Longitudinal evaluation of morphological, functional and vascular alterations in a rat model of experimental glaucoma.

Glaucoma, the leading cause of irreversible blindness worldwide, is a neurodegenerative disease characterized by chronic axonal damages and progressive loss of retinal ganglion cells, with increased intraocular pressure (IOP) as the primary risk factor. While current treatments focus solely on reducing IOP, understanding glaucoma through experimental models is essential for developing new therapeutic strategies and biomarkers for early diagnosis. Our research group developed an ocular hypertension rat model based on limbal plexus cautery, which provides significant glaucomatous neurodegeneration up to four weeks after injury. We evaluated long-term morphological, functional, and vascular alterations in this model. Our results showed that transient ocular hypertension, lasting approximately one week, can lead to progressive increase in optic nerve cupping and retinal ganglion cells loss. Remarkably, the pressure insult caused several vascular changes, such as arteriolar and venular thinning, and permanent choroidal vascular swelling. This study provides evidence of the longitudinal effects of a pressure insult on retinal structure and function using clinical modalities and techniques. The multifactorial changes reported in this model resemble the complex retinal ganglion cell degeneration found in glaucoma patients, and therefore may also provide a unique tool for the development of novel interventions to either halt or slow down disease progression.

Macular perfusion changes in people administered two types of COVID-19 vaccines: optical coherence tomography angiography study.

PURPOSE: To evaluate macular chorioretinal flow changes on optical coherence tomography angiography, in participants who received inactivated and messenger RNA (mRNA) vaccines to prevent Coronavirus disease 2019 (COVID-19). METHODS: In this prospective cohort study, healthy participants who received two doses of an inactivated COVID-19 vaccine (CoronaVac) and then one dose of an mRNA vaccine (BNT162b2) were examined before and after each vaccination. Ophthalmologic examination and imaging with optical coherence tomography angiography were performed during each visit. We evaluated vascular densities in the superficial and deep capillary plexuses in foveal, parafoveal, and perifoveal areas; the foveal avascular zone; and choriocapillaris flows (in 1- and 6-mm-diameter areas). RESULTS: One eye in each of the 24 participants was assessed. Superficial capillary plexus vascular densities in the parafoveal area were significantly lower after the second dose of the CoronaVac vaccine than after the first dose. In the deep capillary plexus, vascular attenuation was observed only in the parafoveal region after the first CoronaVac dose. However, in all regions, the deep capillary plexus vascular densities and subfoveal choriocapillaris flow were significantly decreased after the second CoronaVac dose. After the BNT162b2 dose, the superficial capillary plexus vascular densities, the deep capillary plexus vascular densities, and subfoveal choriocapillaris flow of most regions were significantly lower than those before vaccinations. CONCLUSION: Vascular attenuation, observed particularly after the second dose of the CoronaVac vaccine, may explain the pathogenesis of postvaccine ocular ischemic disorders reported in the literature. However, these disorders are extremely rare, and the incidence of thrombotic events caused by COVID-19 itself is higher.

Optic nerve head vascular variations in pseudoexfoliative and primary open-angle glaucoma.

PURPOSE: The purpose of this study was to assess the optic nerve head microvascular changes in pseudoexfoliative and primary open-angle glaucoma and define the relationship between vessel density and retinal nerve fiber layer thickness. METHODS: This observational cross-sectional study assessed 72 eyes with primary open-angle glaucoma, 41 eyes with pseudoexfoliative glaucoma, and 60 healthy eyes. On the basis of optic nerve head-centered, 4.5 mm × 4.5 mm scan size images, we evaluated the vessel density, as well as the peripapillary sector, inside disk, and all sectoral quadrants. RESULTS: Both glaucoma Groups had lower vessel density in all regions compared with the healthy Group (p<0.05 for all variables). Vessel densities of the nasal inferior, inferior nasal, and inferior temporal sectors in both glaucoma Groups showed similar results (p=0.157, p=0.128, p=0.143, respectively). Eyes with pseudoexfoliative glaucoma had significantly lower vessel densities than eyes with primary open-angle glaucoma in all other regions (p<0.05 for all variables). For both glaucoma Groups, the average retinal nerve fiber layer thickness positively correlated with vessel density in all peripapillary sectors (p<0.05 for all variables). CONCLUSIONS: Reduction in vessel density correlated with the thinning of retinal nerve fiber layer in both glaucoma Groups. Decreased vessel density in the optic nerve head can be used to demonstrate the microvascular pathologies and possible ischemic changes that lead to faster progression and worse prognosis in pseudoexfoliative glaucoma.

Superior ophthalmic vein and cavernous sinus thrombosis associated with COVID-19: a case report / Trombose de veia oftálmica superior e seio cavernoso associada à COVID-19: relato de caso

ABSTRACT Cavernous sinus and superior ophthalmic vein thrombosis is a rare clinical condition, and little described in the literature. The clinical presentation is nonspecific and highly variable, and symptoms may include red eye, ophthalmoplegia, coma, and death. The main etiology results from infection of the paranasal sinuses. The final diagnosis must be made through imaging tests such as magnetic resonance imaging. We describe a case of cavernous sinus and superior ophthalmic vein thrombosis after COVID-19 infection in a 64-year-old patient with persistent ocular hyperemia and pain on eye movement. Ophthalmological examination showed preserved visual acuity, conjunctival hyperemia, dilation of episcleral vessels and retinal vascular tortuosity in the right eye. Magnetic resonance imaging confirmed the diagnosis. The association with the COVID-19 was raised, excluding other infectious causes. Enoxaparin and Warfarin were started with significant improvement in the ocular clinical presentation and maintenance of initial visual acuity after 12 months of follow-up.

RESUMO A trombose de seio cavernoso e veia oftálmica superior é uma condição clínica rara e pouco descrita na literatura. A apresentação clínica é inespecífica e altamente variável. Os sintomas podem incluir olho vermelho, oftalmoplegia, coma e morte. A etiologia principal resulta da infecção dos seios paranasais. O diagnóstico final deve ser efetuado por meio de exames de imagem, como ressonância magnética. Descrevemos um caso de trombose de seio cavernoso e veia oftálmica superior após COVID-19 em paciente de 64 anos e com quadro de hiperemia ocular persistente e dor à movimentação ocular. Ao exame oftalmológico, observou-se acuidade visual preservada, hiperemia conjuntival, dilatação de vasos episclerais e tortuosidade vascular retiniana em olho direito. A ressonância confirmou o diagnóstico. A associação com a COVID-19 foi levantada, excluindo-se demais causas infecciosas. Prescrevemos enoxaparina e varfarina, com melhora do quadro clínico ocular e manutenção da acuidade visual inicial após 12 meses de acompanhamento.

Comparison of radial peripapillary capillary density results of individuals with and without Helicobacter pylori infection.

PURPOSE: To evaluate the radial peripapillary capillary density using optical coherence tomography angiography in patients with and without Helicobacter pylori infection. METHODS: This prospective, cross-sectional study comprised 52 patients (52 eyes: Group 1) and 38 patients (38 eyes: Group 2) with and without H. pylori infections, respectively. The radial peripapillary capillary density and retinal nerve fiber layer thickness in 4 equal quadrants and 2 equal hemispheres in the peripapillary region were calculated using optical coherence tomography angiography. The optic nerve head parameters of the patients were also assessed. RESULTS: The groups were similar in terms of age, gender, and the optic nerve head parameters. The radial peripapillary capillary densities in the superior hemisphere and quadrant were significantly lower in Group 1 than in Group 2 (p=0.039 and p=0.028, respectively) and were positively correlated with the superior hemisphere's retinal nerve fiber layer thickness (p<0.001 and p<0.001, respectively). Similarly, the radial peripapillary capillary densities in the inferior hemisphere and quadrant were also significantly lower in Group 1 compared to Group 2 (p=0.03 and p=0.017, respectively) and were positively correlated with the inferior hemisphere's retinal nerve fiber layer thickness (p<0.001 and p<0.001, respectively). The retinal nerve fiber layer thickness in the nasal and temporal quadrants were significantly decreased in Group 1 when compared to Group 2 (p=0.013 and p=0.022) and were positively correlated with the corresponding radial peripapillary capillary densities of the 2 quadrants (p=0.002 and p=0.022). CONCLUSION: The decreased radial peripapillary capillary density in the H. pylori-positive patients suggests that H. pylori may play a role in the etiopathogenesis of glaucoma.

Paracentral acute middle maculopathy in Susac syndrome after dual exposure to SARS-CoV-2 antigen.

We report a case of Susac syndrome after SARS-CoV-2 infection and subsequent vaccination that presented with meningitis and retinal microembolisation in the form of paracentral acute middle maculopathy (PAMM). After presenting with headache, fever and myalgia followed by scotomata, a woman in her 50s was hospitalised for meningitis; she had had mild COVID-19 infection 2 months prior to admission, having received the first vaccine dose 1 month prior to the neurological manifestation. Eye fundus examination and optical coherence tomography were suggestive of PAMM. D-dimer levels and erythrocyte sedimentation rate were elevated. Before infectious investigation results were available, she was started on empirical antibiotic and antiviral treatment. Having ruled out infectious causes, she was started on high-dose prednisolone. After 1 month, there was partial resolution of retinal lesions. This case highlights that exposure to SARS-CoV-2 antigen may be related to this rare syndrome; treatment with steroids may improve central and retinal impairment.

Fractal evaluation in retinographies of individuals with different grades of diabetic retinopathy / Avaliação fractal de retinografias de indivíduos com diferentes graus de retinopatia diabética

ABSTRACT Purpose To evaluate the retinal blood vascular network of the retinographies of patients with different grades of diabetic retinopathy. Methods Ninety Retinographies (MESSIDOR database) were used, with different grades of diabetic retinopathy divided into 4 groups: no retinopathy (n=23), grade one (n=20), grade two (n=20) and grade three (n=27) diabetic retinopathy. The grades of diabetic retinopathy were classified according to the number of microaneurysms, number of hemorrhages and the presence of neovascularization. The images were skeletonized and quantified by fractal methods: dimension of box-counting (Dbc) and information (Dinf). Results The means of Dbc values of groups were around 1.25, without statistically significant difference in the dimension values between groups for whole retina. There was also no statistical difference in Dinf values between groups, whose means ranged between 1.294 ± 0.013 (group of grade 1) and 1.3 ± 0.017 (group of grade 3). The retinographies were divided into regions of equal areas. The fractal values of some retinal regions showed statistical differences, but these differences were not enough to show the sensitivity of fractal methods in identifying diabetic retinopathy. Conclusion The fractal methods were not able to identify the different grades of diabetic retinopathy in retinographies.

RESUMO Objetivo Avaliar a rede vascular sanguínea da retina a partir de retinografias de pacientes com diferentes graus de retinopatia diabética. Métodos Foram utilizadas 90 retinografias (banco de dados MESSIDOR), com diferentes graus de retinopatia diabética divididas em quatro grupos: sem retinopatia (n=23), retinopatia diabética de grau um (n=20), grau dois (n=20) e grau três (n=27). Os graus de retinopatia foram classificados conforme o número de microaneurismas, número de hemorragias e presença de neovascularização. As imagens foram esqueletizadas e quantificadas pelos métodos fractais: dimensão da contagem de caixas e informação. Resultados As médias dos valores das dimensões de contagem de caixas para todos os grupos foram próximas a 1,25, sem diferença estatisticamente significativa nos valores das dimensões entre os grupos para retina inteira. Também não houve diferença estatística nos valores da dimensão de informação entre os grupos, cujas médias variaram entre 1,294 ± 0,013 (grupo do grau 1) e 1,3 ± 0,017 (grupo do grau 3). As imagens retinianas foram divididas em regiões de áreas iguais. Os valores fractais de algumas regiões retinais mostraram diferenças estatísticas, mas estas não foram suficientes para mostrar a sensibilidade dos métodos fractais na identificação da retinopatia diabética. Conclusão Os métodos fractais não foram capazes de identificar os diferentes graus de retinopatia diabética em retinografias.

Quantification of retinal blood leakage in fundus fluorescein angiography in a retinal angiogenesis model.

Blood leakage from the vessels in the eye is the hallmark of many vascular eye diseases. One of the preclinical mouse models of retinal blood leakage, the very-low-density-lipoprotein receptor deficient mouse (Vldlr-/-), is used for drug screening and mechanistic studies. Vessel leakage is usually examined using Fundus fluorescein angiography (FFA). However, interpreting FFA images of the Vldlr-/- model is challenging as no automated and objective techniques exist for this model. A pipeline has been developed for quantifying leakage intensity and area including three tasks: (i) blood leakage identification, (ii) blood vessel segmentation, and (iii) image registration. Morphological operations followed by log-Gabor quadrature filters were used to identify leakage regions. In addition, a novel optic disk detection algorithm based on graph analysis was developed for registering the images at different timepoints. Blood leakage intensity and area measured by the methodology were compared to ground truth quantifications produced by two annotators. The relative difference between the quantifications from the method and those obtained from ground truth images was around 10% ± 6% for leakage intensity and 17% ± 8% for leakage region. The Pearson correlation coefficient between the method results and the ground truth was around 0.98 for leakage intensity and 0.94 for leakage region. Therefore, we presented a computational method for quantifying retinal vascular leakage and vessels using FFA in a preclinical angiogenesis model, the Vldlr-/- model.

Obstructive sleep apnea and the retina: a review.

CITATION: This review's objective was to synthesize the literature on the repercussions of obstructive sleep apnea (OSA) in the retinal vascular system. Two independent investigators conducted a search using the MEDLINE/PubMed database using the following terms: sleep apnea syndrome, obstructive sleep apnea, retina, vascular tortuosity, central serous chorioretinopathy, diabetes mellitus, and subfoveal choroidal thickness. Patients with OSA present increased vascular tortuosity compared with patients without OSA, decreased parafoveal and peripapillary vessel density, and increased retinal vein occlusion incidence. In central serous chorioretinopathy patients and patients who are poor responders to intravitreal anti-VEGF (-vascular endothelial growth factor) treatment for macular edema, OSA is more frequent. Macular choroidal thickness alterations are controversial, and OSA may worsen diabetic maculopathy, thus being a risk factor for diabetic retinopathy, proliferative diabetic retinopathy, and macular edema. OSA is a prevalent syndrome with many systemic vascular changes. The retina and choroid are the most affected ocular structures, with primarily vascular changes. New noninvasive technologies such as optical coherence tomography and optical coherence tomography angiography could help to better understand retinal structures and help clarify the ophthalmological repercussions of OSA. CITATION: Nakayama LF, Tempaku PF, Bergamo VC, et al. Obstructive sleep apnea and the retina: a review. J Clin Sleep Med. 2021;17(9):1947-1952.

Retinal ischemia as the first manifestation of antiphospholipid antibody syndrome / Isquemia retiniana como primeira manifestação da síndrome do anticorpo antifosfolipídio

ABSTRACT Antiphospholipid antibody syndrome (APS) is characterized by the development of venous and/or arterial thrombosis and by gestational morbidity (recurrent fetal losses) in the presence of antiphospholipid antibodies. We report the case of a 38-year-old woman who was diagnosed with primary APS from thromboembolic abnormalities in the retinal periphery that led to retinal ischemia. The aim of this study is to share with physicians and medical undergraduates an atypical manifestation of the syndrome that is the most common acquired thrombophilia, that should be part of the diagnostic routine of all clinical specialties.

RESUMO A síndrome do anticorpo antifosfolipídio (SAAF) caracteriza-se pelo desenvolvimento de tromboses venosas e/ou arteriais e pela morbidade gestacional (perdas fetais recorrentes) na presença de anticorpos antifosfolipídicos. Foi relatado o caso de uma paciente de 38 anos que foi diagnosticada com SAAF primária, a partir de alterações tromboembólicas na periferia da retina, que levaram à isquemia retiniana. O objetivo desse estudo é compartilhar com médicos e acadêmicos de medicina uma manifestação atípica da síndrome que é a trombofilia adquirida mais comum, devendo fazer parte da rotina diagnóstica de todas as especialidades clínicas.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FINDINGS IN ACUTE RETINAL NECROSIS.

PURPOSE: To report clinical features of acute retinal necrosis (ARN) using optical coherence tomography angiography. METHODS: A 59-year-old female patient presented with blurred vision in the left eye for 1 day. The patient presented posterior uveitis with multiple peripheral areas of retinal pallor with presumed acute retinal necrosis. Herpes simplex virus Type 1 infection was confirmed after serologic tests, and the polymerase chain reaction analysis of the aqueous humor tested positive. RESULTS: The left eye examination revealed anterior chamber reaction, mild vitritis, optic disk swelling, and yellowish white retinal lesions with discrete borders along the superotemporal arcade and temporal periphery. Baseline optical coherence tomography angiography revealed decreased vascular density of superficial and deep plexuses of superotemporal macular region. One month after oral valacyclovir 2,000 mg twice daily, visual acuity and retinal lesions improved, and optical coherence tomography angiography images showed improvement of vascular density. CONCLUSION: Occlusive arterial vasculopathy is one of the main clinical characteristics of acute retinal necrosis. We herein describe for the first time the features of retinal vasculature in acute retinal necrosis revealed by optical coherence tomography angiography, showing decreased vascular density of superficial and deep plexuses.

Retinal changes in COVID-19 hospitalized cases.

The main objective of this study was to evaluate the retinas of severely or critically ill COVID-19 patients during their hospital stay, at varying time points after symptoms onset. This was a case series observed during May 2020 in two referral centers for COVID-19 treatment in Rio de Janeiro, Brazil. 47 eyes from 25 hospitalized patients with severe or critical confirmed illness were evaluated. A handheld retinal camera was used to acquire bilateral fundus images at several time points after symptoms onset. Electronic health records were retrospectively analyzed and clinical data collected. Severe and critical diseases were noticed in 52% (13/25) and 48% (12/25) of enrolled patients, respectively. Retinal changes were present in 12% (3/25) of patients: a 35 year-old male demonstrated bilateral nerve fiber layer infarcts and microhemorrhages in the papillomacular bundle, but required mechanical ventilation and developed severe anemia and systemic hypotension, acute kidney injury and neurologic symptoms during the course of the disease (critical illness); a 56 year-old male, who required full enoxaparin anticoagulation due to particularly elevated D-dimer (>5.0 mcg/mL), demonstrated unilateral and isolated flame-shaped hemorrhages; and a 49 year-old hypertensive male showed bilateral and discrete retinal dot and blot microhemorrhages. The other 22 patients evaluated did not demonstrate convincing retinal changes upon examination. There was no correlation between disease severity and admission serum levels of CRP, D-dimer and ferritin. This was the first study to show that vascular retinal changes may be present in not insignificant numbers of severe or critical COVID-19 inpatients. These retinal changes, only seen after morbid developments, were likely secondary to clinical intercurrences or comorbidities instead of a direct damage by SARS-CoV-2, and may be important and easily accessible outcome measures of therapeutic interventions and sentinels of neurologic and systemic diseases during COVID-19 pandemic.

Epigallocatechin 3-Gallate Has a Neuroprotective Effect in Retinas of Rabbits with Ischemia/Reperfusion through the Activation of Nrf2/HO-1.

Retinal ischemia-reperfusion (rI/R) generates an oxidative condition causing the death of neuronal cells. Epigallocatechin 3-gallate (EGCG) has antioxidant and anti-inflammatory properties. Nonetheless, its correlation with the pathway of nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) for the protection of the retina is unknown. We aimed to evaluate the neuroprotective efficacy of single-doses of EGCG in rI/R and its association with Nrf2/Ho-1 expression. In albino rabbits, rI/R was induced and single-doses of EGCG in saline (0-30 mg/kg) were intravenously administered to select an optimal EGCG concentration that protects from retina damage. To reach this goal, retinal structural changes, gliosis by glial fibrillary acidic protein (GFAP) immunostaining, and lipid peroxidation level by TBARS (thiobarbituric acid reactive substance) assay were determined. EGCG in a dose of 15 mg/kg (E15) presented the lowest levels of histological damage, gliosis, and oxidative stress in the studied groups. To determine the neuroprotective efficacy of E15 in a timeline (6, 24, and 48 h after rI/R), and its association with the Nrf2/HO-1 pathway, the following assays were done by immunofluorescence: apoptosis (TUNEL assay), necrosis (high-mobility group box-1; HMGB1), Nrf2, and HO-1. In addition, the Ho-1 mRNA (qPCR) and lipid peroxidation levels were evaluated. E15 showed a protective effect during the first 6 h, compared to 24 and 48 h after rI/R, as revealed by a decrease in the levels of all damage markers. Nuclear translocation Nrf2 and HO-1 staining were increased, including Ho-1 mRNA levels. In conclusion, a single dose of E15 decreases the death of neuronal cells induced by oxidative stress during the first 6 h after rI/R. This protective effect is associated with the nuclear translocation of Nrf2 and with an elevation of Ho-1 expression.

Indocyanine green angiography for identifying telangiectatic capillaries in diabetic macular oedema.

AIMS: During diabetic macular oedema (DME), a spectrum of capillary abnormalities is commonly observed, ranging from microaneurysms to large microvascular abnormalities. Clinical evidence suggests that targeted photocoagulation of large microvascular abnormalities may be beneficial, but their detection is not done in a routine fashion. It was reported that they are better identified by indocyanine green angiography (ICGA) than by fluorescein angiography. Here, we investigated the prevalence and ICGA and optical coherence tomography (OCT) features of retinal microvascular abnormalities in a group of patients with DME. METHODS: Observational study. The fundus photographs, ICGA and structural and angiographic OCT charts of 35 eyes from 25 consecutive patients with DME were reviewed. RESULTS: 22 eyes (63%) had at least one focal area of microvascular abnormalities showing prolonged indocyanine green (ICG) staining (ie, beyond 10 mins after injection). In particular, all eyes (n=9) with circinate hard exudates showed foci of late ICG staining. These areas were either isolated globular capillary ecstasies or a cluster of ill-defined capillary abnormalities. They were located at a median distance of 2708 µm from the fovea (range: 1064-4583 µm). Their diameter ranged from 153 to 307 µm. During ICGA, 91% showed increased their contrast and apparent size in late frames, whereas 79% of microaneurysms showed reduced contrast on late frames. OCT angiography was not contributive for the detection of these lesions. CONCLUSION: Late ICG staining revealing large microvascular abnormalities is commonly observed during DME. Because of their specific angiographic and OCT features relative to microaneurysms, we propose to name them telangiectatic capillaries (TelCaps).

Optical coherence tomography angiography findings in patients with branch retinal vein occlusion treated with Anti-VEGF.

PURPOSE: To investigate retinal microvasculature changes in patients treated with anti-VEGF for macular edema secondary to branch retinal vein occlusion. METHODS: We examined 38 eyes of 19 patients for the study. We measured superficial and deep capillary plexus vessel densities (%), foveal avascular zone areas (mm2), and central macular thicknesses. RESULTS: Parafoveal superficial and deep capillary plexus values were significantly lower in eyes with branch retinal vein occlusion than in fellow eyes (p<0.001). We found a significant increase in parafoveal deep capillary plexus values after the anti-VEGF treatment (p=0.032). The mean foveal avascular zone was larger in eyes with branch retinal vein occlusion than in control eyes (p<0.001). The mean central macular thickness was significantly higher in eyes with branch retinal vein occlusion than in controls, and we observed a significant decrease in central macular thickness after anti-VEGF treatment (<0.001). In addition, the cystic structures in the deep capillary plexus regressed. CONCLUSION: Optical coherence tomography angiography enables qualitative and quantitative evaluations during follow-up of patients treated for branch retinal vein occlusion.

Projection-Resolved Optical Coherence Tomography Angiography Parameters to Determine Severity in Diabetic Retinopathy.

Purpose: The purpose of this study was to assess projection-resolved optical coherence tomography angiography (PR-OCTA) vessel density (VD) and foveal avascular zone (FAZ) in determining severity within diabetic retinopathy (DR) and their accuracy in identifying high-risk DR patients. Methods: This was a retrospective study with 72 eyes of 52 DR patients, assessing the VD and FAZ area of the superficial capillary plexus (SCP) and deep vascular plexus (DVP), for both 3 × 3-mm and 6 × 6-mm scans between the DR groups (mild to moderate, severe and proliferative DR [PDR]). For accuracy, the severe and PDR groups were merged, representing the high-risk DR group for receiver operator characteristic analysis. VD of OCTA images with and without PR were compared. Results: In mild to moderate, severe, and PDR groups, there were 31, 21, and 20 eyes, respectively. PR-OCTA improved VD analysis only in the DVP and particularly in advanced DR stages (P = 0.042). In the 3 × 3-mm PR scans, all superficial and deep parameters were significantly different between severe and PDR groups (P ≤ 0.020), but only the mean VD of SCP and DVP was also significant between the mild to moderate and severe groups (P ≤ 0.007). In the 6 × 6-mm scans, the superficial VD, deep VD, and superficial FAZ were significantly different between the severe and PDR groups (P ≤ 0.029). The superficial VD and deep VD of the 3 × 3-mm scans were good parameters for detecting high-risk patients (area under the curve = 0.829 and 0.895, respectively). Conclusions: PR-OCTA improved VD analysis of DVP. The 3 × 3-mm SCP and DVP VD were the most accurate in detecting high-risk DR.

Ginsenoside Rb1 attenuates diabetic retinopathy in streptozotocin-induced diabetic rats1.

PURPOSE: To investigated the effects of ginsenoside Rb1 on diabetic retinopathy in streptozotocin-induced diabetic rats. METHODS: Diabetes was induced by a single intraperitoneal injection of streptozotocin (80 mg/kg) in male Wistar rats. Ginsenoside Rb1 (20, 40 mg/kg) was injected (i.p.) once a day for 4 weeks. Then, using fundus photography, the diameter and vascular permeability of retinal vessels were investigated. Retinal histopathology was undertaken. Contents of malondialdehyde (MDA) and glutathione (GSH) in retinas were assayed. Levels of nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione cysteine ligase catalytic subunit (GCLC), and glutathione cysteine ligase modulatory subunit (GCLM) were measured. RESULTS: Treatment with ginsenoside Rb1 attenuated the diabetes-induced increase in the diameter of retinal blood vessels. Ginsenoside Rb1 reduced extravasation of Evans Blue dye from retinal blood vessels. Ginsenoside Rb1 partially inhibited the increase in MDA content and decrease in GSH level in rat retinas. Nrf2 levels in the nuclei of retinal cells and expression of GCLC and GCLM were increased significantly in rats treated with ginsenoside Rb1. CONCLUSION: These findings suggest that ginsenoside Rb1 can attenuate diabetic retinopathy by regulating the antioxidative function in rat retinas.

Optical coherence tomography angiography findings in malignant hypertensive retinopathy / Achados da angiografia por tomografia de coerência óptica na retinopatia hipertensiva maligna

ABSTRACT A 33-year-old male presented to our clinic with low vision in both eyes that started during the previous week. Visual acuity was 20/63 in the right eye and 20/50 in the left eye. Fundus examination revealed signs of hypertensive retinopathy; thus, a multidisciplinary approach was adopted for the diagnosis and treatment of this patient. We consulted the nephrology and cardiology departments on this case. Upon diagnosing malignant hypertension and renal failure, the patient was put on hemodialysis. His visual acuity was 20/20 at 6 months, whereas foveal assessment on optical coherence tomography angiography revealed neither marked superficial and deep capillary density loss and foveal avascular zone enlargement nor a decrease in disc flow and radial peripapillary capillary density. Early diagnosis and treatment of malignant hypertension are critical in preventing progression of end-organ damage including the eyes. Optical coherence tomography angiography may be useful in cases when fundus fluorescein angiography is relatively contraindicated (e.g., renal failure).

RESUMO Um homem de 33 anos apresentou-se à nossa clínica com baixa visão em ambos os olhos que começou uma semana antes. A acuidade visual foi de 20/63 no olho direito e 20/50 no olho esquerdo. O exame de fundo de olho revelou sinais de retinopatia hipertensiva; então, adotou-se uma abordagem multidisciplinar para o diagnóstico e tratamento desse paciente. Consultamos os departamentos de nefrologia e cardiologia neste caso. Ao diagnosticar hipertensão maligna e insuficiência renal, o paciente foi colocado em hemodiálise. Sua acuidade visual era 20/20 aos 6 meses, enquanto a avaliação foveal com angiotomografia de coerência óptica não revelou perda de densidade capilar superficial e profunda acentuada e aumento da zona avascular foveal nem uma diminuição no fluxo de disco e na densidade capilar peripapilar radial. O diagnóstico precoce e o tratamento da hipertensão maligna são fundamentais na preveção da progressão de danos nos órgãos-alvo, incluindo os olhos. A Angiografia por tomografia de coerência óptica pode ser útil nos casos em que a angiografia com fluoresceína do fundo de olho é relativamente contraindicada (por exemplo, insuficiência renal).

Optical coherence tomography angiography findings in malignant hypertensive retinopathy.

A 33-year-old male presented to our clinic with low vision in both eyes that started during the previous week. Visual acuity was 20/63 in the right eye and 20/50 in the left eye. Fundus examination revealed signs of hypertensive retinopathy; thus, a multidisciplinary approach was adopted for the diagnosis and treatment of this patient. We consulted the nephrology and cardiology departments on this case. Upon diagnosing malignant hypertension and renal failure, the patient was put on hemodialysis. His visual acuity was 20/20 at 6 months, whereas foveal assessment on optical coherence tomography angiography revealed neither marked superficial and deep capillary density loss and foveal avascular zone enlargement nor a decrease in disc flow and radial peripapillary capillary density. Early diagnosis and treatment of malignant hypertension are critical in preventing progression of end-organ damage including the eyes. Optical coherence tomography angiography may be useful in cases when fundus fluorescein angiography is relatively contraindicated (e.g., renal failure).