Choroidal thickness in relation to hypercholesterolemia on enhanced depth imaging optical coherence tomography

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

PURPOSE

Ocular ischemic syndrome can be the first and only hint of life-threatening carotid artery disease. The early recognition of carotid stenosis-related retinal signs, as well as the comprehension of the pathophysiology behind retinal changes could become relevant for physicians to predict the risk of stroke. The aim of this study is to assess the carotid artery disease-induced early structural retinochoroidal changes by means of swept-source optical coherence tomography (SS-OCT).

METHODS

A prospective observational study was conducted in 72 eyes with carotid stenosis. According to the degree of stenosis, the participants were divided into a normal group (34 eyes), a mild-moderate stenosis group (22 eyes), a severe stenosis group (16 eyes). SS-OCT and OCTA were performed to scan macular fovea. Central macular thickness (CMT), subfoveal choroidal thickness (SCT) and foveal avascular zona (FAZ) area were the major measurements for our study.

RESULTS

CMT was significantly thicker in group 3 when compared to group 2 and 1. SCT was significantly thinner in group 3 vs group 1, being thicker in group 2 when compared to group 1. No significant differences were obtained when comparing FAZ in the superficial and middle capillary plexus although it was significant when comparing the FAZ in the deep capillary plexus between group 1 and 3.

CONCLUSION

internal carotid artery stenosis greater than 70% leads to a significant increase in CMT and a decrease in SCT prior the development of clinical findings of ocular ischemia syndrome.

Analysis of the Choroidal Structure in the Early Stage of Type 2 Diabetic Retinopathy

BACKGROUND AND OBJECTIVE

Our aim was to evaluate the choroidal structure in the early stage of Type 2 diabetic retinopathy (DR).

MATERIALS AND METHODS

The study included patients with nonproliferative diabetic retinopathy (NPDR) without edema (n = 30, NPDR group), patients with diabetes without retinopathy (n = 30, No DR group), and healthy subjects (n = 33, control group). Choroidal thickness (CT), total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI) were evaluated.

RESULTS

The hypertension (HT) rate was highest in patients with NPDR (63.3%), and lowest in the control group (27.3%). Subfoveal, nasal, temporal CT, TCA, and LA were thinner in patients with diabetes compared to the control group for both patients with and without HT, although not significantly. CTs, TCA, LA, and SA were lower in hypertensive patients than patients without HT in all groups. CVI and LA/SA were significantly lower in NPDR group compared to the controls for both patients with and without HT.

CONCLUSION

In patients with diabetes and before clinical retinopathy develops, the thinning of the CT and CVI begins. A decrease in CVI continues as the retinopathy progresses. HT appears to be a factor that can reduce CT, TCA, LA, and SA. [Ophthalmic Surg Lasers Imaging Retina 2024;55:392-399.].

Optical coherence tomography choroidal enhancement using generative deep learning

Spectral-domain optical coherence tomography (SDOCT) is the gold standard of imaging the eye in clinics. Penetration depth with such devices is, however, limited and visualization of the choroid, which is essential for diagnosing chorioretinal disease, remains limited. Whereas swept-source OCT (SSOCT) devices allow for visualization of the choroid these instruments are expensive and availability in praxis is limited. We present an artificial intelligence (AI)-based solution to enhance the visualization of the choroid in OCT scans and allow for quantitative measurements of choroidal metrics using generative deep learning (DL). Synthetically enhanced SDOCT B-scans with improved choroidal visibility were generated, leveraging matching images to learn deep anatomical features during the training. Using a single-center tertiary eye care institution cohort comprising a total of 362 SDOCT-SSOCT paired subjects, we trained our model with 150,784 images from 410 healthy, 192 glaucoma, and 133 diabetic retinopathy eyes. An independent external test dataset of 37,376 images from 146 eyes was deployed to assess the authenticity and quality of the synthetically enhanced SDOCT images. Experts' ability to differentiate real versus synthetic images was poor (47.5% accuracy). Measurements of choroidal thickness, area, volume, and vascularity index, from the reference SSOCT and synthetically enhanced SDOCT, showed high Pearson's correlations of 0.97 [95% CI: 0.96-0.98], 0.97 [0.95-0.98], 0.95 [0.92-0.98], and 0.87 [0.83-0.91], with intra-class correlation values of 0.99 [0.98-0.99], 0.98 [0.98-0.99], and 0.95 [0.96-0.98], 0.93 [0.91-0.95], respectively. Thus, our DL generative model successfully generated realistic enhanced SDOCT data that is indistinguishable from SSOCT images providing improved visualization of the choroid. This technology enabled accurate measurements of choroidal metrics previously limited by the imaging depth constraints of SDOCT. The findings open new possibilities for utilizing affordable SDOCT devices in studying the choroid in both healthy and pathological conditions.

Choroidal Changes in Patients with Diabetic Retinopathy: A Retrospective Study

This study aimed to investigate the characteristic choroidal changes in patients with diabetic retinopathy and identify factors affecting choroidal thickness (CTh), choroidal vascular index (CVI), and choriocapillaris flow. We retrospectively analyzed 79 eyes of 48 patients with diabetes between August 2021 and February 2022. We collected laboratory data, including HbA1c, serum creatinine, blood urea nitrogen, triglyceride, total cholesterol, high-density lipoprotein, and low-density lipoprotein (LDL) levels. Optical coherence tomography images of the foveal avascular zone, retinal vascular density, choroidal flow, retinal thickness, CTh, and CVI were analyzed. Possible determining factors affecting CTh, CVI, and choriocapillaris flow were analyzed using nonparametric multivariate analysis. LDL (p < 0.001) positively correlated with CTh, whereas CVI (p = 0.007) was negatively correlated with CTh in diabetic patients with diabetes. We also identified a negative correlation between choriocapillaris flow and deep parafoveal retinal vessel density in patients with low-grade diabetic retinopathy (DR), which diminished in those with more advanced DR. Our study provides further information on the changes in choroidal structure and blood flow in patients with diabetes.

Clinical and biological correlates of optical coherence tomography findings in schizophrenia

There is a growing body of evidence indicating retinal layer thinning in schizophrenia. However, neuropathological processes underlying these retinal structural changes and its clinical correlates are yet to be known. Here, we aim to investigate the clinical and biological correlates of OCT findings in schizophrenia. 50 schizophrenia patients and 40 healthy controls were recruited. Retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and macular and choroidal thicknesses were recorded. A comprehensive battery of neuropsychological tests was applied. Fasting glucose, triglycerides and HDL-cholesterol levels, TNF-α, IL-1β and IL-6 levels were measured. Right IPL was significantly thinner in patients than the controls after controlling for various confounders (F = 5.42, p = .02). Higher IL-6, IL-1β, and TNF-α levels were associated with decreased left macular thickness (r =  - 0.26, p = .027, r =  - 0.30, p = 0.012, and r =  - 0.24, p = .046, respectively) and higher IL-6 was associated with thinning of right IPL (r =  - 0.27, p = 0.023) and left choroid (r =  - 0.23, p = .044) in the overall sample. Thinning of right IPL and left macula were also associated with worse executive functioning (r = 0.37, p = 0.004 and r = 0.33, p = 0.009) and attention (r = 0.31, p = 0.018 and r = 0.30, p = 0.025). In patients with schizophrenia, IPL thinning was associated with increased BMI (r =  - 0.44, p = 0.009) and decreased HDL levels (r = 0.43, p = 0.021). Decreased TNF-α level was related to IPL thinning, especially in the left eye (r = 0.40, p = 0.022). These findings support the hypothesis that OCT might provide the opportunity to establish an accessible and non-invasive probe of brain pathology in schizophrenia and related disorders. However, future studies investigating retinal structural changes as a biological marker for schizophrenia should also consider the metabolic state of the subjects.

The Association Between Lipid Profile and Subfoveal Choroidal Thickness in Chinese Patients with Proliferative Diabetic Retinopathy Secondary to Type 2 Diabetes

Introduction

Extensive studies have studied the factors associated with subfoveal choroidal thickness (SFCT). However, studies of the association between lipid profile and SFCT in patients with proliferative diabetic retinopathy (PDR) in type 2 diabetes remain limited. Thus, we aimed to investigate the relationship between lipid profile and SFCT in patients with PDR.

Materials and Methods

This was a retrospective cross-sectional study. The included participants were inpatients who underwent vitrectomy for PDR with type 2 diabetes and contralateral eyes of PDR patients meeting the criteria. Multivariate linear regression analysis was used to determine the independent association between lipid profile and SFCT.

Results

A total of 131 participants with PDR were enrolled in the final analysis. The average age of the participants was 55.76 ± 9.88 years, and the average SFCT was 276.10 ± 92.92 μm. Multivariate linear regression model results showed that in the fully adjusted model, total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) had a negative association with SFCT (β = -16.51, 95% CI: -29.57, -3.46; P = 0.0148; β = -42.65, 95% CI: -82.60, -2.70; P = 0.0390; β = -17.89, 95% CI: -33.24, -2.54; P = 0.0245, respectively), while triglyceride was not significantly associated with SFCT (β = 5.23, 95% CI: -18.57, 29.02; P = 0.6678). Furthermore, the results of stratified analysis showed that except for triglyceride, the trends of total cholesterol, HDL-C, LDL-C, and SFCT were consistent among different stratifications in participants.

Conclusion

The cholesterol profile had a significant negative association with SFCT in Chinese PDR patients, but triglyceride was not significantly associated with SFCT. This suggests that these systemic imbalances contribute to choroidal changes, and often coexist in diabetic patients.

Retinal and Choroidal Alterations in Diabetic Retinopathy Treatment using Subthreshold Panretinal Photocoagulation with Endpoint Management Algorithm: A Secondary Analysis of a Randomized Clinical Trial

INTRODUCTION

The aim of this study was to compare retinal and choroidal alterations in eyes with severe nonproliferative diabetic retinopathy (NPDR) after panretinal photocoagulation (PRP), using conventional pattern scan laser (PASCAL) and PASCAL with endpoint management (EPM).

METHODS

This was a post hoc analysis of a paired randomized clinical trial. Bilateral treatment-naïve eyes of an individual with symmetric severe NPDR were randomly allocated into the threshold PRP group and subthreshold EPM PRP group. Patients had follow-up visits at 1, 3, 6, 9, and 12 months post-treatment. The retinal thickness (RT), choroidal thickness (CT), choroidal area, and choroidal vascularity index (CVI) were compared between the two groups and among different time points within the same group.

RESULTS

Seventy eyes of 35 patients with diabetes mellitus (DM) were finally included for analysis at the 6- and 12-month visits, respectively. At 3 and 6 months post-treatment, the RT in the subthreshold EPM PRP group was significantly thinner than that in the threshold PRP group. CT, stromal area, and luminal area were reduced earlier in the threshold PRP group than in the subthreshold EPM PRP group. CVI was not significantly different within the same group or between groups at most time points.

CONCLUSION

At 12 months post-treatment, retinal thickening and choroidal disturbance may be slightly less severe and more delayed in eyes receiving PRP using PASCAL with EPM than in those receiving PRP using conventional PASCAL. The EPM algorithm may be a good alternative in PRP when treating severe NPDR.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01759121.

Postoperative Choroidal Vascular Biomarkers in Eyes with Rhegmatogenous Retinal Detachment-Related Giant Retinal Tears

PURPOSE

Choroidal vascularity index (CVI) and choriocapillaris flow area (CFA) are perfusion biomarkers relevant to retinal disease management. There is limited knowledge regarding these biomarkers in eyes that have been successfully treated for rhegmatogenous retinal detachment (RRD) due to giant retinal tears (GRTs). This study aimed to analyze the relationship between choroidal perfusion biomarkers and functional outcomes in surgically treated eyes with GRT-associated RRD and their fellow eyes.

METHODS

A total of 33 GRT eyes and 29 fellow eyes were included in this study. All RRD-GRT eyes were treated with vitrectomy and categorized into two groups based on whether additional scleral buckles (SB) were placed. Visual and choroidal features were compared between the groups.

RESULTS

The subjects had an average age of 55.18 years, a mean time of 2.36 weeks before surgery, and a mean follow-up time of 25.9 months. Best-corrected visual acuity (BCVA) was substantially worse in GRT eyes (1.9 logMAR) than in fellow control eyes (0.23 logMAR) but substantially improved after surgery (0.59 logMAR). There were no differences in the presurgical characteristics and BCVA between the eyes that did and did not undergo SB. Long-term CVI and CFA were lower in eyes with GRT than in their fellow eyes. Among eyes with GRT, those with SB had significantly lower CVI and CFA. Correlation analysis revealed that the CVI and CFA were positively correlated with visual outcomes (negative correlation with logMAR).

CONCLUSION

Despite successful surgical repair, long-term functional and choroidal evaluations showed permanent changes in eyes with GRT. Positive correlations between perfusion biomarkers and visual function suggest that better choroidal vasculature is associated with better visual outcomes. The results of this study highlight the benefits of analyzing choroidal vasculature biomarkers and the relationship between the choroidal anatomy and vision.

Obesity-induced ocular changes in children and adolescents: A review

Childhood obesity has reached epidemic levels worldwide. Overweight and obesity is associated with an increase in several inflammatory markers, leading to chronic low-grade inflammation responsible for macro- and microvascular dysfunction. While the impact of obesity on overall health is well-described, less is known about its ocular manifestations. Still, there are few studies in children and adolescents in this regard and they are inconsistent. However, some evidence suggests a significant role of overnutrition in the development of changes in retinal microvasculature parameters (wider venules, narrower arterioles, lower arteriovenous ratio). Higher values of intraocular pressure were found to be positively correlated with high body mass index (BMI) as well as obesity. In addition, the retinal nerve fiber layer (RNFL) values seem to be lower in obese children, and there is a significant negative correlation between RNFL values and anthropometric and/or metabolic parameters. Changes also could be present in macular retinal thickness and choroidal thickness as well as in the retinal vessel density in children with obesity. However, these associations were not consistently documented. The purpose of this review is to present the most current issues on child obesity and the related potential ocular effects through an overview of international publications from the years 1992-2022.

Retinal Thickness Correlates with Cerebral Hemodynamic Changes in Patients with Carotid Artery Stenosis

Background: We aimed to assess the retinal structural and choroidal changes in carotid artery stenosis (CAS) patients and their association with cerebral hemodynamic changes. Asymptomatic and symptomatic patients with unilateral CAS were enrolled in our study. Material and methods: Swept-source optical coherence tomography (SS-OCT) was used to image the retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCIPL), while SS-OCT angiography (SS-OCTA) was used to image and measure the choroidal vascular volume (CVV) and choroidal vascular index (CVI). Computed Tomography Perfusion (CTP) was used to assess the cerebral perfusion parameters; relative perfusion (r) was calculated as the ratio of the value on the contralateral side to that on the ipsilateral side. Results: Compared with contralateral eyes, ipsilateral eyes showed significantly thinner RNFL (p < 0.001), GCIPL (p = 0.013) and CVV (p = 0.001). Relative cerebral blood volume (rCBV) showed a significant correlation with RNFL (p < 0.001), GCIPL (p < 0.001) and CVI (p = 0.027), while the relative permeability surface (rPS) correlated with RNFL (p < 0.001) and GCIPL (p < 0.001). Conclusions: Our report suggests that retinal and choroidal changes have the potential to detect hemodynamic changes in CAS patients and could predict the risk of stroke.

Choroidal Assessment in Patients with Type 2 Diabetes Mellitus and Non-Proliferative Diabetic Retinopathy by Swept-Source Ocular Coherence Tomography and Image Binarization

Background and Objectives: The aim of this study was to evaluate choroidal structure and vascularity indices in patients with non-proliferative diabetic retinopathy (NPDR). Materials and Methods: Sixty-three eyes from sixty-three patients were evaluated: 21 from healthy subjects, 20 with diabetes mellitus (DM) and no diabetic retinopathy (DR), and 22 with DM and non-proliferative diabetic retinopathy without diabetic macular edema (DME). Each patient underwent ocular examination, macular swept-source ocular coherence tomography (SS-OCT) imaging, glycemic control, and systemic high blood pressure (HBP) evaluation. Subfoveal choroidal thickness (SF-CT) was manually assessed on a line scan. Line scan OCT images were exported to ImageJ program. The areas under a 1.5, 3 and 6 mm horizontal line centered on the fovea were assessed by converting the OCT images to binary images, and total choroidal area (TCA), luminal area (LA), stromal area (SA), LA:SA ratio, and choroidal vascularity index (CVI) were evaluated. SF-CT and choroidal parameters were compared between groups, and correlations with ocular and systemic factors were analyzed. Results: SF-CT, TCA, LA, and SA were similar between groups. CVIs were significantly different between groups for all three studied areas (CVI-1.5: 66.21% vs. 66.06% vs. 63.74%, p = 0.003; CVI-3: 65.88% vs. 66.46% vs. 63.79%, p = 0.008; CVI-6: 64.79% vs. 65.40% vs. 63.61%, p = 0.032). NPDR patients had significantly lower CVIs compared to DM patients (p < 0.05). No association of choroidal parameters with glycemic control, DM duration and HBP was found significant (p < 0.05). Conclusions: Choroidal assessment by SS-OCT and image binarization in healthy subjects, subjects with DM without DR, and subjects with DM and NPDR indicated that CVI changes were identifiable and significant in early DR. The lack of association with ocular and systemic factors suggest that CVIs are reliable assessment parameters of choroidal vascular structure.

Arterial Hypertension and the Hidden Disease of the Eye: Diagnostic Tools and Therapeutic Strategies

Hypertension is a major cardiovascular risk factor that is responsible for a heavy burden of morbidity and mortality worldwide. A critical aspect of cardiovascular risk estimation in hypertensive patients depends on the assessment of hypertension-mediated organ damage (HMOD), namely the generalized structural and functional changes in major organs induced by persistently elevated blood pressure values. The vasculature of the eye shares several common structural, functional, and embryological features with that of the heart, brain, and kidney. Since retinal microcirculation offers the unique advantage of being directly accessible to non-invasive and relatively simple investigation tools, there has been considerable interest in the development and modernization of techniques that allow the assessment of the retinal vessels’ structural and functional features in health and disease. With the advent of artificial intelligence and the application of sophisticated physics technologies to human sciences, consistent steps forward have been made in the study of the ocular fundus as a privileged site for diagnostic and prognostic assessment of diverse disease conditions. In this narrative review, we will recapitulate the main ocular imaging techniques that are currently relevant from a clinical and/or research standpoint, with reference to their pathophysiological basis and their possible diagnostic and prognostic relevance. A possible non pharmacological approach to prevent the onset and progression of retinopathy in the presence of hypertension and related cardiovascular risk factors and diseases will also be discussed.

Choriocapillaris Flow Deficits in Normal Chinese Imaged by Swept-Source Optical Coherence Tomographic Angiography

PURPOSE

To evaluate the ocular and systemic determinants of the choriocapillaris flow deficits percentage (CC FD%) in normal eyes.

DESIGN

Observational cross-sectional study.

METHODS

Healthy Chinese participants without ocular or systemic diseases underwent detailed ophthalmic evaluations, including swept-source optical coherence tomography angiography (SS-OCTA) with 6- × 6-mm macular choriocapillaris images. The CC FD% was assessed in circular regions with diameters of 1.0 and 5.0 mm, rings with 1.0- to 2.5-mm diameters, and rings with 2.5- to 5.0-mm diameters.

RESULTS

The study included 830 individuals (mean ± SD age 58.66 ± 8.75 years). CC FD% (mean ± SD 22.05% ± 1.13%) was the lowest in the 2.5- to 5.0-mm ring, followed by the 1.0- to 2.5-mm ring, and highest in the 1.0-mm circle. In multivariable analysis, a higher CC FD% was associated with older age (β = 0.16 [95% confidence interval {CI}] 0.08-0.24, P < .001), higher intraocular pressure (β = 0.34 [95% CI 0.25-0.42], P < .001), higher serum concentrations of high-density lipoprotein cholesterol (β = 0.24 [95% CI 0.17-0.32], P < .001), and lower image quality score (β = -0.22 [95% CI -0.30 to -0.14], P < .001). CC FD% was also independent of axial length.

CONCLUSIONS

In healthy adult Chinese individuals, a higher CC FD% was associated with older age, higher intraocular pressure, and higher high-density lipoprotein cholesterol serum concentration. These factors may influence clinical assessments of the choriocapillaris. The lack of an association between CC FD% and axial length is consistent with similar findings for Bruch membrane thickness, macular retinal thickness, and macular retinal pigment epithelium cell density.

Choroidal thickness in patients with systemic arterial hypertension: a systematic review and meta-analysis

Background:

The global burden of hypertension is constantly increasing with adverse cardiovascular and ocular sequelae. The association between elevated blood pressure and choroidal thickness (CT), as assessed via optical coherence tomography (OCT), is poorly understood.

Objectives and Design:

Studies including hypertensive adults and normotensive controls undergoing OCT were evaluated for inclusion in this meta-analysis. The primary endpoint was CT difference between hypertensive and normotensive adults.

Data Sources and Methods:

We conducted a systematic review and after searching 1011 results from MEDLINE, ClinicalTrials.gov, medRxiv and Cochrane Library, six studies were deemed eligible and were pooled according to a random-effect model.

Results:

A statistically significant reduction in choroidal thickness was found in hypertensive adults ( n = 454) as compared with normotensive controls ( n = 365) [mean difference: −0.77; 95% confidence intervals: (−1.20, −0.34); p = 0.0004]. The main limitations of this meta-analysis are the relatively small population included and the high statistical heterogeneity ( I2 = 87%) among the various studies. Of note, after excluding one study the heterogeneity was markedly reduced.

Conclusion:

Choroidal thickness is reduced among hypertensive subjects compared with normotensive controls. This finding mandates further examination in the context of long-term clinical outcomes.

The impact of vascular risk factors on the thickness and volume of the choroid in AMD patients

Disturbances in choroidal microcirculation may lead to the onset and progression of age-related macular degeneration (AMD). We aimed to assess changes in the choroidal volume and thickness in the macular region in AMD eyes and to investigate whether coexisting vascular risk factors alter choroidal status. We enrolled 354 AMD patients (175 dry, 179 wet AMD) and 121 healthy controls. All participants underwent a complete ophthalmologic examination and assessment of choroidal thickness and volume. A multivariate analysis adjusted for age, sex, and smoking status revealed that wet AMD was an independent factor associated with higher average thickness of the central ring area (ATC) and average volume of the central ring area (AVC) and lower choroidal vascularity index (CVI) compared to controls (β =  + 0.18, p = 0.0007, β =  + 0.18, p = 0.0008, respectively) and to dry AMD (β =  + 0.17, p = 0.00003 for both ATC and AVC and β =  - 0.30 p < 0.0001 for CVI). ATC, AVC and average volume (AV) were lower in AMD patients with hypertension and ischaemic heart disease (IHD). The duration of hypertension was inversely correlated with ATC, AVC and AV (Rs =  - 0.13, p < 0.05; Rs =  - 0.12; p < 0.05, Rs =  - 0.12; p < 0.05, respectively) while IHD duration negatively correlated with AV (Rs =  - 0.15, p < 0.05). No such associations were observed in the control group. Our findings show that the choroidal vascular system in eyes with AMD is much more susceptible to damage in the presence than in the absence of systemic vascular disease.

Changes in choroidal thickness after anti-vascular endothelial growth factor treatment of diabetic macular edema, real-life data, 2-year results

PURPOSE

To evaluate the effect of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection on central choroidal thickness (CCT), central macular thickness (CMT) and best-corrected visual acuity (BCVA) in diabetic macular edema (DME).

METHODS

Retrospective, cohort analysis of 90 eyes of 90 patients receiving anti-VEGF therapy for DME. In patients' records, measurements of CCT, CMT, and BCVA before treatment and at 2 years after treatment were recorded. Using enhanced-depth imaging optical coherence tomography (EDI-OCT) images, choroidal thickness and macular thickness measurements were recorded in the subfoveal area and 1 mm nasal to 1 mm temporal to the central foveal area. The baseline and final CMT and CCT values measured from all three quadrants were analyzed statistically.

RESULTS

Mean age of the patients was 59.60 ± 9.78 (range, 40-77) years. Mean baseline nasal-CT 226.4 ± 52.5 µm, central-CT 243.2 ± 51.1 μm and temporal-CT 224.6 ± 47.9 μm. Mean final nasal-CT 220.0 ± 50.2 µm, central-CT 235.3 ± 53.6 μm, temporal-CT 220.5 ± 48.1 μm (p = 0.122, p = 0.056, p = 0.184, respectively). Mean baseline nasal- MT 385.3 ± 67.7, central-MT 345.5 ± 119.7 μm and temporal-MT 365.0 ± 64.9 μm. Mean final nasal-MT 359.6 ± 59.2 µm, central-MT 306.2 ± 98.4 μm and temporal-MT 353.4 ± 63.3 μm (p = 0.001, p = 0.002, p = 0.234, respectively). The BCVA improved from 0.52 ± 0.44 logMAR at baseline to 0.38 ± 0.33 at final (p = 0.002).

CONCLUSION

After treatment of diabetic macular edema with intravitreal anti-VEGF injection, CMT and BCVA improved significantly, but CCT did not decrease significantly.

Heart, Eye, and Artificial Intelligence: A Review

Heart disease continues to be the leading cause of death in the USA. Deep learning-based artificial intelligence (AI) methods have become increasingly common in studying the various factors involved in cardiovascular disease. The usage of retinal scanning techniques to diagnose retinal diseases, such as diabetic retinopathy, age-related macular degeneration, glaucoma and others, using fundus photographs and optical coherence tomography angiography (OCTA) has been extensively documented. Researchers are now looking to combine the power of AI with the non-invasive ease of retinal scanning to examine the workings of the heart and predict changes in the macrovasculature based on microvascular features and function. In this review, we summarize the current state of the field in using retinal imaging to diagnose cardiovascular issues and other diseases.

Comparison of choroidal thicknesses in patients with coronary artery disease and patients at risk of coronary artery disease

PURPOSE

The study aimed to compare choroidal thicknesses (CTh) in patients with coronary artery disease (CAD) and patients at risk of coronary artery disease and investigate whether thinning of the choroid can be used as a biomarker for development of coronary artery disease in patients at risk.

MATERIALS AND METHODS

The study group was composed of 103 eyes of 53 patients with coronary artery disease, and the control group was composed of 62 eyes of 32 patients with diabetes mellitus, hypertension and/or hyperlipidemia without coronary artery disease. CAD was diagnosed in patients with one of the following: myocardial infarction with/without ST segment elevation, clinically proven history of cardiac catheterization testifying greater than 50% obstruction in at least one coronary artery, revascularization operations. The control group consisted of clinically proven patients with normal coronary arteries. The choroidal thickness was measured with enhanced depth imaging optical coherence tomography under the fovea and at six other points, located at 500 micron, 1000 micron and 1500 micron nasal to the fovea and 500 micron, 1000 micron, 1500 micron temporal to the fovea.

RESULTS

The subfoveal choroidal thickness was significantly thinner in the coronary artery disease group compared to the control group (244 µm vs. 289 µm; p < 0,001). In all other measured regions (nasal 500, nasal 1000, nasal 1500, temporal 500, temporal 1000, and temporal 1500 micron), CTh was statistically significant thinner in the CAD group. A negative significant linear relationship (low level) between CAD duration and choroidal thickness in the subfoveal, nasal 1000, nasal 1500, temporal 500, temporal 1000 micron regions was detected.

CONCLUSION

Patients with CAD have a decreased choroidal thickness compared to patients at risk of CAD. Detection of CTh thinning in a patient with diseases, such as diabetes, hypertension and/or hypercholesterolemia, which pose a risk for CAD may be a predictor of development of coronary artery disease. Clinical Trials Registration Kocaeli Derince Training and Research Hospital ethics committee-protocol number: 2020-106.

Patterns and Determinants of Choroidal Thickness in a Multiethnic Asian Population: The Singapore Epidemiology of Eye Diseases Study

PURPOSE

To describe the distribution and determinants of choroidal thickness (CT) in participants in a population study based on spectral-domain (SD)-OCT measurements.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

Ethnic Chinese, Indian, and Malay adults aged more than 50 years without any retinal diseases (e.g., diabetic retinopathy, macular edema, age-related macular degeneration, central serous chorioretinopathy) that might affect the CT were recruited from the Singapore Epidemiology of Eye Diseases Study.

METHODS

Choroidal imaging was performed by SD-OCT (Spectralis, Heidelberg Engineering, Heidelberg, Germany) in enhanced depth imaging (EDI) mode. Subfoveal choroidal thickness (SFCT) was measured on the foveal line scan by 2 retinal experts independently (YS and KT), and the average was used in the analyses. In Chinese and Indian cohorts in whom macular raster scans were captured, the manufacturer-supplied research software (Heyex SP-X version 6.4.8.116; Heidelberg Engineering) was used to obtain automated segmentation yielding mean choroidal thickness in each of the 9 ETDRS grid sectors.

MAIN OUTCOME MEASURES

Subfoveal choroidal thickness and regional CT in the 9 ETDRS grid sectors.

RESULTS

For the SFCT analysis, 2794 eyes of 1619 participants (Chinese, Indian, and Malay ) were included. The mean age was 60.9 years (standard deviation, 7.7), and 797 (49.2%) were male. Mean SFCT was 255.2 μm (standard deviation, 102.6). The normal range of SFCT was 106 to 447 μm (corresponding to 5^th and 95^th percentile limits of SFCT, respectively). In multivariable models, thinner SFCT was associated with older age, female gender, longer axial length, and Malay (vs. Chinese) ethnicity. In the subset of Chinese and Indian eyes (n = 1842) in whom regional variation was evaluated, the choroid was thickest at the superior and temporal sectors and thinner at the inferior and nasal sectors.

CONCLUSIONS

Subfoveal choroidal thickness is influenced by age, gender, and ethnicity along with regional differences even within individual eyes. Subfoveal choroidal thickness also shows a wide range in physiologic limits. These data may be used as a reference in future studies.

Evaluation of Peripapillary and Subfoveal Choroid Thickness in Asymptomatic Carotid Artery Stenosis

Objective

In this study, it aims to investigate the effect of asymptomatic carotid artery stenosis on peripapillary and subfoveal choroid thickness using enhanced depth imaging optical coherence tomography.

Patients and Methods

While investigating for coronary artery disease, 76 patients with asymptomatic carotid artery stenosis and 35 patients with normal carotid artery (total = 111) were evaluated. Patients according to the degree of stenosis were divided into four categories as non-stenosis (n = 35), mild (n = 26), moderate (n = 27) and severe stenosis (n = 23). Subfoveal and peripapillary choroid thickness, ocular perfusion and intraocular pressures of all patients were measured using a Fourier-domain optical coherence tomography after general ophthalmological examination. In addition, hypertension, hyperlipidemia, and whether there is a relationship between smoking status and choroid thickness was compared.

Results

As the degree of carotid artery stenosis increased, subfoveal and peripapillary choroidal thickness decreased significantly. However, no changes were detected in ocular perfusion and intraocular pressure values (p=0.935, p=0.519). Decrease in peripapillary and subfoveal choroid thickness values was found to be particularly between the group with severe stenosis and the group with control and mild stenosis (p = 0.003, p = 0.001). In addition, as the degree of carotid stenosis increased in patients with hypertension and smoking, peripapillary choroid thickness was found to be thinner (p=0.003).

Conclusion

We believe that the possibility of carotid artery stenosis should be considered in cases with decreased choroid thickness. In addition, we think that even if it is asymptomatic, in cases with severe carotid stenosis, in the presence of choroidal thinning, a chance of surgical intervention should be given to the stenosis.

Impact of Cardiovascular Disease Risk Factors on Subfoveal Choroidal Thickness by Enhanced-depth Spectral Domain Optical Coherence Tomography

SIGNIFICANCE

Risk stratification plays a large role in cardiovascular disease (CVD) management. Spectral-domain optical coherence tomography (SD-OCT) allows for noninvasive analysis of the ophthalmic vasculature, with potential for systemic disease surveillance. Subfoveal choroidal thickness (SFCT) may serve as a marker for CVD risk and play a role in risk stratification.

PURPOSE

This study aimed to explore the association of major CVD risk factors CVD on SFCT measured from SD-OCT images in a general population of U.S. veterans.

METHODS

One hundred fifty veterans were prospectively recruited at the Jamaica Plain VA Hospital (Boston, MA). A total of 143 participants were included in the final analysis. The SFCT was manually measured from Spectralis SD-OCT macular scans, and medical chart review was analyzed for CVD data. The SFCT measurements were correlated with CVD risk factors and CVD clinical makers while controlling for age and refractive error. Mean differences in SFCT between those with and without CVD risk factors were analyzed.

RESULTS

In multivariate analysis, diabetes diagnosis was independently associated with thinner subfoveal choroid (P = .001) and hypertension and hyperlipidemia with thicker subfoveal choroid (P = .006 and P = .05). After adjusting for age and refractive error, veterans with diabetes had thinner choroids than those without (P = .02), and veterans with hypertension and hyperlipidemia had thicker choroids than those without, although these differences did not reach statistical significance (P = .07 and P = .1).

CONCLUSIONS

Comorbid risk factors for CVD are independently associated with optical coherence tomography-derived measurements of subfoveal choroidal thickness in a vasculopathic population of U.S. veterans, and there are detectable differences in subfoveal choroidal thickness between groups with and without CVD risk factors. Larger studies with adequate controls and longitudinal design are necessary to assess the clinical role of SFCT measurements in CVD risk analysis.

CHOROIDAL THICKNESS, VASCULAR FACTORS, AND AGE-RELATED MACULAR DEGENERATION: The ALIENOR Study

PURPOSE

To study the associations of subfoveal choroidal thickness with vascular risk factors and age-related macular degeneration.

METHODS

Two hundred sixty-one participants of the Alienor study had gradable enhanced-depth imaging optical coherence tomography scans of the macula and available data on vascular and genetic risk factors (assessed through face-to-face interview and fasting blood samples) and age-related macular degeneration status (assessed from retinal photographs and optical coherence tomography). Subfoveal choroidal thickness was measured manually on one horizontal scan passing through the fovea.

RESULTS

In a multivariate mixed linear model, subfoveal choroidal thickness was independently associated with age greater than 80 years (-21.77 μm, P = 0.02), axial length (-21.77 μm, P < 0.0001), heavy smoking (≥20 pack-years: -24.89 μm, P = 0.05), fasting blood glucose higher than 7 mmol/L (-53.17 μm, P = 0.02), and lipid-lowering treatment (+18.23, P = 0.047). After multivariate adjustment for age, sex, axial length, and vascular and genetic risk factors, subfoveal choroidal thickness was thinner in eyes with central hyperpigmentation (-45.39 μm, P = 0.006), central hypopigmentation (-44.99 μm, P = 0.001), and central pigmentary abnormalities (-44.50 μm, P = 0.001), but not in eyes with late age-related macular degeneration (-18.05 μm, P = 0.33) or soft drusen.

CONCLUSION

These findings indicate a relationship between vascular risk factors and choroidal thinning and suggest an early involvement of the choroid in the pathogenesis of age-related macular degeneration.

Alteration of choroidal vascular structure in diabetic macular edema

PURPOSE

The aim of this study was to analyze choroidal structures in healthy subjects and patients with/without diabetic macular edema (DME).

METHODS

This was a retrospective observation case control study. Four hundred and two eyes of patients with diabetes mellitus (DM), and 124 age-matched eyes of healthy subjects were enrolled in this study. DM patients were divided into 3 groups: presence of central-involved (CI) DME (n = 81) and nonCI-DME/non-DME (n = 321), based on OCT findings. Central choroidal thickness (CCT) and total choroidal, luminal, and stromal areas were determined using EDI-OCT and a binarization method, respectively. The luminal area expressed as a ratio of the total choroidal area was defined as the L/C ratio.

RESULTS

DM eyes showed a significantly lower L/C ratio than control eyes, whereas there was no significant difference in CCT or total choroidal, luminal, or stromal areas. There was no significant difference between CI-DME and non-DME groups in HbA1c, blood pressure, dyslipidemia, or renal function. CCT and total choroidal, luminal, and stromal areas were significantly greater in the CI-DME group than non-DME group (each P < 0.05).

CONCLUSIONS

These results suggest that CCT was thickened in the presence of DME, associated with both increased luminal and stromal areas, which might be related to the pathology of DME.

Analysis of central macular thickness and choroidal thickness changes in patients with cardiovascular risk factors

OBJECTIVES

The aim of this study was to evaluate central macular thickness (CMT) and choroidal thickness (CT) in the eyes of patients with cardiovascular risk factors (CVRF).

METHODS

A cross-sectional, prospective observational study of 92 patients with CVRF and 21 healthy individuals was conducted. Patients were divided into four groups according to the SCORE system. CMT was evaluated via spectral-domain-optical coherence tomography (SD-OCT). CT at five defined points (subfoveal) [SF] and nasal 500 μm [N0.5] and 1500 μm [N1.5] and 500 μm [T0.5] and temporal 1500 μm [T1.5] from the center of the fovea were measured via enhanced depth imaging (EDI)-OCT.

RESULTS

Mean SFCT at right eyes (RE) and left eyes (LE) were 311.21 ± 77.7 μm and 303.5 ± 49.6 μm, respectively, in patients with mild CVRF (Group 1); 266.5 ± 63.2 μm and 267.0 ± 62.6 μm, respectively, in patients with moderate CVRF (Group 2); 264.7 ± 57.5 μm and 272.3 ± 64.6 μm, respectively, in patients with high CVRF (Group 3); 272.3 ± 64.6 μm and 271.2 ± 63.4 μm, respectively, in patients with very high-risk CVRF (with coronary arterial disease (CAD) (Group 4); and 352.0 ± 74.4 μm and 363.1 ± 89.0 μm, respectively, in the control group. CT (at both eyes) was significantly lower at the subfoveal location in all study groups (P < 0.05), but at nasal and at temporal quadrants of group 3 and group 4 (P < 0.05). No significant difference in CMT was detected between the study and control groups.

CONCLUSIONS

This study demonstrated that CVRF might result in a remarkably thinner CT. Furthermore, subretinal drusenoid deposits were detected at a higher rate in the patients with CVRF than controls, and that rate increased in accordance with the severity of CAD. In the future, changes in CT may be used as a promising novel biomarker as part of the SCORE system prior to the development of CAD.

Choroidal thickness in patients with cardiovascular disease: A review

The choroid is a vascular network that supplies the bulk of the retina's oxygen and nutrient supply. Prior studies have associated changes in the thickness of the choroid with the presence of various cardiovascular diseases. This is the first review that summarizes current knowledge on the relationship between choroidal thickness and cardiovascular diseases while highlighting important findings. Acute hypertension increases choroidal thickness. Chronic hypertension and heart failure may decrease choroidal thickness, but controversy exists. Both coronary artery disease and carotid artery stenosis result in decreased choroidal thickness and blood flow. Carotid endarterectomy may reverse these changes. Choroidal thickening in early stages of carotid stenosis may arise from mechanisms compensating for ischemia. Hyperlipidemia is linked to choroidal thickening, while caffeine intake is linked to choroidal thinning. The effects of smoking and exercise are mixed. Changes in choroidal thickness have been linked to cardiovascular disease. Clarity regarding these changes could lead to the use of choroidal thickness changes as a noninvasive screening or prognostic test for pathological cardiovascular changes. Future studies should also investigate the effect of cardiovascular disease treatments on the choroid.

Systemic and Ocular Determinants of Choroidal Structures on Optical Coherence Tomography of Eyes with Diabetes and Diabetic Retinopathy

Knowledgeof the choroidal structures in eyes with diabetes and diabetic retinopathy (DR) should provide information on the pathogenesis of DR. A prospective study was performed to determine the systemic and ocular factors that affect the choroidal structures in eyes with diabetes. Two-hundred consecutive diabetic subjects consisted of 160 treatment-naïve patients with different stages of DR and 40 patients with proliferative DR with prior panretinal photocoagulation (PRP). All underwent blood and urine tests and enhanced depth imaging optical coherence tomography (EDI-OCT). The cross-sectional EDI-OCT images of the subfoveal choroid were binarized to measure the total choroidal area (TCA), luminal area, and stromal area. Multivariate regression analyses were performed to determine the systemic and ocular factors that were significantly correlated with the choroidal structures. The subfoveal choroidal thickness, TCA, luminal area, and stromal area were larger at more advanced stage of DR, and smaller in eyes with PRP than those without (P < 0.001). The TCA and stromal area were significantly and positively correlated with the degree of albuminuria (P = 0.034, P = 0.025, respectively). The choroidal lumen and stroma may increase as the stages of DR progress and decrease after PRP. Albuminuria may be associated with the choroidal stromal edema.

Short-term variations of optic coherence tomography findings in mild and severe chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the short-term changes in subfoveal choroidal thickness (SFCT), ganglion cell complex (GCC) analysis, and retinal nerve fiber length (RNFL) of patients with chronic obstructive pulmonary disease (COPD) in a 3-month follow-up.

MATERIALS AND METHODS

Forty-eight patients with COPD (96 eyes) and 40 control subjects (80 eyes) were enrolled in our study. COPD patients were grouped according to disease severity as Group 1 (mild-moderate) and Group 2 (advanced). GCC, RNFL, and SFCT analysis by Cirrus SD-OCT were obtained for all eyes, in two consecutive examinations with a 3-month interval.

RESULTS

SFCT in Group 2 was lower than Group 1 and control group in the initial and 3rd month examination (p < 0.001, respectively). Inferior RNFL in Group 2 were lower than control group in the initial and 3rd month examination (p = 0.002, p < 0.001, respectively) Temporal RNFL were lower in Group 2 than Group 1 in 3rd month examination (p = 0.009). Average, superior, superotemporal, inferior, and inferonasal GCC analyses of the Group 2 were lower than control group both in the initial and 3rd month examination (p = 0.001, p < 0.001, respectively) SFCT, average, and superior GCC of Group 2 were significantly reduced during the 3-month follow-up (p < 0.001).

CONCLUSION

Hypoxia is thought to be the underlying mechanism in COPD, which may influence retinal and choroidal OCT parameters. Decrease in blood flow of optic nerve head, increased vascular resistance, and reduced blood flow in choroid may affect the visual ability in these patients, which should be kept in mind during their follow-up.

A longitudinal study of choroidal changes following cataract surgery in patients with diabetes

OBJECTIVE

To study the structural changes in the choroid of diabetic patients following cataract surgery, using choroidal vascularity index and choroidal thickness.

METHODS

A prospective case-control study was conducted in 18 diabetic and 18 non-diabetic patients undergoing cataract surgery (phacoemulsification) in one eye. Enhanced depth imaging optical coherence tomography images were obtained before and after surgery. Niblack's image binarization of images was performed to derive the choroidal vascularity index. Independent sample T-test compared the differences of choroidal vascularity index and choroidal thickness between diabetic and non-diabetic patients.

RESULTS

The baseline choroidal vascularity index was significantly lower in diabetic patients for both operated (mean difference vs non-diabetic: 0.0184, 95% CI: 0.004-0.0324, p = 0.012) and non-operated (mean difference vs non-diabetic: 0.0145, 95% CI: 0.003-0.0256, p = 0.012) eyes. Choroidal thickness increased following cataract surgery (diabetes: mean difference = 12.4, 95% CI: 0.70-24.0, adjusted p = 0.036; non-diabetic: mean difference = 21.0, 95% CI: 4.39-37.6, adjusted p = 0.011).

CONCLUSION

Diabetic patients have reduced choroidal vascularity index than non-diabetic patients, suggestive of possible reduction in choroidal vascularity in diabetes. Choroidal thickness increased following cataract surgery in both diabetic and non-diabetic patients.

Alteration of choroidal vascular structure in diabetic retinopathy

PURPOSE

The aim of this study was to analyse choroidal structures in normal patients and patients with diabetes with various severities of diabetic retinopathy (DR).

METHODS

This is a retrospective observation case control study. Three hundred and forty-two diabetic eyes, and age-matched 112 eyes without diabetes mellitus (DM) were enrolled in this study. Patients with DM were classified into no DR, mild/moderate non-proliferative DR (mNPDR), severe NPDR and proliferative DR (PDR). Patients with DM were further divided into two groups based on information regarding systemic DM treatment situation: DM-treated and untreated groups. Central choroidal thickness (CCT), and total choroidal area (TCA), luminal area (LA) and stromal area (SA) were determined using enhanced depth imaging optical coherence tomography and a binarisation method, respectively. The ratio of LA in the TCA was defined as L/C ratio.

RESULTS

The haemoglobin A1c (HbA1c) value was significantly higher in the DM-untreated than in the DM-treated subjects. L/C ratio was significantly lower in all the diabetic eyes than control eyes (p<0.05). TCA, LA, L/C ratio and CCT were significantly greater in the DM-untreated than treated group (each p<0.05). In the DM-untreated group, TCA and LAs (p<0.05) and L/C ratio (p<0.01) were significantly lower in mNPDR subjects than normal controls (p<0.05). PDR in the DM-untreated group showed significantly larger SA and LA, and greater CCT than normal controls (each p<0.05).

CONCLUSIONS

These results suggest that choroidal vasculature was initially involved at an early DR, whereas thickened LA and SA were noted in advanced DR.

Choroidal vascularity index changes after vitreomacular surgery

PURPOSE

To study the structural changes in the choroid using swept-source (SS) optical coherence tomography (OCT), a tool for the choroidal vascularity index (CVI) following epiretinal membrane removal.

METHODS

Fifty-two eyes of 26 patients were evaluated in this prospective, single-centre, observational study. Twenty-six eyes underwent vitrectomy for epiretinal membrane removal (VT-group), and the control group consisted of 26 corresponding fellow eyes (F-group). All patients were evaluated at baseline, 30 and 90 days postsurgery. Using a modified image binarization algorithm for SS-OCT scans, the subfoveal choroidal area was segmented into the luminal and stromal areas, and the CVI was measured by calculating the proportion of the luminal area (LA) to the cross-sectional choroid area.

RESULTS

The mean CVI in the VT-group was 63.86 ± 4.04% at the baseline, 62.45 ± 4.21% at 30 days postsurgery and 61.06 ± 3.79% at 90 days (p < 0.001). The F-group had a mean CVI of 61.12 ± 2.29% at the baseline, 60.91 ± 2.25% at 30 days postsurgery and 61.05 ± 2.28% at 90 days (p = 0.29).

CONCLUSION

The CVI decreases following epiretinal membrane removal when compared to the fellow eyes, which suggests structural changes in the vascular layers of the choroid. The implication of these results may be that secondary inflammation resulting from mechanical traction induces choroidal thickness by way of increased vascularization of the choroid.

Looking into the eye of patients with chronic obstructive pulmonary disease: an opportunity for better microvascular profiling of these complex patients

Chronic obstructive pulmonary disease (COPD) is a complex disease with many patients suffering from cardiovascular comorbidity. However, cardiovascular diseases remain often undiagnosed in COPD. Assessment of the retinal microvasculature can provide value in cardiovascular profiling of these patients. Retinal microvascular assessment carried out via a noninvasive eye exam represents an easy to use tool when examining patients with COPD. The purpose of this review was to provide an overview of studies assessing structural and functional changes in the retinal microvasculature of patients with COPD. Findings demonstrated that structural and functional microvascular changes were more common and severe in COPD patients as compared to non-COPD controls, although few retinal investigations have been performed in patients with COPD. As cardiovascular comorbidities are highly prevalent in COPD, we advocate more research to investigate the value of an eye exam for microvascular phenotyping of COPD patients.

The effect of obesity and insulin resistance on macular choroidal thickness in a pediatric population as assessed by enhanced depth imaging optical coherence tomography

BACKGROUND

The purpose of this study was to evaluate the macular choroidal thickness in obese children with and without insulin resistance (IR).

METHODS

Thirty-six patients with obesity and 26 healthy volunteers were included in this cross-sectional study. The choroidal thickness was measured with enhanced depth imaging optical coherence tomography (EDI-OCT) at the fovea and at positions 500 μm, 1000 μm, 1500 μm nasal and temporal to the fovea. The choroidal thickness measurements of the groups were compared and the correlation between the homeostasis model assessment of insulin resistance (HOMA-IR) and choroidal thickness values was evaluated.

RESULTS

The average choroidal thickness in the obese group was significantly lower than that of controls at locations 1000 μm (303.31±58.52 vs. 340.58±69.47, p=0.026) and 1500 μm (284.14±65.06 vs. 336.85±71.37, p=0.004) temporal to the fovea. A subgroup analysis depending on the presence of IR revealed that the choroidal thickness measurements at all positions were thinner in obese children without IR compared to children with IR and healthy controls. This thinning reached a statistical significance at locations 500 μm temporal, 1000 μm temporal and 1500 μm temporal to the fovea (p=0.03, p=0.009 and p=0.006; respectively). There was a moderate correlation between the choroidal thickness measurements and HOMA-IR values (r-values between 0.37 and 0.48; p<0.05).

CONCLUSIONS

Our results suggest that obesity and IR may have an influence on the choroidal thickness in children. Longitudinal studies will clarify whether these choroidal changes are progressive and are a sign of microvascular dysfunction in childhood obesity.

Choroidal Haller's and Sattler's Layers Thickness in Normal Indian Eyes

AIM:

This study aims to study normative choroidal thickness (CT) and Haller's and Sattler's layers thickness in normal Indian eyes.

MATERIALS AND METHODS:

The choroidal imaging of 73 eyes of 43 healthy Indian individuals was done using enhanced depth imaging feature of spectralis optical coherence tomography. Rraster scan protocol centered at fovea was used for imaging separately by two observers. CT was defined as the length of the perpendicular line drown from the outer border of hypereflective RPE-Bruch's complex to inner margin of choroidoscleral junction. Choroidal vessel layer thickness was measured after defining a largest choroidal vessel lumen within 750 μ on either side of the subfoveal CT vector. A perpendicular line was drawn to the innermost border of this lumen, and the distance between the perpendicular line and innermost border of choroidoscleral junction gave large choroidal vessel layer thickness (LCVLT, Haller's layer). Medium choroidal vessel layer thickness (MCVLT, Sattler's layer) was measured as the distance between same perpendicular line and outer border of hypereflective RPE-Bruch's complex.

RESULTS:

The mean age of individuals was 28.23 ± 15.29 years (range 14–59 years). Overall, the mean subfoveal CT was 331.6 ± 63.9 μ. Mean LCVLT was 227.08 ± 51.24 μ and the mean MCVLT was 95.65 ± 23.62 μ. CT was maximum subfoveally with gradual reduction in the thickness as the distance from the fovea increased.

CONCLUSION:

This is the first study describing the choroidal sublayer thickness, i.e., Haller's and Sattler's layer thickness along with CT in healthy Indian population.

Changes in choroidal thickness following trabeculectomy and its correlation with the decline in intraocular pressure

PURPOSE

Evaluate whether there are significant changes in choroidal thickness following trabeculectomy, and how they relate do the decline in intraocular pressure.

METHODS

This was a prospective evaluation of 28 eyes who underwent Moorfields modified trabeculectomy. The choroidal thickness was measured via OCT with enhanced depth imaging, before surgery and 1 day, 1 week and 1 month after surgery. Measurements were taken at the fovea, 1000 µm temporal to the fovea and 1000 µm nasal to the fovea. The relationship between choroidal thickness and intraocular pressure was statistically evaluated.

RESULTS

The mean intraocular pressure before surgery was 25.07 ± 4.64 mmHg; 8.57 ± 3.62 mmHg after 1 day; 10.36 ± 4.39 mmHg after 1 week and 13.71 ± 5.13 mmHg after 1 month. Mean choroidal thickness increased after trabeculectomy with maximal values at 1 week. The largest increase was found at the fovea, with an average before surgery of 253.54 ± 62.01 µm; 286.75 ± 64.20 µm at 1 day, 286.36 ± 63.14 µm at 1 week and 271.00 ± 60.31 µm at 1 month. Increase in choroidal thickness was significant 1 day and 1 week after surgery in the foveal (p = 0.012, p = 0.007) and temporal (p = 0.040, p = 0.000) locations and 1 week postoperatively on the nasal location (p = 0.016). None of them were significant at 1 month after surgery. Preoperative IOP and choroidal thickness were correlated at all macular locations (ρ = 0.449-0.525, p = 0.004-0.016) yet no correlation was found between increase in choroidal thickness and decline in intraocular pressure in the postoperative period.

CONCLUSION

Choroidal thickness appears to increase temporarily after trabeculectomy and these changes were not correlated with the decline in intraocular pressure. Further research is required to fully understand this phenomenon.

Subfoveal choroidal thickness and volume in severe internal carotid artery stenosis patients

AIM

To demonstrate the differences of retinal and choroidal structure changes in internal carotid artery (ICA) patients of China by enhanced-depth imaging optical coherence tomography (EDI-OCT).

METHODS

A retrospective review was conducted of 46 patients with a diagnosis of ICA stenosis greater than 65% on only one side (the opposite ICA Stenosis had less than 40% stenosis) from June 2015 through June 2016. All of the patients were combined with amaurosis fugax, but without any abnormality with other ocular examination. Thickness and volume of choroid and retina were manually measured by EDI-OCT. Differences were compared between ICA stenosis eyes and fellow eyes.

RESULTS

There were no significant differences in the retinal thickness, macular retinal nerve fiber layer (mRNFL) thickness, inner thickness, or outer retinal thickness between the ICA Stenosis group and the control group (P=0.834, 0.187, 0.552, and 0.903, respectively). The mean central choroidal thickness of the ICA Stenosis group was significantly lower than that of the control group (239.70±23.76 µm vs 257.46±22.13 µm, P<0.001). The percentage of ICA stenosis was significantly associated with the central choroidal thickness, central retinal thickness, foveal center choroidal volume, and foveal center retinal volume (r=0.854, 0.678, 0.729, and 0.785, respectively; P<0.001). There were no significant differences in the retinal and choroidal volume values in the 4 inner and 4 outer sectors between the two groups.

CONCLUSION

The choroidal thickness in severe ICA stenosis eyes is lower than in fellow eyes. The choroidal thinning may occur before the retinal changes in patients with ocular ischemic syndrome. Evaluations of choroidal thickness may be useful to choose the optimal therapeutic schedule for ICA patients.

Influence of glycosylated hemoglobin on the choroidal thickness

PURPOSE

The aim of the study reported here was to assess the influence of serum HbA1c levels on foveal choroidal thickness in diabetic patients.

METHODS

A total of 122 eyes from 122 patients who had type 2 DM were studied in this prospective, cross-sectional study. Patients were divided into three groups: 43 patients (43 eyes) without diabetic retinopathy (NDR), 39 patients (39 eyes) with diabetic retinopathy and no macular edema (DR/ME-), 40 patients (40 eyes) with diabetic retinopathy and macular edema (DR/ME+). Central foveal thicknesses and subfoveal choroidal thicknesses were noted. Subfoveal choroidal thickness measurement was taken perpendicularly from the outer part of the retinal pigment epithelial layer to the line corresponding to the choroidal-scleral junction. Serum glycosylated hemoglobin (HbA1c) levels were evaluated.

RESULTS

No significant differences in age, gender, pseudophakia were observed between the groups. There was no significant difference in HbA1c value among the three diabetic groups. Mean foveal choroidal thickness was 270.09 ± 42.41 in NDR group, 243.18 ± 30.21 in DR/ME- group and 250.90 ± 40.06 in DR/ME+ group. Mean foveal choroidal thickness in NDR group was significantly different from DR/ME- group. There was no statistically significant difference between the other groups among foveal choroidal thicknesses. There was no correlation between HbA1c and foveal choroidal thickness. Multiple regression analyses of two diabetic retinopathy groups showed no significant correlation between foveal choroidal thickness and HbA1c and also no significant correlation between foveal choroidal thickness and duration of diabetes.

CONCLUSIONS

Serum HbA1c levels were not correlated with foveal choroidal thickness. Choroidal thickness is effected by several factors as axial length, age and systemic diseases.

Choroidal Thickness and Choroidal Vessel Density in Nonexudative Age-Related Macular Degeneration Using Swept-Source Optical Coherence Tomography Imaging

Purpose

To analyze the relationship between choroidal thickness and the distribution of choroidal blood vessels in eyes with nonexudative AMD.

Methods

Eyes with a diagnosis of nonexudative AMD were imaged using a prototype 100-kHz swept-source (SS) optical coherence tomography (OCT) instrument (Carl Zeiss Meditec, Dublin, CA, USA) with a central wavelength of 1050 nm. We used an OCT cube scan pattern consisting of 512 × 512 A-scans over a 12 × 12 mm retinal area. The eyes were partitioned into two groups based on the presence or absence of reticular pseudodrusen (RPD). All scans were segmented using an automated algorithm. In addition, five eyes from each of the two groups were randomly chosen for manual segmentation. Binary choroidal vessels maps were generated from suitable OCT choroidal slabs, and the relationship between the density of large choroidal vessels and choroidal thickness was analyzed using an Early Treatment Diabetic Retinopathy Study–like target centered on the fovea.

Results

Twenty-five eyes were enrolled in each group. The automated algorithm produced accurate choroidal thickness maps with an average difference between the manual and automated segmentations of 13.7 μm. There was a significant and stable correlation between choroidal thickness and choroidal vessel density across the two groups. Both average choroidal thickness and vessel density were significantly lower in eyes with RPD.

Conclusions

Our fully automated choroidal segmentation algorithm was able to capture the different patterns of choroidal thickness over a wide area. Choroidal thickness has a clear relationship with the density of large choroid vessels in our sample, irrespective of the presence or absence of RPD.

Choroidal thickness in patients with coronary artery disease

Purpose

To evaluate choroidal thickness (CTh) in patients with coronary artery disease (CAD) compared to healthy controls.

Design

Cross-sectional.

Methods

Setting: Ambulatory clinic of a large city hospital. Patient population: Thirty-four patients had documented CAD, defined as history of >50% obstruction in at least one coronary artery on cardiac catheterization, positive stress test, ST elevation myocardial infarction, or revascularization procedure. Twenty-eight age-matched controls had no self-reported history of CAD or diabetes. Patients with high myopia, dense cataracts, and retinal disease were excluded. Observation procedures: Enhanced depth imaging optical coherence tomography and questionnaire regarding medical and ocular history. Main outcome measures: Subfoveal CTh and CTh 2000 μm superior, inferior, nasal, and temporal to the fovea in the left eye, measured by 2 readers.

Results

CTh was significantly lower in patients with CAD compared to controls at the subfoveal location (252 vs. 303 μm, P = 0.002) and at all 4 cardinal macular locations. The mean difference in CTh between the 2 groups ranged from 46 to 75 μm and was greatest in the inferior location. Within the CAD group, CTh was significantly lower temporally (P = 0.007) and nasally (P<0.001) than subfoveally, consistent with the pattern observed in controls. On multivariate analysis, CAD was negatively associated with subfoveal CTh (P = 0.006) after controlling for diabetes, hypertension, and hypercholesterolemia.

Conclusions and relevance

Patients with CAD have a thinner macular choroid than controls, with preservation of the normal spatial CTh pattern. Decreased CTh might predispose patients with CAD to high-risk phenotypes of age-related macular degeneration such as reticular pseudodrusen and could serve as a potential biomarker of disease in CAD.

Ocular Image and Haemodynamic Features Associated with Different Gradings of Ipsilateral Internal Carotid Artery Stenosis

OBJECTIVES

To analyse the changes of ocular haemodynamics and morphology in Chinese patients with internal carotid artery (ICA) stenosis in the current study.

METHODS

A retrospective case-control study was conducted with 219 patients. The haemodynamic characteristics, the calibre of retinal vessels, and the subfoveal choroidal thickness (SFChT) were compared. We analysed the correlations with the degree of ipsilateral ICA stenosis.

RESULTS

There were no significant differences among the groups in the central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and AVR (p = 0.073, p = 0.188, and p = 0.738, resp.). The peak systolic velocity (PSV) and end diastolic velocity (EDV) in the central retinal artery (CRA) and the posterior ciliary artery (PCA) were significantly lower than normal eyes (p < 0.001). The outer retinal layer thickness and SFChT values of the ICA stenosis groups were significantly lower than normal eyes (p = 0.030 and p < 0.001, resp.).

CONCLUSION

The PSV and EDV in CRA and PCA and the SFChT and outer retinal layer thickness of ICA eyes were significantly lower than normal eyes. ICA stenosis may impact choroidal haemodynamics, and decreased choroidal circulation might affect the discordance of the SFChT and the outer retinal layer thickness.

Macular Choroidal Thickness May Be the Earliest Determiner to Detect the Onset of Diabetic Retinopathy in Patients with Prediabetes: A Prospective and Comparative Study

PURPOSE

To evaluate the macular and peripapillary choroidal thickness and retinal volume in prediabetes.

MATERIAL AND METHODS

This prospective comparative study included 53 patients with prediabetes and 53 age- and sex-matched healthy subjects. Only right eyes were selected. Choroidal thicknesses (CT) and retinal volume were measured by optical coherence tomography. Macular CT was measured at the seven points including macular center, 1, 2, and 3 mm distances along the temporal and nasal scans. Peripapillary CT was measured at the eight points of the optic disk area. Systemic and laboratory findings of the subjects were also recorded.

RESULTS

There were no significant differences in blood pressures, ocular findings including intraocular pressure, visual acuity, and refractive powers, and macular volumes between the two groups (p > 0.005). Macular and peripapillary CT at all measuring points, body mass index (BMI), fasting blood glucose (FBG), hemoglobinA1C, and lipid profile were significantly higher in prediabetic patients (p < 0.05). There was a significant positive correlation between all points of macular choroidal thicknesses with BMI, FBG, and hemoglobin A1C (p < 0.05).

CONCLUSION

Prediabetic factors including impaired FBG, increased hemoglobinA1C, and BMI are independent risk factors for increase in choroidal thickness. Increased macular choroidal thickness may be the earliest determiner to detect the onset of diabetic retinopathy in prediabetes.

Investigation of the choroidal thickness in patients with hypothyroidism

Purpose:

The effect of hypothyroidism on the choroidal thickness (CT) was investigated in patients with subclinical hypothyroidism and overt hypothyroidism, and biochemically and clinically euthyroid patients receiving levothyroxine treatment. The patients were compared with healthy subjects.

Materials and Methods:

One eye of 71 hypothyroid and 22 healthy subjects between 20 and 40 years of age were included in this study. CT measurements were taken at the fovea and at 2 points that were 1500 μm nasal and temporal to the fovea using spectral-domain optical coherence tomography. Independent sample t-test's and was used for statistical analysis of the data.

Results:

The CT was significantly thicker in hypothyroid patients compared to healthy subjects (P values were 0.013 for subfoveal, 0.015 for temporal and 0.020 for nasal segments). The intraocular pressure (IOP) and body mass index (BMI) were also significantly higher in hypothyroid patients (P values were 0.021 and 0.003, respectively). There was not a statistically significant difference in the BMI and IOP measurements between healthy subjects and euthyroid patients (P > 0.05). However, there was a statistically significant difference in the subfoveal, temporal and nasal CT measurements between healthy subjects and euthyroid patients (P values were 0.006, 0.031 and 0.013, respectively).

Conclusions:

All subgroups of hypothyroid patients had thicker CT compared to healthy subjects. Euthyroid patients receiving levothyroxine treatment had lower IOP, BMI levels, and serum lipid levels than patients with subclinical hypothyroidism and overt hypothyroidism.

In Vivo Choroidal Vascular Lesions in Diabetes on Swept-Source Optical Coherence Tomography

Diabetes induces microvascular diseases including diabetic retinopathy and choroidopathy which reciprocally promote the pathogenesis, although optical coherence tomography images of diabetic choroidopathy remains to be documented. Here we evaluated the qualitative characteristics of choroidal vascular lesions in patients with diabetes and their association with diabetic retinopathy on swept-source optical coherence tomography (SS-OCT) images. We retrospectively reviewed 110 consecutive eyes of 110 patients with diabetes and 35 eyes of 35 healthy subjects for whom SS-OCT images (6x6-mm scans centered on the fovea) of sufficient quality were acquired. The curve of chorioretinal sections was flattened using Bruch’s membrane as a reference surface, followed by generation of en-face images. We characterized choroidal vascular lesions and evaluated their association with the logarithm of the minimum angle of resolution visual acuity (logMAR VA), retinal and choroidal thicknesses, and diabetic retinopathy severity. En-face SS-OCT images showed unvisualized vessels in Sattler’s layer in 33 eyes (30.0%). Focal narrowing was seen in choroidal vessels in Haller’s layer in 56 eyes (50.9%). The choroidal vessels ended in the superficial or middle portion of Haller’s layer, referred to as vascular stumps, in 20 eyes (18.2%). Diabetic eyes had these findings more frequently than nondiabetic eyes. The subfoveal choroid was thicker in eyes with focal vascular narrowing and vascular stumps than in eyes without such lesions. Vascular stumps in Haller’s layer were significantly related to diabetic retinopathy severity, logMAR VA, and central retinal and choroidal thicknesses. These novel findings on SS-OCT images would promote the better understanding of complicated pathogenesis in diabetic retinopathy and choroidopathy.

New aspect for systemic effects of COPD: eye findings

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) has multisystemic implications and comorbidities. Hypoxia and systemic inflammation are thought to involve oculary structures. In this study, our aim is to evaluate retinal nerve fiber and choroidal thickness and retinal vessel diameter using the spectral-domain optical coherence tomography (SD-OCT) in COPD subjects.

METHODS

Forty-three subjects diagnosed with COPD according to the Global Initiative for Chronic Obstructive Lung Disease criteria at the Pulmonology Department of Pamukkale University were enrolled in the study. All subjects underwent respiratory function testing and a carbon monoxide diffusion test. To determine hypoxic state, arterial blood gas analysis was performed. The control group consisted of 31 subjects with comparable age and gender distribution. All participants underwent a standard ophthalmic examination including visual acuity assessment, biomicroscopy, air-puff tonometry, indirect retinoscopy, and SD-OCT measurements.

RESULTS

The mean subfoveal choroidal thickness (SFCT), foveal thickness, and retinal arteriolar caliber were found to be similar in both groups, while the mean retinal venular caliber value was markedly higher in the COPD group. The mean peripapillary retinal nerve fiber layer (RNFL) thickness was 100.2±11.8 µm in the COPD group and 105.6 ± 8.1 µm in the control group (P = .03). The inferior quadrant RNFL was significantly thinner in the COPD group.

CONCLUSIONS

The results of this study showed increasing diameter of the retinal veins, thinning of the RNFL, and SFCT may be associated to chronic inflammation and hypoxia in subjects with COPD. Future guidelines may include ocular findings to the present systemic manifestations of COPD.