USE OF CHOROIDAL VASCULARITY INDEX FOR CHOROIDAL STRUCTURAL EVALUATION IN CENTRAL SEROUS CHORIORETINOPATHY WITH CHOROIDAL NEOVASCULARIZATION

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.

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.

Vascular changes of the choroid and their correlations with visual acuity in diabetic retinopathy

Objective

To investigate changes in the choroidal vasculature and their correlations with visual acuity in diabetic retinopathy (DR).

Methods

The cohort was composed of 225 eyes from 225 subjects, including 60 eyes from 60 subjects with healthy control, 55 eyes from 55 subjects without DR, 46 eyes from 46 subjects with nonproliferative diabetic retinopathy (NPDR), 21 eyes from 21 subjects with proliferative diabetic retinopathy (PDR), and 43 eyes from 43 subjects with clinically significant macular edema (CSME). Swept-source optical coherence tomography (SS-OCT) was used to image the eyes with a 12-mm radial line scan protocol. The parameters for 6-mm diameters of region centered on the macular fovea were analyzed. Initially, a custom deep learning algorithm based on a modified residual U-Net architecture was utilized for choroidal boundary segmentation. Subsequently, the SS-OCT image was binarized and the Niblack-based automatic local threshold algorithm was employed to calibrate subfoveal choroidal thickness (SFCT), luminal area (LA), and stromal area (SA) by determining the distance between the two boundaries. Finally, the ratio of LA and total choroidal area (SA + LA) was defined as the choroidal vascularity index (CVI). The choroidal parameters in five groups were compared, and correlations of the choroidal parameters with age, gender, duration of diabetes mellitus (DM), glycated hemoglobin (HbA1c), fasting blood sugar, SFCT and best-corrected visual acuity (BCVA) were analyzed.

Results

The CVI, SFCT, LA, and SA values of patients with DR were found to be significantly lower compared to both healthy patients and patients without DR (P < 0.05). The SFCT was significantly higher in NPDR group compared to the No DR group (P < 0.001). Additionally, the SFCT was lower in the PDR group compared to the NPDR group (P = 0.014). Furthermore, there was a gradual decrease in CVI with progression of diabetic retinopathy, reaching its lowest value in the PDR group. However, the CVI of the CSME group exhibited a marginally closer proximity to that of the NPDR group. The multivariate regression analysis revealed a positive correlation between CVI and the duration of DM as well as LA (P < 0.05). The results of both univariate and multivariate regression analyses demonstrated a significant positive correlation between CVI and BCVA (P = 0.003).

Conclusion

Choroidal vascular alterations, especially decreased CVI, occurred in patients with DR. The CVI decreased with duration of DM and was correlated with visual impairment, indicating that the CVI might be a reliable imaging biomarker to monitor the progression of DR.

CHOROIDAL VASCULARITY AND VISUAL OUTCOMES IN MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT

PURPOSE

To investigate the association between visual outcomes and choroidal changes in patients with macula-off rhegmatogenous retinal detachment.

METHODS

This study retrospectively reviewed 63 eyes of patients with macula-off rhegmatogenous retinal detachment who underwent vitrectomy. Their fellow eyes were analyzed as a control group. The choroidal vascularity index (CVI), ellipsoid zone/external limiting membrane integrity, central foveal thickness, and subfoveal choroidal thickness were documented and analyzed. Linear regression analyses were performed to identify factors affecting the final best-corrected visual acuity.

RESULTS

Eyes with rhegmatogenous retinal detachment showed increased CVI (68.8 ± 4.1) compared with the control group (66.1 ± 8.8, P = 0.028). Multivariate linear regression analysis revealed that patients with a poor final best-corrected visual acuity had a longer detachment duration ( P = 0.002), worse baseline best-corrected visual acuity ( P = 0.034), thinner central foveal thickness ( P = 0.005), and greater CVI ( P = 0.001) and were more likely to be tamponated with silicone oil ( P = 0.001). Choroidal vascularity index was particularly increased in eyes with poor ellipsoid zone/external limiting membrane integrity, prolonged detachment duration, thin central foveal thickness, and worse best-corrected visual acuity.

CONCLUSION

Increased CVI could indicate poor visual outcomes in patients with macula-off rhegmatogenous retinal detachment. Choroidal remodeling could be associated with the disruption of the ellipsoid zone/external limiting membrane integrity.

Characteristics of the retina and choroid in fibromyalgia patients and their correlation with disease severity and quality of life

BACKGROUND

To evaluate retinal and choroidal characteristics of fibromyalgia (FM) patients using spectral-domain optical coherence tomography (SD-OCT), to compare them with healthy controls, and to determine the correlation of these measurements with disease severity and quality of life.

METHODS

Thirty-nine eyes of 39 patients with FM and 44 eyes of 44 age- and sex-matched healthy subjects were enrolled. The retinal nerve fiber layer (RNFL), central macular thickness (CMT), and choroidal thickness (CT) measurements of the subjects were obtained using SD-OCT (Maestro, Topcon Co. Tokyo, Japan), choroidal vascular index (CVI) was calculated by using the binarization method and the results were compared. Disease duration (DD), widespread pain index (WPI), symptom severity scale (SSS), visual analog scale (VAS), ocular pain assessment survey (OPAS), FM impact questionnaire (FIQ), European Quality of Life-5 Dimensions-3 level (EQ-5D-3 L), European Quality VAS score (EQ-VAS) and use of pregabalin were recorded. Correlations between the SD-OCT results and the FM parameters were evaluated.

RESULTS

No significant difference was found in terms of age and gender (p = 0.612, p = 0.244 respectively). Patients in the FM group had significantly thinner RNFL superior quadrant and CT (p = 0,009 and p < 0.001, respectively). CVI was significantly higher in the FM group (p < 0.001). There was an inverse correlation between OPAS and CT (r = -0.379, p = 0.027) and between VAS and CVI (r = -0.398, p = 0.020). The use of pregabalin had no effect on SD-OCT (p > 0.05).

CONCLUSION

Patients with FM demonstrated reduced RNFL superior quadrant and CT and increased CVI. Ocular and general body pain in FM was found to be associated with SD-OCT.

Three-Year Follow-Up Detecting Choroidal Neovascularization with Swept Source Optical Coherence Tomography Angiography (SS-OCTA) after Successful Half-Fluence Photodynamic Therapy for Chronic Central Serous Chorioretinopathy

Purpose: To assess the clinical course, structural changes, and choroidal neovascularization detection by SS-OCTA in long-standing and resolved patients with chronic central serous chorioretinopathy (cCSC) after successful half-fluence photodynamic therapy (hf-PDT) treatment. Methods: Twenty-four eyes presenting with cCSC were examined with SS-OCTA and were classified as choroidal neovascular (CNV) or non-choroidal neovascular (non-CNV) cCSC depending on the vascular pattern detected by SS-OCTA after one, two, and three years after hf-PDT. Two groups were compared based on the following clinical findings: demographic characteristics, time of clinical signs, best corrected visual acuity (BCVA), central retinal thickness (CRT), central choroidal thickness (CFT), subretinal fluid (SRF), flat, irregular pigment epithelial detachment (FIPED), and features of fluorescein angiography (FA) and vascular pattern by SS-OCTA. Results: All patients showed resolved cCSC during follow-up after hf-PDT. A total of 5 of 24 (20.8%) eyes showed a neovascular pattern by SS-OCTA. No differences between BCVA, CRT, SRF, FIPED, or FA features were found between both groups (p > 0.05). However, CFT and older age were associated with a neovascular pattern by SS-OCTA (p < 0.05) in follow-up. No signs of neovascular activity were detected by SS-OCT during follow-up in CNV cCSC patients, and no antiVEGF treatment was required for three-year follow-ups. Conclusions: Despite patients with cCSC showing a favorable clinical response after hf-PDT, lower foveal thickness and older age were associated with CNV patterns by SS-OCTA during follow-up.

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.

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.

Association between central serous chorioretinopathy susceptibility genes and choroidal parameters

PURPOSE

To evaluate the association between central serous chorioretinopathy (CSC) susceptibility genes and choroidal parameters in a large Japanese cohort.

STUDY DESIGN

Retrospective cohort study.

METHODS

Of the 9850 individuals in the Nagahama study whose second visit was between 2013 and 2016, those with optical coherence tomography (OCT) images with enhanced depth imaging (EDI), axial length, and genome-wide single nucleotide polymorphism (SNP) genotyping data were included. We calculated subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), normalized choroidal intensity (NCI), and vertical asymmetry of choroidal thickness. Genome-wide quantitative trait locus (QTL) analyses were performed for each parameter. We screened for four CSC susceptibility SNPs: CFH rs800292, TNFRSF10A rs13278062, GATA5 rs6061548, and VIPR2 rs3793217. Whenever an SNP was not included in the genotyping data after quality control, its proxy SNP was selected.

RESULTS

In total, 4586 participants were evaluated. CFH rs800292 was significantly associated with SFCT (P < 0.001) and CVI (P < 0.001). VIPR2 rs3793217 was significantly associated with SFCT (P < 0.001) but not with CVI. Whereas, TNFRSF10A rs13254617 and GATA5 rs6061548 were not significantly associated with SFCT or CVI. None of these SNPs was associated with NCI_EDI and asymmetry of choroidal thickness.

CONCLUSION

CFH, VIPR2, TNFRSF10A, and GATA5 showed different association patterns with choroidal parameters. Although the mechanism of CSC pathogenesis by choroidal changes is not fully understood, this finding suggests that each gene may be involved in different mechanisms of CSC development. Our genetic study provides a basis for understanding the role of CSC susceptibility genes.

Peripapillary and Macular Choroidal Vascularity Index in Eyes with Fuchs' Uveitis

BACKGROUND

To investigate the choroidal vascularity alterations of macula and peripapillary area in eyes with unilateral Fuchs uveitis (FU).

METHODS

This study included 18 eyes with unilateral FU and 18 healthy fellow eyes. The choroidal vascularity index (CVI) was analyzed, and the results were compared between eyes with FU and healthy fellow eyes (control group).

RESULTS

The mean subfoveal (s)CVI (%) value was significantly lower in the FU group as compared with the control group: 60.92 ± 2.63 vs. 64.01 ± 2.54, respectively (p = .001). The mean pCVI (%) values of superior and inferior quadrant were significantly lower in the Fuchs group as compared with the control group:58.87 ± 4.48 vs. 61.98 ± 3.32, respectively, in superior quadrant (p = .035); and 57.29 ± 6.65 vs. 61.44 ± 4.76, respectively, in inferior quadrant (p = .014).

CONCLUSION

The chronic continuous inflammation in FU causes inflammation-mediated thinning in the vascular area of the subfoveal and peripapillary choroid. The changes in the peripapillary region are remarkable in terms of the further glaucoma risk of these eyes.

CVIS: Automated OCT-scan-based software application for the measurements of choroidal vascularity index and choroidal thickness

PURPOSE

To develop an automated image recognition software for the objective quantification of choroidal vascularity index (CVI) and choroidal thickness (CT) at different choroidal locations on images obtained from enhanced depth imaging optical coherence tomography (EDI-OCT), and to validate its reliability and investigate the difference and correlation between measurements made by manual and software.

METHODS

A total of 390 EDI-OCT scans, captured from 130 eligible emmetropic or myopic subjects, were categorized into four grades in terms of their accessibility to identify the choroidal-scleral interface (CSI) and were further assessed for CT and CVI at five locations (subfoveal, nasal, temporal, superior and inferior) by the newly developed Choroidal Vascularity Index Software (CVIS) and three ophthalmologists. Choroidal parameters acquired from CVIS were evaluated for its reliability and correlation with ocular factors, in comparison to manual measurements. Distribution of difference and correlation coefficient between CVIS and manual measurements were also analysed.

RESULTS

Choroidal Vascularity Index Software (CVIS) demonstrated excellent intra-session reliability for CT (ICC: 0.992) and CVI (ICC: 0.978) measurements, compared to the relatively lower intra- and inter-observer reliability of manual measurements. Choroidal Vascularity Index Software (CVIS) and manual assessments had the highest correlation at nasal choroid (CT: r = 0.829, p < 0.001; CVI: r = 0.665, p < 0.001). Choroidal parameters identified with CVIS showed stronger correlations with axial length than manual measurements.

CONCLUSION

This automated software, CVIS, exhibited excellent reliability compared to manual measurements, which are subject to image quality and clinical experience. With its validated clinical relevance, CVIS holds promise to serve as a flexible and robust tool in future vitreoretinal and chorioretinal studies.

Choroidal vascularity index change in macular telangiectasia type 2

Purpose

To analyze choroidal structure using subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) in Macular Telangiectasia (MacTel) type 2.

Methods

Medical records of 43 eyes with MacTel type 2 and 30 sex and age-matched healthy eyes were retrospectively reviewed. Their SFCT and CVI were measured using the SS-OCT scan passing through the central fovea and image binarization. The difference in baseline SFCT and CVI from each group and their yearly changes up to second year of follow up were analyzed. The baseline characteristics of the groups were also compared.

Results

The baseline characteristics, including CVI and SFCT, of the MacTel group and the control group were not significantly different, except for BCVA. The mean CVI of MacTel group were 64.59 ± 2.92%, 63.76 ± 2.67%, and 62.97 ± 2.74% (p < 0.001) whereas that of control group were 63.33 ± 2.45%, 63.04 ± 2.46%, and 63.43 ± 2.25% (p = 0.636) at baseline, 1 and 2 years, respectively. The mean SFCT of MacTel group were 324.65 ± 89.65μm, 326.14 ± 93.11μm, and 322.65 ± 91.77μm (p = 0.436), whereas that of control group were 304.30 ± 51.86 μm, 300.86 ± 52.64μm, and 298.55 ± 53.71μm (p = 0.275) at baseline, 1 and 2 years, respectively.

Conclusion

CVI decreases at a faster rate in MacTel type 2 in comparison with healthy subjects. This may suggest possible choroidal involvement in the progression of MacTel type 2.

Quantitative analysis of choroidal blood flow parameters in optical coherence tomography and angiography in central serous chorioretinopathy

PURPOSE

To evaluate the choriocapillaris (CC) flow in central serous chorioretinopathy (CSC) and determine the relationship between CC flow void with the choroidal thickness (CT) and choroidal vascularity index (CVI).

METHODS

Retrospective analysis of 20 patients with CSC (40 eyes, including unaffected fellow eyes) and 20 age- and sex-matched controls. After compensation with optical coherence tomography (OCT) en-face structural image, the CC flow void (%) was measured using the phansalkar threshold with a window radius of 3 and 15 pixels. The mean CC flow voids of acute CSC, recovered-acute CSC, unaffected fellow, and control eyes were compared by matched data analysis. A regression analysis was performed on the choroidal parameters (CT and CVI) and CC flow voids.

RESULTS

The CC flow void had an increasing tendency in the following order: control, fellow, recovered-acute CSC, and acute CSC eyes. Acute/recovered comparison showed a significant P value (0.008) in the foveal lesion. Recovered/fellow and fellow/control presented significant P values regardless of location to fovea (all <0.05). There were significant positive correlations between CT and CC flow void (P < 0.05) in the acute CSC, recovered-acute CSC eyes.

CONCLUSION

The CC flow on OCT angiography decreased in acute CSC eyes, especially in the foveal lesion, with a published compensation method. The findings suggest that unmodulated choroidal blood flow contributed to partially reversible diminished CC flow.

Characteristics and Associated Factors of Flat Irregular Pigment Epithelial Detachment With Choroidal Neovascularization in Chronic Central Serous Chorioretinopathy

Purpose: Flat irregular pigment epithelial detachment (FIPED) in chronic central serous chorioretinopathy (CSC) is strongly associated with type 1 choroidal neovascularization (CNV). The present study aimed to describe the multimodal imaging characteristics of FIPED in patients with chronic CSC and investigate the factors associated with vascularized FIPED.

Methods: We included 55 chronic CSC eyes with vascularized FIPED (47 patients) and 55 chronic CSC eyes with avascular FIPED from age-matched patients (47 patients). None of the included eyes had a history of previous treatment with anti-vascular endothelial growth factor, photodynamic therapy, focal laser, or vitrectomy. The demographic and multimodal imaging data were reviewed. The location, angiography features, height and width, presence of retinal pigment epithelium (RPE) aggregations, RPE thickness, and choroid status of the FIPED area were compared between the groups.

Results: The mean age of the included chronic CSC patients was 54.3 ± 7.8 years (range: 33–72 years), and 85.1% were male. Vascularized FIPED eyes had a larger width (1,556.4 ± 731.6 vs. 931.1 ± 486.2 μm, p < 0.001), larger subfoveal RPE thickness (33.4 ± 15.3 vs. 26.3 ± 6.6 μm, p = 0.004), larger maximum RPE thickness of the FIPED area (46.3 ± 20.5 vs. 31.5 ± 8.3 μm, p < 0.001), and more RPE aggregations in the FIPED area (94.5 vs. 54.5%, p < 0.001) than avascular FIPED eyes. RPE aggregations in the FIPED area were an independent factor strongly associated with vascularized FIPED (OR = 7.922, 95% CI = 1.346–46.623, p = 0.022).

Conclusion: FIPED with a larger width and RPE thickening may suggest the presence of an underlying type 1 CNV. FIPED with RPE aggregations had an increased occurrence of neovascularization in chronic CSC.

Choroidal features in flat irregular pigment epithelial detachment associated with Chronic central serous chorioretinopathy: Avascular versus vascularized

PURPOSE

To investigate the differences in the choroidal biomarkers between two forms of flat irregular pigment epithelial detachment (FIPED): avascular (aFIPED) and vascularized (vFIPED) in eyes with chronic central serous chorioretinopathy (CSC).

MATERIALS AND METHODS

Enhanced depth imaging optical coherence tomography (EDI-OCT) was done in eyes with FIPED correlated to chronic CSC, fellow eyes, and also in healthy eyes from gender- and age-matched subjects. Eyes with FIPED were classified into two subgroups based on optical coherence tomography angiography (OCTA) findings: vFIPED and aFIPED. Different choroidal biomarkers such as subfoveal choroidal thickness (SFCT), total choroidal area (TCA), and choroidal vascular index (CVI) were compared between the groups.

RESULTS

Forty-four eyes from 42 patients with chronic CSC and FIPED along with 40 eyes from 20 healthy subjects were included. OCTA identified vascularization in 14 eyes in the FIPED group (31.8%). Mean SFCT was higher in the FIPED group compared to two other groups (p = 0.005). In comparison to patients with aFIPED, patients with vFIPED had lower SFCT (p = 0.003) and higher CVI (p = 0.020) based on multivariate analysis.

CONCLUSIONS

It seems that measurement of CVI along with SFCT may help to differentiate aFIPED from vFIPED in patients with CSC. Further longitudinal studies would be required to confirm the clinical significance of these findings.

Choroidal vascularity index in adults with different refractive status

AIM

We aimed to perform structural analysis of the choroid in adults with different refractive status.

MATERIALS AND METHODS

A prospective, comparative study of 100 right eyes of 100 patients ages 18-40 years was conducted. The patients were divided into four groups according to spherical equivalent (SE): Group 1: -0.5 and above, low-to-moderate myopia; Group 2: -6 and above, high myopia; Group 3: +0.5 and above, hyperopia; Group 4: +/- 0.5, emmetropia. With the images obtained using enhanced depth imaging optical coherence tomography (EDI-OCT), the total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascular index (CVI) were calculated using the binarization method. The anterior chamber depth (ACD), axial length (AL), and central corneal thickness (CCT) values were measured by optical biometry. All parameters were compared between groups. The correlation of biometric parameters with CVI was examined.

RESULTS

Parameters were found to be statistically different between the four groups. TCA, LA, and SA values were the highest in Group 3 and lowest in Group 2. L/S ratio and CVI values in Group 3 were significantly lower than in the other groups. There was a negative correlation between AL with SE and CT, and no correlation between the CVI and other parameters.

CONCLUSION

CVI decreases when emmetropization is disrupted and changes to hypermetropia or myopia. The reason for the decrease in myopia is the reduction of the luminal area, while in hyperopia it is due to an increase in the stromal area. When there is a shift toward myopia, there is a decrease in the TCA, but the CVI does not change significantly. Unlike CT, the CVI is not affected by factors such as SE and AL; therefore, the CVI can be a useful parameter for examining choroidal changes in refractive errors.

Multimodal Imaging in Pachychoroid Spectrum

Diagnostic investigation on pachychoroid spectrum disease (PSD) has been growing along with the rapid advancement of imaging technology. In optical coherence tomography (OCT)-based studies, choroidal thickness profile, luminal and stromal choroidal ratio, and abnormalities in the neurosensory retina have demonstrated various patterns in different clinical entities related to PSD. The emerging role of OCT angiography (OCTA) has been expanded to involve the quantitative analysis of the OCTA parameters in different clinical entities of PSD and to evaluate the choriocapillaris signal void and vessel density as indicators of choriocapillaris ischemia. OCTA has broadened our knowledge in characterization and assessment of both active and quiescent choroidal neovascularization and its association with treatment response. Recent studies using indocyanine green angiography (ICG) have focused on the evaluation of choroidal vascular hyperpermeability and its relationship with other pachychoroid related features. Ultrawidefield ICG enables observation and characterization of peripheral choroidal pathologies and their associations with macular abnormalities. Multicolor imaging is an emerging modality with the capability to demonstrate early abnormalities in PSD. We summarize all investigations reflecting the new insights into the application of multimodal imaging for PSD and focuses on novel findings observed in different clinical entities with each imaging modality.

Applications of Multimodal Imaging in Central Serous Chorioretinopathy Evaluation

Central serous chorioretinopathy (CSCR) is a macular disease characterized by serous retinal detachment commonly involving the macular region. CSCR has a wide spectrum of clinical presentations. Although a significant proportion of CSCR cases are self-limiting, patients can suffer from persistent or recurrent disease, sometimes complicated with choroidal neovascularization, resulting in permanent visual loss. Multimodal imaging, including fluorescein angiography, indocyanine green angiography, fundus autofluorescence, and optical coherence tomography, has advanced the diagnosis and classification of CSCR cases. Evolution of new imaging techniques including optical coherence tomography angiography, wide-field imaging, and en face reconstruction imaging has also contributed to better understandings of the pathophysiology of CSCR. This review article summarizes the features of multimodal imaging for CSCR and discusses the application of such features in evaluating the disease.

CHOROIDAL VASCULARITY INDEX IN YOUNG CHOROIDEREMIA PATIENTS

PURPOSE

To evaluate choroidal features in young patients affected by choroideremia (CHM).

METHODS

Young CHM patients and control subjects were recruited at the Eye Clinic in Florence. High-resolution choroidal imaging was obtained using swept-source optical coherence tomography with long optical coherence tomography scans (12 × 9 mm optical coherence tomography scans). We considered the subfoveal choroidal area within 9 mm of the optic disk in the horizontal plane and the subfoveal choroidal area within a 3-mm diameter centered over the fovea. The subfoveal choroidal thickness, total choroidal area, luminal area, stromal area, and choroidal vascularity index were assessed using the "ImageJ" software in both groups.

RESULTS

Eight patients (16 eyes; mean age, 19.3 ± 5.2 years) and seven control subjects (14 eyes; mean age, 19.0 ± 5.0 years) were included in this study. Best-corrected visual acuity was 20/20 in both eyes of seven CHM patients and in all control subjects and 20/25 in both eyes in one CHM patient. Mean subfoveal choroidal thickness did not differ between CHM patients and control subjects. Luminal area9mm, stromal area9mm, and total choroidal area9mm were reduced in patients compared with the control group. Luminal area3mm, stromal area3mm, and total choroidal area3mm did not differ between patients and control subjects. Choroidal vascularity index9mm and choroidal vascularity index3mm were not different between patients and control subjects.

CONCLUSION

There are no differences in the choroidal vascularity index between young CHM patients and control subjects; this result suggests a simultaneous, proportional impairment of both the stromal and vascular components of the choroid in the early stages of the disease.

Serous business: Delineating the broad spectrum of diseases with subretinal fluid in the macula

A wide range of ocular diseases can present with serous subretinal fluid in the macula and therefore clinically mimic central serous chorioretinopathy (CSC). In this manuscript, we categorise the diseases and conditions that are part of the differential diagnosis into 12 main pathogenic subgroups: neovascular diseases, vitelliform lesions, inflammatory diseases, ocular tumours, haematological malignancies, paraneoplastic syndromes, genetic diseases, ocular developmental anomalies, medication-related conditions and toxicity-related diseases, rhegmatogenous retinal detachment and tractional retinal detachment, retinal vascular diseases, and miscellaneous diseases. In addition, we describe 2 new clinical pictures associated with macular subretinal fluid accumulation, namely serous maculopathy with absence of retinal pigment epithelium (SMARPE) and serous maculopathy due to aspecific choroidopathy (SMACH). Differentiating between these various diseases and CSC can be challenging, and obtaining the correct diagnosis can have immediate therapeutic and prognostic consequences. Here, we describe the key differential diagnostic features of each disease within this clinical spectrum, including representative case examples. Moreover, we discuss the pathogenesis of each disease in order to facilitate the differentiation from typical CSC.

A comparative study on the choroidal vascularity index and the determination of cut-off values in the pachychoroid spectrum diseases

PURPOSE

To determine the cut-off levels for choroidal thickness and choroidal vascularity index (CVI) to differentiate among pachychoroid spectrum diseases.

STUDY DESIGN

A retrospective comparative study METHODS: A total of 143 eyes were included. Of these 29 had uncomplicated pachychoroid (UCP), 29 had pachychoroid pigment epitheliopathy (PPE), 25 had pachychoroid neovasculopathy (PNV), 30 had central serous chorioretinopathy (CSC), and 30 had polypoidal choroidal vasculopathy (PCV). The choroidal areas were measured with ImageJ software. The CVI, the proportion of the luminal area to the total choroidal area, was assessed.

RESULTS

The cut-off points of central choroidal thickness were determined as 360 µm for the PPE and PCV group pair (p < 0.001), 422 µm for the PNV and CSC group pair (p = 0.026), 271 µm for the PNV and PCV group pair (p < 0.001), and 341 µm for the CSC and PCV group pair (p < 0.001). The cut-off points of CVI were 72.7 for the PPE and PCV group pair (p < 0.001), 74.7 for the PNV and CSC group pair (p = 0.005), 72.6 for the PNV and PCV group pair (p = 0.001), and 73.6 for the CSC and PCV group pair (p < 0.001).

CONCLUSION

Pachychoroid spectrum may be composed of a combination of distinct choroidal diseases with different vascular and structural characteristics.

Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA)

The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.

Peripapillary and macular choroidal vascularity index in patients with clinically unilateral pseudoexfoliation syndrome

PURPOSE

To investigate choroidal vascular changes using an image binarization tool in patients with clinically unilateral pseudoexfoliation syndrome (XFS).

METHODS

This cross-sectional study included 150 eyes of 100 patients. The eyes were divided into three groups: (1) 50 affected eyes of patients with clinically unilateral XFS; (2) 50 unaffected fellow eyes; and (3) 50 healthy control eyes. Enhanced depth imaging optical coherence tomography scans of the macula and peripapillary regions were acquired. Images were binarized using ImageJ software (National Institutes of Health, Bethesda, MD, USA). The choroidal vascularity index (CVI) was defined as proportion of the luminal area to the total circumscribed choroidal area.

RESULTS

Horizontal and vertical scans revealed that the macular CVI values of the affected eyes (60.08 ± 2.06 and 62.21 ± 2.10, respectively) were lower compared with control eyes (67.31 ± 2.24; p = 0.001 and 68.11 ± 2.36; p < 0.001, respectively). Conversely, no significant difference in the macular CVI was found between unaffected fellow and control eyes (p = 0.094 and p = 0.120, respectively). The mean peripapillary CVI values of the temporal (58.73 ± 3.15), superior (59.84 ± 3.09), and inferior (56.94 ± 2.47) sectors were significantly lower in affected eyes compared to control eyes (63.21 ± 3.00, 62.07 ± 3.05, and 60.78 ± 2.88, respectively; p < 0.05 for all). In addition, the unaffected fellow eyes had significantly lower CVI values in the temporal (61.42 ± 3.07) and inferior (57.61 ± 2.56) peripapillary sectors compared with the control eyes (p = 0.007 and p = 0.005, respectively).

CONCLUSIONS

These findings suggest that XFS is associated with decreased macular and peripapillary choroidal vascularity. Furthermore, the unaffected eyes of patients with unilateral XFS may show vascularity changes in the peripapillary choroid.

Topographic Variations of Choroidal Thickness in Healthy Eyes on Swept-Source Optical Coherence Tomography

Purpose

To assess topographic variations of choroidal thickness (CT) in the fovea and beyond in healthy eyes.

Methods

This cross-sectional study included healthy subjects ≤ 55 years of age with axial lengths (22-26 mm) and refractive error margins (-4D, +4D) in normal ranges. Images were acquired using swept-source optical coherence tomography angiography (OCT-A). Corneal thickness (CT) maps from 12 × 12-mm radial scans and 9 × 9-mm OCT-A B-scans were analyzed.

Results

The study included 64 eyes of 33 subjects (mean age, 37 years). Mean CT was >300 µm in all locations except the nasal outer macula. The subfoveal CT was >395 µm in 30% of cases; in 38.7% of cases, >50% of the CT map was thicker than 395 µm. The mean thickest choroidal point was 395.2 µm (range, 164-548 µm), located superior and temporal to the macula in 72.2% of cases and subfoveally in 1.8% of cases. The CT pattern was symmetrical (58%) or asymmetrical (42%) along a horizontal axis correlating with choroidal vein distribution. Half of the asymmetrical patterns were thicker in the inferior quadrants, with an oblique temporal watershed of venous drainage, and the other half were thicker superiorly. The mean vascularity index was ∼75% regardless of the mean CT.

Conclusions

One-third of healthy eyes of patients younger than age 55 had a thick choroid (>395 µm). In these normal eyes, the thickest choroidal point was not subfoveal, CT symmetry above and below the fovea depended on choroidal vein distribution, and choroidal vascularity index was independent from CT. No patients demonstrated fundus autofluorescence abnormalities, and the choriocapillaris remained visible even in thick choroids. These features could be interesting when differentiating normal versus pathological states.

Choroidal Vascularity Index: An In-Depth Analysis of This Novel Optical Coherence Tomography Parameter

Remarkable improvements in optical coherence tomography (OCT) technology have resulted in highly sophisticated, noninvasive machines allowing detailed and advanced morphological evaluation of all retinal and choroidal layers. Postproduction semiautomated imaging analysis with dedicated public-domain software allows precise quantitative analysis of binarized OCT images. In this regard, the choroidal vascularity index (CVI) is emerging as a new imaging tool for the measurement and analysis of the choroidal vascular system by quantifying both luminal and stromal choroidal components. Numerous reports have been published so far regarding CVI and its potential applications in healthy eyes as well as in the evaluation and management of several chorioretinal diseases. Current literature suggests that CVI has a lesser variability and is influenced by fewer physiologic factors as compared to choroidal thickness. It can be considered a relatively stable parameter for evaluating the changes in the choroidal vasculature. In this review, the principles and the applications of this advanced imaging modality for studying and understanding the contributing role of choroid in retinal and optic nerve diseases are discussed. Potential advances that may allow the widespread adoption of this tool in the routine clinical practice are also presented.

Central Serous Chorioretinopathy: Pathogenesis and Management

Central serous chorioretinopathy (CSC) is a common retina disease and has a relative high recurrence rate, etiology, and pathogenesis of which remains largely ambiguous. The effects on the retina are usually self-limited, although some people are left with permanent vision loss due to progressive and irreversible photoreceptor damage or retinal pigment epithelium atrophy. There have been a number of interventions used in CSC, including, but not limited to, laser treatment, photodynamic therapy (PDT), intravitreal injection of anti-vascular endothelial growth factor agents, and subthreshold lasers. It is not clear whether there is a clinically important benefit to treating acute CSC, which often resolves spontaneously as part of its natural history. Of the interventions studied to date, PDT and micropulse laser treatment appear the most promising.