Arteriovenous Crossings Research Articles

Portable color retinography findings in COVID-19 patients admitted to the ward

Retinal lesions, including cotton-wool exudates, microbleeds, vascular occlusions and vasculitis, occur in a minority of Coronavirus Disease-19 (COVID-19) patients. Retinal assessments using retinography can help document these lesions. The objective of this work was to identify retinal changes in patients admitted to the ward with a positive Real Time Quantitative Polymerase Chain Reaction (RT-qPCR) exam for COVID-19. A cross-sectional, observational study was carried out of patients with mild and moderate symptoms admitted to the Hospital de Base in São José do Rio Preto. The Eyer® portable retinal camera (Phelcom® Technologies) was used to evaluate 30 male and 21 female patients. The ages ranged from 21 to 83 years (mean: 47 years). Systemic arterial hypertension was identified in 21 (41.2 %) and diabetes mellitus in 12 (23.5 %) patients. Six (11.7 %) reported worsening visual acuity, however, none of these patients had ocular findings to justify this complaint. Ten patients (19.6 %) had intraretinal hemorrhages; one (1.9 %) had cotton-wool exudates and seven (13.7 %) had dilations of veins. Thirteen patients (25.4 %) had vascular tortuosity and six (11.7 %) had pathological arteriovenous crossings. Portable retinography is useful to evaluate patients admitted to isolation wards due to COVID-19. It is important to remember that some of the patients investigated had comorbidities like diabetic maculopathy and systemic arterial hypertension. Hence, some care should be taken in attributing these observations uniquely to COVID-19 infection.

Research of branched retinal vein occlusion with arteriovenous crossing site

Aims/Purpose: The study was designed to analyse the incidence of branch retinal vein occlusion with characteristics of arteriovenous crossing.Methods: Patients diagnosed with branch retinal vein occlusion from January 2012 to January 2017 were enrolled. We selected 117 patients with recognizable arteriovenous crossing on fundus photography. The control group consisted of 120 patients who had no eye disorders and normal fundus photography. To analyse the characteristics of BRVO arteriovenous crossing, the sites were compared with arteriovenous crossing sites in similar locations in the contralateral vascular arcade of the BRVO site. Second, the numbers of arteriovenous crossings and crossings in which the positions of an artery and a vein alternated in the main venous pathways were studied. Last, distances between arteriovenous crossings at the main venous pathway were analysed.Results: Of branch retinal vein occlusion patients, 75.2% showed an artery anterior to the vein at arteriovenous crossing sites. In the control group, 61.5% of arteriovenous crossing sites showed artery anterior to the vein. The total number of arteriovenous crossing sites was not different from that of the contralateral arcade in the same eye, but the number of arteries anterior to veins was significantly different. The total number of arteriovenous crossing sites was statistically different from that of the control group of normal people. Distance between arteriovenous crossings were measured by the ImageJ program. Group A showed a 2.619 ± 0.859 DD (Disc Diameter) and group C was 3.505 ± 0.859 DD, a significant difference.Conclusions: The study shows that arteriovenous crossing sites play an important role in branch retinal vein occlusion, and an artery anterior to a vein is more important at such crossing sites. Moreover, the distance between arteriovenous crossing sites can affect the incidence of BRVO.

Edge-Guided Contrastive Adaptation Network for Arteriovenous Nicking Classification Using Synthetic Data.

Retinal arteriovenous nicking (AVN) manifests as a reduced venular caliber of an arteriovenous crossing. AVNs are signs of many systemic, particularly cardiovascular diseases. Studies have shown that people with AVN are twice as likely to have a stroke. However, AVN classification faces two challenges. One is the lack of data, especially AVNs compared to the normal arteriovenous (AV) crossings. The other is the significant intra-class variations and minute inter-class differences. AVNs may look different in shape, scale, pose, and color. On the other hand, the AVN could be different from the normal AV crossing only by slight thinning of the vein. To address these challenges, first, we develop a data synthesis method to generate AV crossings, including normal and AVNs. Second, to mitigate the domain shift between the synthetic and real data, an edge-guided unsupervised domain adaptation network is designed to guide the transfer of domain invariant information. Third, a semantic contrastive learning branch (SCLB) is introduced and a set of semantically related images, as a semantic triplet, are input to the network simultaneously to guide the network to focus on the subtle differences in venular width and to ignore the differences in appearance. These strategies effectively mitigate the lack of data, domain shift between synthetic and real data, and significant intra- but minute inter-class differences. Extensive experiments have been performed to demonstrate the outstanding performance of the proposed method.

Narrowing Ratio of Retinal Veins at Arteriovenous Crossing in Patients With Branch Retinal Vein Occlusion Versus That in Healthy Individuals.

This cross-sectional study aimed to clarify the differences in the retinal venous narrowing ratio (VNR) at retinal arteriovenous crossing by optical coherence tomography (OCT) among the eyes with branch retinal vein occlusion (BRVO), fellow eyes of patients with BRVO, and eyes of individuals without BRVO and to determine factors that influence the VNR. We studied 31 eyes of young participants, 54 eyes of an older control group, 56 fellow eyes of patients with BRVO, and 48 eyes with BRVO. Cross-sectional OCT images were used to determine the VNR at two arteriovenous crossings per eye. Overall, 378 arteriovenous crossings were analyzed. The VNR of arterial overcrossings of fellow eyes (27.7% ± 11.1%) and BRVO eyes (27.3% ± 9.76%) were significantly higher than those in the young (16.0% ± 7.9%, all P<0.001) and control (22.0% ± 8.81%, P<0.001, P=0.003, respectively) groups. The VNR of arterial overcrossings was significantly larger than that of venous overcrossings (24.0% ± 10.5% vs. 20.6% ± 13.0%, P=0.021). A linear mixed-effects model showed that the VNR was significantly higher in arterial overcrossings, crossings with larger arterial internal diameters, smaller venous internal diameters, and participants with older age and a BRVO history. The VNR in arterial overcrossings was higher in BRVO eyes and even in the fellow eyes. Thus, a higher VNR in arterial overcrossings may contribute to BRVO development, and crossings with factors contributing to higher VNR might be associated with a risk of BRVO.

Primary hyperaldosteronism in Acute Central Serous Chorioretinopathy: a real need for screening?

Central Serous Chorioretinopathy (CSCR) is a prevalent ocular disease classified in the pachychoroidal spectrum with an elevated morbidity. Although the pathogenesis is yet unclear, mineralocorticoid-mediated pathways seem to be implicated. Primary hyperaldosteronism (PA) is a relatively frequent, albeit underdiagnosed, cause of hypertension, and has a specific therapy. A previous study assessed the prevalence of CSCR-like signs in a cohort of patients diagnosed with PA and found signs in seven out of thirteen PA patients. The present study aims to study the contrary, screening for PA in a cohort of acute CSCR patients. Between March 2017 and September 2018 all patients with acute CSCR were systematically referred to Endocrinology Department after complete ophthalmic evaluation was performed with visual acuity, spectral domain optical coherence tomography, fundus autofluorescence, fluorescein and indocyanine green angiography. The method applied for detection of PA was the 2-h 25mg captopril challenge test (CCT). Of the nineteen patients screened, two of them had a CCT positive for PA (2-h plasma aldosterone/renin ratio > 50 and/or an aldosterone level of 130pg/ml or higher), and were treated with mineralocorticoid receptor antagonists (MRA). No ophthalmic pattern was identified in them in terms of time to resolution, recurrences or features of the acute episode. The only differential feature in the fundus of PA patients was pathological arteriovenous crossings (AVC) as well as elevated BP levels. a high incidence of PA was found among acute CSCR patients. This preliminary study suggests a need for screening for PA in hypertensive CSCR patients in real clinical practice.

End-to-End Automatic Classification of Retinal Vessel Based on Generative Adversarial Networks with Improved U-Net

The retinal vessels in the human body are the only ones that can be observed directly by non-invasive imaging techniques. Retinal vessel morphology and structure are the important objects of concern for physicians in the early diagnosis and treatment of related diseases. The classification of retinal vessels has important guiding significance in the basic stage of diagnostic treatment. This paper proposes a novel method based on generative adversarial networks with improved U-Net, which can achieve synchronous automatic segmentation and classification of blood vessels by an end-to-end network. The proposed method avoids the dependency of the segmentation results in the multiple classification tasks. Moreover, the proposed method builds on an accurate classification of arteries and veins while also classifying arteriovenous crossings. The validity of the proposed method is evaluated on the RITE dataset: the accuracy of image comprehensive classification reaches 96.87%. The sensitivity and specificity of arteriovenous classification reach 91.78% and 97.25%. The results verify the effectiveness of the proposed method and show the competitive classification performance.

Three-Dimensional High-Resolution Temporal Bone Histopathology Identifies Areas of Vascular Vulnerability in the Inner Ear

Objectives: Hypothesized causes of vestibular neuritis/labyrinthitis include neuroinflammatory or vascular disorders, yet vascular disorders of the inner ear are poorly understood. Guided by known microvascular diseases of the retina, we developed 2 hypotheses: (1) there exist vascular vulnerabilities of artery channels in cases of hypothetical nerve swelling for the superior, inferior, and vestibulocochlear artery and (2) there are arteriovenous crossings that could compromise vascular flow in disease states. Methods: Two fully mounted and stained temporal bones were used to render three-dimensional reconstructions of the labyrinth blood supply. Using these maps, areas of potential vascular compression were quantified in 50 human temporal bones. Results: Although inner ear arteries and veins mostly travel within their own bony channels, they may be exposed (1) at the entrance into the otic capsule, and (2) where the superior vestibular vein crosses the inferior vestibular artery. At the entry into the otic capsule, the ratio of the soft tissue to total space for the superior vestibular artery was significantly greater than the inferior vestibular artery/cochleovestibular artery (median 44, interquartile range 34–55 vs. 14 [9–17], p < 0.0001). Conclusions: Three-dimensional reconstruction of human temporal bone histopathology can guide vascular studies of the human inner ear. Studies of retinal microvascular disease helped identify areas of vascular vulnerability in cases of hypothetical nerve swelling at the entrance into the otic capsule and at an arteriovenous crossing near the saccular macula. These data may help explain patterns of clinical findings in peripheral vestibular lesions.

The Importance of Molecular Testing for the Diagnosis of Fabry Disease Manifested by Cornea Verticillata Only

Aims: To describe a Fabry disease, that it’s diagnosis was only possible through the molecular test&#x0D; Presentation of Case: L.A.P. female, 42 years old, lawyer, seen by the ophthalmology department for routine consultation only with refractive complaints. Fundus of the eye: Mild narrowing with increased vascular brightness and presence of pathological arteriovenous crossings. The rest of the exam was within normal limits.&#x0D; Therefore, a genetic test with the dosage of the α-Gal enzyme was requested, which evidenced the alteration in it, confirming the diagnosis of Fabry disease.&#x0D; Discussion: A Fabry Disease (FD) is an inborn error of glycosphingolipid (GL) metabolism, resulting from deficient activity of the enzyme alpha-galactosidase A (α -Gal). It has X-chromosome-linked inheritance, affecting mainly males, with an estimated prevalence of 1:40,000 males. The expression of the disease in heterozygous female patients can vary from an asymptomatic condition to a severe systemic disease, like that which occurs in men.&#x0D; Conclusions: The ophthalmological examination played an important role in the diagnosis, as this change is highly suggestive of the disease, in order to avoid erroneous and late diagnoses that can cause consequences for patients with this condition.

Prevalence of Retinal Vein Occlusions and Estimated Cerebrospinal Fluid Pressure: The Kailuan Eye Study.

PurposeTo investigate the prevalence of retinal vein occlusions (RVOs) and associated factors in a Chinese population.Patients and MethodsThe cross-sectional community-based Kailuan Eye Study included individuals who participated in the Kailuan Study. RVOs were diagnosed on the fundus photographs. Estimated cerebrospinal fluid pressure (eCSFP) was calculated as “eCSFP=0.44*Body Mass Index+0.16*Diastolic Blood Pressure-0.18*Age”.ResultsThe study included 12,499 participants with a mean age of 52.9±13.1 years. The overall prevalence of RVO was 120/12,499 or 0.96%, with branch RVOs observed in 116/12,499 individuals and central RVOs in 4/12,499 individuals. RVOs started at the optic disc in 19 participants (15.8% of all RVOs), and in 101 (84.2%) individuals arterio-venous crossings outside the optic disc. In multivariable analysis, a higher RVO prevalence was associated with older age (P<0.001), higher eCSFP (P<0.001), and higher fasting serum glucose concentration (P<0.001). Differentiating between RVOs at arterio-venous crossings and RVOs at the optic disc revealed that the prevalence of both RVO types was associated with higher eCSFP (P<0.001 and P=0.004, respectively) after adjusting for age and fasting serum glucose concentration.ConclusionIn this adult Chinese population recruited on a community basis, the prevalence of any RVO (mean: 0.96) was associated with older age, higher eCSFP and higher fasting serum glucose concentration. Higher eCSFP may play an etiologic role in RVOs.

Association of systemic cardio-vasculature status with retinal vascular endothelium in diabetes

The relationship between diabetic retinopathy and macro-vascular complications in diabetes suggests a pathogenic association between these conditions. Vascular endothelium has been identified as a main site of blood vessel injury in diabetes. Diabetic retinopathy is associated with systemic arterial stiffness and altered vascular endothelium function and structure. Retinal vasculature endothelium at the macula, arterio-venous crossings, and in the optic nerve at the lamina cribrosa region is reported to differ from the endothelium in the rest of the retinal blood vessels. The central retinal artery and vein are in close proximity in the optic nerve where they share a common adventitia; thus, increased arterial wall stiffness and thickness may affect blood flow in the neighboring central retinal vein in this region. Moreover, increased arterial stiffness in small arterial beds is associated with retinal venular widening; it suggests the possibility of central retinal artery compressing the central retinal vein at the lamina cribrosa, thereby compromising venular outflow in the retina of diabetic patients. Altered blood flow in the central retinal vein in the postlaminar region has been detected in patients who experience progression of diabetic retinopathy. Increased hydrostatic pressure in the central retinal vein may play a major role in the pathogenesis of diabetic retinopathy. The aim of this review article is to emphasize this pathogenetic mechanism that has often been overlooked.

Angiographic Risk Features of Branch Retinal Vein Occlusion Onset as Determined by Optical Coherence Tomography Angiography.

PurposeExamine associations between the vasculature at arteriovenous (AV) crossings and the onset of branch retinal vein occlusion (BRVO).MethodsWe included 78 patients with major BRVO, 35 patients with macular BRVO, and 110 controls without BRVO and determined the vessel positions at AV crossings, where the first- or second-order branches of the retinal veins associate, using a viewing angle of 12 × 12 mm2 in optical coherence tomography angiography (OCTA).ResultsWe reviewed 1349 and 1276 AV crossings in BRVO patients and control subjects, respectively. The proportions of venous overcrossing were 26.5%, 28.6%, and 26.8% at non-causative crossings in BRVO eyes, non-BRVO fellow eyes, and unaffected control eyes, respectively; however, the rate of venous overcrossings at the causative crossings was 45.1%. In OCTA analyses, we divided the branches into macular- or non-macular veins. The rate of venous overcrossing was 52.5% at causative crossings in major BRVO but was 28.6% in macular BRVO. Odds ratios for whether venous overcrossing was a risk factor for BRVO were 3.09 (95% confidence interval [CI], 1.96–4.88) and 0.94 (95% CI, 0.44–2.00) for non-macular veins and macular veins, respectively. The patients with major BRVO caused by venous overcrossing were younger than patients for whom the cause was arterial overcrossing (P < 0.001). The onset of macular BRVO did not differ between crossing patterns at causative crossings (P = 0.60).ConclusionsIn eyes with BRVO, venous overcrossing was a common angiographic feature at causative crossings and might be a risk factor for major BRVO onset.

High resolution imaging of radiation retinopathy

AbstractWe explored by fundus photographs, OCT and adaptive optics ophthalmoscopy (AOO) the vessels of eyes after proton beam therapy for uveal melanoma in 10 eyes. We observed strong fluctuations of diameters in both arteries and veins, without significant changes in vascular wall thickness suggesting that vasoconstriction was involved in this process. Reduction of lumen diameter could be focal or diffuse, and could lead in some cases to branch retinal vein occlusion unrelated to arteriovenous crossings. The ensuing collateral circulation could lead to the development of TelCaps (capillary macroaneurysms), successfully treated by targeted laser in one case. Many areas of capillary closure followed a vascular perfusion or drainage scheme, suggesting that vasoconstriction played a role in the complex pattern of radiation retinopathy. This may provide the basis for therapeutic trials based on the modulation of vasomotricity.

Pharmacological correction of morphofunctional retinal injury using 11-amino acid fragment of darbepoetin in the experiment

Introduction: The retinoprotective effect of the 11-amino acid fragment of darbepoetin PRK-002 on the models of hypertensive retinal angiopathy and hypertensive neuroretinopathy in Wistar rats was investigated in comparison with carbamylated darbepoetin and sulodexide.&#x0D; Materials and methods: The protective effects of the pharmacological agents were assessed using the following criteria: a semi-quantitative assessment of changes in the eye fundus when performing ophthalmoscopy, the retinal blood flow, the b/a coefficient, eNOs expression in retinal vessels, specific number of neuronal nuclei in the inner nuclear layer, and p53 expression in the retina.&#x0D; Results and discussion: A pronounced protective effect, exceeding sulodexide at a dose of 150 LRU/kg and carbamylated darbepoetin at a dose of 300 μg/kg when correcting retinal angiopathy was observed in PRK-002 at a dose of 4 µg/kg, which expressed in adjustment of the retinal vessels’ calibers, removing retinal arterio-venous crossings, reaching the target levels of the retinal microcirculation, the b/a coefficient, and the restoration of eNOs expression in the endothelium of retinal vessels. PRK-002 at a dose of 4 µg/kg has a pronounced neuroprotective effect comparable to carbamylated darbepoetin at a dose of 300 µg/kg in correction of hypertensive neuroretinopathy, which expressed in the normalization of the fundus image, reaching the b/a target values, the specific number of neuronal nuclei in the inner nuclear layer, inhibition of p53 expression in the neurons of the inner nuclear and ganglionic layers.&#x0D; Conclusion: The study revealed angio- and neuroprotective activity of the 11-amino acid fragment of darbepoetin PRK-002 in correction of retinal injury formed on the background of hypertension.

Arteriovenous crossing associated with branch retinal vein occlusion.

Branch retinal vein occlusion (BRVO) is defined as the focal occlusion of a first or second-order branch of retinal vein, which occurs most frequently at an arteriovenous (AV) crossing. Direct ophthalmoscopy, color fundus photography, and fluorescein angiography facilitate observation of AV crossings parallel to the retinal plane. Optical coherence tomography (OCT), with its high-depth resolution, enables observation of retinal lesions perpendicular to the retinal plane. OCT angiography (OCTA) provides depth-resolved images of the retinal vasculature by segmenting three-dimensional data. In this review, we discuss novel findings related to affected AV crossings associated with BRVO obtained via OCT and OCTA. The high-depth resolution of OCT or OCTA is useful for observation of the narrowed vein and determination of the vessel position of the affected AV crossing. Studies using OCT and OCTA have shown that BRVO caused by a venous overcrossing is more prevalent than previously reported, and that venous narrowing was significantly greater in instances caused by a venous overcrossing than in those caused by an arterial overcrossing. Moreover, OCTA also revealed that the retinal nonperfusion area size was larger in eyes with BRVO caused by a venous overcrossing than in those with BRVO caused by an arterial overcrossing. This contrasts with earlier findings obtained by conventional imaging modalities predating OCT, which showed that an arterial overcrossing was more common than a venous overcrossing at the causative venous occlusion site in eyes with BRVO. This review discusses these findings and their significance in the study of AV crossing associated with BRVO.

Accuracy and Reliability in Differentiating Retinal Arteries and Veins Using Widefield En Face OCT Angiography.

PurposeTo evaluate the accuracy and reliability in differentiating retinal arteries from veins using widefield optical coherence tomography angiography (OCTA).MethodsTen healthy eyes and 12 eyes from diabetic patients were included. Foveal-centered swept-source OCTA images (12 × 12 mm) were obtained using the PLEX Elite 9000. Vessels were graded as arteries or veins by two independent, masked readers. Arteriovenous crossings were also evaluated in healthy eyes. The vessel identification gold standard was defined using color fundus photographs (CFP) for normal eyes and both CFP and fluorescein angiography for diabetic eyes. Grading accuracy was compared to the gold standard and reliability between readers assessed.ResultsThe study evaluated 538 vessels (119 first order, 110 second, 309 third) in healthy eyes and 645 vessels (184 first order, 159 second, 302 third). In healthy eyes, the average accuracies identifying all, first-, second-, and third-order vessels were 98.61%, 99.16%, 100%, and 98.06%, respectively. Cohen's κ between graders in all vessels was 0.948. In diabetic eyes, the average accuracies identifying vessels were 96.90%, 99.46%, 97.77%, and 94.85%, respectively. Cohen's κ between graders for all vessels was 0.888. For crossing identification, the average accuracy and Cohen's κ were low (60.71% and 0.659, respectively).ConclusionsEn face OCTA allows for accurate and reliable artery and vein identification; for small branches and crossings, identification by en face OCTA alone may be less accurate and reliable.Translational RelevanceArteries and veins can be differentiated on OCTA, assisting in clinically identifying pathology as arterial or venous side.

The impact of IGF-I, puberty and obesity on early retinopathy in children: a cross-sectional study

BackgroundChildhood obesity has been correlated with coronary heart disease, but the correlation with microvascular disease remains unclear. The retinal microcirculation is affected early in the process of atherosclerosis and it offers the opportunity to indirectly study the effects of obesity on small brain vessels. Insulin-like growth factor 1 (IGF-I) is involved in angiogenesis and it has a crucial role in retinal vascularization.MethodsA single-centre cross-sectional study was performed in 268 children and adolescents (116 males; mean age 13.03 ± 1.9 years,) with overweight/obesity, in order to identify risk factors for early retinopathy.ResultsNine patients (3.3%) showed signs of retinopathy, defined as arteriovenous crossings and/or papilledema. Body mass index and fat mass, analysed by Dual X-ray Absorptiometry, were not different in patients with or without retinopathy. Patients with retinopathy were pubertal and showed higher waist circumference (107.78 ± 15.83 versus 99.46 ± 10.85 cm; p: 0.027), waist circumference/height ratio (0.66 ± 0.07 versus 0.62 ± 0.05; p: 0.04) and IGF-I SDS (0.03 ± 1.3 versus − 0.66 ± 0.9; p: 0.04). Multivariate analysis (after correction for sex, age, family history of type 2 diabetes mellitus, obesity, cardiovascular disease, hypertension and dyslipidaemia) showed that waist circumference/height ratio and IGF-I SDS were the only variables independently correlated with the presence of retinopathy.ConclusionsRetinal vascular changes may become evident as an early complication of overweight and obesity, even during childhood and adolescence. Relatively high levels of IGF-I during this phase may act as an additional risk factor for microvascular damage. The screening for retinopathy should be proposed to all children and adolescents with overweight/obesity.

RELATION BETWEEN FLUORESCEIN ANGIOGRAPHIC AND SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY FINDINGS OF BLOOD FLOW TURBULENCE AT ARTERIOVENOUS CROSSINGS IN THE RETINA.

To examine retinal blood flow at arteriovenous crossings using spectral-domain optical coherence tomography (SD-OCT). Retrospective observational case series of 11 arteriovenous crossings in 10 eyes examined by SD-OCT and fluorescein angiography on suspicion of manifest or imminent branch retinal vein occlusion. Fluorescein angiographic evidence of turbulence was seen at 5 of 11 arteriovenous crossings, whereas laminar angiographic flow was intact at the crossing and downstream thereof at the remaining 6 crossings. On SD-OCT, chaotic reflectivity patterns were seen at the point of crossing and downstream thereof in all 5 cases with angiographic turbulence, whereas an intravascular trilayer SD-OCT pattern consistent with laminar flow was seen throughout the examined course of the vein in the eyes with laminar angiographic flow. We examined retinal blood flow at and near arteriovenous crossings and found that SD-OCT may rival fluorescein angiography in the ability to demonstrate turbulent venous blood flow.

Retinal Changes with Clinical Observations in Patients of Hypertensive Disorders of Pregnancy

Background: Hypertension is one of the common complications encountered in pregnancy and contributes significantly to maternal and perinatal morbidity and mortality. Identification of hypertension and its effective management plays a significant role in the outcome of pregnancy, both for the mother and the baby. The finding of retinopathy may be an indication for a termination of pregnancy, since its continuance may lead to serious complications like loss of vision or the life of the mother as well as a stillbirth. The eyes serve as windows for studying the pattern of the cerebral circulation. The retina acts as an indicator of the state of the renal parenchyma. Since there is a close correlation among retinal, cerebral and renal vessels, fundoscopy gives opportunity of observing the changes in the vascular pattern and drawing inferences about the general condition of the vascular system of the body. Method: The fundi of 150 patients admitted in the Department of Obstetrics and Gynaecology in Agartala Government Medical College, Agartala, were examined and the findings were documented according to Keith, Wagner and Barkers classification of hypertensive retinopathy, along with documentation of biochemical and haematological parameters. The neonatal parameters were also noted. Indirect ophthalmoscopy was done to look for retinopathy of prematurity in the babies delivered by mothers included in the study. The data was analysed by descriptive statistics, chi-square test and estimation of p value using SPSS software. Results: Retinal changes were found in 49.33% of the patients and the rest showed normal retina. Focal constriction of the arterioles was the commonest finding in the fundus of those who had retinopathy. Grade 1 hypertensive retinopathy was the commonest grade of retinopathy. Retinopathy was commoner in patients with severe hypertension. Presence of retinopathy in the mother significantly affected neonatal parameters like mode of delivery, sex and birth weight of the baby. Conclusion: Retinal changes were found in about half of the patients. The commonest grade of retinopathy was Grade 1 hypertensive retinopathy and the least common grade was Grade 4 retinopathy. Focal constriction of retinal arterioles was the commonest finding. Arterio-venous ratio was 2:3 in most of the cases. Nicking at the arterio-venous crossings was found in 10% of the cases. Macular edema was found in 12% of the cases. Hypertensive disorders of pregnancy were associated with low APGAR scores in some of the babies.

Pathogenesis of Retinal Vein Occlusion

Retinal vein occlusion (RVO) has multiple pathogenetic mechanism that including local anatomical susceptibility, degenerative changes of the vessel wall and abnormal hematological abnormalities. All of these mechanisms could contribute to develop vascular obstruction. Anatomic features of arteriovenous crossings and common adventitial sheath shared by artery and vein could cause turbulent flow. Turbulence in vessel flow promotes endothelial phenotypic changes that cause endothelial f-actin expression increase. Intercellular adhesions and endothelial functions are affected by high f-actin levels. Damaged arteries and hypoxic tissues express endothelin-1 (ET-1). Endothelin-1 can diffuse from the neighboring veins and stimulate venous vasoconstriction. Vasoconstiriction of veins lead to an increase in pressure. High blood viscosity is another important factor in pathogenesis of RVO. Pathogenesis of RVO is very complex and these factors can lead to a vicious cycle of worsening the other factor.

Cerebral white matter lesions and microcirculation retinal in stroke lacunar

Background: The blood vessels in the retina are available for viewing in a noninvasive way and have similar anatomical, physiological as features small vessel brain. Also the white matter lesions (WMLs) brain are most frequently associated with lacunar stroke Objective: To determine the relationship between cerebral white matter lesions and retinal microvascular alteration in lacunar stroke. Material and methods: Cross-sectional study, patients with acute stroke was evaluated. Arteriovenous crossings, focal or diffuse arteriolar narrowing, retinal hemorrhages, cotton wool spots, alteration in vascular path, microaneurysms, the presence of retinal microvascular abnormalities was assessed. The WMLs were evaluated with a ranking of 1 to 9. Lacunar Stroke was classified by the score of TOAST. Results: A total of 67 patients were evaluated, classified as lacunar stroke 23.88% (n:16), the average age was 70.06 years, 50% were men, the main risk factors hypertension 68.75%, hypercholesterolemia 50%, diabetes 31.25%. In reference to the degree of WMLs grade 4-9 was superior to no lacunar stroke with 68.75% vs. 56.86%, the presence of retinopathy was also higher in lacunar stroke with 68.75% vs. 52.94%, but we found the presence of retinopathy in patients without diabetes and hypertension. Conclusion: WMLs and altering of retinal microcirculation are more prevalence in patients with lacunar stroke. Likewise, the retinopathy may be present in these patients despite not having recognized cardiovascular risk factors.