Exploring choroidal angioarchitecture in health and disease using choroidal vascularity index

Changes in the outer nuclear layer and choroidal vascularity during the manifest and quiescent phases of acute central serous chorioretinopathy

To investigate alteration of outer nuclear layer (ONL) and choroidal vascularity index (CVI) in different status of central serous chorioretinopathy (CSC). A retrospective review of 65 CSC eyes with subretinal fluid (manifest CSC) and 40 control eyes was conducted in a single tertiary university hospital. Differences in best-corrected visual acuity (BCVA), ONL, and CVI were compared. CVI was assessed both in the entire choroid (CVI-EC) and around the 1500 μm leakage area (CVI-1500). Measurements were repeated after the subretinal fluid resorption (quiescent CSC), and compared. CSC eyes showed worse BCVA, thinner ONL and greater CVI than controls. Quiescent CSC showed a recovery of ONL compared to the manifest CSC, along with the BCVA improvement. The resolution of the CSC revealed a decrease across all three choroidal areas (total, stromal and luminal), with a more pronounced reduction in the stromal than in the luminal choroidal area, leading to an increase in the CVI. This phenomenon was shown in both CVI-EC and CVI-1500. Conclusively, ONL thickness can be used as a quantitative biomarker for photoreceptor function in CSC. Increased CVI may reflect a disease activity. The stromal choroidal area is particularly sensitive in illustrating leakage from the choroidal vasculature.

Optical coherence tomography angiography in the diagnosis of ocular disease

Clinical imaging provided by optical coherence tomography (OCT) and its variant, OCT-angiography (OCT-A), has revolutionised eyecare practice. The imaging techniques allow for the identification and quantification of ocular structures, supporting the diagnosis and prognosis of eye disease. In this review, an overview of the usefulness of OCT-A imaging in the diagnosis and management of a range of ocular conditions is provided when used in isolation or in combination with other imaging modalities and measures of visual function (visual field results). OCT-A imaging has the capacity to identify and quantify ocular vasculature non-invasively, thereby assisting the clinician in the diagnosis or to determine the efficacy of intervention in ocular conditions impacting retinal vasculature. Thus, additional clinically useful information can be obtained in eye diseases involving conditions such as those impacting retinal vessel occlusion, in diabetic retinopathy, inherited retinal dystrophy, age-related macular degeneration, choroidal neovascularisation and optic nerve disorders. Through a clinical case series, various ocular conditions are reviewed, and the impact of OCT-A imaging is discussed. Although OCT-A imaging has great promise and is already used in clinical management, there is a lack of set standards to characterise altered vascular features in disease and consequently for prognostication, primarily due to a lack of large-scale clinical trials and variability in OCT-A algorithms when generating quantitative parameters.

Effect of orbital decompression surgery on the choroidal profile in patients with thyroid eye disease

This study aimed to investigate the effect of orbital wall decompression surgery and reduction of proptosis on the choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) in patients with thyroid eye disease (TED). Fifty-one eyes from 38 patients with controlled TED and proptosis were enrolled in this study. The majority of the patients (50.9%) had a clinical activity score (CAS) of zero, and none had a CAS greater than 2. The patients underwent a complete baseline ophthalmologic examination, and their choroidal profile alterations were monitored using enhanced depth imaging optical coherence tomography (EDI-OCT) before and during the three months after surgery. Changes in SFCT, luminance area (LA), total choroidal area (TCA), and the choroidal vascularity index (CVI) were measured as the ratio of LA to TCA in EDI-OCT images. The participants had an average age of 46.47 years, and 22 were female (57.9%). The SFCT of the patients exhibited a significant reduction over the follow-up period, decreasing from 388 ± 103 to 355 ± 95 µm in the first month (p < 0.001) and further decreasing to 342 ± 109 µm by the third month compared to baseline (p < 0.001). The CVI exhibited a drop from 0.685 ± 0.037 at baseline to 0.682 ± 0.035 and 0.675 ± 0.030 at 1 and 3 months post-surgery, respectively. However, these changes were not statistically significant, indicating comparable decreases in both LA and TCA. There was a significant correlation between improved proptosis and reduction in SFCT (p < 0.001) but not with CVI (p = 0.171). In conclusion, during the three months of follow-up following orbital wall decompression, CVI did not change, while SFCT reduced significantly. Additionally, SFCT was significantly correlated with proptosis reduction, whereas CVI was not.

Choroidalyzer: An Open-Source, End-to-End Pipeline for Choroidal Analysis in Optical Coherence Tomography

Purpose

To develop Choroidalyzer, an open-source, end-to-end pipeline for segmenting the choroid region, vessels, and fovea, and deriving choroidal thickness, area, and vascular index.

Methods

We used 5600 OCT B-scans (233 subjects, six systemic disease cohorts, three device types, two manufacturers). To generate region and vessel ground-truths, we used state-of-the-art automatic methods following manual correction of inaccurate segmentations, with foveal positions manually annotated. We trained a U-Net deep learning model to detect the region, vessels, and fovea to calculate choroid thickness, area, and vascular index in a fovea-centered region of interest. We analyzed segmentation agreement (AUC, Dice) and choroid metrics agreement (Pearson, Spearman, mean absolute error [MAE]) in internal and external test sets. We compared Choroidalyzer to two manual graders on a small subset of external test images and examined cases of high error.

Results

Choroidalyzer took 0.299 seconds per image on a standard laptop and achieved excellent region (Dice: internal 0.9789, external 0.9749), very good vessel segmentation performance (Dice: internal 0.8817, external 0.8703), and excellent fovea location prediction (MAE: internal 3.9 pixels, external 3.4 pixels). For thickness, area, and vascular index, Pearson correlations were 0.9754, 0.9815, and 0.8285 (internal)/0.9831, 0.9779, 0.7948 (external), respectively (all P < 0.0001). Choroidalyzer's agreement with graders was comparable to the intergrader agreement across all metrics.

Conclusions

Choroidalyzer is an open-source, end-to-end pipeline that accurately segments the choroid and reliably extracts thickness, area, and vascular index. Especially choroidal vessel segmentation is a difficult and subjective task, and fully automatic methods like Choroidalyzer could provide objectivity and standardization.

THE DIAGNOSTIC VALUE OF MULTISPECTRAL FUNDUS IMAGING IN HYPERTENSIVE RETINOPATHY

PURPOSE

To observe the diagnostic value of multispectral fundus imaging (MSI) in hypertensive retinopathy (HR).

METHODS

A total of 100 patients with HR were enrolled in this cross-sectional study, and all participants received fundus photography and MSI. Participants with severe HR received fundus fluorescein angiography (FFA). The diagnostic consistency between fundus photography and MSI in the diagnosis of HR was calculated. The sensitivity of MSI in the diagnosis of severe HR was calculated by comparison with FFA. Choroidal vascular index was calculated in patients with HR using MSI at 780 nm.

RESULTS

MSI and fundus photography were highly concordant in the diagnosis of HR with a Kappa value = 0.883. MSI had a sensitivity of 96% in diagnosing retinal hemorrhage, a sensitivity of 89.47% in diagnosing retinal exudation, a sensitivity of 100% in diagnosing vascular compression indentation, and a sensitivity of 96.15% in diagnosing retinal arteriosclerosis. The choroidal vascular index of the patients in the HR group was significantly lower than that of the control group, whereas there was no significant difference between the affected and fellow eyes.

CONCLUSION

As a noninvasive modality of observation, MSI may be a new tool for the diagnosis and assessment of HR.

Effect of adalimumab on choroidal thickness and choroidal vascularity index in eyes with non-infectious uveitis using enhanced-depth imaging optical coherence tomography

OBJECTIVE

To evaluate the effect of adalimumab (ADA) on choroidal thickness (ChT) and choroidal vascularity index (CVI) in eyes with non-infectious uveitis (NIU).

METHODS

Thirty-seven eyes with NIU including Behçet disease (BD), sarcoidosis, ankylosing spondylitis (AS), juvenile idiopathic arthritis and idiopathic arthritis, 38 eyes of non-uveitic (NU) patients including BD, AS and rheumatoid arthritis, and 40 healthy control eyes were included. ADA was used for anti-TNF-naive adult (80 mg) or paediatric (40 mg) patients with refractory NIU, then 40 mg every 2-week (20 mg in children<30 kg) with controls at weeks 1, 4, 12, and 24. Images were used to measure central, nasal, and temporal ChT, and the luminal area (LA), stromal area, and total choroidal area (TCA) were analysed using enhanced-depth imaging optical coherence tomography (EDI-OCT) by ImageJ software. The CVI was then calculated as the ratio of LA to TCA.

RESULTS

Mean ages were similar between the groups. Mean (SE) subfoveal ChT measurements for each location were also similar (for each, p > 0.05). However, calculated CVI values in eyes with NIU (0.63 ± 0.007) were significantly (p < 0.001) lower than NU eyes (0.66 ± 0.006) and controls (0.70 ± 0.007) (p < 0.001). Moreover, CVI was significantly lower in NU eyes compared to controls (p < 0.001). There were no significant CVI changes between the consecutive visits after ADA therapy in eyes with NIU (for each, p > 0.05).

CONCLUSIONS

Decreased CVI in NIU and NU eyes indicates that systemic inflammation affects the choroidal vasculature and perfusion both in the presence and absence of ocular involvement. Although CVI may be used as a possible novel tool in monitoring ocular involvement and progression of NIU, CVI does not seem to be a biomarker for treatment monitoring in NIU.

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.

Assessment of the effects of myopic and hyperopic anisometropia on choroidal vascular structure in children using SS-OCTA

OBJECTIVE

To compare large- and medium-sized choroidal vascularity and the choriocapillaris (CC) flow area in children with different refractive errors using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

Forty-two anisometropic children were enrolled and divided into hyperopic anisometropia (HA) and myopic anisometropia (MA) groups. SS-OCTA was performed to analyse choroidal vascularity. Mean choroidal thickness (CT), choroidal vascularity volume (CVV), choroidal vascularity index (CVI) and CC flow area were compared between the two eyes. The inter-ocular differences between the two groups were also determined.

RESULTS

Mean CT and CVV were highest in eyes with shorter axial lengths in both refractive groups, and the difference between the two eyes was positively correlated with the difference in axial length at the foveal region. Significant differences in the CVI in the MA group were only found in the parafoveal region. Inter-ocular differences in the CC were significantly reduced in eyes with longer axial lengths in the foveal and parafoveal regions of the HA and MA groups, respectively. Comparing inter-ocular differences, CC was significantly greater in the parafoveal region of the MA group than the HA group.

CONCLUSIONS

All layers of choroidal vasculature were thinner in eyes with longer axial lengths in all groups. The inter-ocular CC difference was greater in the MA than in the HA group, with similar differences in axial length. This suggests that both medium-to-large choroidal vascular and choroidal capillaries may play a role in myopia development.

Diurnal Variation in Choroidal Parameters Among Healthy Subjects Using Wide-Field Swept-Source Optical Coherence Tomography Angiography

Purpose

The purpose of this study was to evaluate the diurnal variation in choroidal parameters in a wide field area among healthy subjects and to identify correlations between choroidal luminal area and stromal area and various systemic factors.

Methods

In this cross-sectional study, 42 eyes from 21 healthy participants (mean age = 32.4 ± 8.8 years) were examined using wide-field swept-source optical coherence tomography angiography (WF SS-OCTA, 24 mm × 20 mm). Measurements of choroidal parameters, including choroidal volume (CV), choroidal thickness (CT), choroidal vessel volume (CVV), and choroidal stromal volume (CSV), were taken at 8:00, 12:00, 18:00, and 22:00. Systemic factors, such as blood pressure and heart rate, were concurrently monitored.

Results

Our study observed significant diurnal variations in the mean total CV, CT, CVV, and CSV, with minimum measurements around 12:00 (P < 0.001) and peak values at 22:00 (P < 0.001). Furthermore, changes in CV in specific regions were more closely associated with fluctuations in CVV than CSV in the same regions. No significant diurnal variations were found in systolic (P = 0.137) or diastolic blood pressure (P = 0.236), whereas significant variations were observed in the heart rate (P = 0.001).

Conclusions

Our study reveals diurnal variations in choroidal parameters and their associations, emphasizing that changes in choroidal volume relate more to the luminal than the stromal area in vessel-rich regions. This enhances our understanding of choroidal-related ocular diseases.

Translational Relevance

Regions with higher choroidal vasculature observed greater choroidal volume changes.

Macular choroidal thickness, volume, and vascularity index in patients with systemic sclerosis

PURPOSE

The aim of this study was to investigate choroidal parameters in patients with systemic sclerosis (SSc) using enhanced depth imaging spectral-domain optical coherence tomography (EDI-SD-OCT) and to determine their relationships with clinical variables and ocular features.

METHODS

Thirty-three patients with SSc and 40 controls were enrolled. The groups did not differ with regard to age, sex, and axial length. The mean choroidal thickness and volume were obtained in each conventional Early Treatment of Diabetic Retinopathy Study grid subfield. The choroidal vascularity index (CVI), which provides a quantitative analysis of vasculature by calculating the proportion of the luminal area (LA) to the total choroidal area (TCA), was determined.

RESULTS

Lower choroidal thickness and volume were observed in the SSc group. The CVI was significantly higher in SSc patients, whereas the TCA, LA, and stromal area were significantly lower in the SSc group; however, the significant difference of the stromal component was more pronounced than that of the luminal component. Regression analyses did not identify any clinical factors associated with the CVI (except Ca-blocker use), central macular thickness, or volume. No significant differences in choroidal parameters were found within the SSc subtypes (diffuse cutaneous systemic sclerosis (dcSSc) vs. limited cutaneous systemic sclerosis (lcSSc)), or between eyes stratified according to SSc pattern (early, active, or late) using nailfold capillaroscopy (p > 0.05 for all).

CONCLUSION

Our results, with notably higher CVI values, may shed new light on choroidal impairment in patients with SSc. Stromal involvement appeared to dominate the vascular component.

COMPARISON OF THE CHOROIDAL VASCULARITY INDEX MEASUREMENTS OF IMAGES ACQUIRED WITH DIFFERENT OPTICAL COHERENCE TOMOGRAPHY SCAN SCALE TYPES

PURPOSE

To evaluate the differences in choroidal vascularity index (CVI) measurements between images acquired at the 1:1 pixel scale and at the 1:1 µ m scale of the Heidelberg optical coherence tomography device.

METHODS

Forty-five healthy eyes of 45 healthy subjects were included for this study. Fovea-centered scans were obtained with an enhanced-depth imaging mode with a high-speed protocol scan. Each scan was exported in 3 different types: 1) 1:1 pixel scale type; 2) 1:1 µ m scale type (MST); and 3) 4×-magnified MST (4×MST; 400%-magnified 1:1 µ m images exported via screenshot). A comparison between CVI measurements based on the different scale types of optical coherence tomography images was conducted using the Bland-Altman analysis and intraclass correlation coefficient.

RESULTS

The image with the worst clarity was acquired via the MST, and the CVI was found to be higher in MST images (69.05 ± 3.21) compared with the other groups. The intraclass correlation coefficient between the CVI values of the 4×MST and pixel scale type images was 0.92, between those of the 4×MST and MST images was 0.33, and between those of the pixel scale type and MST images was 0.44.

CONCLUSION

The optical coherence tomography scale and export method type significantly influence the image resolution, CVI, and choroidal area measurements.

The relationship between Choroidal Vascular Index and non-invasive ultrasonographic atherosclerosis predictors

BACKGROUND

This study explores the intricate connections between choroidal vascular index (CVI) and non-invasive ultrasonographic atherosclerosis predictors, shedding light on the potential links between ocular vascular dynamics and systemic cardiovascular health.

METHODS

We conducted a cross-sectional analysis of 81 participants, assessing CVI, intima-media thickness (IMT), extra-media thickness (EMT), and the PATIMA index. The presence of coronary artery disease (CAD) was also evaluated. Statistical methods included descriptive statistics, t-tests for group comparisons, Spearman correlation analysis, and receiver operating characteristic (ROC) curve analysis.

RESULTS

Our findings revealed that patients with CAD had lower CVI values compared to those without CAD, underscoring a potential association between CVI and CAD. Significant negative correlations were observed between CVI and IMT, EMT, PATIMA, and CAD. ROC curve analysis identified optimal CVI cutoff values for hypertension and CAD detection, showcasing its potential as a diagnostic marker.

DISCUSSION

Our results align with existing literature on ocular vascular changes, supporting the notion that CVI may be a promising indicator of systemic vascular conditions. The study contributes to the broader understanding of the relationships between ocular and cardiovascular health, providing a foundation for future research and clinical applications.

CONCLUSION

The study suggests that CVI holds clinical relevance as a non-invasive marker for identifying systemic conditions, offering insights into the fields of neurology, physical therapy, and rehabilitation. Addressing its limitations, this research encourages further investigation into the multifaceted connections between CVI and atherosclerosis predictors.

Distribution and determinants of choroidal vascularity index in healthy eyes from deep-learning choroidal analysis: a population-based SS-OCT study

AIMS

To quantify the profiles of choroidal vascularity index (CVI) using fully artificial intelligence (AI)-based algorithm applied to swept-source optical coherence tomography (SS-OCT) images and evaluate the determinants of CVI in a population-based study.

METHODS

This cross-sectional study included adults aged ≥35 years residing in the Yuexiu District of Guangzhou, China, a follow-up population-based study. All participants (n=646) underwent comprehensive ophthalmic examinations, including SS-OCT for quantifying choroidal parameters. The CVI and subfoveal choroidal thickness (SFCT) were measured by a novel AI-based system.

RESULTS

A total of 556 participants were included, with a mean age of 56.4±9.9 years and 44.96% women. The average CVI and SFCT of the overall population were 69.7% (95% CI 69.2 to 70.3) and 263.0 µm (95% CI 257.2 to 268.8), respectively. After adjusting for other factors, older age and longer AL were significantly associated with a lower CVI. The CVI decreased by -0.13% (-0.19 to -0.06, p<0.001) with each 1-year increase in age, -2.10% (-3.29 to -0.92, p=0.001) with each 1 mm increase in AL. Furthermore, significantly positive correlation between CVI and SFCT has been observed, with coefficient of 0.059 (0.052 to 0.065, p<0.001).

CONCLUSION

Using new AI-based choroidal segmentation software, we provided a fast, reliable and objective CVI profile for large-scale samples. Older age and longer AL were independent correlates of choroidal thinning and CVI decline. These factors should be considered when interpreting SS-OCT-based choroidal measurements.

Quantitative assessment of OCT and OCTA parameters in diabetic retinopathy with and without macular edema: single-center cross-sectional analysis

Aim

The retinal and choroidal parameters were analyzed to understand the impairment of microcirculation of both retina and choroid in patients with diabetic retinopathy (DR).

Methods

Fifty-five treatment-naive non-proliferative diabetic retinopathy (NPDR) patients (75 eyes) with type 2 diabetes mellitus (T2DM), including 28 patients (36 eyes) with diabetic macular edema (DME) and 27 patients (39 eyes) without DME, and 25 healthy subjects (47 eyes) were enrolled in this study. The following parameters of DR patients with and without DME were evaluated: the foveal avascular zone area (FAZ-a), FAZ perimeter (FAZ-p), FAZ circularity index (FAZ-CI), total subfoveal choroidal area (TCA), luminal area (LA), stromal area (SA), choroidal vascularity index (CVI), choriocapillaris flow area percentage, superficial capillary plexus (SCP), and deep capillary plexus (DCP).

Results

SCP, DCP, and the percentage of choriocapillaris flow area were significantly different between DR patients with and without DME. The DR patients presented lower LA, CVI, and FAZ-CI compared to those of healthy controls (all p < 0.05). The percentage of choriocapillaris flow area in DR patients with and without DME was significantly lower than that in healthy controls (p < 0.05). SCP and DCP were significantly correlated with FAZ-a and FAZ-p but presented insignificant associations with FAZ-CI.

Conclusions

Optical coherence tomography (OCT) and OCT angiography (OCTA) parameters, such as LA, CVI, FAZ-CI, and the percentage of choriocapillaris flow area, were reduced compared to those in controls, indicating that the microcirculations of the retina and choroid in the macular area were impaired in DR patients with DME and without DME.

Quantitative Evaluation of the Topographical Maps of Three-Dimensional Choroidal Vascularity Index in Children With Different Degrees of Myopia

Purpose

To investigate topographical maps of the three-dimensional choroidal vascularity index (3D-CVI) in children with different levels of myopia.

Methods

We enrolled 274 eyes from 143 children with various severity of myopia, including emmetropia (EM), low myopia (LM), and moderate-high myopia (MHM). The choroidal vessel volume (CVV), choroidal stroma volume (CSV), and 3D-CVI in different eccentricities (fovea, parafovea, and perifovea) and quadrants (nasal, temporal, superior, and inferior) were obtained from swept-source optical coherence tomography angiography (SS-OCTA) volume scans. All choroidal parameters were compared among groups, and the associated factors contributing to different 3D-CVIs were analyzed.

Results

Compared to the less myopic group, the more myopic group showed a significant decrease in CVV and CSV (MHM < LM < EM) and a significant increase in the 3D-CVI (MHM > LM > EM) in most areas (all P < 0.05). The nasal quadrant had the greatest 3D-CVI and lowest CSV and CVV, and vice versa in the temporal quadrant. The 3D-CVIs of the EM and LM groups gradually increased from the fovea to the perifovea, whereas the 3D-CVI of the MHM group first decreased and then increased. Regression analysis showed that axial length was an independent risk factor affecting foveal and parafoveal 3D-CVIs. Restricted cubic spline analysis revealed that the 3D-CVI increased with spherical equivalent (SE) when the SE was less than threshold and decreased when the SE was greater than threshold (SE thresholds for foveal, parafoveal, and perifoveal 3D-CVIs were -5.25 D, -5.125 D, and -2.00 D, respectively; all P < 0.05).

Conclusions

Children with myopia exhibited decreased CSV and CVV, increased 3D-CVIs, and altered 3D-CVI eccentricity characteristics (from the fovea to the perifovea). The quadratic relationship between the 3D-CVI and SE should be explored in longitudinal investigations.

Choroidal Vascularity Index and Choroidal Structural Changes in Children With Nephrotic Syndrome

Purpose

To investigate the choroidal vascularity index (CVI) and choroidal structural changes in children with nephrotic syndrome.

Methods

This was a cross-sectional study involving 45 children with primary nephrotic syndrome and 40 normal controls. All participants underwent enhanced depth imaging-optical coherence tomography examinations. An automatic segmentation method based on deep learning was used to segment the choroidal vessels and stroma, and the choroidal volume (CV), vascular volume (VV), and CVI within a 4.5 mm diameter circular area centered around the macular fovea were obtained. Clinical data, including blood lipids, serum proteins, renal function, and renal injury indicators, were collected from the patients.

Results

Compared with normal controls, children with nephrotic syndrome had a significant increase in CV (nephrotic syndrome: 4.132 ± 0.464 vs. normal controls: 3.873 ± 0.574; P = 0.024); no significant change in VV (nephrotic syndrome: 1.276 ± 0.173 vs. normal controls: 1.277 ± 0.165; P = 0.971); and a significant decrease in the CVI (nephrotic syndrome: 0.308 [range, 0.270-0.386] vs. normal controls: 0.330 [range, 0.288-0.387]; P < 0.001). In the correlation analysis, the CVI was positively correlated with serum total protein, serum albumin, serum prealbumin, ratio of serum albumin to globulin, and 24-hour urine volume and was negatively correlated with total cholesterol, low-density lipoprotein cholesterol, urinary protein concentration, and ratio of urinary transferrin to creatinine (all P < 0.05).

Conclusions

The CVI is significantly reduced in children with nephrotic syndrome, and the decrease in the CVI parallels the severity of kidney disease, indicating choroidal involvement in the process of nephrotic syndrome.

Translational Relevance

Our findings contribute to a deeper understanding of how nephrotic syndrome affects the choroid.

Correlation between choroidal vascularity and retrobulbar ocular blood flow changes and thyroid-associated ophthalmopathy activity: a cross-sectional study

OBJECTIVE

To evaluate the alterations in retrobulbar color Doppler imaging (CDI) parameters and retinal/choroidal optical coherence tomography angiography (OCTA) parameters and their association with the clinical activity and severity in thyroid-associated orbitopathy (TAO) patients.

METHODS

In this study, the retrobulbar flow parameters including resistance index (RI), Pulsatile Index(PI), peak systolic velocity (PSV) and end diastolic velocity (EDV) in posterior ciliary artery (PCA), central retinal artery (CRA) and ophthalmic artery (OA) were determined by CDI. Moreover, the retina and choroidal vascularity including the superficial vessel density (SVD), deep vessel density (DVD), choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA) and Choroidal Vascularity Index (CVI), were determined by OCTA. All patients grouped as active TAO and inactive TAO based on Clinical activity score (CAS). We picked the severe eye among the subjects and compared all parameters between two groups. We analyzed the correlations among those parameters.

RESULTS

There was a significant difference in CAS score, proptosis value, ChT, LA, CVI between patients with active TAO and inactive TAO. In the active group, PSV and EDV of PCA were significantly higher than the inactive group. On logistic regression analysis, CAS was closely associated with PSV-PCA. On multiple linear regression, proptosis value was closely associated with ChT, LA, SA and CVI.

CONCLUSION

Choroidal vascularization and retrobulbar blood flow were concurrently higher in active TAO patients and several variables in choroid circulation was closely related to TAO clinical features.

Integrity of the Hyperreflective Layer in the Inner Choroid in Eyes with Drusen

INTRODUCTION

This study aimed to compare the integrity of the hyperreflective layer of the inner choroid in eyes with and without drusen.

METHODS

Swept-source optical coherence tomography images of patients with drusen and normal controls were reviewed. Using a line plot of ImageJ, choroidal reflectivity was measured at the subfovea, and the integrity of the hyperreflective layer of the inner choroid was determined.

RESULTS

In total, 63 eyes with drusen and 30 control eyes without drusen were included. The integrity of the hyperreflective layer of the inner choroid was preserved in 81.0% of eyes with drusen and 93.3% of normal controls. The proportion of eyes with the hyperreflective layer did not differ between eyes with and without drusen. Of the 63 subjects with drusen, this hyperreflective layer was observed in all 28 eyes (100%) with pachydrusen but only in 68.6% of the 35 eyes with soft drusen, and its prevalence was significantly different (P = 0.001).

CONCLUSION

The prevalence of the hyperreflective layer between the choriocapillaris and medium or large choroidal vessels in eyes with soft drusen differed from that in eyes with pachydrusen. These findings support the suggestion that changes within the choroidal stroma may be involved in the pathogenesis of age-related macular degeneration.

Quantitative analysis of deep learning-based denoising model efficacy on optical coherence tomography images with different noise levels

BACKGROUND

To quantitatively evaluate the effectiveness of the Noise2Noise (N2N) model, a deep learning (DL)-based noise reduction algorithm, on enhanced depth imaging-optical coherence tomography (EDI-OCT) images with different noise levels.

METHODS

The study included 30 subfoveal EDI-OCT images averaged with 100 frames from 30 healthy participants. Artificial Gaussian noise at 25.00, 50.00, and 75.00 standard deviations were added to the averaged (original) images, and the images were grouped as 25N, 50N, and 75N. Afterward, noise-added images were denoised with the N2N model and grouped as 25dN, 50dN, and 75dN, according to previous noise levels. The choroidal vascularity index (CVI) and deep choroidal contrast-to-noise ratio (CNR) were calculated for all images, and noise-added and denoised images were compared with the original images. The structural similarity of the noise-added and denoised images to the original images was assessed by the Multi-Scale Structural Similarity Index (MS-SSI).

RESULTS

The CVI and CNR parameters of the original images (68.08 ± 2.47 %, and 9.71 ± 2.80) did not differ from the only 25dN images (67.97 ± 2.34 % and 8.50 ± 2.43) (p:1.000, and p:0.062, respectively). Noise reduction improved the MS-SSI at each noise level (p < 0.001). However, the highest MS-SSI was achieved in 25dN images.

CONCLUSIONS

The DL-based N2N denoising model can be used effectively for images with low noise levels, but at increasing noise levels, this model may be insufficient to provide both the original structural features of the choroid and structural similarity to the original image.

Optical coherence tomography in the management of diabetic macular oedema

Diabetic macular oedema (DMO) is the major cause of visual impairment in people with diabetes. Optical coherence tomography (OCT) is now the most widely used modality to assess presence and severity of DMO. DMO is currently broadly classified based on the involvement to the central 1 mm of the macula into non-centre or centre involved DMO (CI-DMO) and DMO can occur with or without visual acuity (VA) loss. This classification forms the basis of management strategies of DMO. Despite years of research on quantitative and qualitative DMO related features assessed by OCT, these do not fully inform physicians of the prognosis and severity of DMO relative to visual function. Having said that, recent research on novel OCT biomarkers development and re-defined classification of DMO show better correlation with visual function and treatment response. This review summarises the current evidence of the association of OCT biomarkers in DMO management and its potential clinical importance in predicting VA and anatomical treatment response. The review also discusses some future directions in this field, such as the use of artificial intelligence to quantify and monitor OCT biomarkers and retinal fluid and identify phenotypes of DMO, and the need for standardisation and classification of OCT biomarkers to use in future clinical trials and clinical practice settings as prognostic markers and secondary treatment outcome measures in the management of DMO.

Interocular Symmetry of Choroidal Parameters in Patients with Diabetic Retinopathy with and without Diabetic Macular Edema

This study focuses on the interocular comparison of choroidal parameters in diabetic patients with diabetic retinopathy (DR) with and without diabetic macular edema (DME), as well as in patients with unilateral DME (present in only one eye). The aim of this study was to determine the symmetry in order to obtain better insights into the pathophysiology of diabetic choroidopathy. This retrospective single-center cross-sectional study included 170 eyes from 85 patients (61 with DR and 24 controls), divided into subgroups depending on the presence of DME. The patients underwent fluorescein angiography and spectral domain optical coherence tomography examination, and the analysis included various choroidal parameters: choroidal thickness, volume, and the choroidal vascularity index (CVI). In terms of the choroidal thickness, one eye of a patient with DR, regardless of the presence, absence, or unilaterality of DME, may be treated as representative for that patient. CVI proved symmetrical for controls and patients with DR without DME. However, there was some asymmetry of CVI in patients with bilateral or unilateral DME. There was no straightforward relationship between choroidopathy and DME. Other mechanisms were also involved in the pathogenesis.

Evaluation of the effect of sodium-glucose cotransporter-2 inhibitor treatment on choroidal vascular parameters in patients with type 2 diabetes mellitus

BACKGROUND

To evaluate the effect of sodium-glucose cotransporter-2 inhibitor treatment on choroidal vascular parameters in patients with type 2 diabetes mellitus (T2DM).

METHODS

Twenty eyes of 20 patients with T2DM without diabetic retinopathy and 20 eyes of 20 age- and sex-matched patients as the control group were included in the study. The patients were evaluated using enhanced depth imaging optic coherence tomography before treatment and at the third month of treatment. The choroidal images were binarized into luminal areas (LAs) and stromal areas (SAs). The choroidal vascularity index (CVI) was defined as the ratio of the LA to the total circumscribed choroid area (TCA).

RESULTS

The mean age of the patients was 56.65±8.41 years. The patients' mean disease duration was 6.65±5.72 years, the mean HbA1c level was 8.89±1.62%, and the mean body mass index was 33.13±4.84 kg/m2. The subfoveal TCA, subfoveal LA, subfoveal SA, total TCA, total LA, and total SA values ​​of the patient group were found to be significantly lower than those of the control group (p = 0.006, p = 0.003, p = 0.028, p = 0.001, p = 0.001, and p = 0.006, respectively). There was a significant increase in the subfoveal TCA, subfoveal LA, subfoveal SA, subfoveal CVI, total TCA, total LA, and total SA values ​​after empagliflozin treatment compared to before empagliflozin treatment (p = 0.005, p = 0.003, p = 0.021, p = 0.032, p < 0.001, p < 0.001, and p = 0.001 respectively).

CONCLUSIONS

Empagliflozin provides an improvement in diabetic choroidal changes through its effect on choroidal vascularity parameters.

Patterns of Structural Changes in the Fundus Measured by Optical Coherence Tomography Angiography as Potential Markers of Acute Mountain Sickness

Purpose

To use optical coherence tomography angiography (OCTA) to assess the pattern of changes in retinal and choroidal blood flow and structure in healthy volunteers who quickly went from sea level to a plateau and to determine the parameters associated with acute mountain sickness (AMS).

Methods

Forty-five individuals (89 eyes) were examined by OCTA and filled out the AMS questionnaire. One baseline examination was performed on the plain, followed by examinations at days 1, 3, and 5 after entering the plateau. Parameters were self-controlled to explore patterns of change, analyzed for correlation with AMS score, and modeled as a nomogram of AMS risk.

Results

On the plateau compared to the plain, vascular morphology showed dilated superficial macular retinal vessels and constricted deeper layers with increased vessel length density and fractal dimension; vessel density increased in all retinal strata and decreased in the choroidal macrovascular layer; and thickness increased except for a decrease in mean retinal thickness in the central macular sulcus. The rate of increase in retinal nerve fiber layer (RNFL) thickness in the inner and outer macular rings correlated with AMS score (r = -0.211). The nomogram showed moderate accuracy (AUC = 0.672) and consistency (C-index = 0.659) in assessing AMS risk.

Conclusions

In high-altitude hypoxia, retinal vessels dilate and distort, resulting in increased blood flow density and thickness. Increased RNFL thickness in the paracentral macula may be a marker of low AMS risk.

Translational Relevance

The changes in the retinal structure of the fundus can be used to assess the risk of developing AMS.

Choroidal structural changes in patients with early diabetic nephropathy

PURPOSE

To determine alterations of the choroidal thickness (CT) and the choroidal vascularity index (CVI) in patients with glomerular hyperfiltration, a marker of early diabetic nephropathy (DN).

METHODS

Twenty-two patients with type 2 diabetes (T2D) with glomerular hyperfiltration (early DN group) and 28 patients with T2D without DN (NDN group) were included in the study. Patients with diabetic retinopathy were excluded. Parameters including subfoveal CT, the subfoveal choroidal vascularity index (CVI), and total CVI were measured using spectral-domain enhanced depth imaging optical coherence tomography method.

RESULTS

The early DN group included 22 patients and the NDN group comprised 28 patients. The groups were similar in terms of age and sex (p>0.05). The CT values were statistically significantly lower in the early DN group than in the NDN group (p < 0.001). There was no significant difference between the early DN group and the NDN group in terms of total and subfoveal CVI (p>0.05).

CONCLUSION

The choroidal thickness decreased in patients with T2D with glomerular hyperfiltration, but there were no differences in CVI when they were compared with patients with T2D without DN.

Changes in the choroid detected by ultrawide-field optical coherence tomography angiography in type 2 diabetes mellitus patients without diabetic retinopathy

AIM

The study objective was to investigate the choroidal changes in type 2 diabetes mellitus (T2DM) patients without diabetic retinopathy (DR).

METHODS

This was a cross-sectional study. Controls without diabetes and T2DM patients without DR (NDR) were included. Ultrawide-field (24 × 20 mm2) optical coherence tomography angiography (OCTA) was performed to analyse choroidal thickness and vessel density. All OCTA images were divided into 3 × 3 grids. The grid centre was considered the central area, while the rest was defined as the peripheral area.

RESULTS

No differences between groups were observed in the flow density of the choriocapillaris (CC), choroidal thickness (ChT) and choroidal vascular index (CVI) of the large and medium choroidal vessel (LMCV) in the central area. In the eight peripheral areas, the mean flow density of the CC did not differ between the groups, while the mean CVI and ChT were decreased in the NDR group (P< 0.05). In each peripheral area, the mean CVI and ChT were decreased in the NDR group (P< 0.05, except in the infratemporal area and nasal area for ChT and in the infratemporal area for CVI). In the correlation analysis, both mean peripheral CVI and ChT correlated with age and the duration of diabetes.

CONCLUSION

Early choroidal lesions tended to be peripheral in the LMCV in patients with diabetes without DR and correlated with age and the duration of diabetes.

Choroidal vascular changes in silicone oil-filled eyes after vitrectomy for rhegmatogenous retinal detachments

INTRODUCTION

The tamponade of silicone oil (SO) can affect both the structure and blood flow of the retina. However, there are few studies on the effect of SO tamponade on choroidal blood flow. Our study aimed to compare the effects of SO tamponade on the choroidal vascular index (CVI) and choroidal thickness (CT) in patients with unilateral rhegmatogenous retinal detachment (RRD) with operated eyes and fellow healthy eyes.

METHODS

We retrospectively collected demographic and clinical data from 36 patients who underwent 23G pars plana vitrectomy and SO tamponade for unilateral complicated RRD. Enhanced depth imaging-optical coherence tomography (EDI-OCT) scans were performed both within 1 week before SO removal and at the last follow-up visit after SO removal. Using ImageJ software, images were binarized to segment the total choroidal area, luminal area, and stromal area, respectively. The CVI was calculated as CVI=(luminal area)/(total choroidal area), and CT was also evaluated.

RESULTS

During SO tamponade, the CVI and luminal area in operated eyes were significantly lower compared to fellow eyes (57.616 ± 0.030 vs. 60.042 ± 0.019, P < 0.0001; 0.909 [0.694; 1.185] vs. 1.091 [0.785; 1.296], P = 0.007). Even after SO removal, the CVI remained lower in operated eyes than in fellow eyes (59.530 ± 0.018 vs. 60.319 ± 0.020, P = 0.031). Both CVI and luminal area were lower in operated eyes before SO removal than after SO removal (57.616 ± 0.030 vs. 59.530 ± 0.018, P = 0.0003; 0.909 [0.694; 1.185] vs. 0.994 [0.712; 1.348], P = 0.028). The duration of SO tamponade was positively correlated with the difference in CVI between fellow eyes and operated eyes during SO tamponade (P = 0.035). Total choroidal area, stromal area, and CT did not differ significantly between fellow eyes and operated eyes or between pre- and post-SO removal.

CONCLUSIONS

SO tamponade reduces CVI and decreases choroidal blood circulation in patients with retinal detachments required vitrectomy combined with SO tamponade. The longer the SO tamponade time, the more CVI reduction. In future work, we will aim to reduce these side effects by shortening the duration of silicone oil filling.

Choroidal features in non-neovascular and neovascular pachychoroid diseases

PURPOSE

To evaluate choroidal findings on multimodal imaging in eyes within pachychoroid spectrum diseases and to compare quantitative and qualitative choroidal features between non-neovascular (NNV-PDS) and neovascular (NV-PDS) pachychoroid diseases.

METHODS

Retrospective cross-sectional study comparing between NV-PDS and NNV-PDS. All patients underwent multimodal imaging including infracyanine green angiography (IFCGA) and swept source optical coherence tomography (OCT) and angiography (OCT-A). The following parameters were analyzed: subfoveal choroidal thickness (SFCT), choroidal vascular index (CVI), presence of pachyvessels and choroidal vascular interconnections (CVIC), presence of choroidal neovascularization and choriocapillaris density.

RESULTS

Of the 87 eyes included in the study, 63 eyes (73%) had NNV-PDS and 24 eyes (27%) had NV-PDS. Mean SFCT and CVI were significantly higher in NNV-PDS group (p = 0.01; p = 0.022). Pachyvessels were more diffusely distributed in NNV-PD group and more focally distributed in NV-PDS group (p = 0.029). CVIC were more frequently noted in NV-PDS group (p = 0.024). A higher CVI was associated to a thicker choroid (p < 0.001), with significant negative correlations between the presence of CVIC and both SFCT (p = 0.015) and CVI (p = 0.002). We also observed a lower choriocapillaris vascular density and higher number of choriocapillaris flow voids in eyes with NNV-PDS (p = 0.24; p = 0.61).

CONCLUSION

NNV-PDS eyes had a significantly thicker SFCT, higher CVI and a lower rate of detected CVIC than eyes with NV-PDS. These highlighted choroidal vascular changes might lead to a better understanding of pachychoroid disease pathophysiology. More frequently observed in NV-PDS group, CVIC are believed to assess the development of vortex vein anastomoses as a remodelling process for vascular decongestion.

Choriocapillaris and progressive ganglion cell-inner plexiform layer loss in non-glaucomatous eyes

AIMS

To explore the relationship between choriocapillaris (CC) flow deficit percentage (FD%) and ganglion cell-inner plexiform layer (GCIPL) thickness in a population-based sample of non-glaucomatous eyes.

METHODS

This is a longitudinal cohort study and prospective cross-sectional study. Non-glaucoma Chinese subjects aged 18 years or older were enrolled. All participants underwent a detailed ophthalmic examination, including swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography. Average, inner average, outer average and nine Early Treatment Diabetic Retinopathy Study sub-regions of GCIPL thickness and CC FD% were measured. The correlation between CC FD% and GCIPL was assessed using a linear regression model, and the relationship between the rate of change of GCIPL thickness and CC FD% was further validated in a 2year longitudinal study.

RESULTS

In the cross-sectional study including 3514 participants (3514 non-glaucoma eyes), a higher CC FD% was significantly associated with a thinner GCIPL (β=-0.32; 95% CI -0.43 to -0.21; p<0.001). Further, in a longitudinal study (453 eyes of 453 participants), a faster increase in CC FD% was found to be significantly associated with a faster decrease in GCIPL thickness (β=-0.10; 95% CI -0.17 to -0.03; p=0.004) after adjusting for age, sex, axial length and image quality score.

CONCLUSIONS

This is the first time to show that CC FD% and GCIPL thickness were correlated in both cross-sectional and longitudinal studies of non-glaucomatous individuals, which may potentially provide further insights on the role of CC perfusion in glaucoma development and progression.

The Correlation between Retinal and Choroidal Thickness with Age-Related White Matter Hyperintensities in Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease. Recently, several retinal layers in PSP compared to healthy controls. were found to be thinner. However, no studies evaluating the correlation between retinal layers and cerebral white matter changes, nor eventual choroidal changes in PSP, have been conducted so far. The goals of the present study were to explore potential differences in choroidal structure between PSP and healthy controls, and to describe the relationship between retinal layers' thickness and volume, using spectral-domain optical coherence tomography (SD-OCT) and age-related white matter change scores (ARWMC) using magnetic resonance imaging (MRI) of the brain. Choroidal structures of 26 PSP patients and 26 healthy controls using standard SD-OCT with an enhanced depth imaging (EDI) approach were analyzed; then, retinal the structures of 16 of these PSP patients using standard SD-OCT were examined; finally, the same patients underwent brain MRI, and their cerebral white matter changes were calculated. Non-statistically significant differences between PSP patients' and healthy controls' choroidal structure were found. On the contrary, PSP patients' inner retinal layers (INR), retinal pigmented epithelium (RPE) and all retinal layers' thicknesses in the macular region were found to be significantly correlated with ARWMC, independently from age and axial length (AL). PSP patients' neurological alterations go hand in hand with retinal ones, independently from age and axial length. Our results suggest a mutual relationship between cerebral and retinal structure pathological alterations. On the other hand, no significant differences in the choroidal evaluation compared to healthy controls have been found.

Peripapillary choroidal vascularity index and thickness in patients with systemic sclerosis

Introduction

Patients with systemic sclerosis (SSc) present an increased risk of developing glaucomatous optic neuropathy (GON). We investigated peripapillary choroidal parameters and peripapillary retinal nerve fiber layer (RNFL) thickness using spectral domain optical coherence tomography (SD-OCT) to determine the relationships of these factors with clinical variables.

Methods

A total of 33 patients with SSc were enrolled and compared to 40 controls. After obtaining circular scans around the optic disc, the global and quadrant peripapillary choroidal thickness (pCT) and RNFL thickness were measured. Additionally, the peripapillary choroidal vascularity index (pCVI), which allows for a quantitative analysis of the choroidal vasculature, was determined.

Results

No significant differences were found in pCT and RNFL thickness between patients with SSc and controls, or within SSc subtypes (diffuse cutaneous systemic sclerosis (dcSSc) compared to limited cutaneous systemic sclerosis (lcSSc)) (p > 0.05). The pCVI was significantly lower in patients with SSc than in control subjects (64.25 ± 1.94 vs.65.73 ± 2.12, p < 0.001).

Conclusion

Our results suggest that the statistically significant decrease in pCVI in patients with SSc compared to the control group is probably due to a decrease in the vascular layer, which would partially explain an increased risk of GON in patients with SSc.

Effects of posterior staphyloma on choroidal structure in myopic adults: a retrospective study

BACKGROUND

Studies on the choroid of myopic eyes with posterior staphyloma have shown that choroidal thickness decreased. This retrospective study further analysed the effects of posterior scleral staphyloma on choroidal blood vessels and matrix components compared to non-pathological myopia.

METHODS

In this cross-sectional study, ninety-one eyes were divided into pathological (posterior staphyloma) and non-pathological myopia. The latter was further divided into three groups (Group 1: 26 mm ≤ axial length; Group 2: 24 mm ≤ axial length < 26 mm; Group 3: 22 mm ≤ axial length < 24 mm). Choroidal thickness, total choroidal area, luminal area, stromal area, and choroidal vascularity index were calculated.

RESULTS

The CVI in N1, N2, I1, S2 of the posterior staphyloma group were lower than those of group 1 (both P < 0.05). The mean height of posterior staphyloma was associated with mean CT (Pearson correlation: r = -0.578, P = 0.039) but not with the mean CVI in posterior staphyloma group. In all groups, the mean choroidal thickness, total choroidal area, luminal area, and stromal area were significantly associated with axial length (P < 0.001), and the mean choroidal vascularity index was significantly associated with the mean choroidal thickness (P < 0.001).

CONCLUSION

The choroidal structure of pathological myopia with posterior staphyloma and non-pathological myopia with longer axial length demonstrates alterations in which choroidal vessels are more impaired than the stroma. A lower choroidal vascularity index should be alert to pathological changes for myopia with axial length > 26 mm.

Characteristics of the Peripapillary Structure and Vasculature in Patients With Myopic Anisometropia

Purpose

To evaluate the interocular differences of the peripapillary structural and vascular parameters and that of association with axial length (AL) in participants with myopic anisometropia using swept-source optical coherence tomography.

Methods

This prospective cross-sectional study included 90 eyes of 45 participants. Each participant's eyes were divided into the more and less myopic eye respectively according to spherical equivalent. The β- and γ-parapapillary atrophy (PPA) areas, Bruch's membrane opening distance, border length, and border tissue angle were measured manually. Peripapillary choroidal vascularity index and choroidal thickness (CT) values in superior, nasal, inferior, and temporal were calculated using a custom-built algorithm based on MATLAB.

Results

The interocular difference in AL and spherical equivalent was 0.62 ± 0.26 mm and -1.50 (-2.13, -1.25) diopters (D), respectively. The interocular difference in spherical equivalent was highly correlated with that of the AL. The β- and γ-PPA areas were significantly greater in more myopic eyes. The mean and inferior peripapillary choroidal vascularity index and all regions of peripapillary CT were significantly lower in the more myopic eyes. The interocular difference in AL was significantly positively correlated with the interocular differences in γ-PPA area and border length and negatively correlated with the interocular differences in temporal choroidal vascularity index and mean, inferior, and temporal peripapillary CT. There was an independent correlation between the interocular differences in AL and the interocular differences in γ-PPA area, inferior, and temporal peripapillary CT.

Conclusions

Significant differences between both groups were detected in most peripapillary parameters, especially in peripapillary CT. The γ-PPA area, border length, and peripapillary CT were significantly correlated with the elongation of AL.

Translational Relevance

The current study characterized and analyzed the peripapillary parameters in myopic anisometropia, which helped to monitor myopic progression.

Effects of blue light exposure on ocular parameters and choroidal blood perfusion in Guinea pig

PURPOSE

To investigate the impact of different duration of blue light exposure on ocular parameters and choroidal blood perfusion in guinea pigs with lens-induced myopia.

METHOD

Three-week-old Guinea pigs were randomly assigned to different light-environment groups. All groups were subjected to 12-h light/dark cycle. The control (NC) group was conditioned without intervention. While lens-induced myopia (LIM) groups had a -10D lens placed in the right eye and 0D in the left eye. The guinea pigs were exposed to increasing periods of blue-light (420 nm) environment for 3,6,9,12 h per day. Changes in refraction, axial length (AL), the radius of corneal curvature (CCR), choroidal thickness (ChT), and choroidal blood perfusion (ChBP)were measured in both LIM-eye and fellow-eye during the second and fourth week of LIM duration.

RESULTS

During the first two weeks of the experiment, blue light exposure raised ChBP and ChT, and the effect of suppressing myopia was proportional to the duration of blue light exposure. However, in the fourth week of the experiment, prolonged blue light (12BL) exposure led to a reduction in retinal thickness and the increase in ChT and ChBP ceased. Shorter blue light exposure had a better effect on myopia suppression, with all blue light groups statistically different from the LIM group.

CONCLUSION

Exposure to blue-light appears to have the potential to improve ChBP and ChT, thereby inhibiting the development of myopia. we speculate that blue-light inhibits the development of myopia for reasons other than longitudinal chromatic aberration (LCA). However,long-term exposure to blue-light may have adverse effects on ocular development. The next step is to investigate in depth the mechanisms by which the rational use of blue light regulates choroidal blood flow, offering new hope for the treatment of myopia.

Quantitative evaluation of retinal and choroidal microcirculation in inactive ocular sarcoidosis

Purpose

To evaluate retinal and choroidal alterations in eyes with inactive ocular sarcoidosis and to compare the findings with healthy controls.

Methods

This cross-sectional study included 11 patients with inactive ocular sarcoidosis (study group) and 11 healthy individuals (control group). Retinal and choroidal vascular differences were evaluated using optical coherence tomography angiography (OCTA) and enhanced depth imaging-optical coherence tomography (EDI-OCT).

Results

A total of 21 eyes of ocular sarcoidosis patients without active inflammation and 22 eyes of healthy controls were analyzed. The mean whole-image deep capillary plexus vessel density was significantly lower in the study group than in the control group (P = 0.03). The acircularity index values were significantly higher, and the foveal density-300 values were significantly lower in the study group than in the control group (P = 0.01, both). The flow areas of the choriocapillaris at 1-, 2-, and 3-mm radius areas were also significantly lower in the study group (all P < 0.01). The mean choroidal thickness (CT) was significantly lower in all regions between nasal and temporal at 3000 μm in the study group (all P < 0.05). The choroidal vascularity index (CVI) values were also significantly lower in the study group (P < 0.01).

Conclusion

Ocular sarcoidosis was associated with a reduction in CT and the CVI with a decrease in retinal vessel density and choriocapillary flow parameters. The combination of OCTA and EDI-OCT imaging may be useful in monitoring ocular sarcoidosis eyes to detect alterations in the retinal and choroidal layers.

Retinal and Choroidal Changes Following Implantable Collamer Lens V4c Implantation in High Myopia Patients-A 1-Year Follow-Up Study

This prospective study aimed to evaluate the impact of Visian Implantable Collamer Lens (ICL) V4c implantation on retinal and choroidal morphology in patients with high myopia. A total of 97 eyes from 52 high myopic patients who underwent ICL V4c implantation were followed up for 12 months. Preoperative and postoperative evaluations included comprehensive ophthalmic assessments and enhanced depth imaging optical coherence tomography (EDI-OCT) to analyze changes in central retinal thickness (CRT), retinal volume (CRV), choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), and choroidal vascular index (CVI). Repeated measures mixed-effects models were used for comparing pre- and postoperative measurement variables and exploring relationships among age, axial length (AL), spherical equivalent refraction (SER), and postoperative retinal and choroidal changes, with statistical significance set at p < 0.05. Follow-up assessments were conducted at various time points, with participation rates ranging from 21% to 98%. Baseline characteristics showed a median age of 26.7 years, -10.14 diopters of SER, and an AL of 27.44 mm. Throughout the 12-month follow-up, CRT and 3.0 mm CRV consistently increased compared to the baseline, with statistically significant rises observed at postoperative day 1, week 1, and month 12. Most ChT measurements, including subfoveal ChT, declined over the 12 months, except at postoperative 6 months. Horizontal and vertical TCA and LA values significantly increased throughout the follow-up, except for month 6. After surgery, both horizontal and vertical CVI parameters exhibited an increase compared to the baseline, with some changes reaching statistical significance. Correlation analysis performed by repeated measures mixed-effects models showed that no relationship was found between age, AL, and SER and changes in postoperative retinal parameters and CVI parameters. However, postoperative changes in ChT and choroidal area parameters showed a negative correlation with AL and a positive correlation with SER. Our research demonstrated that ICL V4c implantation resulted in noteworthy alterations in retinal and choroidal morphology over a 1-year follow-up period. Moreover, in patients with high myopia, individuals with longer AL and higher degrees of myopia exhibited more pronounced postoperative changes in the choroid and retina. Further studies with extended follow-up durations are necessary to comprehensively understand the long-term effects of ICL implantation on retinal and choroidal morphology and function.

Choroidal vascularity index and submacular choroidal thickness in patients with Behçet disease assessed with enhanced-depth OCT

PURPOSE

To investigate changes in the choroid using the choroidal vascularity index (CVI) and choroidal thickness (ChT) in patients with ocular (OBD) and non-ocular Behçet disease (non-ocular BD).

METHODS

Sixty-eight OBD patients, 40 non-ocular BD patients, and 40 healthy control subjects were included. ChT was measured using optical coherence tomography (OCT) in enhanced-depth imaging (EDI) mode (EDI-OCT; sub-foveal ChT at 1000 μm, nasal ChT at 1000 μm temporal ChT). The CVI value (%) was calculated by dividing the luminal area by the sub-foveal total choroidal area.

RESULTS

The mean sub-foveal ChT (297 ± 68 µm), nasal ChT (261 ± 66 µm), and temporal ChT (272 ± 68 µm) in eyes with OBD and the mean sub-foveal ChT (286 ± 31 µm), nasal ChT (266 ± 29 µm), and temporal ChT (269 ± 32 µm) in eyes with non-ocular BD were significantly decreased compared with those regions in healthy control subjects (333 ± 69, 301 ± 75, and 312 ± 70 µm, respectively). Additional subgroup analysis was performed for active OBD, inactive OBD, non-ocular BD, and the control group, and in pairwise comparisons, the CVI value was significantly decreased in both active (64.3 ± 3.1) and inactive OBD groups (64.2 ± 4.5) compared with healthy control subjects (67.2 ± 3.6; p = 0.026 and p < 0.001, respectively). There was no significant difference between non-ocular BD (65.9 ± 3.4) and control subjects (67.2 ± 3.6) for CVI measurements (p > 0.05).

CONCLUSIONS

Decreased CVI values in OBD suggest that uveitis affects the choroidal vasculature and that perfusion is affected by uveitis, whereas systemic inflammation in non-ocular BD does not affect them. In addition, the choroid in uveitis is affected by the chronicity of the disease rather than disease activity. ChT measurements and CVI values may be a novel and robust prognosticating biomarker to evaluate choroidal vasculature and to monitor disease progression in OBD patients because EDI-OCT is a non-invasive imaging modality. However, CVI does not seem to be a biomarker for monitoring of disease activity or treatment efficacy.

Functional and Morphological Responses to Fluocinolone Acetonide 0.19 mg in Noninfectious Uveitic Macular Edema Evaluated as the Area-Under-the-Curve

Purpose: This study investigated the impact of baseline clinical and optical coherence tomography (OCT) factors on the response to a 0.19-mg fluocinolone acetonide (FAc) implant in patients with noninfectious uveitic macular edema evaluated by the area under the curve over 24 months. Methods: A retrospective study was conducted of eyes of patients with noninfectious uveitic macular edema undergoing FAc treatment, with follow-up from baseline to 24 months. The area under the curve (AUC) of best-corrected visual acuity (BCVA) and the central macular thickness (CMT) were calculated using the trapezoidal rule. Clinical and OCT data at the time of FAc administration were collected, and associations with AUC of BCVA and CMT changes were investigated. Results: Twenty-three patients were enrolled. BCVA and CMT significantly improved after FAc implantation (P < 0.05). AUCBCVA and AUCCMT were 0.41 ± 0.33 logarithm of minimal angle of resolution/6 months and 320.15 ± 321.64 μm/6 months, respectively. Better baseline BCVA (coefficient [coef.] = 0.83, P < 0.001) and macular thickness reduction after FAc administration (coef. = -0.0001, P < 0.05) were associated with better BCVA after FAc treatment. In contrast, baseline OCT biomarkers such as ellipsoid zone reflectivity and choroidal vascularity index, sex, or disease duration before FAc injection showed no correlation with AUCBCVA and AUCCMT (P > 0.05). The younger the patient at the time of FAc injection, the greater the reduction in CMT (coef. = 1.76, P < 0.05). Conclusions: Among all clinical and morphological baseline factors, Baseline BCVA was the strongest predictor for AUCBCVA, while no association with baseline OCT features was observed. Overall, improvement of BCVA and CMT after FAc injection was maintained over 24 months. This study is registered in the German Clinical Trials Register under the DRKS-ID: DRKS00024399.

Choroidal vascularity index in hereditary optic neuropathies

PURPOSE

To assess the choroidal vascularity index (CVI) in patients affected by Leber hereditary optic neuropathy (LHON) compared to patients affected by dominant optic atrophy (DOA) and healthy subjects.

METHODS

In this retrospective study, we considered three cohorts: LHON eyes (48), DOA eyes (48) and healthy subjects' eyes (48). All patients underwent a complete ophthalmologic examination, including best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) acquisition. OCT parameters as subfoveal choroidal thickness (Sub-F ChT), mean choroidal thickness (ChT), total choroidal area (TCA), luminal choroidal area (LCA) were calculated. CVI was obtained as the ratio of LCA and TCA.

RESULTS

Subfoveal ChT in LHON patients did not show statistically significant differences compared to controls, while in DOA a reduction in choroidal thickness was observed (p = 0.344 and p = 0.045, respectively). Mean ChT was reduced in both LHON and DOA subjects, although this difference reached statistical significance only in DOA (p = 0.365 and p = 0.044, respectively). TCA showed no significant differences among the 3 cohorts (p = 0.832). No changes were detected in LCA among the cohorts (p = 0.389), as well as in the stromal choroidal area (SCA, p = 0.279). The CVI showed no differences among groups (p = 0.898): LHON group was characterized by a similar CVI in comparison to controls (p = 0.911) and DOA group (p = 0.818); the DOA group was characterized by a similar CVI in comparison to controls (p = 1.0).

CONCLUSION

CVI is preserved in DOA and LHON patients, suggesting that even in the chronic phase of the neuropathy the choroidal structure is not irreversibly compromised.

The Choroidal Vascularity Index Versus Optical Coherence Tomography Angiography in the Evaluation of the Choroid with a Focus on Age-Related Macular Degeneration

The choroid is the most vascularized structure of the eye and it is fundamental for the trophism of the outer retina. Its proper functioning and homeostasis represent key points in maintaining normal retinal physiology. Choroidal alterations may be implicated in the development and progression of numerous pathologies; therefore, in-depth studies using imaging techniques can be of crucial relevance to understanding the pathophysiology of retinal-choroidal diseases. The advent of spectral-domain optical coherence tomography (SDOCT) has enabled the non-invasive study of the choroid in vivo and the most recent development, optical coherence tomography angiography (OCTA), allows for the high-resolution visualization of the choriocapillaris and the choroid in regard to vascularization. The choroidal vascularity index (CVI) is a new parameter calculated on SDOCT scans and is defined as the ratio of the luminal area to the total choroidal area. In this review, a study of the choroid using OCTA and CVI will be evaluated in depth and the pros and cons of these two methods will be analyzed, with a particular focus on age-related macular degeneration.

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.

Longitudinal Assessment of the Choroidal Vascularity Index in Eyes with Branch Retinal Vein Occlusion-Associated Cystoid Macular Edema

INTRODUCTION

Cystoid macular edema (CME) is the most common cause of central vision loss in eyes with branch retinal vein occlusion (BRVO eyes). In recent literature, choroidal vascularity index (CVI) has been proposed to be an enhanced depth imaging optical coherence tomography (EDI-OCT) metric that may help characterize choroidal vascular changes in the setting of retinal ischemia, and potentially prognose visual outcomes and treatment patterns for patients with BRVO-related CME. This study sought to further characterize choroidal vascular changes in BRVO by comparing the CVI, subfoveal choroidal thickness (SFCT), and central subfield thickness (CST) in BRVO eyes with CME compared to unaffected fellow eyes.

METHODS

This was a retrospective cohort study. Subjects included treatment-naïve BRVO eyes with CME diagnosed within 3 months of onset of symptoms and unaffected fellow eyes. EDI-OCT images were collected at baseline and at the 12-month follow-up visit. CVI, SFCT, and CST were measured. Demographics, treatment patterns, and best-corrected visual acuity (VA) were abstracted. Median CVI, SFCT, CST, and VA were compared between the two cohorts. Longitudinal relationships between these variables were analyzed.

RESULTS

A total of 52 treatment-naïve eyes with BRVO and CME and 48 unaffected fellow eyes were identified. Baseline CVI was lower in eyes with BRVO than in fellow eyes (64.7% vs. 66.4%, P = 0.003). At 12 months, there was no difference in CVI between BRVO eyes and fellow eyes (65.7% vs 65.8%, P = 0.536). In BRVO eyes, there was a strong correlation between reduced CST and improved VA over the 12-month study period (r = 0.671, P < 0.001).

CONCLUSION

There are differences in CVI in treatment-naïve BRVO eyes with CME at presentation compared to fellow eyes, but these differences resolve over time. Anatomic changes in macular thickness in BRVO eyes with CME may be correlated with VA outcomes.

Longitudinal Changes in Choroidal Structure Following Repeated Low-Level Red-Light Therapy for Myopia Control: Secondary Analysis of a Randomized Controlled Trial

PURPOSE

Repeated low-level red-light (RLRL) therapy has been confirmed as a novel intervention for myopia control in children. This study aims to investigate longitudinal changes in choroidal structure in myopic children following 12-month RLRL treatment.

MATERIALS AND METHODS

The current study is a secondary analysis from a multicenter, randomized controlled trial (NCT04073238). Choroidal parameters were derived from baseline and follow-up swept-source optical coherence tomography scans taken at 1, 3, 6, and 12 months. These parameters included the luminal area (LA), stromal area (SA), total choroidal area (TCA; a combination of LA and SA), and choroidal vascularity index (CVI; ratio of LA to TCA), which were automatically measured by a validated custom choroidal structure assessment tool.

RESULTS

A total of 143 children (88.3% of all participants) with sufficient image quality were included in the analysis (n=67 in the RLRL and n=76 in the control groups). At the 12-month visit, all choroidal parameters increased in the RLRL group, with changes from baseline of 11.70×10 3  μm 2 (95% CI: 4.14-19.26×10 3  μm 2 ), 3.92×10 3  μm 2 (95% CI: 0.56-7.27×10 3  μm 2 ), 15.61×10 3  μm 2 (95% CI: 5.02-26.20×10 3  μm 2 ), and 0.21% (95% CI: -0.09% to 0.51%) for LA, SA, TCA, and CVI, respectively, whereas these parameters reduced in the control group.

CONCLUSIONS

Following RLRL therapy, the choroidal thickening was found to be accompanied by increases in both the vessel LA and SA, with the increase in LA being greater than that of SA. In the control group, with myopia progression, both the LA and SA decreased over time.

Choroidal vascularity index (CVI)-Net-based automatic assessment of diabetic retinopathy severity using CVI in optical coherence tomography images

A deep learning model called choroidal vascularity index (CVI)-Net is proposed to automatically segment the choroid layer and its vessels in overall optical coherence tomography (OCT) scans. Clinical parameters are then automatically quantified to determine structural and vascular changes in the choroid with the progression of diabetic retinopathy (DR) severity. The study includes 65 eyes consisting of 34 with proliferative DR (PDR), 17 with nonproliferative DR (NPDR), and 14 healthy controls from two OCT systems. On a dataset of 396 OCT B-scan images with manually annotated ground truths, overall Dice coefficients of 96.6 ± 1.5 and 89.1 ± 3.1 are obtained by CVI-Net for the choroid layer and vessel segmentation, respectively. The mean CVI values among the normal, NPDR, and PDR groups are consistent with reported outcomes. Statistical results indicate that CVI shows a significant negative correlation with DR severity level, and this correlation is independent of changes in other physiological parameters.

Ocular Perfusion Characteristics of Children with Newly Diagnosed Epilepsy

BACKGROUND

To investigate the vascular changes of the optic nerve head(ONH) and macula by using optical coherence tomography angiography(OCT-A), and also the choroidal vascular structure by using an image binarization tool in children with newly diagnosed epilepsy and to then compare these parameters with healthy subjects.

METHODS

Forty-one epilepsy children and 36 healthy controls were included in this prospective and cross-sectional study.The radial peripapillary capillary(RPC) vessel density(VD) and macular foveal,parafoveal,perifoveal of superficial capillary plexus(SCP),deep capillary plexus(DCP) and choriocapillaris(CC) VD, and CC flow area were analyzed.Enhanced depth imaging(EDI) OCT scans of the macula were obtained and the images were binarized using the ImageJ software (National Institutes of Health, Bethesda, MD, USA).The subfoveal choroidal thickness(SFCT),the area of choroidal, luminal, and interstitial and the percentage of luminal area in the choroid(Choroidal vascular index (CVI)) were analyzed.We also evaluated the thickness of the peripapillary retinal nerve fiber layer(RNFL),the macular ganglion cell layer(GCL), and the inner plexiform layer(IPL).

RESULTS

There was a significant decrease in the VD of the CC and the CC flow area in children with epilepsy compared to healthy subjects(p<0.05).However, the VD of the RPC, and of the SCP and DCP of the macula were similar between the two groups(p>0.05).The SFCT,choroidal area,luminal area, and CVI were statistically significant lower in children with newly diagnosed epilepsy compared to healthy subjects.

CONCLUSION

This study has demonstrated that the choroidal perfusion from the microcirculation is lower in children with newly diagnosed epilepsy.The pathophysiology of epilepsy and neurodegenerative processes may also include this vascular dysfunction as one of the factors.

Microvascular and structural analysis of the retina and choroid in heart failure patients with reduced ejection fraction

This cross-sectional study was designed to assess alterations of choroidal and retinal microvasculature in patients with Heart Failure with Reduced Ejection Fraction (HFrEF) and compare them with a normal age and sex-matched population. Fifty-two eyes of 26 patients with HFrEF (left ventricular ejection fraction [LVEF] < 40%) and 64 eyes of 32 healthy individuals were considered as the patient and the control groups, respectively. We found no statistically significant differences in age-adjusted mean central macular thickness (CMT), superficial or deep retinal capillary plexus vascular densities, and choriocapillaris flow (CC flow) density between the HFrEF group and the normal controls, with the exception of the parafoveal mean superficial capillary plexus vascular density (P = 0.023), which remained statistically significant after adjusting for age (P = 0.034). The patients with HFrEF had a significantly lower subfoveal choroidal thickness (SFCT) than the normal subjects (264 ± 82 vs 313 ± 72; P = 0.009), and the difference was still statistically significant after age adjustment (P = 0.026). Although choroidal vascularity index (CVI) was lower in the HFrEF group than in the control group, the difference was not statistically significant before and after age adjustment (73.45 ± 6.67 vs 75.77 ± 5.92; P = 0.118 and P = 0.096, respectively). In conclusion, in patients with HFrEF, we observed a reduction in parafoveal retinal VD in the superficial capillary plexus, as well as SFCT, but no significant change in CVI, CMT, or CC flow density.

Diurnal changes in choroidal optical coherence tomography angiography indices over 24 hours in healthy young adults

This prospective study investigated the magnitude and pattern of variation in choroidal optical coherence tomography angiography (OCT-A) indices every 4 h over 24 h in healthy young myopic (n = 24) and non-myopic (n = 20) adults. Choriocapillaris and deep choroid en-face images from macular OCT-A scans were analysed from each session to extract magnification-corrected vascular indices including choriocapillaris flow deficit number, size and density and deep choroid perfusion density in the sub-foveal, sub-parafoveal, and sub-perifoveal regions. Choroidal thickness was also obtained from structural OCT scans. Significant variations over 24 h (P < 0.05) were observed in most of the choroidal OCT-A indices excluding sub-perifoveal flow deficit number, with peaks observed between 2 to 6 AM. For myopes, peaks occurred significantly earlier (3-5 h), and the diurnal amplitude was significantly greater for sub-foveal flow deficit density (P = 0.02) and deep choroidal perfusion density (P = 0.03) compared with non-myopes. Choroidal thickness also showed significant diurnal changes (P < 0.05) with peaks between 2 to 4 AM. Significant correlations were found between diurnal amplitudes or acrophases of choroidal OCT-A indices and choroidal thickness, intraocular pressure, and systemic blood pressure. This provides the first comprehensive diurnal assessment of choroidal OCT-A indices over 24 h.

A Deep Learning-Based Fully Automated Program for Choroidal Structure Analysis Within the Region of Interest in Myopic Children

Purpose

To develop and validate a fully automated program for choroidal structure analysis within a 1500-µm-wide region of interest centered on the fovea (deep learning-based choroidal structure assessment program [DCAP]).

Methods

A total of 2162 fovea-centered radial swept-source optical coherence tomography (SS-OCT) B-scans from 162 myopic children with cycloplegic spherical equivalent refraction ranging from -1.00 to -5.00 diopters were collected to develop the DCAP. Medical Transformer network and Small Attention U-Net were used to automatically segment the choroid boundaries and the nulla (the deepest point within the fovea). Automatic denoising based on choroidal vessel luminance and binarization were applied to isolate choroidal luminal/stromal areas. To further compare the DCAP with the traditional handcrafted method, the luminal/stromal areas and choroidal vascularity index (CVI) values for 20 OCT images were measured by three graders and the DCAP separately. Intraclass correlation coefficients (ICCs) and limits of agreement were used for agreement analysis.

Results

The mean ± SD pixel-wise distances from the predicted choroidal inner, outer boundary, and nulla to the ground truth were 1.40 ± 1.23, 5.40 ± 2.24, and 1.92 ± 1.13 pixels, respectively. The mean times required for choroidal structure analysis were 1.00, 438.00 ± 75.88, 393.25 ± 78.77, and 410.10 ± 56.03 seconds per image for the DCAP and three graders, respectively. Agreement between the automatic and manual area measurements was excellent (ICCs > 0.900) but poor for the CVI (0.627; 95% confidence interval, 0.279-0.832). Additionally, the DCAP demonstrated better intersession repeatability.

Conclusions

The DCAP is faster than manual methods. Also, it was able to reduce the intra-/intergrader and intersession variations to a small extent.

Translational Relevance

The DCAP could aid in choroidal structure assessment.

The Association between Decreased Choriocapillary Flow and Electroretinogram Impairments in Patients with Diabetes

PURPOSE

To evaluate the association between choriocapillary flow (CCF) and electroretinogram (ERG) in patients with diabetes.

METHOD

This was a cross-sectional study. Patients with type 2 diabetes and healthy controls who had undergone both flicker ERG and optical coherence tomography angiography (OCTA) were included, while patients with severe diabetic retinopathy (DR) and macular edema were excluded. Correlations among OCTA and ERG parameters were conducted by generalized linear mixed models (GLMM).

RESULT

One hundred ninety-four eyes of 102 patients with diabetes and fifty-six eyes of 28 controls were included. The implicit time of 30-Hz flicker ERG successively increased, while the amplitudes, inner-retina vessel density and CCF were decreased from the control to the nondiabetic retinopathy (NDR) to DR group. In patients with diabetes, all GLMM models of ERG parameters had statistically significance (P<0.05), and CCF was correlated with ERG parameters (coefficient index=-0.601, P< 0.001 with 16 Td-s implicit time; coefficient index=-0.687, P< 0.001 with 32 Td-s implicit time; coefficient index=0.933, P=0.035 with 32 Td-s amplitude) and the thickness of retinal pigment epithelium, while in the GLMM model of CCF, it was correlated with the thickness of retinal pigment epithelium and the level of glycosylated hemoglobin(both P= 0.001).

CONCLUSION

CCF decreased in patients with diabetes, and it was related with ERG. Choroidopathy and its functional impairment in the retina may occur very early in patients with diabetes by influencing the outer retina.