Retinal vascular findings in patients with COVID-19

Purpose:

The purpose of this study was to compare the retinal vascular caliber of COVID-19 patients with that of healthy subjects.

Methods:

This was a prospective case–control study. Forty-six patients who had COVID-19 were successfully treated, and 38 age- and gender-matched healthy subjects were enrolled in this study. Fundus photography was taken using fundus fluorescein angiography (FA; Visucam 500; Carl Zeiss Meditec, Jena, Germany). Retinal vascular caliber was analyzed with IVAN, a semi-automated retinal vascular analyzer (Nicole J. Ferrier, College of Engineering, Fundus Photography Reading Center, University of Wisconsin, Madison, WI, USA). Central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and artery–vein ratio (AVR) were compared between groups.

Results:

The mean age was 37.8 ± 9.5 years in the COVID-19 group (n = 46) and 40 ± 8 years in the control group (n = 38) (p = 0.45). The mean CRAE was 181.56 ± 6.40 in the COVID-19 group and 171.29 ± 15.06 in the control group (p = 0.006). The mean CRVE was 226.34 ± 23.83 in the COVID-19 group and 210.94 ± 22.22 in the control group (p = 0.044). AVR was 0.81 ± 0.09 in the COVID-19 group and 0.82 ± 0.13 in the control group (p = 0.712).

Conclusion:

Patients who had COVID-19 have vasodilation in the retinal vascular structure after recovery. As they may be at risk of retinal vascular disease, COVID-19 patients must be followed after recovery.

Retinal Vascular Caliber Association with Nonperfusion and Diabetic Retinopathy Severity Depends on Vascular Caliber Measurement Location

PURPOSE

To evaluate the association of retinal nonperfusion and diabetic retinopathy (DR) severity with location of vascular caliber measurement using ultrawide field (UWF) imaging.

DESIGN

Retrospective image review.

PARTICIPANTS

Adults with diabetes mellitus.

METHODS

All images from subjects with same-day UWF fluorescein angiography (FA) and color imaging were evaluated. Predominantly peripheral lesions (PPL) and DR severity were graded from UWF color images. Nonperfusion was quantified using UWF-FA in defined retinal regions [posterior pole (PP), mid-periphery (MP), far-periphery (FP)]. Retinal vessel calibers were measured at an optic disc centered inner and outer zone.

MAIN OUTCOME MEASURES

Nonperfusion index (NPI) in the PP, MP and FP. Mean arteriole and venule diameter in the inner and outer zones.

RESULTS

Two hundred eighty-five eyes of 193 patients (24.9% mild nonproliferative DR [NPDR], 22.8% moderate NPDR, 37.5% severe NPDR and 14.7% proliferative DR [PDR]) were reviewed. No significant associations between inner zone arteriolar diameter and retinal NPI overall or in any retinal region. In the outer zone, eyes with thinnest arteriolar calibers (quartile 1) were associated with a 1.7- to 2.4-fold nonperfusion increase across all retinal regions compared to the remaining eyes (P = 0.002 [PP] to 0.048 [FP]). In the outer zone, the percentage of eyes in the thinnest quartile of retinal arteriolar diameter increased with worsening DR severity (mild NPDR: 10% vs PDR: 31%, P = 0.007). This association was not observed when measured within the inner zone (P = 0.129). All venular caliber associations were not statistically significant when corrected for potentially confounding factors. Thinner outer zone retinal arteriolar caliber (quartile 1) was more common in eyes with PPL compared to eyes without PPL (34.1% vs 20.8%, P = 0.017) as were thicker outer venular calibers (quartile 4) (33% vs 21.3%, P = 0.036). Presence of PPL was associated with thinner outer zone arteriolar caliber (109.7 ± 26.5μm vs 123.0 ± 29.5μm, P = 0.001).

CONCLUSIONS

The association of vascular caliber with nonperfusion and DR severity differs based upon the retinal location at which vascular caliber is measured. Peripheral arterial narrowing is associated with increasing nonperfusion, worsening DR severity and presence of PPL. In contrast, inner zone retinal arteriolar caliber is not associated with these findings.

Abnormal retinal microvasculature found in active rheumatoid arthritis:a different perspective of microvascular health

Background/aim

We aimed to assess the association between retinal vascular caliber (RVC) scores and disease activity in rheumatoid arthritis (RA) patients.

Materials and methods

Forty-seven RA patients, 32 systemic lupus erythematosus (SLE) patients, and 45 healthy people were enrolled. RA and SLE patients were subdivided into groups according to C-reactive protein (CRP) levels. RA patients were also grouped according to Disease Activity Score-28 (DAS-28). Fundus photography was performed for all patients. RVC was summarized as the central retinal artery and vein equivalents (CRAE and CRVE).

Results

Mean CRVE for RA patients was 213.3 ± 17.8 µm compared with 209.2 ± 14.1 µm for SLE and 217.5 ± 26.2 µm for the control group (P = 0.17). RVC scores did not differ between the CRP-high and CRP-low groups. As the RA disease activity increased, the widening of CRVE became more prominent and statistically significant. When the DAS-28 > 5.1 (CRVE, 220.4 (211.8–246.5) µm) group and DAS-28 ≤ 3.2 (CRVE, 214.4 (172.4–242.3) µm) group were compared, statistical significance was more pronounced (P = 0.03) than when comparing the DAS-28 > 3.2 and DAS-28 ≤ 3.2 groups (P = 0.05).

Conclusion

CRVE, which reflects systemic inflammation and possibly increased cardiovascular risk, was significantly increased in active RA patients. The association between retinal venular widening and disease activity, regardless of CRP, may be a sign that RA-related inflammation may have systemic vascular effects even with normal levels of CRP.

Update on retinal vascular caliber

Retinal vessels are the only blood vessels that can be viewed directly, in vivo, repetitively and non-invasively. Retinal vessel caliber is influenced by physiological (age, sex, race, blood pressure, blood glucose, body mass index) and pathological (atherosclerosis, dyslipidemia, smoking) determinants. There are studies on large population groups that demonstrate the associations between retinal vasculature and subclinical or clinical changes in systemic diseases (hypertension, diabetes, stroke, renal or cardiac diseases). The assessment of retinal vessels can provide information about the pathophysiology of many diseases, but it also has a direct applicability in clinic, being used as a screening method that predicts the risk of their occurrence.

Retinal vascular diameters in relation to physical activity in Danish children - The CHAMPS Eye Study

Our objective was to determine associations between retinal vascular caliber and physical activity (PA) in a school-based child cohort. In a prospective study, we created a childhood cumulative average PA-index using objectively measured PA (accelerometry) assessed at four periods between 2009 and 2015. Cumulative exposure to PA intensities was estimated. Cross-sectional examinations on biomarkers, anthropometry, and ophthalmological data including retinal fundus photographs were performed in 2015. Semi-automated measurements of retinal vascular diameters were performed and summarized into central retinal arteriolar and venular equivalents (CRAE, CRVE). We included 307 participants. Mean age in 2015 was 15.4 years (0.7). The mean CRAE and CRVE were 156.5 μm (2.8) and 217.6 μm (7.7), respectively. After adjusting for age, gender, and axial length, more time in PA was independently related to thinner retinal venules (β-coefficient = -1.25 μm/%, 95% confidence interval = -2.20, -0.30, P < .01). Sedentary time was associated with wider venules (P < .01). Furthermore, birthweight (β-coefficient = 0.56 μm/%, 95% confidence interval = 0.18, 0.95, P < .01) was associated with CRVE. Blood pressure was associated with thinner retinal arterioles (β-coefficient = -0.19 μm/mmHg, 95% confidence interval = -0.36, -0.01, P = .04). We concluded that children with higher PA in childhood had thinner retinal venular caliber. Our results suggest that PA during childhood positively impacts the retinal microcirculation and that retinal vascular analysis may be a possible assessment to detect microvascular impairments in children with an increased risk of future cardiovascular disease.

Association of Retinal Vascular Caliber and Age-Related Macular Degeneration in Patients With the Acquired Immunodeficiency Syndrome

Purpose

To evaluate the relationship between retinal vascular caliber and AMD in patients with AIDS.

Methods

Participants enrolled in the Longitudinal Study of the Ocular Complications of AIDS had retinal photographs taken at enrollment. Retinal vascular caliber (central retinal artery equivalent [CRAE] and central retinal vein equivalent [CRVE]) and intermediate-stage AMD were determined from these retinal photographs. Photographs were evaluated by graders at a centralized reading center, using the Age-Related Eye Disease Study grading system for AMD and semiautomated techniques for evaluating retinal vascular caliber.

Results

Of the 1171 participants evaluated, 110 (9.4%) had AMD and 1061 (90.6%) did not. Compared with participants without AMD, participants with AMD had larger mean CRAEs (151 ± 16 μm versus 147 ± 16 μm; P = 0.009) and mean CRVEs (228 ± 24 μm versus 223 ± 25 μm; P = 0.02). The unadjusted differences were: CRAE, 4.3 μm (95% confidence interval [CI] 1.1-7.5; P = 0.009) and CRVE, 5.5 μm (95% CI 0.7-10.3; P = 0.02). After adjustment for age, race/ethnicity, sex, human immunodeficiency syndrome (HIV) transmission category, smoking, enrollment and nadir CD4+ T cells, and enrollment and maximum HIV load, the differences between patients with and without AMD were as follows: CRAE, 5.4 μm (95% CI 2.3-8.5; P = 0.001) and CRVE, 6.0 μm (95% CI 1.4-10.6; P = 0.01).

Conclusions

In patients with AIDS, AMD is associated with greater retinal arteriolar and venular calibers, suggesting a role for shared pathogenic mechanisms, such as persistent systemic inflammation.

Personality and Total Health Through Life Project Eye Substudy: Methodology and Baseline Retinal Features

PURPOSE

To describe the methodology and present the retinal grading findings of an older sample of australians with well-defined indices of neurocognitive function in the Personality and total Health (PATH) through life project.

DESIGN

A cross-sectional study.

METHODS

Three hundred twenty-six individuals from the PatH through life project were invited to participate. Participants completed a general questionnaire and 2-field, 45-degree nonmydriatic color digital retinal photography. Photographs were graded for retinal pathology according to established protocols.

RESULTS

Two hundred fifty-four (77.9%) subjects, aged 72 to 78 years, agreed to participate in the eye substudy. gradable images of at least 1 eye were acquired in 211 of 254 subjects (83.1%). retinal photographic screening identified 1 or more signs of pathology in 130 of the 174 subjects (74.7%) with gradable images of both eyes. a total of 45 participants (17.7%) had self-reported diabetes and diabetic retinopathy was observed in 22 (48.9%) of these participants.

CONCLUSIONS

This well-defined sample of older australians provides a unique opportunity to interrogate associations between retinal findings, including retinal vascular geometric parameters, and indices of neurocognitive function.

Retinal Vascular Caliber and Kidney Function in Children and Adolescents with Type 1 Diabetes

PURPOSE

To evaluate the relationship between retinal vascular caliber and kidney function in a cohort of Australian children and adolescents with type 1 diabetes.

METHODS

This was a cross-sectional study of 483 children and adolescents with type 1 diabetes, aged 7-18 years. An audit of medical files of participants who attended the Royal Children's Hospital, Melbourne, between January 2009 and March 2014 was performed. Albumin to creatinine ratio (ACR) was acquired through spot urine samples and microalbuminuria was classified as ACR >3.5 mg/mmol in females and >2.5 mg/mmol in males. Retinal vascular caliber was measured using a standardized protocol and later summarized as central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE).

RESULTS

CRAE was significantly narrower in participants with microalbuminuria compared to those with normo-albuminuria in crude analysis (mean ± standard deviation 159.07 ± 9.90µm vs 164.49 ± 12.45 µm; p = 0.006). After adjustment for key confounders and known or potential mediators of microalbuminuria (age, sex, ethnicity, hemoglobin A1c, systolic blood pressure, total cholesterol, body mass index, duration of diabetes and CRVE) the association between narrower CRAE and microalbuminuria was attenuated and was no longer significant (95% confidence interval 0.94-1.02, p = 0.222). No significant associations between CRVE or arteriole-to-venule ratio and microalbuminuria were observed in univariate or multivariate models.

CONCLUSIONS

After adjustment for potential confounding variables, retinal vascular caliber was not significantly associated with microalbuminuria in this sample of children and adolescents with type 1 diabetes. Future prospective longitudinal research is warranted to further evaluate these findings.

Retinal vessels caliber changes after strabismus surgery: results of 6mo follow-up

AIM

To evaluate the effect of strabismus surgery on retinal vessels calibers with digital color fundus photographs.

METHODS

Two hundred consecutive strabismus patients underwent surgery, and 118 patients (female/male, 55/63) who finished 6-month follow-up were finally included in this study. Optic disc-centered digital color fundus photographs of both eyes of all patients were taken prior to surgery and 6mo post surgery. The retinal vascular caliber of 116 operated eyes were measured using the computer program IVAN. The operated eyes were divided into 3 groups according to the surgical methods, recession of one muscle, one muscle recession and one muscle folding, one muscle resection and one muscle recession. The effect of number of altered muscles on retinal vessels was analyzed using statistic software SPSS 16.0.

RESULTS

The mean age was 12.4±8.6y. Averaged central retinal artery equivalent (CRAE) of all patients was 120.31±23.02 µm preoperatively, and 122.87±15.93 µm six months after surgery. Averaged central retinal vein equivalent (CRVE) was 171.11±31.73 µm preoperatively and 175.02±21.00 µm postoperatively. There was no significant difference of averaged CRAE (P=0.22) or CRVE (P=0.19) before and after operation. Averaged arteriole to venule ratio (AVR) was 0.71±0.07 before surgery and 0.70±0.07 after surgery. Comparison of preoperative and postoperative retinal vessels calibers among different surgical groups did not show significant differences. Also, there was no advantage of rectus muscle folding to muscle resection.

CONCLUSION

Up to 6mo after strabismus surgery, the retinal vascular calibers were not altered. No more than two muscles in one surgery are safe for retinal perfusion.

Choroidal thickness and retinal vascular caliber correlations with internal carotid artery Doppler variables

PURPOSE

Decreased retinal arteriolar caliber and increased retinal venular caliber have been associated with increased cardiovascular mortality. This study aimed to evaluate correlations of choroidal thickness and retinal vascular caliber measurements with internal carotid artery (ICA) Doppler ultrasound variables.

METHODS

In this cross-sectional and observational study, 43 eyes and ICAs of 43 healthy volunteers were examined. Spectral domain optical coherence tomography was used to measure subfoveal choroidal thickness (SFCT) and retinal vascular caliber. The ICA Doppler ultrasonographic parameters were diameter, flow volume, peak-systolic velocity, end-diastolic velocity, resistance index (RI), and pulsatility index (PI).

RESULTS

Negative correlations emerged between ICA RI and SFCT (p = 0.017, r = -0.36) as well as between ICA PI and retinal arteriolar caliber (p = 0.015, r = -0.37). A negative linear correlation appeared between ICA diameter and SFCT (p = 0.005, r = -0.42), although ICA diameter and flow volume showed no association with retinal vessel caliber (p > 0.05).

CONCLUSIONS

Choroidal thickness is negatively correlated with ICA diameter and ICA RI, while retinal arteriolar caliber is inversely related with ICA PI in normal volunteers.

Retinal vascular caliber, iris color, and age-related macular degeneration in the Irish Nun Eye Study

PURPOSE

To evaluate the relationship between retinal vascular caliber (RVC), iris color, and age-related macular degeneration (AMD) in elderly Irish nuns.

METHODS

Data from 1233 participants in the cross-sectional observational Irish Nun Eye Study were assessed from digital photographs with a standardized protocol using computer-assisted software. Macular images were graded according to the modified Wisconsin Age-related Maculopathy Grading System. Regression models were used to assess associations, adjusting for age, mean arterial blood pressure, body mass index, refraction, and fellow RVC.

RESULTS

In total, 1122 (91%) participants had gradable retinal images of sufficient quality for vessel assessment (mean age: 76.3 years [range, 56-100 years]). In an unadjusted analysis, we found some support for a previous finding that individuals with blue iris color had narrower retinal venules compared to those with brown iris color (P < 0.05), but this was no longer significant after adjustment. Age-related macular degeneration status was categorized as no AMD, any AMD, and late AMD only. Individuals with any AMD (early or late AMD) had significantly narrower arterioles and venules compared to those with no AMD in an unadjusted analysis, but this was no longer significant after adjustment. A nonsignificant reduced risk of any AMD or late AMD only was observed in association with brown compared to blue iris color, in both unadjusted and adjusted analyses.

CONCLUSIONS

Retinal vascular caliber was not significantly associated with iris color or early/late AMD after adjustment for confounders. A lower but nonsignificant AMD risk was observed in those with brown compared to blue iris color.

Reduced cranial parasympathetic tone during the remission phase of cluster headache

BACKGROUND

Cluster headache (CH) attacks are accompanied by cranial autonomic symptoms indicative of parasympathetic hyperactivity and sympathetic dysfunction ipsilateral to the pain. We aimed to assess cranial autonomic function in CH patients during the remission phase of cluster headache.

MATERIALS AND METHODS

During a remission phase, 38 episodic CH patients underwent the following: dynamic pupillometry, measurement of the superficial temporal artery diameter by ultrasound, and measurement of the retinal vessel diameters from digital retinal photographs. Pupillometry was also performed on 30 age- and sex-matched healthy controls.

RESULTS

Thirty patients were included (27 men, three women, mean age 50.2 years ± 12.6). Seven patients reported occasional side shift of their headache, but with a clear predominating side. Significantly reduced average pupillary constriction velocity and retinal venular diameter on the CH pain side were found. There was no asymmetry of the superficial temporal artery diameters. Compared to healthy controls, cluster patients displayed bilaterally reduced pupillary average and maximum constriction velocities, reduced constriction in percentage and increased latency of the light reflex.

CONCLUSIONS

The present findings indicate a bilaterally reduced cranial parasympathetic tone in CH patients in remission phase, with significant lateralization to the CH pain side. This implies a central origin, and a central pathophysiological model of CH is discussed.

Association of retinal vessel attenuation with visual function in eyes with retinitis pigmentosa

Purpose

To investigate the association between visual changes and retinal vessel attenuation in patients with retinitis pigmentosa (RP).

Design

A retrospective, longitudinal, observational cohort study.

Methods

We analyzed 45 eyes from 45 subjects who were followed-up for ≥3 years at our clinic. Using the computer-based Interactive Vessel Analysis program, central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) were determined. Age- and sex-matched controls from normal subjects were selected from our archived fundus photograph library. Visual acuity, visual field area (Goldmann perimetry, V4e white test light), mean deviation (Humphrey perimetry, central 10-2 program), and central macular thickness (optical coherence tomography) were analyzed for correlations with CRAE and CRVE.

Results

Both CRAE and CRVE were significantly decreased in RP eyes (94.9±13.5 μm and 155.6±20.0 μm, respectively) compared with control eyes (138.1±14.7 μm and 215.0±20.4 μm, respectively, both P<0.001). After 3 years of follow-up, visual field area was associated with both CRAE (r=0.584, P<0.01) and CRVE (r=0.500, P=0.008). A significant association was also observed between mean deviation and CRAE (r=0.298, P=0.047). In eyes with RP, a narrower vessel caliber at baseline was associated with a larger decline in visual acuity over the 3-year follow-up interval (CRAE: r=−0.344, P=0.021; CRVE: r=−0.314, P=0.035).

Conclusion

Retinal vessel caliber is associated with some visual functions in patients with RP.

Familial correlation of retinal vascular caliber in Singapore Chinese

PURPOSE

Our study aimed to explore the heritability of retinal vascular caliber among Singapore Chinese families.

METHODS

In the Strabismus, Amblyopia, and Refractive Error Study in Singaporean Chinese Preschoolers (STARS) family study conducted from 2008 to 2010, a total of 727 participants (304 parent-child pairs, 83 sibling pairs, and 87 spouse pairs) were included in the analysis. According to standardized protocols, retinal photography, blood pressure measurements, anthropometric measurements, and interviews were performed at clinic. Retinal vascular caliber was assessed by a computer-assisted imaging program (IVAN). Familial correlation of retinal vascular caliber among family pairs was calculated by the FCOR procedure with S.A.G.E. computer software program package and heritability was double the value of the familial correlation.

RESULTS

Mean age was 8.59 years in 304 children and 39.90 years in 423 parents. Mean CRAE and CRVE were 157.09 and 220.80 μm in children, and 150.29 and 220.70 μm in parents, respectively. In multivariate analysis, familial correlation of CRVE was 0.36 (P < 0.001) among parent-child pairs and 0.28 (P < 0.05) among sibling pairs, respectively. Heritability of CRVE was 0.72 and 0.56 among parent-child pairs and sibling pairs, respectively. Family correlation and heritability of CRAE were not significant.

CONCLUSIONS

This familial correlation study showed a strong correlation of retinal venular caliber in Singapore Chinese families among parent-child pairs and sibling pairs, independent of age, sex, blood pressure, and BMI. Our findings provide further evidence on substantial heritability of the microvasculature.

Antenatal Mental Health and Retinal Vascular Caliber in Pregnant Women

PURPOSE

Depression, anxiety, and poor sleep are associated with increased risks of cardiovascular diseases. Previous studies have demonstrated the relationship between negative emotion and retinal microvascular changes among adults, yet no study has been done in pregnant women so far. This study aims to examine the association of antenatal mental health and retinal vascular caliber among Asian pregnant women.

METHODS

Nine hundred and fifty two Asian pregnant women aged 18 to 46 years were included in this study, who were recruited from two Singapore cohort studies, the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) study and the In Vitro Fertilization (IVF) study conducted from 2009 onwards. A total of 835 Asian pregnant women underwent retinal photography at 26 weeks follow up, of whom 800 had gradable photographs. Symptoms of depression, anxiety, and sleep quality were assessed with self-administered questionnaires.

RESULTS

In multiple linear regression models adjusted for age, ethnicity, household income, pregnancy outcome history, means of conception, hypertension history, diabetes history, cigarette smoking history, mean arterial blood pressure, body mass index, and spherical equivalent, each standard deviation (SD) increase in the Edinburgh Postnatal Depression Scale (EPDS) (4.49 scores) and in the Pittsburgh Sleep Quality Index (PSQI) (2.90 scores) was associated with a 0.80 μm (P = 0.03) and a 1.22 μm (P = 0.01) widening in retinal arteriolar caliber, respectively.

CONCLUSIONS

Our study demonstrates relationships of antenatal depressive symptoms and poor sleep quality with retinal arteriolar widening in pregnant women.

TRANSLATIONAL RELEVANCE

We speculate that this might possibly indicate an effect of antenatal depression and poor sleep on the microcirculation during pregnancy.

Vital exhaustion and retinal microvascular changes in cardiovascular disease: atherosclerosis risk in communities study

OBJECTIVE

To determine if vital exhaustion, a measure of negative emotion, is associated with microvascular changes in the retina. Negative psychological factors, such as depression, have been implicated in the development of cardiovascular disease. Whether this link is mediated by macrovascular or microvascular disease is unknown.

METHODS

We performed a population-based, cross-sectional study of 10,364 White and African Americans aged 48 to 73 years. Vital exhaustion scores were determined from the Maastricht questionnaire and categorized into quartiles. Retinopathy signs and retinal vascular caliber were graded from retinal photographs following standardized protocols.

RESULTS

After adjusting for age, gender, race, study center, education, smoking, blood pressure, diabetes, and other risk factors, higher vital exhaustion scores (highest versus lowest quartiles) were associated modestly with the presence of retinopathy (odds ratio [OR] = 1.27; 95% Confidence Interval [CI] = 1.01-1.59), particularly retinal hemorrhages (OR = 1.71; 95% CI = 1.20-2.44), and with generalized retinal venular widening (OR = 1.19; 95% CI = 1.03-1.38). Analyzing vital exhaustion as a continuous variable did not change the pattern of the associations.

CONCLUSIONS

Middle-aged people with vital exhaustion may be more likely to have retinopathy signs that have been identified as risk predictors of cardiovascular events. Further research is needed to explore the possible adverse effects of negative emotion on the microcirculation.