Choroidal Vascularity Map in Unilateral Central Serous Chorioretinopathy: A Comparison with Fellow and Healthy Eyes

Choroidal vascularity index as an activity criterion and a treatment response measure in chronic central serous chorioretinopathy

PURPOSE

This study aimed to evaluate the choroidal vascularity index (CVI) as an activity criterion in chronic central serous chorioretinopathy (CSC) and as a measure of treatment response after full-dose-full-fluence photodynamic therapy (fd-ff-PDT).

METHODS

This fellow-eye-controlled, retrospective cohort study included 23 patients with unilateral chronic CSC treated with fd-ff-PDT (6 mg/m2 ; 50 μcm2 ; 83 s). Subfoveal choroidal thickness (SFCT, μm) and CVI (%) of the affected and fellow eyes at baseline as well as at 1, 3 and 6 months after fd-ff-PDT were compared.

RESULTS

The patients' mean age was 43.4 ± 7.3 years, and 18 (78.3%) were male. CVI was comparable between the affected and fellow eyes at baseline (66.09 ± 1.56 vs. 65.84 ± 1.57, p = 0.59). However, it became significantly lower in the affected eyes 1 (64.45 ± 1.68 vs. 65.87 ± 1.19, p = 0.002), 3 (64.21 ± 2.08 vs. 65.71 ± 1.59, p = 0.009) and 6 (64.47 ± 2.19 vs. 65.62 ± 1.52, p = 0.045) months after fd-ff-PDT. The mean SFCT and the mean CVI were significantly decreased in the affected eyes at all follow-up visits compared with baseline after fd-ff-PDT (p < 0.001).

CONCLUSION

At baseline, CVI was comparable between affected and fellow eyes. Therefore, its use as an activity criterion in chronic CSC patients is questionable. However, it was significantly decreased in fd-ff-PDT-treated eyes, supporting its role as a measure of treatment response in chronic CSC.

Choroidal vascularity index in different types of central serous chorioretinopathy: A meta-analysis

PURPOSE

To evaluate the choroidal vascularity index (CVI) in different types of central serous chorioretinopathy (CSC), healthy control eyes, and fellow eyes.

METHODS

Relevant studies published up to January 2023 were identified by searching multiple databases, including PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure (CNKI). Studies investigating the difference in CVI between CSC and control eyes were included. Data from these studies were analyzed using Stata (version 17) software. Weighted mean difference (WMD) and 95% confidence interval (95%CI) were calculated for the CVI in CSC eyes, control eyes, and fellow eyes.

RESULTS

The meta-analysis included 15 studies, with 213 acute CSC eyes, 153 chronic CSC eyes, 92 uncategorized CSC eyes, 40 resolved CSC eyes, 409 eyes of normal healthy controls, and 318 fellow eyes. The result revealed that CVI was higher in acute CSC eyes (WMD = 5.40, 95%CI = 2.36-8.44, P = 0.001) compared to control eyes. Also, CVI in chronic CSC eyes was higher than in control eyes (WMD = 1.26, 95%CI = 0.03-2.49, p = 0.046). The fellow eyes of acute CSC had a higher CVI when compared to control eyes (WMD = 2.53, 95%CI = 0.78-4.28, p = 0.005). There was no significant difference in CVI between acute and chronic CSC eyes (WMD = 0.75, 95%CI = -0.31-1.82, P = 0.167). In the sub-analysis based on the area selected for CVI calculation, the WMDs in the whole image subgroups were lower than the main analysis for the comparisons of fellow eyes of acute CSC and control eyes, acute CSC eyes and control eyes, and acute CSC eyes and fellow eyes. In the macular area subgroups, the WMDs were higher than in the whole image subgroups, suggesting a potential regional variation of CVI in CSC eyes.

CONCLUSIONS

The results demonstrated that CVI is increased in CSC eyes and fellow eyes of acute CSC. There is no significant difference in CVI between acute and chronic CSC eyes. The area selected for CVI calculation can influence the outcome, which requires further clinical research to clarify.

Choroidal Vascularity Index versus Choroidal Thickness as Biomarkers of Acute Central Serous Chorioretinopathy

INTRODUCTION

The aim of this study was to analyze the choroidal vascularity index (CVI) versus choroidal thickness (CT) as biomarkers in acute central serous chorioretinopathy (CSCR).

METHODS

In this multicenter retrospective, cross-sectional, noninterventional study carried out at Puerta de Hierro-Majadahonda University Hospital, Madrid, Spain; Jules-Gonin, Lausanne, Switzerland; and Pittsburg University, USA. 40 eyes from 40 patients with acute CSCR, 40 eyes from 40 patients with keratoconus (KC), and 40 eyes from 40 healthy patients were included. The variables analyzed were age, CT, CVI, and the presence of neurosensory retinal detachment. CT and the CVI were obtained from a 12-mm horizontal single-line B-scan (Triton SS-OCT, Topcon Co., Japan). Blinded measurements of the subfoveal CT were performed manually by two independent investigators. The images of the choroid were automatically binarized using a validated algorithm, and a percentage of vascularity was calculated.

RESULTS

There were no significant differences in age between the three groups (ANOVA, p = 0.092). There were statistically significant differences in CT and the CVI (ANOVA, p < 0.001). After Bonferroni correction, pairwise analysis between CSCR group against the KC group showed no significant differences in age and CT (p = 0.10 and p = 0.27, respectively). CVI was statistically greater among CSCR patients (p = 0.03).

CONCLUSION

CT does not meet the criteria to be considered a biomarker of acute CSCR, while CVI may prove to be a more specific and reliable biomarker. Further studies with larger sample sizes, standardized procedures, and a wider representation of all CSCR stages are necessary to confirm the validity of CVI as biomarker in this disease. Further studies with larger samples are required in order to validate the use of CVI/CT correlation as a new biomarker.

Influence of protocol scan on choroidal vascularity measurements: a spectralis optical coherence tomography study

OBJECTIVES

To compare choroidal vascularity index (CVI) measurements using the automated image binarization algorithm in healthy subjects with two Spectralis spectral-domain optical coherence tomography (SD-OCT) protocol scans.

METHODS

Sixty-nine eyes of 69 healthy volunteers were included in this cross-sectional prospective study. Two subsequent horizontal 20°line scans passing through the fovea were acquired with enhanced-depth imaging mode with high speed (HS) and high resolution (HR) protocol scans. CVI and its subcomponents were measured with the previously validated automated algorithm. Differences between choroidal measurements obtained with HS and HR protocol scans were evaluated with t-test and Bland & Altman plots.

RESULTS

A total of 33 male (47.8%) and 36 female (52.2%) subjects with a mean age of 35.1 ± 13.4 years were included. Overall, HS protocol scan was associated with significant lower values of total choroidal area (-0.047 mm²) and stromal choroidal area (-0.036 mm²), and a significant greater value of CVI (+0.010%) if compared to HR protocol. Luminal choroidal area was lower when calculated with the HS protocol, although it did not reach significance. To compare the two different protocols, the number of pixels should be multiplied for 3.87 ×5.73 when the CVI is measured on a HR OCT b scan and 3.87 ×11.46 for the HS OCT b scan.

CONCLUSIONS

HS and HR acquisition modes significantly influence CVI and its subcomponents values measured with the automated software. However, adopting the scale factors can minimize the differences between the two protocol scans.

Three-dimensional choroidal vascularity index in central serous chorioretinopathy using ultra-widefield swept-source optical coherence tomography angiography

Background

To map and compare the three-dimensional choroidal vascularity index (3D-CVI) in eyes with unilateral central serous chorioretinopathy (CSC), fellow eyes and control eyes using ultra-widefield swept source optical coherence tomography (UWF SS-OCTA).

Methods

In this prospective observational study, the 3D-CVIs were measured in 9 subfields or 1 × 1 mm grids by the UWF SS-OCTA with a viewing angle of horizontal 24 × vertical 20 mm. The proportions of vortex vein anastomoses and their corresponding CVI in the central regions were compared among the CSC, fellow and control eyes. Correlations of CVI and vascular density of the large choroidal vessel layer/choriocapillaris layer/choroidal thickness (CT) were also assessed.

Results

Thirty-two eyes in 32 patients with unilateral CSC and 32 normal eyes were included in the study. The mean CVI in the eyes with CSC was significantly greater than that in the fellow eyes of CSC and control eyes (41.99 ± 3.56% vs. 40.38 ± 3.855%, P = 0.003; 41.99 ± 3.56% vs. 38.93 ± 4.067%, P = 0.004, respectively). The CVIs in superotemporal, inferotemporal and inferonasal regions were significantly higher in CSC eyes than control eyes (P = 0.03, P = 0.02, P = 0.008). In CSC eyes, there was a linear positive correlation between 3D-CVI and vascular density of the large choroidal vessel layer and CT in all subfields. The proportion of vortex vein anastomoses in CSC was 25/32 (78.1%), and significantly higher in fellow and control eyes (P < 0.001). The average central CVI was significantly higher in CSC eyes with anastomoses than in CSC eyes without anastomoses (42.8 ± 5.1% vs. 38.4 ± 2.7%, P = 0.039). CVIs in superior, central, inferior, superonasal, nasal and inferonasal regions were significantly correlated with vortex vein anastomoses (P < 0.05), regardless of CSC, fellow or healthy eyes. In addition, whether there were vortex vein anastomoses, CVI in superotemporal region was significantly higher in eyes with CSC (P = 0.002) and fellow eyes (P = 0.014), compared to control eyes. No significant correlation was found between hypertension and CVIs in the three groups.

Conclusion

Remodeling of choroidal drainage routes by venous anastomosis between superior and inferior vortex veins may be common in CSC. The 3D-CVI could be a comprehensive parameter to evaluate the choroid vasculature and help understand the pathogenesis of pachychoroid spectrum disease.

Volumetric quantification of choroid and Haller's sublayer using OCT scans: An accurate and unified approach based on stratified smoothing

BACKGROUND AND OBJECTIVE

The choroid, a dense vascular structure in the posterior segment of the eye, maintains the health of the retina by supplying oxygen and nutrients, and assumes clinical significance in screening ocular diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR). As a technological assist, algorithmic estimation of choroidal biomarkers has been suggested based on sectional (B-scan) optical coherence tomography (OCT) images. However, most such 2D estimation techniques are compute-intensive, yet enjoy limited accuracy and have only been validated on OCT image datasets of healthy eyes. Not surprisingly, fine-scale analyses, including those involving Haller's sublayer, remain relatively rare and unsophisticated. Against this backdrop, we propose an efficient algorithm to quantify desired biomarkers with improved accuracy based on volume OCT scans. Specifically, we attempted an accurate, computationally light volumetric segmentation method involving stratified smoothing to detect choroid and Haller's sublayer.

METHODS

For detecting the various boundaries of the choroid and the Haller's sublayer, we propose a common volumetric method that performs suitable exponential enhancement and maintains smooth spatial continuity across 2D B-scans. Further, we achieve suitable volumetric smoothing by primarily deploying light-duty linear regression, and sparingly using compute-intensive tensor voting, and hence significantly reduce overall complexity. The proposed methodology is tested on five health and five diseased OCT volumes considering various metrics including volumetric Dice coefficient and corresponding quotient measures to facilitate comparison vis-à-vis intra-observer repeatability.

RESULTS

On five healthy and five diseased OCT volumes, respectively, the proposed method for choroid segmentation recorded volumetric Dice coefficients of 93.53 % and 93.30 %, which closely approximate the respective reference observer repeatability values of 95.60 % and 95.49 %. In terms of related quotient measures, our method achieved more than 50 % improvement over a recently reported method. In detecting Haller's sublayer as well, our algorithm records statistical performance closely matching that of reference manual method.

CONCLUSION

Advancing the state-of-the-art, the proposed volumetric segmentation, tested on both healthy and diseased datasets, demonstrated close match with the manual reference. Our method assumes significance in accurate screening of chorioretinal diseases including AMD, CSCR and pachychoroid. Further, it enables generating accurate training data for developing deep learning models for improved detection of choroid and Haller's sublayer.

Applications of Optical Coherence Tomography in the Ocular Diagnosis: From the Tear Film to the Sclera

The latest technological developments have radically impacted the daily practice of ophthalmologists, thanks to the advent of novel diagnostic tools that facilitate an early diagnosis and allow a better management of ocular disorders [...]