Retinal Signs Research Articles

Swept-source optical coherence tomography early findings in patients with carotid artery disease.

Ocular ischemic syndrome can be the first and only hint of life-threatening carotid artery disease. The early recognition of carotid stenosis-related retinal signs, as well as the comprehension of the pathophysiology behind retinal changes could become relevant for physicians to predict the risk of stroke. The aim of this study is to assess the carotid artery disease-induced early structural retinochoroidal changes by means of swept-source optical coherence tomography (SS-OCT). A prospective observational study was conducted in 72 eyes with carotid stenosis. According to the degree of stenosis, the participants were divided into a normal group (34 eyes), a mild-moderate stenosis group (22 eyes), a severe stenosis group (16 eyes). SS-OCT and OCTA were performed to scan macular fovea. Central macular thickness (CMT), subfoveal choroidal thickness (SCT) and foveal avascular zona (FAZ) area were the major measurements for our study. CMT was significantly thicker in group 3 when compared to group 2 and 1. SCT was significantly thinner in group 3 vs group 1, being thicker in group 2 when compared to group 1. No significant differences were obtained when comparing FAZ in the superficial and middle capillary plexus although it was significant when comparing the FAZ in the deep capillary plexus between group 1 and 3. internal carotid artery stenosis greater than 70% leads to a significant increase in CMT and a decrease in SCT prior the development of clinical findings of ocular ischemia syndrome.

Assessment of retinal atrophy in mixed breed dogs using spectral domain optical coherence tomography (SD-OCT) and electroretinography.

The aim of the study was to characterize retinal atrophy (RA) with progressive retinal atrophy symptoms in mixed breed dogs using ophthalmoscopy, spectral domain optical coherence tomography (SD-OCT) and electroretinography (ERG).The study was performed on 13 mixed breed dogs affected by retinal atrophy (11 males and 2 females that were 1.5-14 years old). Depending on the advancement of RA, SD-OCT examinations identified retinal abnormalities ranging from layer disorganisation to advanced atrophy. The most advanced RA occurred ventral to the optic disc. Total retinal thickness in both eyes (mean ± SD) was lower in dogs with RA compared to controls dorsally (77.7 ± 39.5 μm vs 173.5 ± 13.3 μm), ventrally (33.4 ± 29.9 μm vs 139.5 ± 10.8 μm), nasally (65.0 ± 34.5 μm vs 163.9 ± 11.0 μm) and temporally (61.8 ± 41.7 μm vs 171.9 ± 11.1 μm) to the optic disc. In dogs with locally normal architecture of inner retina, loss of definition of outer retinal layers occurred in many regions. Dark and light-adapted ERGs were reduced in 2 dogs with RA and were unrecordable in 11 dogs. Lesions evident in SD-OCT scans of mixed breed dogs affected with retinal atrophy initially appear ventrally to the optic disc and ventro-dorsally in advanced RA. In all mixed breed dogs with retinal atrophy, clinical signs and SD-OCT results correlate with ERG findings.

Association between retinal microvascular abnormalities and late-life brain amyloid-β deposition: the ARIC-PET study

BackgroundRetinal microvascular signs are accessible measures of early alterations in microvascular dysregulation and have been associated with dementia; it is unclear if they are associated with AD (Alzheimer’s disease) pathogenesis as a potential mechanistic link. This study aimed to test the association of retinal microvascular abnormalities in mid and late life and late life cerebral amyloid.MethodsParticipants from the ARIC‐PET (Atherosclerosis Risk in Communities‐Positron Emission Tomography) study with a valid retinal measure (N = 285) were included. The associations of mid- and late-life retinal signs with late-life amyloid-β (Aβ) by florbetapir PET were tested. Two different measures of Aβ burden were included: (1) elevated amyloid (SUVR > 1.2) and (2) continuous amyloid SUVR. The retinal measures’ association with Aβ burden was assessed using logistic and robust linear regression models. A newly created retinal score, incorporating multiple markers of retinal abnormalities, was also evaluated in association with greater Aβ burden.ResultsRetinopathy in midlife (OR (95% CI) = 0.36 (0.08, 1.40)) was not significantly associated with elevated amyloid burden. In late life, retinopathy was associated with increased continuous amyloid standardized value uptake ratio (SUVR) (β (95%CI) = 0.16 (0.02, 0.32)) but not elevated amyloid burden (OR (95%CI) = 2.37 (0.66, 9.88)) when accounting for demographic, genetic and clinical risk factors. A high retinal score in late life, indicating a higher burden of retinal abnormalities, was also significantly associated with increased continuous amyloid SUVR (β (95% CI) = 0.16 (0.04, 0.32)) independent of vascular risk factors.ConclusionsRetinopathy in late life may be an easily obtainable marker to help evaluate the mechanistic vascular pathway between retinal measures and dementia, perhaps acting via AD pathogenesis. Well-powered future studies with a greater number of retinal features and other microvascular signs are needed to test these findings.

Efficacy and safety of large-scale use of vancomycin injection in infusion bottle during vitreoretinal procedures.

The purpose of this study was to assess the safety and efficacy of large-scale use of vancomycin injection in an infusion bottle during vitreoretinal procedures. This was a retrospective evaluation of all vitreoretinal procedures done in the last 70 months, where intraoperatively vancomycin injection (0.2 mg/mL) was used in an infusion bottle prophylactically as standard care. Vitreoretinal procedures were categorized as major (duration >30 min), minor (duration <30 min), and silicone oil removal. Postoperatively, a detailed ocular examination was done to rule out hemorrhagic occlusive retinal vasculitis (HORV) or signs of postoperative bacterial endophthalmitis. Over the last 70 months, a total of 31,720 vitreoretinal procedures were performed, which included 24,371 major vitreoretinal procedures, 1401 minor vitreoretinal procedures, and 5948 silicone oil removal cases. None of these cases developed HORV or bacterial endophthalmitis. Vancomycin (0.2 mg/mL) in infusion fluid during vitreoretinal procedures is safe and can be advocated as a prophylactic measure against postvitrectomy bacterial infections.

RETINAL MICROVASCULAR CHANGES AND RISK OF CORONARY HEART DISEASE: A Systematic Review and Meta-Analysis.

To quantify associations between various retinal microvascular changes and the risk of the development of coronary heart disease (CHD). PubMed, Embase, Web of Science, and Cochrane Library databases were searched for cohort studies on the association between retinal microvascular changes and incident CHD up to July 31, 2023. The summary risk estimates were estimated using the random-effects model. Subgroup and sensitivity analyses were performed to investigate the potential source of heterogeneity. The authors identified 21 studies that met the inclusion criteria of this meta-analysis through database searching. This study yielded significant associations between retinal microvascular changes, including arteriolar narrowing, venular widening, vessel occlusion, and other retinal vascular signs, and the risk of CHD, with pooled adjusted hazard ratios of 1.20 (95% confidence interval: 1.13-1.27). In sex- and age-stratified analyses, retinal microvascular changes were associated with a greater risk of developing CHD in female patients and younger adults. A range of retinal microvascular changes was associated with the risk of CHD, particularly in female patients and younger ages. The results of this study support the concept that retinal microvascular abnormalities may be markers for future CHD. Noninvasive retinal microvascular assessments may be helpful in screening patients with increased CHD risk.

Clinical profile and demographic distribution of Stargardt disease phenotypes: An Electronic medical record-driven big data analytics from a multitier eye care network.

To describe the demographics and clinical profile of Stargardt disease in patients presenting a multitier ophthalmology hospital network in India. This cross-sectional hospital-based study was performed among 2,834,616 new patients presenting between August 2010 and June 2021 in our network. Patients with a clinical diagnosis of Stargardt disease in at least one eye were included as cases. The data were collected using an electronic medical record system. Overall, 1,934 (0.069%) patients were diagnosed with Stargardt disease. Most of the patients were male (63.14%). The most common age group at presentation was during the second decade of life, with 626 (31.87%) patients. The overall prevalence was higher in patients from a higher socioeconomic status (0.077%), in those presenting from the urban geography (0.079%), and in students (0.197%). Systemic history of hypertension was seen in 56 (2.85%) patients, while diabetes mellitus was seen in (2.49%) patients. Of the 3,917 eyes, 1,910 (48.76%) eyes had moderate visual impairment (>20/70-20/200) followed by severe visual impairment (>20/200 to 20/400) in 646 (16.49%) eyes. The most commonly associated retinal signs were retinal flecks in 1,260 (32.17%) eyes, followed by RPE changes in 945 (24.13%) eyes. The most documented investigations were autofluorescence (39.85%), followed by optical coherence tomography (23.90). Cataract surgery was the commonest performed surgical intervention in (0.66%) eyes, followed by intravitreal injection in 4 (0.10%) eyes. The family history of parent consanguinity marriage was reported by 212 (10.79%) patients. Stargardt disease was seen more commonly in males presenting during the second decade of life. It is predominantly a bilateral disease, with the majority of the eyes having moderate visual impairment.

OCT-based deep-learning models for the identification of retinal key signs

A new system based on binary Deep Learning (DL) convolutional neural networks has been developed to recognize specific retinal abnormality signs on Optical Coherence Tomography (OCT) images useful for clinical practice. Images from the local hospital database were retrospectively selected from 2017 to 2022. Images were labeled by two retinal specialists and included central fovea cross-section OCTs. Nine models were developed using the Visual Geometry Group 16 architecture to distinguish healthy versus abnormal retinas and to identify eight different retinal abnormality signs. A total of 21,500 OCT images were screened, and 10,770 central fovea cross-section OCTs were included in the study. The system achieved high accuracy in identifying healthy retinas and specific pathological signs, ranging from 93 to 99%. Accurately detecting abnormal retinal signs from OCT images is crucial for patient care. This study aimed to identify specific signs related to retinal pathologies, aiding ophthalmologists in diagnosis. The high-accuracy system identified healthy retinas and pathological signs, making it a useful diagnostic aid. Labelled OCT images remain a challenge, but our approach reduces dataset creation time and shows DL models’ potential to improve ocular pathology diagnosis and clinical decision-making.

Insights into Novel Choroidal and Retinal Clinical Signs in Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF1) is a rare inherited neurocutaneous disorder with a major impact on the skin, nervous system and eyes. The ocular diagnostic hallmarks of this disease include iris Lisch nodules, ocular and eyelid neurofibromas, eyelid café-au-lait spots and optic pathway gliomas (OPGs). In the last years, new manifestations have been identified in the ocular district in NF1 including choroidal abnormalities (CAs), hyperpigmented spots (HSs) and retinal vascular abnormalities (RVAs). Recent advances in multi-modality imaging in ophthalmology have allowed for the improved characterization of these clinical signs. Accordingly, CAs, easily detectable as bright patchy nodules on near-infrared imaging, have recently been added to the revised diagnostic criteria for NF1 due to their high specificity and sensitivity. Furthermore, subclinical alterations of the visual pathways, regardless of the presence of OPGs, have been recently described in NF1, with a primary role of neurofibromin in the myelination process. In this paper, we reviewed the latest progress in the understanding of choroidal and retinal abnormalities in NF1 patients. The clinical significance of the recently revised diagnostic criteria for NF1 is discussed along with new updates in molecular diagnosis. New insights into NF1-related neuro-ophthalmic manifestations are also provided based on electrophysiological and optical coherence tomography (OCT) studies.

Purtscher-like retinopathy following coronary artery bypass grafting in an antiphospholipid syndrome patient: a case report

BackgroundPurtscher retinopathy is a rare occlusive microangiopathy comprising a constellation of retinal signs including cotton wool spots, retinal hemorrhages and Purtscher flecken. While classical Purtscher must be antedated by a traumatic incident, Purtscher-like retinopathy is used to refer to the same clinical syndrome in the absence of trauma. Various non-traumatic conditions have been associated with Purtscher-like retinopathy e.g. acute pancreatitis, preeclampsia, parturition, renal failure and multiple connective tissue disorders. In this case study, we report the occurrence of Purtscher-like retinopathy following coronary artery bypass grafting in a female patient with primary antiphospholipid syndrome (APS).Case presentationA 48-year-old Caucasian female patient presented with a complaint of acute painless diminution of vision in the left eye (OS) that occurred approximately two months earlier. Clinical history revealed that the patient underwent coronary artery bypass grafting (CABG) two months earlier and that visual symptoms started 4 days thereafter. Furthermore, the patient reported undergoing percutaneous coronary intervention (PCI) one year before for another myocardial ischemic event. Ophthalmological examination revealed multiple yellowish-white superficial retinal lesions i.e. cotton-wool spots, exclusively in the posterior pole and predominantly macular within the temporal vascular arcades only OS. Fundus examination of the right eye (OD) was normal and the anterior segment examination of both eyes (OU) was unremarkable. A diagnosis of Purtscher-like retinopathy was made based on clinical signs, suggestive history and consolidated by fundus fluorescein angiography (FFA), spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA) of macula, optic nerve head (ONH) according to the diagnostic guidelines of Miguel. The patient was referred to a rheumatologist to identify the underlying systemic cause and was diagnosed with primary antiphospholipid syndrome (APS).ConclusionsWe report a case of Purtscher-like retinopathy complicating primary antiphospholipid syndrome (APS) following coronary artery bypass grafting. This conveys a message to clinicians that patients presenting with Purtscher-like retinopathy should undergo meticulous systemic work-up in order to identify potentially life-threatening underlying systemic diseases.

Automated malarial retinopathy detection using transfer learning and multi-camera retinal images

Cerebral malaria (CM) is a fatal syndrome found commonly in children less than 5 years old in Sub-saharan Africa and Asia. The retinal signs associated with CM are known as malarial retinopathy (MR), and they include highly specific retinal lesions such as whitening and hemorrhages. Detecting these lesions allows the detection of CM with high specificity. Up to 23% of CM, patients are over-diagnosed due to the presence of clinical symptoms also related to pneumonia, meningitis, or others. Therefore, patients go untreated for these pathologies, resulting in death or neurological disability. It is essential to have a low-cost and high-specificity diagnostic technique for CM detection, for which We developed a method based on transfer learning (TL). Models pre-trained with TL select the good quality retinal images, which are fed into another TL model to detect CM. This approach shows a 96% specificity with low-cost retinal cameras.

Role of neuroproteins in retinal neurodegeneration in diabetic retinopathy

Aim. To evaluate the serum levels of S100b protein, brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) in patients with type 2 diabetes mellitus, as well as to establish a correlation between the studied parameters and retinal neurodegeneration.Methods. In total, 80 patients with confirmed type 2 diabetes (experimental group) and 30 healthy volunteers (control group) were included in the study. All patients were examined using an RTVue-100 optic coherence tomography scanner (Optovue, USA) and a MAIA microperimeter (CenterVue, Italy). The serum levels of S100b, BDNF, and NGF were determined by a sandwich-type solid-phase enzyme immunoassay using reagents produced by R&amp;D Diagnostics Inc. (USA).Results. The serum level of S100b protein was found to be significantly (p = 0.001) higher in the experimental group, comprising 56.86 (31,12–104,02) pg/ml, compared to that in the control group of 45.19 (37.27–51.79) pg/ml. Conversely, the brain-derived neurotrophic factor (BDNF) showed a significant (p = 0.02) decrease to the level of 27.38 (25.15–29.12) pg/ml in the experimental group compared to the level of 30.19 (27.38–32.14) pg/ml in the control group. The serum level of nerve growth factor (NGF) in the experimental group was found to be 7.53 (5.63–10.54) pg/ml, thereby exceeding significantly (p = 0.02) the level of 5.96 (4.77–8.13) pg/ml in the control group.Conclusions. The results obtained indicate an imbalance in the serum levels of the studied neuroproteins in patients with type 2 diabetes mellitus and retinal neurodegeneration signs. The identified variations require further research in order to determine the feasibility of their use as additional criteria for predicting the development of retinal neurodegeneration in such patients.

Ocular lesions in systemic lupus erythematosus: An overview

Systemic lupus erythematosus (SLE) is a life-threatening, multisystemic, chronic autoimmune disease. Ocular manifestations of SLE are diverse, affecting any part of the eye. It is a potentially blinding disease with ocular manifestations as the presenting feature. The prevalence of retinal involvement is estimated to be 3% to 29% and it tends to be bilateral and asymmetrical. Retinal signs often concur with the severity of systemic inflammation. Microangiopathy in SLE mimics diabetic and hypertensive retinopathy, moderately severe SLE can have presentation that mimic Purtscher-like retinopathy with a prevalence of 0.14%. Vaso-occlusive disease can either have isolated/combined, retinal artery or vein occlusion. Associated antiphospholipid antibody also increases the risk of vaso-occlusion. The occurrence of optic neuritis and ischemic optic neuropathy is rare in SLE. Presence of peripheral ulcerative keratitis, and scleral, orbital, retinal, choroidal, and neurological manifestations require immediate systemic therapy. Hydroxychloroquine &gt;6.5 mg/kg for 5 years is associated with high risk of toxicity. Modern imaging techniques like fluorescein angiography (FA), indocyanine green angiography (ICGA), optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) help in diagnosis and monitoring of disease activity.

The effects of vitamin E on non-proliferative diabetic retinopathy in type 2 diabetes mellitus: Are they sustainable with 12 months of therapy.

Introduction:Prolonged uncontrolled hyperglycaemia has shown to cause oxidative stress, inflammation, thrombosis and upregulation of angiogenesis in diabetics, which all contributes to diabetic retinopathy development and progression. Vitamin E is found to have anti-inflammatory, anti-oxidative, anti-thrombogenic and anti-angiogenesis which could play an important role in early treatment of diabetic retinopathy. This study aims to investigate the effect of Tocotrienol-rich vitamin E (Tocovid) on the progression of retinal microhaemorrhages and diabetic macular oedema in patients with diabetic retinopathy.Method:This is a multi-centred, randomized, double-blinded, placebo-controlled trial which involved 55 eligible participants. The participants in the treatment group (n = 22) received Tocovid 200 mg twice daily while those in the placebo group (n = 23) would receive placebo twice daily. Both groups will be on the treatment for a total duration of 12 months. Both retinal signs will be assessed at baseline, 2 months, 6 months and 12 months of treatment to determine the progression of diabetic retinopathy. Serum vascular endothelial growth factor which reflects on the angiogenesis process in the eye was analysed as well at similar time points as the retinal findings.Results:After 12 months of treatment, the placebo group had a significant increase of 23.42% in retinal microhaemorrhages (p < 0.05), but the Tocovid group had no significant changes. Moreover, the Tocovid group showed a significant decrease of 48.38% in area of diabetic macular oedema over the 12 months period (p < 0.05), but the placebo group had no significant changes. Meanwhile, there was no significant difference in serum vascular endothelial growth factor level when comparing between both groups.Conclusion:These findings could indicate that Tocovid has an important role in preventing early diabetic retinopathy progression.

Retinal vascular abnormalities and blood-retinal barrier breakdown in Alzheimer's disease.

Vascular changes including cerebral amyloid angiopathy (CAA), reduced blood flow, pericyte loss and vascular platelet-derived growth factor receptor-β (PDGFRβ) deficiency have emerged as prominent features of Alzheimer's disease (AD). We previously identified the existence of the pathological hallmarks of AD, amyloid β-protein (Aβ) plaques, along with intracellular and vascular Aβ deposits in the neurosensory retina of AD patients. Data suggest that certain retinal signs manifest early in disease progression and appear similar to those observed in the brain. Yet, retinal vascular abnormalities in AD and their ability to predict cerebral pathology and cognitive decline are poorly understood. Here, we assessed vascular changes including capillary degeneration, PDGFRβ expression, vascular amyloidosis, pericyte loss, and blood-retinal barrier (BRB) permeability in postmortem retinas from a cohort of mild cognitively impaired (MCI) and AD patients. We evaluated retinal cross-sections from pre-defined topographical regions and isolated retinal vascular networks labeled by periodic acid-Schiff or immunofluorescence. We further quantified capillary degeneration, PDGFRβ expression, vascular amyloidosis, and inner BRB tight-junction molecule expression and BRB leakage in transgenic APPSWE /PS1ΔE9 mouse models of AD (ADtg mice) at different disease stages. Early and progressive PDGFRβ deficiency and pericyte loss were found in retinas from AD patients. PDGFRβ deficiency associated with vascular Aβ deposits in postmortem retinas from a cohort of MCI and AD patients. In ADtg mice as compared to age- and sex-matched wild-type mice, we found significant degeneration of retinal capillaries (P<0.0001). ADtg retinas also displayed a substantial vascular PDGFRβ deficiency (∼50% reduction, P=0.0017) and vascular Aβ deposition, which inversely correlated with the extent of degenerated capillaries (Pearson's r=-0.8, P=0.0016). Tight-junction alterations including claudin-1 downregulation and increased BRB permeability were found in ADtg mice. In postmortem retinas from the human cohort, retinal PDGFRβ loss significantly associated with increased retinal vascular Aβ40 and Aβ42 burdens. Decreased vascular LRP-1 and early apoptosis of pericytes in AD retina were further revealed. Correlations were identified between retinal vascular abnormalities and cerebral Aβ burden, CAA, and clinical status. Overall, the identification of age- and Alzheimer's-dependent retinal capillary degeneration and compromised BRB integrity starting at early disease stages provide novel targets for AD diagnosis and therapy.

Clinical Presentation and Demographic Distribution of Retinitis Pigmentosa in India and Implications for Potential Treatments: Electronic Medical Records Driven Big Data Analytics: Report I

ABSTRACT Aim To describe the clinical presentation and demographic distribution of retinitis pigmentosa in patients presenting to a multi-tier ophthalmology hospital network in India and implications for potential treatments. Design Cross-sectional hospital-based study. Methods This study included 2,541,810 patients presenting between March 2012 and October 2020. Patients with a clinical diagnosis of retinitis pigmentosa in at least one eye were included as cases. The data were collected using an electronic medical record system. Results Overall, 15,062 (0.59%) new patients were diagnosed with retinitis pigmentosa and were included for analysis. The median age was 35 (IQR: 21–49) years and adult age (84.56%) presented more often. The most common presenting age group was between 21 and 30 years (20%). Majority of patients were male (61.68%) and had bilateral (96.39%) affliction. There was a family history in a tenth of the patients (10.46%) and a history of consanguinity in a minority (5.53%). The majority of the eyes had mild or no central visual acuity impairment of <20/70 (34.25%) followed by blindness <20/400 to 20/1200 (21.26%). The predominant retinal signs included disc pallor (76.43%), attenuated arterioles (82.61%) and bony spicule pigmentation (90.15%), and almost all had retinal pigmentary changes. A minority of the eyes underwent a surgical procedure (4.96%). Conclusion Retinitis pigmentosa is commonly bilateral and predominantly affects males. Most patients present in the third decade of life with severe visual acuity impairment. More than half of the eyes from our study are potential candidates for newer therapies. These results have implications for upcoming treatment choices and planning.

Retinal Vascular Signs as Screening and Prognostic Factors for Chronic Kidney Disease: A Systematic Review and Meta-Analysis of Current Evidence.

Background: The substantial burden of kidney disease fosters interest in new ways of screening for early disease diagnosis, especially by non-invasive imaging. Increasing evidence for an association between retinal microvascular signs and kidney disease prompted us to investigate the relevant current literature on such an association systematically by performing a meta-analysis of our findings. Methods: We scrutinized the current literature by searching PubMed and Embase databases from for clinical studies of the association between retinal microvascular signs and prevalent or incident kidney disease. After excluding cases that did not meet our criteria, we extracted relevant data from 42 published studies (9 prospective, 32 cross-sectional, and 1 retrospective). Results: Our investigation yielded significant associations between retinal vascular changes (including retinopathy and retinal vascular diameter) and kidney dysfunction (including chronic kidney disease (CKD), end-stage renal disease (ESRD), albuminuria, and estimated glomerular filtration rate (eGFR) decline). According to our meta-analysis, retinopathy was associated with ESRD (hazard ratio (HR) 2.12 (95% confidence interval CI; 1.39–3.22)) and with CKD prevalence in the general population (odds ratio (OR) 1.31 (95% CI; 1.14–1.50)), and specifically in type 2 diabetic patients (OR 1.68 (95% CI; 1.68–2.16)). CRAE was associated with prevalent CKD (OR 1.41 (95% CI; 1.09–1.82)). Conclusions: Our findings suggest that the retinal microvasculature can provide essential data about concurrent kidney disease status and predict future risk for kidney disease development and progression.

Ocular ischemic manifestations in fibromuscular dysplasia.

To report visual, clinical and radiological outcomes of three patients with fibromuscular dysplasia (FMD) that presented different ocular ischemic events, supported by different multimodal imaging. A retrospective study including patients who attended a tertiary referral hospital from July 2016 to June 2019 referring acute visual loss and later diagnosed of FMD. Ophthalmological examination included best corrected visual acuity (BCVA), biomicroscopy, fundoscopy, fluorescein angiography (FA), and macular and retinal nerve fiber layer spectral domain optic coherence tomography (SD-OCT). Patients were admitted by the Neurology service, completing the study with blood and cerebrospinal fluid (CSF) test, serology and cultures, cerebral magnetic resonance angiography (angioMRI), and arteriography. Three patients were included; one male and second females. All referred unilateral acute visual loss, with BCVA of counting fingers or hand-motion. Relative afferent pupilar defect was present in all patients. Two patients associated neurological focal signs and one had chronic hypertension. Fundoscopy revealed hemorrhages and exudates in all patients, and the typical sign of "string-of-beads" in one. FA showed dye filling delay and macular and peripheral hypofluorescence. SD-OCT revealed acute and chronic retinal ischemic signs. Blood and CSF tests, serologies and cultures resulted negative. All presented cerebral vascular involvement, objectified in the cerebral angioMRI or arteriography. FMD should be considered in cases with unilateral sudden visual loss associated to neurological focal deficits in young patients. The typical "string-of-beads" image is rare in small arteries such as the retinal vasculature. When suspected, a complete ophthalmological examination and cerebral vascular imaging is essential to confirm the diagnosis.

Ultra-wide field swept-source optical coherence tomography angiography in patients with diabetes without clinically detectable retinopathy

BackgroundTo investigate alterations in retinal microvasculature in eyes with preclinical diabetic retinopathy (DR) using ultra-wide field swept-source optical coherence tomography angiography (UWF SS OCTA).MethodsProspective cross-sectional study. Fifty-five eyes of 30 diabetic patients without clinical retinal signs were included. All subjects underwent OCTA examination with a 12 × 12 mm2 field of view of 5 visual fixations (1 central fixation and 4 peripheral fixations) to compose a UWF OCTA image. In the UWF images, the central area corresponded to the original central image obtained using central fixation, and the peripheral area was the remaining area. Lesions, including nonperfusion areas (NPAs), microvascular dilation and tortuosity, and neovascularization (NV), were recorded in different areas. Diabetes history was also recorded.ResultsPeripheral areas presented significantly more microvascular dilation and tortuosity than central areas (P = 0.024) and more NPAs than central areas, with borderline significance (P = 0.085). The number of lesion types was associated with HbA1c levels in the peripheral and overall areas (all P values < 0.001).ConclusionsUWF SS OCTA is a promising imaging method for detecting vascular alterations in diabetic eyes without clinical signs to reveal retinal microvascular alterations. These alterations were correlated with systemic conditions.

Retinal microvascular signs in COVID-19

Background/aimsTo explore if retinal findings are associated with COVID-19 infection.MethodsIn this prospective cross-sectional study, we recruited participants positive for COVID-19 by nasopharyngeal swab, with no medical history. Subjects underwent retinal...

An experimental study of resveratrol effect on neurotrophic and structural changes in retinal ischemia

Purpose . To investigate the effect of resveratrol antioxidant on neurotrophic and structural changes of retina/choroid tissue complex in experimental ischemia/reperfusion (I/R) injury of retina induced by endothelin-1 (ET-1) injection in rats. Material and methods . 60 male Wistar albino rats were divided into 3 groups. 50 rats underwent I/R (Group 1 [n = 20]; Group 2 [n = 30]) while 10 animals served as controls. Retinal I/R was induced in Group 1 and Group 2 by subconjunctival injection of 0.2 mL 4 x 10 -6 М ET-1. The animals in Group 1 received no resveratrol; those in Group 2 received 20 mg/kg resveratrol per os during 1 month before I/R and continued to receive it after I/R up to the moment they were euthanazied. Factors regulating mitochondrial apoptosis (BAX/BCL-2) and external pathways of apoptosis (sFas/FasL), inflammatory marker — monocyte chemoattractant protein-1 (МСР-1) and neurotrophic factors – brain-derived neurotrofic factor (BDNF), nerve growth factor (NGF) were quantified in retinal/choroidal tissue homogenates. In each group, laboratory assessment of retina/choroid complex samples and morphological investigations were performed 3 days (16 eyes), 7 days (16 eyes), 30 days (18 eyes) after ischemia. Results . After 30 days, a statistically significant decrease of apoptotic factors BAX/BCL-2 (p &lt; 0.001) and reduced level of MCP-1 in animals of Group 2 (p &lt; 0.05) as compared to those in Group 1 were noted. The histological examination of the retina on day 3 showed reduced retinal ischemic lesions and signs of inflammation, decrease of the apoptosis of ganglion cells and zones of preserved retina with intact nuclear layers and a layer of photoreceptors in late post-ischemic period (after 30 days). Conclusions . The experimental results demonstrate that resveratrol has neuroprotective properties after retinal I/R injury. This suggests that resveratrol has therapeutic potential in the treatment of diseases of the retina and optic nerve.