy (BPD) and adult foveomacular vitelliform dystrophy (AFVD). METHODS: This case-control study included BPD and AFVD patients in a tertiary university hospital. Eyes with known ocular disease and prior ocular surgery other than uncomplicated cataract surgery were excluded. Right eyes of healthy individuals without systemic or ocular disease were included as controls. En face 6×6mm angiograms were obtained with the RTVue XR Avanti (Optovue, USA). We used the Kruskal-Wallis test to compare vessel density (VD) values of the retina, optic disc and foveal avascular zone (FAZ) between groups. Dunn-Bonferroni correction was used for pairwise comparisons. RESULTS: Eighteen eyes of 10 BPD patients, 17 eyes of 9 AFVD patients, and 26 right eyes of 26 controls were included. Six patients in the BPD, 4 patients in the AFVD, and 16 patients in the control group were female. The groups did not differ by sex (P=0.650). AFVD patients were of higher mean age (64.3±7.8) than BPD patients (55.9±11.1) and controls (53.6±5.5) (P=0.008, p=0.009). In BPD (P=0.008, P=0.044) and AFVD (P=0.006, P=0.002), parafoveal and perifoveal vessel density (VD) of the superficial capillary plexus were lower than controls. Parafoveal VD of the deep capillary plexus in AFVD was lower than in controls (P=0.012). There was no difference in the foveal avascular area between groups (P=0.563). Optic discs parameters did not differ. CONCLUSION: A comparable loss in vascular density may indicate shared pathophysiology or represent a common sign of impairment in retinal homeostasis. Further research is needed to clarify underlying microvascular pathogenetic mechanisms in pattern dystrophies.

Optical coherence tomography angiography findings in optic disc drusen and idiopathic intracranial hypertension.

PURPOSE: To evaluate the changes in peripapillary microvascularity in idiopathic intracranial hypertension (IIH) and optic disc drusen (ODD) patients, by comparing them with those in healthy individuals, via optical coherence tomography angiography (OCTA). METHODS: Sixty-two eyes of 33 patients with ODD, 58 eyes of 30 patients with IIH, and 70 eyes of 70 healthy people were imaged for 6 × 6-mm optic disc scans on a spectral-domain OCTA. Vascular densities in superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) of ODD, IIH, and healthy eyes were compared with a one-way analysis of variance. Post-hoc analysis was performed with the Gabriel test. RESULTS: There was a significant decrease in peripapillary vessel density in SCP, DCP, and CC in patients with IIH compared to the control group (p < 0.05). In ODD patients, especially peripapillary vessel density in DCP was significantly reduced compared to the control group (p < 0.05). Peripapillary vessel density in DCP was significantly lower in the IIH group than ODD group (p < 0.05). CONCLUSIONS: Peripapillary vascular density may be affected during the course of the disease in both IIH and ODD. Compared to healthy individuals, the decrease in vascular density in these patients and the consequent decrease in perfusion in the peripapillary region may guide the pathogenesis of the complications in the course of these two diseases. Although vascular density in DCP and CC differs significantly between IIH and ODD, case-controlled studies are needed to evaluate the role of OCTA in the differential diagnosis of IHH and ODD.

Mouse model of radiation retinopathy reveals vascular and neuronal injury.

PURPOSE: To characterize the neuronal and vascular pathology in vivo and in vitro in a mouse model of radiation retinopathy. METHODS: C57Bl/6J mice underwent cranial irradiation with 12 Gy and in vivo imaging by optical coherence tomography and of relative blood flow velocity by laser speckle flowgraphy for up to 3-6 months after irradiation. Retinal architecture, vascular density and leakage and apoptosis were analyzed by histology and immunohistochemistry before irradiation or at 10, 30, 240, and 365 days after treatment. RESULTS: The vascular density decreased in the plexiform layers starting at 30 days after irradiation. No impairment in retinal flow velocity was seen. Subtle perivascular leakage was present at 10 days, in particular in the outer plexiform layer. This corresponded to increased width of this layer. However, no significant change in the retinal thickness was detected by OCT-B scans. At 365 days after irradiation, the nuclear density was significantly reduced compared to baseline. Apoptosis was detected at 30 days and less prominent at 365 days. CONCLUSIONS: By histology, vascular leakage at 10 days was followed by increased neuronal apoptosis and loss of neuronal and vascular density. However, in vivo imaging approaches that are commonly used in human patients did not detect pathology in mice.

Mechanical Regulation of Retinal Vascular Inflammation and Degeneration in Diabetes.

Vascular inflammation is known to cause degeneration of retinal capillaries in early diabetic retinopathy (DR), a major microvascular complication of diabetes. Past studies investigating these diabetes-induced retinal vascular abnormalities have focused primarily on the role of molecular or biochemical cues. Here we show that retinal vascular inflammation and degeneration in diabetes are also mechanically regulated by the increase in retinal vascular stiffness caused by overexpression of the collagen-cross-linking enzyme lysyl oxidase (LOX). Treatment of diabetic mice with LOX inhibitor ß-aminopropionitrile (BAPN) prevented the increase in retinal capillary stiffness, vascular intracellular adhesion molecule-1 overexpression, and leukostasis. Consistent with these anti-inflammatory effects, BAPN treatment of diabetic mice blocked the upregulation of proapoptotic caspase-3 in retinal vessels, which concomitantly reduced retinal capillary degeneration, pericyte ghost formation, and the diabetes-induced loss of contrast sensitivity in these mice. Finally, our in vitro studies indicate that retinal capillary stiffening is sufficient to increase the adhesiveness and neutrophil elastase-induced death of retinal endothelial cells. By uncovering a link between LOX-dependent capillary stiffening and the development of retinal vascular and functional defects in diabetes, these findings offer a new insight into DR pathogenesis that has important translational potential.

CHOROIDAL AND RETINAL ABNORMALITIES IN CUSHING SYNDROME: Correlation with the Cortisol Level.

PURPOSE: To investigate the structure and blood flow of the retina and choroid in Cushing syndrome and their relationship with cortisol levels. METHODS: A consecutive series of patients with Cushing syndrome with adrenocortical carcinoma were included in this study. Cortisol levels gradually returned to normal after adrenalectomy. Optical coherence tomography and optical coherence tomography angiography were used to assess patients with Cushing syndrome before and after the surgery for retina and choroid. Correlation analysis was performed between cortisol level and fundus changes. RESULTS: Compared with normal cortisol levels, patients with Cushing syndrome had significantly lower central macular thickness with increased cortisol level (220.82 ± 16.59 µ m and 223.68 ± 15.78 µ m, P = 0.019). However, the central choroidal thickness was higher with increased cortisol level (255.18 ± 105.89 µ m and 205.94 ± 87.04 µ m, P < 0.001). The choriocapillaris flow area was higher with increased cortisol level (2.05 ± 0.14 mm 2 and 2.00 ± 0.13 mm 2 , P = 0.02). The change of choriocapillaris flow area was correlated with the score of Huaxi Emotional-distress Index and 24-hour urine-free cortisol (24h-UFC). CONCLUSION: The increased cortisol level was correlated with lesser central macular thickness and thicker central choroidal thickness. The decrease of choriocapillaris flow area was correlated with 24h-UFC, indicating the effect of increased cortisol level on choroidal vessels.

FLUORESCEIN ANGIOGRAPHY EVALUATION OF CHILDREN PREVIOUSLY TREATED WITH ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR MONOTHERAPY FOR RETINOPATHY OF PREMATURITY.

PURPOSE: To determine the level of vascularization and peripheral vascular findings by fluorescence angiography in patients with aggressive retinopathy of prematurity or Type 1 retinopathy of prematurity treated with a single dose of anti-vascular endothelial growth factor. METHODS: Data of patients referred to the authors' clinic for fluorescence angiography examination between June 2016 and September 2021 were retrospectively analyzed. Patients who had their first fluorescence angiography examination at the age of 1 year or older were included in the study. RESULTS: A total of 486 eyes of 250 patients were included. Of these, 83 eyes (17.1%) had vascular termination in Zone II and 403 eyes (82.9%) in Zone III. In 62.7% of eyes, the distance from the vascular terminals to the temporal ora serrata was less than two disk diameters, and in 20.2%, it was more than two disk diameters. Abnormal vascular findings were noted, including circumferential vessels (41.2%), finger-like projection anomaly (36.2%), hyperfluorescence (16.9%), fine branching and blunt termination (15%), and arteriovenous shunt (9.9%). CONCLUSION: Fluorescence angiography performed late in the course of treatment can clearly define the vascular termini and detect abnormalities that cannot be detected by indirect ophthalmoscopy. Follow-up with fluorescence angiography can help prevent complications that can lead to vision loss.

Imaging the Retinal Vascular Mural Cells In Vivo: Elucidating the Timeline of Their Loss in Diabetic Retinopathy.

BACKGROUND: Vascular mural cells (VMCs) are integral components of the retinal vasculature with critical homeostatic functions such as maintaining the inner blood-retinal barrier and vascular tone, as well as supporting the endothelial cells. Histopathologic donor eye studies have shown widespread loss of pericytes and smooth muscle cells, the 2 main VMC types, suggesting these cells are critical to the pathogenesis of diabetic retinopathy (DR). There remain, however, critical gaps in our knowledge regarding the timeline of VMC demise in human DR. METHODS: In this study, we address this gap using adaptive optics scanning laser ophthalmoscopy to quantify retinal VMC density in eyes with no retinal disease (healthy), subjects with diabetes without diabetic retinopathy, and those with clinical DR and diabetic macular edema. We also used optical coherence tomography angiography to quantify capillary density of the superficial and deep capillary plexuses in these eyes. RESULTS: Our results indicate significant VMC loss in retinal arterioles before the appearance of classic clinical signs of DR (diabetes without diabetic retinopathy versus healthy, 5.0±2.0 versus 6.5±2.0 smooth muscle cells per 100 µm; P<0.05), while a significant reduction in capillary VMC density (5.1±2.3 in diabetic macular edema versus 14.9±6.0 pericytes per 100 µm in diabetes without diabetic retinopathy; P=0.01) and capillary density (superficial capillary plexus vessel density, 37.6±3.8 in diabetic macular edema versus 45.5±2.4 in diabetes without diabetic retinopathy; P<0.0001) is associated with more advanced stages of clinical DR, particularly diabetic macular edema. CONCLUSIONS: Our results offer a new framework for understanding the pathophysiologic course of VMC compromise in DR, which may facilitate the development and monitoring of therapeutic strategies aimed at VMC preservation and potentially the prevention of clinical DR and its associated morbidity. Imaging retinal VMCs provides an unparalleled opportunity to visualize these cells in vivo and may have wider implications in a range of diseases where these cells are disrupted.

Quantification of dilated deep capillaries in diabetic retinopathy on optical coherence tomography angiography.

Morphological changes in capillaries are one of major clinical signs in diabetic retinopathy (DR). In this study, we quantified the dilated deep capillaries on optical coherence tomography angiography (OCTA) images. Central 3 × 3 mm en face images were obtained using a swept source OCTA device in 105 eyes of 99 patients with DR. Capillaries with a greater diameter in the deep layers were defined as the dilated deep capillaries, using stepwise image processing. The relative areas of automatically selected capillaries with a great diameter were calculated as the index of the dilated deep capillaries. Most eyes with DR had string-like or dot-like dilated deep capillaries in the OCTA images, which appeared to be dilated capillary segments or microaneurysms histologically. They were distributed more densely in the parafovea than in the central sector, while there were no differences between individual quadrants. The index of the dilated deep capillaries was higher in eyes with DR than in nondiabetic eyes. The index in the central subfield was modestly associated with visual acuity, diabetic macular edema, and proliferative diabetic retinopathy. The quantitative dilated deep capillaries are designated as a biomarker of vision-threatening DR.

[Multimodal imaging features of acute macular retinopathy in patients with COVID-19].

Objective: To investigate the multimodal imaging characteristics of acute macular retinopathy (AMR) and/or parafoveal acute middle maculopathy (PAMM) in patients with coronavirus disease 2019 (COVID-19). Methods: It was a cross-sectional study. Eight patients (15 eyes) diagnosed with AMN and/or PAMM, who presented for their initial visit at Kaifeng Eye Hospital between December 17 and December 31, 2022 and were also confirmed positive for COVID-19, were enrolled as the observation group. The patients were classified into four types based on swept-source optical coherence tomography (SS-OCT) findings. Fifteen healthy volunteers (15 eyes) without ocular or systemic diseases were recruited as the healthy control group, and one eye was randomly selected for analysis. All participants underwent detailed ophthalmic examinations, including best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, fundus photography (FP), intraocular pressure measurement, fundus infrared imaging, OCT and OCT angiography (OCTA). The foveal avascular zone (FAZ) area of the macular center was measured. General information and multimodal imaging findings were collected and analyzed. The superficial capillary plexus vessel density (SCP-VD) and deep capillary plexus vessel density (DCP-VD) were measured in circular areas with diameters of 1.0 mm, >1.0 mm and ≤3.0 mm, and>3.0 mm and ≤6.0 mm centered on the foveal center, recorded as SCP-VD1.0, 3.0, 6.0 and DCP-VD1.0, 3.0, 6.0. Statistical analyses were performed using t-tests, Mann-Whitney U tests, and chi-square tests. Results: The observation group consisted of 6 males (11 eyes) and 2 females (4 eyes) with a mean age of (26.87±11.56) years. The healthy control group included 11 males (11 eyes) and 4 females (4 eyes) with a mean age of (28.75±12.30) years. There were no statistically significant differences in age and gender distribution between the two groups (all P>0.05). All patients in the observation group experienced high fever (≥39.0 ℃) and developed ocular symptoms during the febrile period or within 24 hours after fever resolution. Among all patients, there were 5 cases (7 eyes) of Type Ⅰ, 1 case (1 eye) of Type Ⅱ, 3 cases (4 eyes) of Type Ⅲ, and 2 cases (3 eyes) of Type Ⅳ. In Type Ⅲ and Ⅳ, 3 cases (4 eyes) exhibited weakly reflective cystic spaces in the outer plexiform or outer nuclear layers, and fundus photography revealed multiple gray or reddish-brown lesions in the macular region. One case (1 eye) showed retinal superficial hemorrhage. Cotton wool spots were observed in 2 cases (4 eyes). Fundus infrared imaging showed that Type Ⅰ manifested as weak reflectivity lesions in the parafoveal central zone, with the tip pointing towards the fovea. Type Ⅱ showed no apparent abnormalities in the macular region, while Type Ⅲ and Ⅳ displayed map-like weak reflective lesions spanning the foveal center. OCTA findings demonstrated that SCP-VD1.0 in the observation group was 6.93% (4.77%, 6.93%), significantly lower than the healthy control group's 10.66% (8.05%, 10.55%) (U=174.00, P=0.016). SCP-VD3.0 in the observation group was 37.14% (32.15%, 43.48%), also lower than the healthy control group's 43.06% (38.95%, 46.55%) (U=174.00, P=0.016). DCP-VD3.0 in the observation group was 48.20% (46.11%, 50.33%), lower than the healthy control group's 51.10% (50.04%, 53.02%) (U=188.00, P=0.009). DCP-VD6.0 in the observation group was 49.27% (47.26%, 51.67%), lower than the healthy control group's 52.43% (50.07%, 53.82%) (U=70.00, P=0.004). There were no significant differences in SCP-VD6.0 and DCP-VD1.0 between the two groups (both P>0.05). Conclusions: Acute macular retinopathy in patients with COVID-19 can involve all retinal layers and present as segmental hyper-reflectivity on SS-OCT. Fundus infrared imaging reveals weak reflectivity in the affected area, fundus photography shows multiple gray or reddish-brown lesions in the macular region, and OCTA demonstrates a decrease in SCP-VD and DCP-VD.

Optical coherence tomography angiography in diabetic retinopathy.

There remain many unanswered questions on how to assess and treat the pathology and complications that arise from diabetic retinopathy (DR). Optical coherence tomography angiography (OCTA) is a novel and non-invasive three-dimensional imaging method that can visualize capillaries in all retinal layers. Numerous studies have confirmed that OCTA can identify early evidence of microvascular changes and provide quantitative assessment of the extent of diseases such as DR and its complications. A number of informative OCTA metrics could be used to assess DR in clinical trials, including measurements of the foveal avascular zone (FAZ; area, acircularity, 3D para-FAZ vessel density), vessel density, extrafoveal avascular zones, and neovascularization. Assessing patients with DR using a full-retinal slab OCTA image can limit segmentation errors and confounding factors such as those related to center-involved diabetic macular edema. Given emerging data suggesting the importance of the peripheral retinal vasculature in assessing and predicting DR progression, wide-field OCTA imaging should also be used. Finally, the use of automated methods and algorithms for OCTA image analysis, such as those that can distinguish between areas of true and false signals, reconstruct images, and produce quantitative metrics, such as FAZ area, will greatly improve the efficiency and standardization of results between studies. Most importantly, clinical trial protocols should account for the relatively high frequency of poor-quality data related to sub-optimal imaging conditions in DR and should incorporate time for assessing OCTA image quality and re-imaging patients where necessary.

EVALUATION OF PARAVASCULAR INNER RETINAL DEFECTS USING EN FACE OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To evaluate the prevalence and risk factors for development of paravascular inner retinal defects (PIRDs) using en face optical coherence tomography. METHODS: This is a retrospective cross-sectional study. En face and cross-sectional optical coherence tomography images were reviewed (9 × 9 mm or 12 × 12 mm). Paravascular inner retinal defects were classified as either Grade 1 (i.e., paravascular inner retinal cysts) when the lesion was confined within the nerve fiber layer without any communication to the vitreous cavity or Grade 2 (i.e., paravascular lamellar hole) when the defects communicated to the vitreous. Paravascular inner retinal defect grading was correlated with presence of high myopia, stage of posterior vitreous detachment, and presence of epiretinal membrane and retinoschisis. RESULTS: Of 1,074 patients (2,148 eyes), PIRDs were detected in 261 eyes with a prevalence of 261 per 2,148 eyes (12.2%) and 176 per 1,074 patients (16.4%). A total of 116 eyes (44.4%) displayed Grade 2 PIRDs while 145 eyes (55.6%) were Grade 1. In the multivariate logistic regression model, the presence of partial/complete posterior vitreous detachment, retinoschisis, and epiretinal membrane was significantly correlated with PIRDs (OR = 2.78 [1.7-4.4], P < 0.001; OR = 2.93 [1.7-5], P < 0.001; and OR = 25.9 [2.8-242.5], P < 0.001, respectively). The presence of partial/complete posterior vitreous detachment and epiretinal membrane was also significantly associated with Grade 2 PIRDs versus Grade 1 PIRDs ( P = 0.03 and P < 0.001). CONCLUSION: Our results indicate that wide-field en face optical coherence tomography facilitates the identification of PIRDs over a large area of retina with a single capture. The presence of PIRDs was significantly associated with posterior vitreous detachment, epiretinal membrane, and retinoschisis, confirming the role of vitreoretinal traction in the pathogenesis of PIRDs.

SEVERE RETINAL ISCHEMIA IN INFANT WITH NEUROFIBROMATOSIS TYPE 1.

PURPOSE: To report a case of severe retinal ischemia in an infant with neurofibromatosis type 1. METHODS: Chart review, analysis of imaging studies, and review of literature. RESULTS: A boy born at 37 weeks postmenstrual age with neurofibromatosis type 1 was noted to have a large plexiform neurofibroma with left-sided involvement of the cavernous sinus, internal carotid artery, orbit, and optic nerve. He was managed for left eye glaucoma with anti-hypertensive eye drops, and at 8 months of age, he was referred for retinal evaluation. Fluorescein angiography showed striking nonperfusion of the left retina with only a small area of perfused vessels in the posterior pole. A large frond of neovascularization extended anteriorly from the posterior pole. The right eye had a crescent of retinal nonperfusion in the far periphery but otherwise normal retinal vessels. CONCLUSION: This case demonstrates a severe form of retinal ischemia in the setting of a large neurofibroma because of neurofibromatosis type 1. We hypothesize that vascular compression from the tumor led to disruption of the neurovascular bundle with resultant severe nonperfusion, neovascularization, and retinal maldevelopment.

Comparison of Diabetic Retinopathy Lesions Identified Using Ultrawide Field Imaging and Optical Coherence Tomography Angiography.

INTRODUCTION: Optical coherence tomography (OCT) angiography (OCTA) has the potential to influence the diagnosis and management of diabetic eye disease. This study aims to determine the correlation between diabetic retinopathy (DR) findings on ultrawide field (UWF) color photography (UWF-CP), UWF fluorescein angiography (UWF-FA), and OCTA. METHODS: This is a cross-sectional, prospective study. One hundred and fourteen eyes from 57 patients with diabetes underwent mydriatic UWF-CP, UWF-FA, and OCTA. DR severity was assessed. Ischemic areas were identified on UWF-FA using ImageJ and the nonperfusion index (NPI) was calculated. Diabetic macular edema (DME) was assessed using OCT. Superficial capillary plexus vessel density (VD), vessel perfusion (VP), and foveal avascular zone (FAZ) area were automatically measured on OCTA. Pearson correlation coefficient between the imaging modalities was determined. RESULTS: Forty-five eyes were excluded due to non-DR findings or prior laser photocoagulation; 69 eyes were analyzed. DR severity was associated with larger NPI (r = 0.55944, p < 0.0001) even after distinguishing between cones (Cone Nonperfusion Index [CPI]: r = 0.55617, p < 0.0001) and rods (Rod Nonperfusion Index [RPI]: r = 0.55285, p < 0.0001). In eyes with nonproliferative DR (NPDR), NPI is correlated with DME (r = 0.51156, p = 0.0017) and central subfield thickness (CST) (r = 0.67496, p < 0.0001). UWF-FA macular nonperfusion correlated with NPI (r = 0.42899, p = 0.0101), CPI (r = 0.50028, p = 0.0022), and RPI (r = 0.49027, p = 0.0028). Central VD and VP correlated with the DME presence (r = 0.52456, p < 0.0001; r = 0.51952, p < 0.0001) and CST (r = 0.50133, p < 0.0001; r = 0.48731, p < 0.0001). Central VD and VP were correlated with macular nonperfusion (r = 0.44503, p = 0.0065; r = 0.44239, p = 0.0069) in eyes with NPDR. Larger FAZ was correlated with decreased central VD (r = -0.60089, p = 0.0001) and decreased central VP (r = -0.59224, p = 0.0001). CONCLUSION: UWF-CP, UWF-FA, and OCTA findings provide relevant clinical information on diabetic eyes. Nonperfusion on UWF-FA is correlated with DR severity and DME. OCTA metrics of the superficial capillary plexus correlate with the incidence of DME and macular ischemia.

A pilot study of diabetic retinopathy in a porcine model of maturity onset diabetes of the young type 3 (MODY3).

Diabetic retinopathy (DR) is a leading cause of blindness in the working population. Because novel therapeutic intervention require testing, there is an urgent need for reliable animal models that faithfully replicate DR. Pig eyes have many similarities to human eyes anatomically and physiologically. Thus, attempts have been made to establish porcine models of DR by surgical, pharmaceutical or genetical induction of insulin deficiency, and dietary intervention. A previous study reported a transgenic pig model of maturity onset diabetes of the young type 3 (MODY3) developed signs of severe DR such as hemorrhage and proliferative tissue at the surface of the retina. However, the course of development of DR has not been studied in detail in this model. The purpose of this study was to investigate the early phase of DR in a MODY3. MODY3 and wild-type (WT) pigs underwent fundus photography and fluorescein angiogram (FA) before they developed cataracts. Animals were euthanized at age 1, 4, 7, and 10 months. Whole-mount retina and 10-µm thick paraffinized sections were stained with isolectin B4, and vessel density was determined by MATLAB software. At 4 and 7 months, retinal arterioles were immediately cannulated, and vasomotor action was measured by incubation with bradykinin and sodium nitroprusside. In the MODY3 pigs, fasting blood sugar levels gradually increased up to 500 mg/dL. Vascular tortuosity and yellowish spindle-shaped lesions were confirmed in MODY3 pigs at the age of 7 months; however, no microaneurysms were detected on FA. Compared with age-matched WT pigs, MODY3 pigs showed a significant decrease in blood vessel density in the intermediate and deep vascular plexus at 4 and 7 months of age and a slight decrease in capillary density in the superficial vascular plexus at 7 months of age. In MODY3 pigs, electron microscopy revealed thickening of the capillary basement membrane and leukostasis in the major blood vessels at 10 months of age. Bradykinin-induced dilation of retinal arterioles was diminished in MODY3 pigs as early as 7 months of age. Within 1 year after birth, MODY3 pigs show all typical early vascular lesions of diabetes except for microaneurysm formation. This pilot study suggests that the MODY3 pigs may serve as a suitable DR model to test effects of newly developed compounds on DR.

Assessment of microvascular involvement in lupus nephritis patients by retinal OCT-angiography and kidney biopsies.

OBJECTIVES: Ocular and renal microvascular damage in lupus nephritis (LN) share similar physiopathological pathways that have investigated using traditional fundus examination and high-resolution colour electroretinography. Optical coherence tomography angiography (OCTA) is a recent, non-invasive technique for imaging the microvasculature of retina and choroid. Aim of the study was to investigate through OCTA analysis the relationship between retinal microvascular alterations and renal functional and histologic features. METHODS: Systemic lupus erythematosus (SLE) patients with LN, SLE without renal involvement and healthy controls were recruited and accomplished an ophthalmological evaluation, including OCTA. SLE-LN patients underwent a rheumatological evaluation, including disease-related clinical and laboratory features collection and kidney biopsy examination. RESULTS: This cross-sectional study enrolled forty-six eyes of 23 LN patients, thirty-two eyes of 16 SLE patients and forty-two eyes of 21 controls. Thirteen SLE-LN patients (56.5%) displayed lupus retinopathy, 10 at moderate (77%) and 3 at severe stage (23%) by fundus oculi examination. Analysis of OCTA data showed with high/moderate accuracy a reduction of retinal capillary vessel density in both SLE and SLE-LN patients compared to controls in superficial and deep plexi. A reduction in fovea thickness and an increase in foveal avascular zone were also detected. OCTA data of LN patients correlated with LN duration, disease activity, kidney function and the presence of LN-vascular lesions at kidney biopsy. CONCLUSIONS: Our results suggest the role of OCTA in early detection of systemic vascular involvement in SLE-LN patients and related kidney functional-histological impairment.

Paracentral Acute Middle Maculopathy in A Young Girl Treated with Interferon-Beta for Nasopharyngeal Carcinoma.

PURPOSE: To describe a case of interferon-beta retinopathy associated with paracentral acute middle maculopathy. CASE REPORT: A 15-year-old girl with Epstein-Barr virus-positive advanced nasopharyngeal carcinoma WAS REFERRED with reduced visual acuity. Multimodal imaging findings, including optical coherence tomography angiography, at presentation and evolution following cessation of interferon therapy are presented. CONCLUSION: The presentation of paracentral acute middle maculopathy in this patient supports the presumed ischaemic pathogenesis in interferon retinopathy. The imaging findings provide evidence of deep capillary plexus involvement in interferon retinopathy with evolution to permanent structural damage within the inner nuclear layer.