Retinal Arterial Diameter Research Articles

Retinal Vascular Changes in Response to Hypoxia: A High-Altitude Expedition Study.

Westwood, Jessica, India Mayhook-Walker, Ciaran Simpkins, Andrew Darby-Smith, Dan Morris, and Eduardo Normando. Retinal vascular changes in response to hypoxia: a high-altitude expedition study. High Alt Med Biol. 25:49-59, 2024. Background: Increased tortuosity and engorgement of retinal vasculature are recognized physiological responses to hypoxia. This can lead to high-altitude retinopathy (HAR), but incidence reports are highly variable, and our understanding of the etiological mechanisms remains incomplete. This study quantitatively evaluated retinal vascular changes during an expedition to 4,167 m. Methods: Ten healthy participants summited Mount Toubkal, Morocco. Fundus images were taken predeparture, daily throughout the expedition, and 1 month postreturn. Diameter and tortuosity of four vessels were assessed, in addition to vessel density and features of HAR. Results: Significant (p ≤ 0.05) increases in tortuosity and diameter were observed in several vessels on high-altitude exposure days. There was a strong correlation between altitude and supratemporal retinal artery diameter on days 2, 3, and 6 of the expedition (r = 0.7707, 0.7951, 0.7401, respectively; p < 0.05). There was a significant increase in median vessel density from 6.7% at baseline to 10.0% on summit day. Notably there were no incidences of HAR. Conclusion: Physiological but not pathological changes were seen in this cohort, which gives insight into the state of the cerebral vasculature throughout this expedition. These results are likely attributable to relatively low altitude exposure, a conservative ascent profile, and the cohort's demographic. Future study must include daily retinal images at higher altitudes and take steps to mitigate environmental confounders. This study is relevant to altitude tourists, patients with diabetic retinopathy or retinal vein occlusion, and critically ill patients.

Sex Variations in Retinal Microcirculation Response to Lower Body Negative Pressure.

Lower body negative pressure (LBNP) is routinely used to induce central hypovolemia. LBNP leads to a shift in blood to the lower extremities. While the effects of LBNP on physiological responses and large arteries have been widely reported, there is almost no literature regarding how these cephalad fluid shifts affect the microvasculature. The present study evaluated the changes in retinal microcirculation parameters induced by LBNP in both males and females. Forty-four participants were recruited for the present study. The retinal measurements were performed at six time points during the LBNP protocol. To prevent the development of cardiovascular collapse (syncope) in the healthy participants, graded LBNP until a maximum of -40 mmHg was applied. A non-mydriatic, hand-held Optomed Aurora retinal camera was used to capture the retinal images. MONA Reva software (version 2.1.1) was used to analyze the central retinal arterial and venous diameter changes during the LBNP application. Repeated measures ANOVAs, including sex as the between-subjects factor and the grade of the LBNP as the within-subjects factor, were performed. No significant changes in retinal microcirculation were observed between the evaluated time points or across the sexes. Graded LBNP application did not lead to changes in the retinal microvasculature across the sexes. The present study is the first in the given area that attempted to capture the changes in retinal microcirculation caused by central hypovolemia during LBNP. However, further research is needed with higher LBNP levels, including those that can induce pre-fainting (presyncope), to fully understand how retinal microcirculation adapts during complete cardiovascular collapse (e.g., during hypovolemic shock) and/or during severe hemorrhage.

Correlation of RETINAL Artery Diameter with Coronary Artery Disease: The RETINA CAD Pilot Study-Are the Eyes the Windows to the Heart?

This study aimed to determine whether there was any correlation between coronary artery disease (CAD) and retinal artery diameter at an academic tertiary medical center in Trinidad and Tobago. This prospective study evaluated patients (n = 77) with recent invasive coronary angiography (CAG) and the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score who subsequently underwent optical coherence tomography-angiography (OCT-A) at the Eric Williams Medical Sciences Complex (EWMSC) from January 2021 to March 2021. Routine medical history and cardiovascular medications were also recorded. Spearman's rank correlation coefficient and Mann-Whitney U-tests were used to compare correlations and medians between groups. The average patient age was 57.8years old, with the majority being male [n = 55 (71.4%)] and of South Asian ethnicity [n = 53 (68.8%)]. Retinal artery diameter was negatively correlated with the SYNTAX score (-0.332 for the right eye, p=0.003 and -0.237 for the left eye, p=0.038). A statistically significant relationship was also demonstrated in females and diabetic patients. There were no serious adverse events (SAEs). A significantly negative correlation was observed between retinal artery diameter and SYNTAX score. This study alludes to the practical use of optical coherence tomography-angiography (OCT-A) as a noninvasive diagnostic modality for patients with cardiovascular disease (CVD). Further large-scale, multicentric studies are required to confirm these exploratory findings. NCT04233619.

Correlation Between Retinal Vessel Diameters and Uveitis Activity.

To assess retinal vein and artery diameters during active and inactive intraocular inflammation in eyes with uveitis. Color fundus photographs and clinical data of eyes with uveitis collected during two visits (active disease [i.e., T0] and inactive stage [i.e., T1]) were reviewed. The images were semi-automatically analyzed to obtain the central retina vein equivalent (CRVE) and central retina artery equivalent (CRAE). Changes of CRVE and CRAE from T0 to T1 were calculated, and their possible correlation with clinical data, including age, gender, ethnicity, uveitis etiology, and visual acuity, were investigated. Eighty-nine eyes were enrolled in the study. Both CRVE and CRAE reduced from T0 to T1 (P < 0.0001 and P = 0.01, respectively), with active inflammation being able to influence the CRVE and CRAE (P < 0.0001 and P = 0.0004, respectively) after accounting for all other variables. The degree of venular (∆V) and arteriolar (∆A) dilation was influenced only by time (P = 0.03 and P = 0.04, respectively). Best-corrected visual acuity was influenced by time and ethnicity (P = 0.003 and P = 0.0006). CRVE and CRAE are increased in eyes with active intraocular inflammation regardless of the type of uveitis, and they decrease when the inflammation wears off.

The effect of palm oil-derived tocotrienol-rich fraction in preserving normal retinal vascular diameter in streptozotocin-induced diabetic rats.

Angiogenesis in diabetic retinopathy (DR) is associated with increased retinal expression of angiopoietin-2 (Ang-2) and protein kinase C (PKC). Tocotrienol-rich fraction (TRF) has been shown to reduce the expression vascular endothelial growth factor (VEGF) in several experimental models. However, its effect against other angiogenic markers such as Ang-2 and PKC in rat modelof diabetes remains unknown. Therefore, we investigated the effect of TRF on the retinal vascular changes and Ang-2 and PKC expressions in rats with streptozotocin (STZ)-induced DR. Sprague-Dawley rats were divided into normal control rats (N) which received vehicle, and diabetic rats which either received vehicle (DV) or 100mg/kg of TRF (DT). Diabetes was induced with intraperitoneal injection of STZ (60mg/kg body weight). Treatments were given orally, once daily, for 12weeks after confirmation of hyperglycaemia. Fundus photographs were captured at baseline, 6- and 12-week post-STZ injection and average diameter of retinal veins and arteries were measured. At 12-week post-STZ injection, rats were euthanised, and retinae were collected for measurement of Ang-2 and PKC gene and protein expressions. Retinal venous and arterial diameters were significantly greater in DV compared to DT at week 12 post-STZ injection (p < 0.001 and < 0.05, respectively). The vesseldiameter measurements in DT were comparable to N and this effect of TRF was associated with significantly lower Ang-2 and PKC gene and protein expressions compared to DV. Oral TRF reduces the expression of retinal angiogenic markers and preserves the retinalvascular diameter of rats withSTZ-induced DR.

Dynamic Changes in Retinal Vessel Diameters and Arteriovenous Ratio within 10 Days of Birth

Purpose This study monitored the dynamic changes in retinal vascular width and the AVR in full-term neonates within 1–10 days of birth. Methods It was conducted at hospitals in the Anhui province from October 2020 to March 2022. A total of 700 full-term, healthy infants were chosen randomly within 10 days of birth, and the Star Pupil Medical Cloud Data System (XBDS) was used to collect fundus images. Infants within 6 days of birth were grouped into groups one to six, while those within the 7th to 10th days were grouped into group seven. The fundus photographs were imported into Image-Pro-Plus (IPP) software. The optic disc diameter was measured. The retinal artery and vein’s diameter was measured at a distance between 0.5- and 1.0-disc diameter from the optic disc’s margin. The AVR was also calculated. Finally, each group’s retinal vessel diameters and AVR were compared separately to show their dynamic changes. Results There were differences in the retinal artery diameter between groups one and two, three and four, four and five, and five and six. For retinal vein diameter, there were differences between groups one and two and groups six and seven. There were also differences in the AVR between all groups. In addition, there was a significant positive correlation between the small retinal artery and vein diameters. Conclusion The retinal artery and vein diameters and AVR in neonates change dynamically during the first 10 days of life. The AVR undergoes the most dramatic change daily and is considerably smaller than the AVR in adults. Hence, this study found that the external environment undergoes significant changes following birth that affect the microcirculation. Then, the retinal central vascular system undergoes similar emergency and adaptive alterations.

Effect of Highly Active Antiretroviral Therapy on Fundus Images and Retinal Microvessel Diameter in HIV/AIDS Patients

We aimed to investigate whether there were changes in fundus picture and retinal microvascularity of patients with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) who were treated with highly active antiretroviral therapy (HAART). From July 2015 to November 2016, 130 HIV/AIDS patients were collected by the Yunnan Institute of Traditional Chinese Medicine, including 63 treatment-naïve patients and 67 that received HAART for 12 months. Fundus picture lesions, retinal microvascular diameters, CD4+ T lymphocyte count and HIV-1 plasma viral loads were compared between the two groups. The recruited patients were mainly young and middle-aged, with more males than females. There were no significant differences in smoking history, comorbidities and opportunistic infections between the two groups. According to the analysis results from SPSS 20.0 software, the number of CD4+ T lymphocytes in the treated patients (563.34±2.56 cells/μL) increased significantly (P=0.009) as compared with untreated patients (451.37±2.10 cells/μL), and the HIV-1 plasma viral load reduced considerably (4794 vs 0 copy/mL, P=0.000). No significant differences were observed from the fundus picture of patients after effective HAART therapy, including the retinal artery diameter, venous diameter and arteriovenous diameter ratio.

Ophthalmic characteristics and retinal vasculature changes in Williams syndrome, and its association with systemic diseases.

We aim to characterise the ophthalmic findings and retinal vasculature changes in patients with WS, and to analyse the correlation between ophthalmic manifestations and the associated systemic diseases. This retrospective case-control study included 27 WS patients and 28 age-matched healthy participants. Stellate pattern of iris, central macular thickness (CMT), foveal width, retinal vessel diameter, superficial vascular density (SVD) of macula and foveal avascular zone (FAZ) were compared between WS patients and healthy participants. Twenty-five patients (93%) had the classic stellate iris presentation. Compared with healthy controls, WS patients had decreased CMT, increased foveal width and a lower SVD of macula (all P < 0.001). Significantly decreased mean retinal arterial (117.9 ± 9.9 µm vs. 133.0 ± 6.7 µm in WS and controls, respectively; p < 0.001) and venous (158.9 ± 11.2 µm vs. 174.0 ± 8.0 µm in WS and controls, respectively; p < 0.001) outer diameters, as well as mean arterial wall thickness (11.2 ± 1.3 µm vs. 12.2 ± 0.8 µm in WS and controls, respectively; p < 0.01) were found in WS. Stellate iris grading was significantly associated with CMT, foveal width, retinal vessel diameter (all p < 0.05), and a significant increase in the odds of having hypertension (Odds ratio (OR), 5.63; P < 0.05). The severity of stellate iris in WS seemed to have the trend of increasing risk of having pulmonary stenosis, tricuspid regurgitation and mitral regurgitation. This study provides the first in vivo evidence reflecting current knowledge on vessel morphology in WS patients that deficient circumferential growth is the predominant pathophysiologic changes resulting from elastin deficiency. The ophthalmic characteristics may serve as a complementary tool to diagnose and follow-up patients suffering from WS.

Abnormal Retinal Vessel Architecture in Albinism and Idiopathic Infantile Nystagmus.

PurposeInfantile nystagmus syndrome (INS) causes altered visual development and can be associated with abnormal retinal structure, to which vascular development of the retina is closely related. Abnormal retinal vasculature has previously been noted in albinism but not idiopathic infantile nystagmus. We compared the number and diameter of retinal vessels in participants with albinism (PWA) and idiopathic infantile nystagmus (PWIIN) with controls.MethodsFundus photography data from 24 PWA, 10 PWIIN, and 34 controls was analyzed using Automated Retinal Image Analyzer (ARIA) software on a field of analysis centered on the optic disc, the annulus of which extended between 4.2 mm and 8.4 mm in diameter.ResultsCompared with controls, the mean number of arterial branches was reduced by 24% in PWA (15.5 vs. 20.3, P < 0.001), and venous branches were reduced in both PWA (29%; 12.9 vs. 18.2, P < 0.001) and PWIIN (17%; 15.1 vs. 18.2, P = 0.024). PWA demonstrated 7% thinner “primary” (before branching) arteries (mean diameter: 75.39 µm vs. 80.88 µm, P = 0.043), and 13% thicker (after branching) “secondary” veins (66.72 µm vs. 59.01 µm in controls, P = 0.009).ConclusionsPWA and PWIIN demonstrated reduced retinal vessel counts and arterial diameters compared with controls. These changes in the superficial retinal vascular network may be secondary to underdevelopment of the neuronal network, which guides vascular development and is also known to be disrupted in INS.

Assessment of the impact of N95 respirators or surgical masks use on the retinal microvasculature.

To determine the possible impact of wearing N95 respirator or surgical masks on retinal vessel diameters and choroidal thickness in healthy healthcare workers. Diameters of peripapillary retinal arteries and veins and choroidal thickness values at the foveal center and at 1000 μm distances from the foveal center in both nasal and temporal directions were measured before mask wearing using a spectral-domain optical coherence tomography. After four hours (h) of N95 or surgical mask wearing vessel diameter and choroidal thickness measurements were repeated. A total of 52 eyes from 52 participants (28 F [53.8%]; 24 M [46.2%]) were enrolled in this study. The mean age of patients was 34.58 ± 5.24 years (25-44 years). The diameters of all measured arteries [inferior temporal artery (p = 0.003), superior temporal artery (p < 0.001), inferior nasal artery (p = 0.003), and superior nasal artery (p = 0.004)] and veins,with the exception of superior nasal vein, (inferior temporal vein (p = 0.031), superior temporal vein (p = 0.027), inferior nasal vein (p < 0.001), and superior nasal vein (p = 0.063)] increased significantly after four hour use of N95 respirators and surgical maskswhen compared to baseline. There was also a significant diameter increase of the superior temporal (p < 0.001), inferior nasal veins (p < 0.001), and superior temporal artery (p = 0.037) for N95 respirators and surgical masks use, respectively. The differences in central subfoveal, temporal, and nasal choroidal thickness between baseline and after 4 h use of N95 respirators were statistically significant (From 366.73 ± 70.81 μm to 381.23 ± 69.29μm,p < 0.001 for the subfoveal; from 324.00 ± 64.13μm to 335.40 ± 61.35 μm, p = 0.007 for the temporal; from 297.40 ± 68.18 μm to 308.23 ± 74.51μm, p = 0.002 for the nasal thicknesses). Choroidal thickness values were also increased with surgical mask use. But only the increase in central subfoveal thickness was statistically significant (From 366.78 ± 71.00 μm to 372.58 ± 76.56 μm, p = 0.031 for the central subfoveal; from 297.42 ± 68.35 μmto 302.79 ± 73.05 μm, p = 0.068 for the nasal; from 324.01 ± 64.21μm to 330.33 ± 65.84, p = 0.117 for the temporal thicknesses). With four hours use of N95 respirators or surgical face masks, retinal vessel diameters and choroidal thicknesses showed an increase in comparison to baseline measurements. Hemodynamic changes seen secondary to hypercapnia due to prolonged use of N95 respirators or surgical masks may also be observed in the retinal and choroidal circulation. Furthermore, the use of face masks should be taken into account while assessing the retinal microvasculature.

Retinal nerve fiber layer thickness and retinal vascular caliber alterations in coal miners in northern China: a community-based observational study.

To evaluate retinal nerve fiber layer thickness and retinal vascular caliber alterations in coal mine workers. The community-based observational cross-sectional study included 4004 participants of a sub-population of the Kailuan Study. All the study participants underwent structured interviews with a standardized questionnaire, fundus photography and spectral-domain optical coherence tomography (OCT) examinations performed by trained doctors. The retinal nerve fiber layer thickness was significantly higher (P=0.006) and the central macular thickness was lower in coal miners (n=659, 51.0±7.8y) as compared to the control (working above the ground; n=477, 51.8±7.5y; P=0.032). Additionally, the downhole workers showed a significantly thicker retinal artery (P=0.012) and vein diameters (P<0.001). In multivariable regression, a thicker retinal nerve fiber layer was associated with a higher cumulative silica dust exposure (P=0.005) after adjusting for younger age and larger spherical equivalent. In a reverse pattern, a higher cumulative silica dust exposure (P=0.004) was significantly associated with a thicker retinal nerve fiber layer after adjusting for age, high-density lipoproteins and uric acid. Wider retinal vein diameters were associated with higher cumulative silica dust exposure (P=0.036) after adjusting for younger age and larger spherical equivalent. The retinal vessels diameters and retinal nerve fiber layer thickness are significantly thicker in long term of coal mining. The results of our study indicate that underground working environment may lead to retinal vessel dilation and inflammation. Thus, ocular examination might be needed within coal miners in order to monitor the occupational eye health as well as the incidence and progression of eye diseases.

Evaluation of choroidal thickness, retinal nerve fiber layer thickness, macular thickness and retinal vessel diameter by optical coherence tomography in patients with peripheral arterial disease

Aim: To evaluate retinal nerve fiber layer thickness, macular thickness and retinal vessel diameter by optical coherence tomography in patients with peripheral artery disease.&#x0D; Materials and Methods: 35 patients with a diagnosis of peripheral arterial disease (PAD) and 32 healthy individuals (control group) were included in the study. Retinal thickness (RT), choroidal thickness (CT) in enhanced depth imaging (EDI) mode, retinal nerve fiber layer (RNFL) thickness, retinal artery and vein diameters were measured with optical coherence tomography (OCT) device.&#x0D; Results: The mean age of the PAH group included in the study was 59.4±11.9 and the mean age of the control group was 55.5±5.3 years. A statistically significant difference was observed between the two groups in the values obtained from the CT in the subfoveal region of the EDI measured from three different regions and the nasal quadrant of the RNFL measured from 7 quadrants (p=0.03 and p=0.03, respectively). On the contrary, no statistically significant difference was observed in EDI and other measurements of RNFL, RT values, artery and vein diameters (p values were between 0.08-1.00).&#x0D; Conclusion: In patients with PAD, it is important to determine the RNFL and CT to be thinner. It can be a guide in more comprehensive studies in the future.

The Use of Fiji Image J as an Image Analysis Tool for Measuring Retinal Vessel Diameter in Rodent Model of Diabetic Retinopathy

The purpose of this study was to evaluate the use of Fiji Image J application for digital fundus image analysis of retinal vessel diameter in diabetic retinopathy rat model. Male Sprague-Dawley rats, weighing 200-250 grams, were divided into two groups: normal and diabetic. The diabetes was induced by intraperitoneal (IP) injection of streptozotocin (STZ, 55 mg/kg body weight). Normal rats received IP citrate buffer. Fundus images were captured at week 0, 6 and 12 post-induction to observe changes in retinal veins and arteries. Images obtained were then analyzed using Fiji Image J software. Retinal venous diameter was increased in both groups at week 6 and 12 compared to baseline (p&lt;0.05). However, no significant differences were seen in the retinal venous diameter at week 12 compared to week 6 in both groups. When comparing between the groups, retinal venous diameter in diabetic group was significantly greater compared to normal group at week 6 and 12 by 1.37- and 1.35-folds (p&lt;0.001), respectively. For the retinal arterial diameter in diabetic group, an increase was observed at week 6 and 12 compared to baseline by 1.17- and 1.2-folds (p&lt;0.05) respectively, however, similar changes were not observed in normal group. There was also no significant difference between the retinal arterial diameter of normal and diabetic group at week 6 and 12. In conclusion, retinal vessels diameter analysis of fundus images using Fiji Image J can be utilized to determine quantitative changes between normal and rats with STZ-induced diabetic retinopathy.

Multimodal Retinal Imaging for Detection of Ischemic Stroke.

Background: This study aims to evaluate ocular changes in patients with ischemic stroke using multimodal imaging and explore the predictive value of ocular abnormalities for ischemic stroke.Methods: A total of 203 patients (ischemic stroke group, 62; control group, 141) were enrolled in this study. Basic data from patients, including age; gender; height; weight; history of hypertension, hyperlipidemia, diabetes, alcohol use, and coronary heart disease; and smoking status, were collected. Consequently, Doppler color ultrasound, color fundus photography, and optical coherence tomography (OCT) examinations were conducted. Differences in traditional risk factors and ocular parameters between the two groups were compared, and binary logistic regression was used for multivariate analysis.Results: The central retinal artery equivalent (CRAE) in the ischemic stroke group was 150.72 ± 20.15 μm and that in the control group was 159.68 ± 20.05 μm. The difference was statistically significant (P = 0.004). Moreover, the subfoveal choroidal thickness (SFChT) in the ischemic stroke group was 199.90 ± 69.27 μm and that in the control group was 227.40 ± 62.20 μm. The difference was statistically significant (P = 0.006). Logistic regression results showed that smoking [odds ratio (OR) = 2.823; 95% confidence interval (95% CI) = 1.477–5.395], CRAE (OR = 0.980; 95% CI = 0.965–0.996), and SFChT (OR = 0.994; 95% CI = 0.989–0.999) are associated with increased risk of ischemic stroke when ocular parameters were combined with traditional risk factors. The area under the receiver operating characteristic (ROC) curve was 0.726, which shows good diagnostic accuracy.Conclusion: SFChT may be a diagnostic marker for early detection and monitoring of ischemic stroke. Combined with traditional risks, retinal artery diameter, and choroidal thickness, the prediction model can improve ischemic stroke prediction.

Retinal Vessel Diameter Changes in COVID-19 Infected Patients

ABSTRACT Purpose: To evaluate the longitudinal changes in retinal vessel diameters in patients with coronavirus disease 2019 (COVID-19). Methods: This study included 25 patients with COVID-19 (Group 1) and 25 healthy subjects (Group 2). The diameters of peripapillary temporal and nasal retinal arteries and veins were measured at baseline and at 4 months after remission. Results: The baseline diameters of the inferior temporal vein and the artery were increased in group 1 compared to controls (p = .007 and p = .041, respectively). There was also an increase in the diameters of the inferior and superior nasal veins and arteries in group 1 at baseline (p = .001, p = .019, p = .037, and p = .008, respectively). Retinal vessel diameters decreased after remission in all quadrants in comparison to baseline measurements (all p < .05). Conclusion: Increased retinal vessel diameters were measured in COVID-19 patients during the disease. Measurement of retinal vessel diameters may be a noninvasive method of estimating the vascular risk.

Correlation between total cerebral small vessel disease score and retinal vessel diameters in patients with mild stroke

Objective: To explore the relationship between the total cerebral small vessel disease (CSVD) score and retinal vessel diameters in patients with mild stroke. Methods: The patients with mild stroke who were hospitalized in the Second People's Hospital of Changzhou, Nanjing Medical University from March to December 2019 were continuously collected (National Institutes of Health Stroke Scale score≤3 points). All patients completed the head magnetic resonance imaging and retinal fundus photography examination, and then the retinal arteriovenous diameter was measured semi-automatically based on the pictures. According to the total CSVD score (0-4 points), the patients were divided into 5 groups. The baseline characteristics of the patients were compared. Moreover, the correlation of total CSVD with retinal blood vessel diameters were analyzed by spearman and linear regression. Results: A total of 206 patients were enrolled. There were 69, 51, 41, 30, and 15 patients with 0, 1, 2, 3, and 4 points, respectively. In CSVD subgroups, there were significant differences in age, duration of hypertension and diabetes (all P<0.05). The central retinal artery equivalent (CRAE), (CSVD scores 0-4 were (126±12) μm, (118±11) μm, (108±11) μm, (99±8) μm, (90±7) μm, P<0.001) and arteriole-to-venule ratio (AVR) (CSVD scores 0-4 were 0.65±0.05, 0.60±0.04, 0.56±0.04, 0.49±0.03, 0.44±0.02, P<0.001) were different in CSVD subgroups. With the increase of CSVD score, the diameter of artery and AVR became smaller. The total CSVD was significantly correlated with AVR by Spearman correlation analysis (r= 0.818, P<0.001). By constructing a linear regression equation model, the coefficient of determination of the total CSVD score (R2=0.694) was higher than that of lacunes, white matter hyperintensities, cerebral microbleeds and enlarged perivascular space. After adjusting for age, course of hypertension and diabetes, and different types of CSVD, further multiple linear regression analysis revealed that the total CSVD score was still an independent related factor of AVR (β=-0.039, P<0.001, 95%CI=-0.051--0.028). Conclusions: Total CSVD score is negatively correlated with retinal artery diameters and AVR. Additionally, the total CSVD score can better reflect the degree of cerebral microvascular lesions than single type CSVD.

Commentary: Retinal manifestations in patients following COVID-19 infection: A consecutive case series.

Coronavirus disease-2019 (COVID-19) pandemic has created a global health challenge owing to widespread mortality and morbidity. Alterations of the immune system, activation of coagulation pathways, and direct cytopathic effect of the virus are purported as the possible mechanisms that are responsible for the pathology of COVID-19. In addition to these, side effects of drugs and complications related to prolonged hospitalization and intensive care all combine to cause systemic manifestations of this virus, including ocular complications.[12] Multiple ophthalmic manifestations related to COVID-19 have been reported. Initially, when the pandemic started, ocular surface involvement was reported with self-limiting conjunctivitis being the earliest reported ocular manifestation.[3] Subsequently, a plethora of retinal manifestations have been reported in these patients, namely cotton wool spots, flame-shaped and dot-blot hemorrhages, retinal vascular occlusions, acute macular neuroretinopathy (AMN), paracentral acute middle maculopathy (PAMM), fungal retinitis, acute retinal necrosis, and serpiginous choroiditis. Neuro-ophthalmic manifestations like optic neuritis, papillo-phlebitis, extra-ocular muscle palsies, neurogenic ptosis, intracranial hypertension, cerebrovascular accident with vision loss, and orbital manifestations like mucormycosis and histiocytic orbital mass have also been reported in patients with COVID-19.[145] In the current study, authors have enumerated varied retinal manifestations following COVID-19. Patients with candida retinitis, tubercular choroidal abscess, and central serous chorioretinopathy (CSC) have been reported for the first time in this cohort.[6] Coagulopathy and endothelial dysfunctions are known associations of COVID-19 infection. In the eye, these manifest as cotton wool spots, central retinal vein occlusion, central retinal artery occlusion, AMN, and PAMM.[57] As reported in the current article, the aforementioned entities may occur during the active phase or even after recovery from COVID-19. Presence of cotton wool spots has been shown to be a potential biomarker in identifying underlying vascular and/or neurological comorbidity in COVID-19 patients.[7] Mean retinal artery diameter and the mean retinal vein diameter (MVD), measured using the Automated Retinal Image analyzer, have been shown to be higher in COVID-19 patients compared to healthy cohorts. MVD was negatively correlated with the time from onset of symptoms and positively correlated with disease severity.[8] Herein lies the role of an ophthalmologist and ocular examination in COVID-19 patients. Fundus examination is a simple, easy to perform and non-invasive. It has been shown to predict systemic endothelial dysfunction and triggering of the inflammatory cascade in subclinical and asymptomatic patients, thereby allowing earlier institution of appropriate therapy and potentially improving long-term morbidity and mortality.

This issue of ACTA, printed and electronic

This issue of ACTA, printed and electronic

Prediabetes influences the structure of the macula: thinning of the macula in the Northern Finland Birth Cohort

Background/AimThe aim of this study was to evaluate the effect of prediabetes and diabetes on macular thickness and retinal vascular calibres in our population-based cohort (Northern Finland Birth Cohort).MethodsThe population...

Diagnosis of chronic stage of hypertensive retinopathy based on spectral domain optical coherence tomography.

Hypertensive retinopathy refers to the retinal vascular changes associated with systemic arterial hypertension. Hypertensive retinopathy can be divided into chronic and acute phases. A cross‐sectional study was performed to explore a method of measurement in the diameters of retinal vessels for diagnosis of chronic hypertensive retinopathy based on spectral domain optical coherence tomography (SD‐OCT). The central retinal artery diameter (CRAD), the central retinal vein diameter (CRVD), and the artery‐to‐vein ratio (AVR) were measured. A total of 119 subjects with 119 eyes were included in this study, in which 56 subjects with 56 eyes were included in hypertensive group and 63 subjects with 63 eyes were included in normotensive group. There were significant differences between the two groups in the CRAD (t = −2.14, P = .04) and the AVR (t = −2.59, P = .01). The cutoff point of 0.75 was determined by receiver operating characteristic (ROC) curve (area under the curve, AUC 0.786; 95% confidence interval, 95% CI 0.70‐0.87). Multivariate logistic regression analysis showed the probability of AVR below to 0.75 was more in patients with high systolic blood pressure (odds ratio OR 4.39; P = .048), more in male (OR 4.15; P = .004) and more in smokers (OR 5.80; P = .01). Bland‐Altman plots showed small mean bias between the measurements of the two technicians in the CRAD, the CRVD, and the AVR. In summary, application of SD‐OCT is an accurate, reproducible, convenient method for measuring the diameters of retinal vessels. It is valuable for the diagnosis of chronic stage of hypertensive retinopathy.