Choroidal structures in polypoidal choroidal vasculopathy, neovascular age-related maculopathy, and healthy eyes determined by binarization of swept source optical coherence tomographic images

Racial Differences in Choroidal Vascularity Index in Healthy Patients: Novel Insights

BACKGROUND AND OBJECTIVE

Choroidal vascularity index (CVI) measures the ratio of blood vessels in the choroid to the total choroidal area. We aimed to compare CVI between young Black and White patients without a history of ocular or systemic disease.

PATIENTS AND METHODS

We used a previously validated algorithm for shadow compensation and choroidal vessel binarization to measure CVI across the Early Treatment of Diabetic Retinopathy Study grid.

RESULTS

Black patients had a lower CVI (ß = -0.05, P < 0.001) compared to White patients. Choroidal volume or luminal volume did not significantly differ with respect to race, whereas there was a trend for Black patients to have a greater stromal volume (ß = 3.08, P = 0.01).

CONCLUSIONS

Black patients have a lower CVI than do White patients, likely due to a greater proportion of stromal volume. Further study of this parameter is warranted to validate the findings of this exploratory study. [Ophthalmic Surg Lasers Imaging Retina 2024;55:30-38.].

Evaluation of choroidal thickness and choroidal vascularity index in patients with Crimean-Congo hemorrhagic fever

PURPOSE

This study aimed to compare choroidal thickness parameters between patients diagnosed with Crimean-Congo hemorrhagic fever (CCHF) and healthy individuals using spectral domain optical coherence tomography.

METHODS

The right eyes of 27 individuals diagnosed with CCHF and 27 healthy subjects were included in this study. CCHF cases were assessed based on a history of tick bites and hospitalization. Choroidal thickness was measured using enhanced depth imaging optical coherence tomography. Measurements of choroidal thickness were taken at 5 different points, including the subfoveal quadrant and the fovea up to 2000 μm with 1000 μm intervals in the temporal and nasal quadrants. Choroidal vascular index (CVI) was calculated as the ratio of luminal area (LA) to total choroidal area (TCA) at the macula's total area and at 1500 μm from the center (CVI and CVI1500).

RESULTS

Choroidal thickness in the CCHF group was found to be thicker in each quadrant compared to the control group, with the subfoveal and nasal quadrants showing significantly greater thickness. TCA, stromal area, and LA were significantly higher in the CCHF group, while no significant difference was observed in CVI and CVI1500.

CONCLUSION

The findings of this study suggest that CCHF disease may have an impact on the choroidal structure.

Changes in choroidal tissue post-supplementation with vitamin D in pediatric patients who are deficient in vitamin D

PURPOSE

To quantitatively assess the choroidal structural parameters of patients in the pediatric age group who were deficient in vitamin D [Vit-D] pre- and post-treatment.

DESIGN

Prospective, case-control study.

METHODS

Choroidal structural parameters, including the choroidal thickness (CT) at five points, total choroidal area (TA), luminal choroidal area (LA), stromal choroidal area (SA), and choroidal vascular index (CVI), in patients in the pediatric age group who were deficient in Vit-D, in Group 1, and those who were not, in Group 2, were compared. The patients were divided into 3 different groups according to how deficient in Vit-D they were. This was re-evaluated after treatment.

RESULTS

Group 1 consisted of 83 patients and group 2 consisted of 85 patients. CT at all five points, and the TA, SA, LA, and CVI, were lower in Group 1. And for all of these, a significant increase was seen post-treatment. While a significant increase was observed in all of the values in the group with the most severe deficiency in Vit-D, significant changes were observed in the TA, LA, SA, and CVI values in the group that was mildly deficient in Vit-D. There was no significant post-treatment value in the CT values (except for the Temporal 1500 CT [P = 0.012]).

CONCLUSION

Decreases in the CT, TA, LA, SA, and CVI were among the structural changes that were seen to occur in the pediatric patient group that was deficient in Vit-D. Moreover, thinning of the choroid and a decrease in the CVI were the most significant in the group with the greatest Vit-D deficiency.

Recent Advances in Imaging Polypoidal Choroidal Vasculopathy with Swept-Source Optical Coherence Tomography Angiography

The gold standard for polypoidal choroidal vasculopathy (PCV) diagnosis is indocyanine green angiography (ICGA), but optical coherence tomography angiography (OCTA) has shown promise for PCV imaging in recent years. However, earlier generations of OCTA technology lacked the diagnostic efficacy to replace ICGA. Swept-source optical coherence tomography angiography (SS-OCTA), the latest generation of OCTA technology, has significantly improved penetrating ability, scanning speed, scanning range, and overall image quality compared with earlier generations of OCTA. SS-OCTA reveals a "tangled vasculature" pattern of polypoidal lesions (PLs), providing evidence that they are neovascular rather than aneurysmal structures. New choroidal biomarkers, such as the choriocapillaris flow void (FV), have been identified to explain the development of PCV lesions. Although no direct comparison between SS-OCTA and previous OCTA generations in terms of diagnostic capability has been performed, SS-OCTA has shown several advantages in differential diagnosis and monitoring early reactivation for PCV. These improvements make SS-OCTA a valuable tool for PCV diagnosis and follow-up, and it may become more important for this disease in the future. This review summarized recent advances in PCV morphology and structure, as well as the possible pathogenesis based on SS-OCTA findings. The value of SS-OCTA for PCV management is discussed, along with remaining issues, to provide an updated understanding of PCV and OCTA-guided management.

A Comparative Study of Choroidal Vascular and Structural Characteristics of Typical Polypoidal Choroidal Vasculopathy and Polypoidal Choroidal Neovascularization: OCTA-Based Evaluation of Intervortex Venous Anastomosis

BACKGROUND

The aim of this study was to compare the choroidal characteristics of typical polypoidal choroidal vasculopathy (T-PCV) and polypoidal choroidal neovascularization (P-CNV) cases, and to investigate the presence of intervortex venous anastomoses in these PCV subtypes by using en face optical coherence tomography angiography (OCTA).

METHODS

A total of 35 eyes of 33 PCV cases were included. The PCV cases were divided into T-PCV and P-CNV groups. The choroidal vascularity index (CVI) was calculated. En face OCTA images were evaluated for the presence of intervortex venous anastomoses. The diameter of the largest anastomotic Haller vessel was measured.

RESULTS

T-PCV cases had significantly higher mean CVI values (73.9 ± 3.7 vs. 70.8 ± 4.5%) than P-CNV cases (p = 0.039). Intervortex venous anastomoses were observed in 85.7% of T-PCV eyes and in 91.7% of P-CNV eyes on en face OCTA (p = 1.000). In the cases with intervortex venous anastomosis, the mean diameter of the largest anastomotic vessel on en face OCTA was 341.2 ± 109.1 µm in the T-PCV and 280.4 ± 68.4 µm in the P-CNV group (p = 0.048).

CONCLUSIONS

The higher CVI value in T-PCV may be an important feature concerning the pathogenesis and classification of PCV. Although there was no difference between the two subtypes in terms of intervortex anastomosis, more dilated anastomotic vessels were observed in the T-PCV.

Influence of scan direction on subfoveal choroidal vascularity index using optical coherence tomography

We investigated the influence of scan direction on subfoveal choroidal vascularity index (CVI) measurements using spectral-domain optical coherence tomography (SD-OCT) in young healthy subjects. Seventy-eight eyes of 41 healthy volunteers were included. Choroidal structures were obtained using SD-OCT with enhanced depth imaging (EDI) through radial scans at the center of the macula. The subfoveal choroidal images in the horizontal (0°), 45°, vertical (90°) and − 45° directions were recorded and CVIs were analyzed according to their respective directions using image binarization. Additionally, subfoveal choroidal thickness (SFCT), and axial eye length were measured. The SFCT and subfoveal CVI showed a negative correlation but were only significant for the 45° scan (Pearson’s r = − 0.262, P = 0.021). The axial eye length and subfoveal CVI had no significant correlation in any direction (all P > 0.05). In the Bland–Altman plot, the subfoveal CVI measurement showed high agreement among the four scan directions. When the SFCT was ≥ 300 µm, there was no difference in the measured values of the subfoveal CVI among the four scan directions; however, when the SFCT was < 300 µm, there was a significant difference in subfoveal CVI among the scan directions (one-way analysis of variance, F = 4.685, P = 0.004). In subfoveal CVI measurement, it is considered that the horizontal (0°) scan can represent the vertical (90°) or oblique (45°, − 45°) scans. However, when the SFCT is thinner, the subfoveal CVI in each direction of radial scan may vary significantly. Hence, caution is required in the interpretation.

Imaging Characteristics of Neovascular and Atrophic Pachychoroidal Spectrum Diseases

Background

This study qualitatively and quantitatively compared imaging characteristics between neovascular and atrophic pachychoroid spectrum disease (PSD) by optical coherence tomography (OCT), and OCT angiography (OCTA).

Methods

The subtypes of PSD were identified by multi-modality imaging approaches. Subfoveal choroidal thickness (SFCT), choroidal vascular index (CVI), and vascular density of choroidal neovascularization (CNV) were measured.

Results

The CVI and SFCT of 174 PSD eyes were 67.6% ± 5.48% and 362.2 ± 131.88 μm, respectively. After adjustment for age, linear regression indicated that SFCT was positively associated with CVI (p &lt; 0.001), and patched hyper-reflective lesions in choriocapillaris layers (p = 0.009). Compared with neovascular PSD eyes, atrophic PSD eyes had similar patient age (57.1 ± 16.72 years, p = 0.639), SFCT (332.0 ± 111.00 μm, p = 0.51), and CVI (67.6% ± 3.94%, p = 0.527). There were no differences between polypoidal choroidal vasculopathy (PCV) eyes with aneurysmal polypoidal lesions and PCV eyes with tangled polypoidal lesions in terms of age, CVI, SFCT, vascular density, or the occurrence of double layer signs (DLSs, all p &gt; 0.05). Logistic regression indicated that age (p = 0.003), SFCT (p = 0.003), patched hyper-reflective lesions in choriocapillaris layers (p = 0.009), and DLSs (p &lt; 0.001) were predictive factors for CNV progression in PSD eyes (all p &lt; 0.05).

Conclusions

Our study highlighted the similarities in SFCT and CVI between neovascular and atrophic PSD, both of which were late stage lesions. Besides, age, SFCT, patched hyper-reflective lesions in choriocapillaris layers, and DLSs were risk factors for CNV in PSD. Our results showed that atrophic PSD is an important change in the late stage of PSD disease, which is helpful for in-depth understanding of the pathological mechanism of PSD and corresponding intervention.

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.

Three-dimensional modelling of the choroidal angioarchitecture in a multi-ethnic Asian population

This study aimed to describe the topographic variation of the macula's choroidal angioarchitecture using three-dimensional (3D) choroidal vascularity index (CVI) of healthy eyes from an Asian population and to investigate the associations of CVI. 50 participants were recruited via stratified randomisation based on subfoveal choroidal thickness from the Singapore Epidemiology of Eye Diseases Study. Macular volume scans were acquired using spectral-domain optical coherence tomography with enhanced depth imaging. CVI was assessed based on B-scan binarisation and choroid segmentation. The 3D CVI of the whole, superior, central, and inferior macula were 62.92 ± 1.57%, 62.75 ± 1.93%, 63.35 ± 1.72%, and 62.66 ± 1.70%, respectively, pairwise comparisons P all > 0.05). 3D CVI (Whole Macula) and 2D CVI (Subfoveal) were associated only with each other and not with other ocular and systemic factors. 2D CVI (Subfoveal) had a moderate agreement with 3D CVI (Central Macula) [intraclass corelation coefficient (ICC) = 0.719], and had poorer agreement with 3D CVI of the whole macula, superior, and inferior macula (ICC = 0.591, 0.483, and 0.394, respectively). Scanning volume did not influence 3D CVI measurements. In conclusion, 3D CVI demonstrated no significant topographic variation. CVI was not correlated with demographic or ocular structural features. 2D CVI of the fovea is partially representative of 3D CVI of the macula.

Comparison of choroidal hyperreflective spots on optical coherence tomography images between both eyes of normal subjects

Background

Advancement of optical coherence tomography (OCT) technology allows for better in vivo visualization of the choroidal architecture, which comprises vessels and stroma. However, most OCT studies using image binarization methods have focused only on choroidal vessels represented by dark pixels. This study aimed to compare the distribution of choroidal hyperreflective spots on swept-source OCT (SS-OCT) images between both eyes of normal subjects.

Methods

In this observational comparative study, we included SS-OCT images of healthy subjects, which were prospectively obtained to compare images among the devices. SS-OCT images acquired using PLEX Elite 9000 and DRI-OCT Triton were analyzed. En-face OCT images were obtained at five different depth positions of the inner choroid at the macula. The mean reflectivity of the choroidal slabs, the number, total area, and circularity of hyperreflective spots were quantitatively compared between the devices and between both eyes of the same subjects.

Results

In 30 eyes of 15 healthy subjects, the mean reflectivity of the choroidal slabs varied with the scan depth on both devices (P<0.001 and P<0.001). Hyperreflective spots were similarly distributed in the images from both devices, but at different depths. The number and area of hyperreflective spots in the second and third layers of the DRI-OCT Triton were positively correlated with those in the fourth and fifth layers of the PLEX Elite 9000, respectively (all P<0.05). The intraclass correlation coefficients (ICC) for the area of hyperreflective spots were excellent for the third slab of the DRI-OCT and the fifth slab of the PLEX Elite (ICC =0.798; 95% CI, -0.576-0.904). The number and area of hyperreflective spots were correlated between both eyes in the third, fourth and fifth layers on DRI-OCT Triton (all P<0.05) and in the first, second, and fifth layers on PLEX Elite 9000 (all P<0.05).

Conclusions

Hyperreflective spots in en-face images from two different SS-OCT devices were similarly observed between both eyes of the same person. The distributions of spots between the two eyes of the same person were correlated. These findings suggest that the distribution of hyperreflective spots on the choroid reflects the choroidal characteristics of the subject.

Associations Between the Choroidal Vascularity Index and Malignant Glaucoma After Trabeculectomy for Primary Angle Closure Glaucoma

Purpose: To compare the choroidal vasculature characteristics by using the choroidal vascularity index (CVI) in eyes with malignant glaucoma (MG), fellow eyes with non-MG, and eyes with uncomplicated primary angle-closure glaucoma (PACG) after trabeculectomy by spectral-domain optical coherence tomography (SD-OCT). Methods: This case-control study included 53 patients diagnosed with MG after trabeculectomy. Eyes with MG (n = 53) and the fellow eyes with non-MG (n = 50) were included. Eyes with PACG without MG after trabeculectomy (n = 60) were also enrolled as controls. The choroidal parameters, including CVI and the subfoveal choroidal thickness (SFCT), were measured by using SD-OCT images. Results: Eyes with MG and the fellow eyes showed a significantly lower CVI than eyes with PACG controls (p < 0.001). After adjusting for age, sex, axial length (AL), and intraocular pressure (IOP), eyes with the greater CVI [odds ratio (OR), 0.44] were significantly related to MG. The area under the receiver operating characteristic curve of the CVI was greater than that of the SFCT in the diagnosis of MG (0.911 vs. 0.840, p = 0.034). Conclusion: Eyes with MG showed a significantly lower macular CVI than eyes with PACG controls. A higher macular CVI was an associated factor of eyes with MG. The CVI serves as a more stable and sensitive indicator for MG than the SFCT in this group of patients with PACG.

Recurrence and visual prognostic factors of polypoidal choroidal vasculopathy: 5-year results

This retrospective study aimed to evaluate the factors affecting recurrence and visual prognosis in patients with treatment-naïve subfoveal polypoidal choroidal vasculopathy (PCV). Patients who had received three consecutive intravitreal injections of ranibizumab or aflibercept and had reached remission were enrolled. They were divided into a group without recurrence (group 1, 26 eyes) and a group with recurrence (group 2, 121 eyes) and followed up for at least 5 years. Patients in group 2 received additional treatment for worsening. Logistic regression analysis revealed that a young age of onset (P = 0.001), high choroidal vascularity index (CVI; P = 0.019), and presence of choroidal vascular hyperpermeability (CVH; P = 0.037) were associated with a low risk of recurrence. Multiple regression analysis revealed that recurrence (P = 0.001), greatest linear dimension (P = 0.003), and polyp configuration (single or cluster; P = 0.043) were associated with final visual acuity. Patients without recurrence had a lower age of onset and higher CVI than those with recurrence, and they tended to have CVH. In addition, patients with recurrence, large lesion, and cluster polyps had worse final visual acuity than those without these factors. CVI and CVH may be used to predict recurrence of PCV.

Long-term effect of intravitreal aflibercept treatment on choroidal vascularity index in neovascular age-related macular degeneration

BACKGROUND

Our aim is to examine the effect of intravitreal aflibercept treatment on the choroidal vascularity index in eyes with neovascular age-related macular degeneration (nARMD) using the binarization method.

METHODS

Included in the study were the 38 eyes of 38 patients diagnosed with nARMD and treated with intravitreal aflibercept at our clinic. The patients' 12-month records were reviewed retrospectively. Patients' choroidal thickness (CT) was measured at baseline, 3rd month, 6th month, and 12th month on EDI-OCT images. We calculated luminal area (LA), stromal area (SA), total choroidal area (TCA), and choroid vascular index (CVI) values using binarization.

RESULTS

The mean age of the patients was 70,1 ± 8 years. The mean of injections over 12 months was 5.6 ± 2. Baseline values were CT 224 µm, LA 0,214 mm², SA 0,119mm², TCA 0,333 mm², and CVI 64% respectively. At the 3rd month, values were CT 223 µm, LA 0,212 mm², SA 0,121 mm², TCA 0,332 mm², and CVI 64%, respectively. The 6th-month values were CT 221 µm, LA 0,204 mm², SA 0,116 mm², TCA 0,320 mm², and CVI 64%, respectively, and 12-month values were CT 218 µm, LA 0,204 mm², SA 0,112 mm², TCA 0,318 mm², and CVI 64%, respectively. According to LogMAR, BCVA was 0.59 at baseline, 0.56 at 3 months, 0.52 at 6 months, and 0.51 at 12 months. At the end of month 12, we observed a statistically significant decrease in CT. No significant changes were observed in other parameters. When the number of injections was correlated with CVI, CT, and BCVA, a significant negative correlation was observed with CVI CONCLUSIONS: Aflibercept treatment reduces CT by affecting not only luminal but also stromal areas of the choroid in the long term but does not change the CVI. However, as the number of injections increases, CVI decreases.

The effect of phacoemulsification performed with vitrectomy on choroidal vascularity index in eyes with vitreomacular diseases

This study evaluated the effects of cataract surgery combined with pars plana vitrectomy (ppV) on choroidal vascularity index (CVI) in eyes with epiretinal membrane (ERM) and full thickness macular hole (FTMH). Medical records of 132 eyes with ERM or FTMH were retrospectively reviewed and classified into a ppV group and a ppV combined with cataract surgery group (phaco + ppV group). The CVI were measured at baseline, 1, 3 and 6 months after the surgery, using the selected swept-source (SS) optical coherence tomography (OCT) scan passing through the central fovea, which was then segmented into luminal and stromal area by image binarization. The mean CVI of phaco + ppV group were 61.25 ± 1.97%, 61.66 ± 1.81%, and 62.30 ± 1.92% at baseline, 1 and 3 months, respectively (p < 0.001). The mean CVI of ppV group were 62.69 ± 1.92%, 62.03 ± 1.51%, and 61.45 ± 1.71% at baseline, 1 and 3 months, respectively (p < 0.001). The final CVI were measured at 6 months and compared with the baseline CVI. The mean CVI of phaco + ppV group were 61.21 ± 1.99% at baseline and 60.68 ± 2.02% at 6 months (p < 0.001). The mean CVI of ppV group were 62.93 ± 1.70% at baseline and 61.77 ± 1.74% at 6 months (p < 0.001). Vitrectomy significantly decreases CVI in vitreomacular diseases possibly due to the removal of vitreomacular traction or postoperative oxygenation change in the eye. On the contrary, combined surgery of vitrectomy and cataract surgery significantly increases CVI in the early stage of postoperative period, which suggests choroidal vascular dilatation or congestion due to postoperative inflammation. Although the CVI were measured lower than the baseline in the end, more thorough inflammation control may be essential after combined surgery.

Peripapillary Choroidal Vascularity Outside the Macula in Patients With Central Serous Chorioretinopathy

Purpose

To investigate choroidal vascularity outside the macula in central serous chorioretinopathy (CSC).

Methods

Fifty normal controls and 103 patients with a history of CSC (31 with acute CSC, 32 with chronic CSC, and 40 with resolved CSC) were included. Using swept-source optical coherence tomography, we measured choroidal thickness (CT) and choroidal vascularity index (CVI) at the subfoveal and nasal peripapillary areas.

Results

Subfoveal CT in the acute CSC group was greater than that in all other groups (all P < 0.05). Peripapillary CT in the acute and chronic CSC groups was significantly greater than that in controls (all P ≤ 0.005). However, subfoveal and peripapillary CT in the resolved CSC group was not different from controls. Subfoveal CVI in the acute group (64.71% ± 2.68%) was higher than that in controls (61.68% ± 5.68%) (P = 0.015). Peripapillary CVIs in the acute (67.35% ± 6.04%) and chronic groups (64.90% ± 5.31%) were higher than controls (54.57% ± 7.02%) (all P < 0.001). Subfoveal CVI in the resolved CSC group was not different from controls (P = 0.252), whereas peripapillary CVI (62.61% ± 6.03%) was higher (P < 0.001).

Conclusions

Unlike CT, CVI outside the macula was increased in all eyes with both current and past history of CSC. These findings suggest that the choroidal vascularity outside the macula may represent choroidal characteristics in addition to the subfoveal area.

Translational Relevance

Peripapillary CVI outside the macula may provide additional information beyond what is known through subfoveal choroid studies.

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

PURPOSE

To evaluate choroidal vascular structure in eyes with central serous chorioretinopathy (CSC) by assessing the choroidal vascular index (CVI).

METHODS

We retrospectively analyzed the medical records of 117 eyes with CSC. Subjects were divided into 4 groups according to clinical characteristics: 1) acute CSC (N = 29), 2) non-neovascularized chronic CSC without flat irregular pigment epithelial detachment (N = 49), 3) non-neovascularized chronic CSC with flat irregular pigment epithelial detachment (N = 21), and 4) chronic CSC with choroidal neovascularization (N = 18). Subfoveal choroidal area (1,500 mm) of swept source optical coherence tomography scans were divided into luminal and stromal areas by the image binarization technique. The CVI was defined as the ratio of the luminal to the total subfoveal choroidal area.

RESULTS

The CVI was significantly lower in eyes of Group 4 than those of other groups (all P < 0.05). The subfoveal choroidal thickness was significantly lower in Group 4 than in Groups 1 and 2 (P < 0.05), but regression analysis showed no association with the CVI.

CONCLUSION

Decreased CVI may reflect choroidal vascular structure changes in eyes with choroidal neovascularization complicating CSC. These findings suggest that the CVI could be useful for evaluating choroidal vascular changes in eyes with 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.

Choroidal vascularity index: a step towards software as a medical device

The choroidal vascularity index (CVI) is a relatively new parameter, calculated off optical coherence tomography (OCT) images, for the quantitative evaluation of choroid vascularity. It is defined as the ratio of vascular area to the total choroidal area, presented as a percentage. The choroid is an important vascular bed, often implicated in ocular and systemic conditions. Since the introduction of CVI, multiple studies have evaluated its efficacy as a tool for disease prognostication and monitoring progression, with promising results. The CVI was born out of the need for more robust and accurate evaluations of choroidal vasculature, as prior parameters such as choroidal thickness and choroidal vessel diameter had their limitations. In this review, we summarise current literature on the CVI, explain how the CVI is derived and explore its potential integration into future research and translation into clinical care. This includes the application of CVI in various disease states, and ongoing attempts to produce an automated algorithm which can calculate CVI from OCT images.

Choroidal vascular changes in age-related macular degeneration: A protocol for systematic review and meta-analysis

BACKGROUND

As an increasing age-related eye disease, age-related macular degeneration (AMD) is becoming a common cause of irreversible visual loss in elder population. The mechanism of AMD remains uncertain and covers a complex risk factors. Choroidal vascularity index (CVI) is a sensitive parameter obtained by enhanced depth imaging of optical coherence tomography which allows the choroid in more detail and accurate assessment in the pathogenesis of AMD. The objective of this current study is to evaluate choroidal structural alternations measured by CVI in AMD.

METHODS

We will review 4 English databases (PubMed, Embase, Cochrane Library, and Web of Science) from their inception until present to select eligible articles. English-language and case-control studies will be accepted. The data extraction content and quantitative analysis will be performed systematically by 2 independent authors. The primary outcome is the alternation of CVI in AMD. The secondary outcomes consist of choroidal thickness (CT), luminal area (LA), stromal area (SA), and total choroidal area (TCA). Subgroup analysis, sensitivity analysis, and publication bias will be performed to check the robustness of the pooled outcome data.

RESULTS

Changes of quantitative parameters such as CVI will be obtained in patients with AMD.

CONCLUSION

This study will elucidate alternations of choroidal vascular and stromal component in AMD and provide robust evidence on the pathophysiology of AMD.

REGISTRATION NUMBER

INPLASY.

Factors associated with serous retinal detachment in highly myopic eyes with inferior posterior staphyloma

PURPOSE

To investigate the factors associated with persistent serous retinal detachment in highly myopic eyes with inferior posterior staphyloma.

METHODS

A total of 27 highly myopic patients (44 eyes) with an inferior posterior staphyloma were recruited. Serous retinal detachment was investigated; 13 eyes had persistent sub-macular fluid (study group), and 31 eyes lacked sub-macular fluid (control group). All patients underwent complete ophthalmologic examinations, including axial length measurement and fluorescein angiography (FA). Triton Deep Range Imaging (DRI) optical coherence tomography (OCT) (Topcon Corp., Tokyo, Japan) scans through the fovea measured choroidal thicknesses, macular bend height, and vitreoretinal interface factors.

RESULTS

Of the 44 eyes, 13 had neurosensory retinal detachment and 31 did not. No significant differences were found in any of the studied variables (age, gender, spherical equivalence, axial length, vitreomacular traction, epiretinal membrane, internal limiting membrane detachment), except a higher macular bend height (p = 0.01), and a reduced macular choroidal thickness (p = 0.02), which were associated with the risk of serous retinal detachment. No statistically significant differences in best-corrected visual acuity (BCVA) were observed between the study and control groups. Serous retinal detachment always occurred at the bisected retinal pigment epithelium of the macula corresponding to the upper edge of the staphyloma, and was characterised by multiple hyperfluorescent granular patches on fluorescein angiography.

CONCLUSIONS

A higher macular bend height and a reduced macular choroidal thickness may be important factors in the development of serous retinal detachment in patients with inferior posterior staphyloma.

A Comparison Study of Polypoidal Choroidal Vasculopathy Imaged with Indocyanine Green Angiography and Swept-Source Optical Coherence Tomography Angiography

PURPOSE

Indocyanine green angiography (ICGA) was compared with swept-source optical coherence tomography angiography (SS-OCTA) for the detection of polypoidal choroidal vasculopathy (PCV).

DESIGN

Retrospective, cross-sectional.

METHODS

Patients with treatment-naïve PCV based on ICGA imaging underwent same-day SS-OCTA imaging at Kyung Hee University Medical Center between April 2017 and November 2018. ICGA and SS-OCTA images were graded independently. SS-OCTA images were graded using both flow and structural information. Images were graded for the number of polypoidal lesions and the total lesion area, which included both the polypoidal lesions and the branching vascular networks (BVNs).

RESULTS

A total of 31 eyes from 30 patients were enrolled. Polypoidal lesions were identified in all eyes using both modalities, and there was agreement on the number of polypoidal lesions in 17 eyes (55%). In 12 eyes (39%), SS-OCTA graders identified a greater number of polypoidal lesions, and in 2 eyes (6%) ICGA graders identified more lesions. There was no significant difference in the lesion area measurements (standard deviation = 1.09, P = .08). The lesion with the largest difference in area measurements resulted from focal areas of atrophy, misdiagnosed as polypoidal lesions on ICGA, and a low-lying serous retinal pigment epithelial detachment erroneously identified as part of the BVN by ICGA graders. SS-OCTA imaging correctly diagnosed the focal areas of atrophy and the serous retinal pigment epitheial detachment.

CONCLUSIONS

SS-OCTA imaging was comparable to ICGA for the diagnosis of treatment-naïve PCV. However, SS-OCTA might be better than ICGA in correctly identifying both polypoidal lesions and BVNs in treatment-naïve PCV.

Features of the Choroidal Structures in Myopic Children Based on Image Binarization of Optical Coherence Tomography

Purpose

To evaluate the features of the choroidal structures in the eyes of myopic children obtained by enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

Ninety-six myopic children with low to moderate myopia (spherical equivalent refractive error [SER], –5.75 to –1.00 diopter) were included in this cross-sectional study. Ocular biometrics were measured using an optical low-coherence reflectometry device. Data of the choroidal structures extracted from a 7500-µm cross-sectional arc of the choroid extending from the temporal optic disc margin, including the total choroidal area, luminal area, stromal area, and choroidal vascularity index, were determined by image binarization of the EDI-OCT. Associations between demographic factors, ocular parameters, and choroidal structures were evaluated using univariate and multiple linear regression analyses.

Results

The study participants (mean age, 11.02 ± 1.70 years) had a mean axial length (AL) of 24.94 ± 0.70 mm. The mean total choroidal area was 2.64 ± 0.49 mm² (luminal area, 1.68 ± 0.32 mm²; stromal area, 0.95 ± 0.19 mm²), and the choroidal vascularity index was 0.64 ± 0.03. Multiple regression analysis showed that the luminal area was significantly associated with the AL (standard β = –0.24, P = 0.022) after adjusting for sex and corneal radius (CR), whereas the stromal area (standard β = –0.30, P = 0.003) and choroidal vascularity index (standard β = 0.36, P = 0.001) were significantly associated with age after adjusting for sex, CR, and lens thickness (LT). Sex, CR, LT, and SER showed no significant association with choroidal structures after adjusting for age and AL (all P > 0.05).

Conclusions

The luminal area of the choroid tends to decrease with a longer AL, whereas the stromal area tends to decrease with increasing age in myopic children. These findings require further exploration in a longitudinal study.

Normal aging changes in the choroidal angioarchitecture of the macula

The choroidal vascularity index (CVI) has been shown to be sensitive in detecting changes in choroidal angioarchitecture in a range of ocular diseases. However, changes in CVI in association with normal physiological aging and spatial distribution remains to be determined. This is significant as a range of ocular conditions with choroidal degeneration are associated with aging. In this study, we assessed CVI for 106 healthy eyes from 106 individuals (range 21–78 years old, ~ 20 individuals/decade) at 15 eccentricities across the macula (0, 230 µm, 460 µm, 690 µm, 1,150 µm, 1,380 µm and 2,760 µm from the fovea in the superior and inferior direction). Total choroidal area, luminal area and stromal area were all significantly decreased with age (p < 0.001 for all parameters). CVI was also significantly decreased with age (p < 0.01) and eccentricity. Fitting of quadratic regression curves to CVI as a function of age yielded a good fit for all eccentricities (r² = 0.55–0.80) and suggested a decrease in CVI from the ages of 33–43 years at a rate of 0.7–2.7% per decade. CVI was lower in the inferior versus superior retina at matching eccentricities and a significant difference in age-related decline of CVI with eccentricity only occurred in inferior locations. These findings suggest choroidal angioarchitecture declines from the 4th decade of life with potential eccentricity differences in the inferior and superior retina. Considering the number of age-related diseases with choroidal dysfunction, these results provide foundational knowledge to understand choroidal involvement in these diseases.

Comparison of choriocapillary flow density between fellow eyes of polypoidal choroidal vasculopathy and neovascular age-related macular degeneration

Background

To compare the choriocapillary flow density (CFD) among the fellow eyes of polypoidal choroidal vasculopathy (PCV), neovascular age-related macular degeneration (nAMD), and healthy controls using spectral-domain optical coherence angiography tomography (SD-OCTA).

Methods

This is a cross-sectional study that includes the fellow eyes of 38 patients with unilateral PCV, 36 patients with unilateral nAMD, and 36 eyes from 36 healthy volunteers. The PCV group was further classified into polypoidal CNV (P-CNV) and typical PCV (T-PCV) for subgroup analysis. The age, subfoveal choroidal thickness (SFCT), Age-Related Eye Disease Study (AREDS) classification, and fellow eye diagnosis were acquired. All subjects underwent SD-OCTA with a 6.0-mm scan pattern. Circles with radius of 1.00, 1.50, and 3.00 mm were manually selected in the choriocapillaris (CC) slab, and the CFD was calculated as the percentage of the flow area to the whole selected area as CFD-1.00, 1.50, and 3.00, respectively. Univariate and multivariate analysis were performed to study the correlation between the aforementioned factors with CFD.

Results

The mean CFD-1.00, 1.50, and 3.00 of the nAMD group were 61.51, 63.18, and 66.20, respectively; these were significantly lower than those of the PCV group (65.90, 66.89, and 67.94; P < 0.001, P < 0.001, and P = 0.010; respectively) and control group (66.28, 66.96, and 68.42; P < 0.001, P < 0.001, and P = 0.001, respectively), and no difference was detected between the PCV and control group or between PCV subtypes. The AREDS classification and fellow eye diagnosis were correlated with CFD in univariate analysis; however, only the fellow eye diagnosis showed a significant correlation after multiple linear regression.

Conclusions

The CFD of nAMD fellow eyes was significantly lower than that of PCV and control eyes, and no difference was detected between PCV and control group, indicating that CC loss plays a different role in the early pathogenesis of nAMD and PCV.

Choroidal vascularity index as a biomarker of systemic inflammation in childhood Polyarteritis Nodosa and adenosine deaminase-2 deficiency

BACKGROUND/PURPOSE

To assess EDI-OCT (enhanced depth imaging optical coherence tomography) of choroid for inflammatory signs in children with polyarteritis nodosa (PAN) and adenosine deaminase-2 deficiency (DADA-2).

METHODS

In this cross-sectional study conducted between June 2017 and September 2018, we evaluated children diagnosed with PAN (n = 11) and DADA-2 (n = 4) and an age- and sex-matched control group (n = 15). Demographic and laboratory data were retrospectively analyzed from patient charts. Disease activity was assessed using the pediatric vasculitis activity score (PVAS). Choroidal images were obtained with spectral domain-OCT to measure choroidal thickness (ChT) at 5 points (750 and 1500 μm from the foveal center in the temporal and nasal quadrants and beneath the fovea), and to calculate the total subfoveal choroidal area (TCA), luminal area (LA), stromal area (SA), and the choroidal vascularity index (CVI).

RESULTS

The median (min-max) age was 8 (4-16) years in PAN patients, 6 (5-16) years in DADA-2 patients and 8 (8-10) years in control group at the OCT visit (p = 0.214). The ChT at 3 points and the TCA, LA, and SA were higher in children with both PAN and DADA-2 patients compared to those of the control group (p < 0.0001, p = 0.049, p = 0.007, p = 0.007, p = 0.006, p = 0.033, respectively). The CVI was similar in both groups. No association was observed between the OCT findings, PVAS, and the erythrocyte sedimentation rate, and serum leukocyte and C-reactive protein levels.

CONCLUSION

Similar CVI scores were obtained from PAN and DADA2 patients under treatment and from healthy controls. Increased subfoveal ChT without any other signs of ocular involvement may suggest choroidal thickening as a sign of mild subclinical inflammation.

Analysis of choroidal thickness and vascularity in patients with unilateral polypoidal choroidal vasculopathy

PURPOSE

This study aimed to analyze the choroidal characteristics in eyes with polypoidal choroidal vasculopathy (PCV, affected eyes) and unaffected fellow eyes, and investigated the longitudinal changes in the choroidal structure of fellow eyes in patients with unilateral PCV.

METHODS

We retrospectively reviewed the medical records of 55 treatment-naïve patients with unilateral PCV. The choroidal thickness and vascularity between PCV affected eyes, unaffected fellow eyes, and normal control eyes were compared. Structural changes in the choroid of the fellow eyes were reviewed during follow-up.

RESULTS

PCV eyes had thicker subfoveal choroidal thickness (SFCT) (p < 0.001), greater ratio of Haller layer to SFCT (p < 0.001), and lower choroidal vascularity index (p = 0.023), compared to controls. In unaffected fellow eyes, the ratio of the Haller layer to SFCT was greater (p < 0.001) than in controls. During a 58.91-month mean follow-up, nine (16%) fellow eyes developed new PCV. These eyes showed a greater ratio of Haller layer to SFCT at baseline (p < 0.001) compared to the other fellow eyes. We also observed a numerical change in the choroidal vascularity index during follow-up of fellow eyes that developed new PCV.

CONCLUSION

The dilation of the Haller layer was prominent in PCV eyes and fellow eyes, compared to normal controls. In the fellow eyes that developed new PCV lesions, there were changes in the choroidal vascularity during follow-up.

Exploring choroidal angioarchitecture in health and disease using choroidal vascularity index

The choroid is one of the most vascularized structures of the human body and plays an irreplaceable role in nourishing photoreceptors. As such, choroidal dysfunction is implicated in a multitude of ocular diseases. Studying the choroid can lead to a better understanding of disease pathogenesis, progression and discovery of novel management strategies. However, current research has produced inconsistent findings, partly due to the physical inaccessibility of the choroid and the lack of reliable biomarkers. With the advancements in optical coherence tomography technology, our group has developed a novel quantitative imaging biomarker known as the choroidal vascularity index (CVI), defined as the ratio of vascular area to the total choroidal area. CVI is a potential tool in establishing early diagnoses, monitoring disease progression and prognosticating patients. CVI has been reported in existing literature as a robust marker in numerous retinal and choroidal diseases. In this review, we will discuss the current role of CVI with reference to existing literature, and make postulations about its potential and future applications.

Choroidal binarization analysis: clinical application

INTRODUCTION

Image processing of optical coherence tomography scans through binarization techniques represent a non-invasive way to separately asses and measure choroidal components, in vivo. In this review, we systematically search the scientific literature regarding binarization studies published so far.

METHODS

A systematic research was conducted at PubMed database, including English literature articles for all of the following terms in various combinations: binarization, choroid/al, enhanced depth spectral domain/swept source optic coherence tomography, and latest publications up to November 2018 were reviewed.

RESULTS

Thirty-seven articles were included and analyzed regarding studied disease, binarization method, studied variables, and outcomes. Most of the studies have focused on the more common retinal pathologies, such as age-related macular degeneration, central serous chorioretinopathy and diabetic retinopathy but binarization techniques have also been applied to the study of choroidal characteristics in ocular inflammatory diseases, corneal dystrophies and in postsurgical follow-up. Advantages and disadvantages of binarization techniques are also discussed.

CONCLUSION

Binarization of choroidal images seems to represent a promising approach to study choroid subcomponents in an increasingly detailed manner.

Visualization of Choriocapillaris and Choroidal Vasculature in Healthy Eyes With En Face Swept-Source Optical Coherence Tomography Versus Angiography

Purpose

To compare the visualization of the choriocapillaris and deeper choroidal vessels in healthy eyes in en face swept-source optical coherence tomography (SS-OCT) versus SS-OCT angiography (SS-OCTA).

Methods

This is a cross-sectional study of consecutive eyes without chorioretinal disease. En face SS-OCT and SS-OCTA images of the choriocapillaris and choroid were assessed for visualization of the vasculature. Choroidal vessel densities (CVD) of the choriocapillaris, inner choroid, midchoroid, and outer choroid were calculated from binarized en face SS-OCT and SS-OCTA images. Paired t-tests and linear regression were used for statistical analysis.

Results

Twenty-seven eyes of 27 patients were included. There was no statistically significant difference between the CVDs of the midchoroid assessed with en face SS-OCT versus SS-OCTA (P = 0.21). However, there were statistically significant differences between the CVDs for the choriocapillaris (P < 0.001), inner choroid (P < 0.001), and outer choroid (P = 0.006). Qualitative analysis revealed incomplete visualization of vessels in the inner choroid and exaggeration of vessel lumens in the outer choroid with SS-OCTA.

Conclusions

Visualization of the choriocapillaris is superior with SS-OCTA, but it has numerous limitations that make visualization of deeper choroidal vessels less reliable when compared with en face SS-OCT. It is important to understand such limitations when using these technologies to study the choroidal vasculature in chorioretinal disease.

Translational Relevance

The presented study of optimal imaging techniques for the choroidal vessels of healthy eyes provides an important foundation for future investigations into the role of the choroidal vasculature in chorioretinal diseases.

Evaluation of Choroidal Thickness, Choroidal Vascularity Index and Peripapillary Retinal Nerve Fiber Layer in Patients with Juvenile Systemic Lupus Erythematosus

Objective

The aim of this study was to conduct a detailed ophthalmological examination in children with systemic lupus erythematosus (jSLE), including choroidal thickness (ChT), choroidal vascularity index (CVI) and peripapillary retinal nerve fiber layer (RNFL).

Methods

The study included all jSLE patients ( n = 21) diagnosed according to the Systemic Lupus International Collaborating Clinics classification criteria between January 2017 and April 2017, and an age- and gender-matched control group ( n = 21). The Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) was used to assess disease activity. After routine eye examinations, ChT at five points (750 µ and 1500 µ from the center of the fovea both in the temporal and nasal quadrants and under the fovea), total subfoveal choroidal area (TCA), luminal area (LA), stromal area (SA), CVI and RNFL thickness at the optic disc were evaluated.

Results

One patient had active ocular involvement in the form of episcleritis. Another patient had corticosteroid-induced cataract. The median age of the patients was 16 years (6-19 years). ChT at five points, TCA, LA and SA were found to be higher in patients with jSLE, whereas RNFL thickness and CVI were similar to those of the healthy control individuals. No correlation was determined between optical coherence tomography findings, SLEDAI and the immunological parameters (antinuclear antibodies, anti-double-stranded DNA, complements 3 and 4, extracted nuclear antigen antibody, antiphospholipid antibody). Intraretinal and subretinal fluid was not present in any of the patients.

Conclusion

The choroid was thicker in patients with jSLE than in the control group. The study results suggest that jSLE may affect the choroid. Ophthalmological evaluation is important in SLE patients, even in the absence of relevant complaints.

Choroid changes in vortex vein-occluded monkeys

AIM

To determine acute and chronic choroidal vascular changes after vortex vein occlusion in monkeys.

METHODS

One or two temporal vortex veins were occluded in 8 cynomolgus monkeys. Fluorescein angiography (FA), indocyanine green angiogram (ICGA), and enhanced-depth imaging optical coherence tomography (EDI-OCT) were performed preoperatively and at 1d, 1, 4, 8 and 12wk after occlusion. EDI-OCT images were binarized to calculate the choroid vascular index (CVI).

RESULTS

ICGA showed delayed filling of choroidal arteries in occluded quadrants in eyes with two occluded temporal vortex veins within 1wk. The thickness of the superotemporal choroid increased 1d and 4wk after occlusion, the thickness of the superonasal and inferonasal choroid increased 12wk after occlusion, and the CVI of the superonasal quadrant increased 8wk after occlusion in eyes with 2 occluded vortex veins.

CONCLUSION

Occlusion of two vortex veins leads to hemodynamic and structural changes in choroidal layers in the acute phase, while autoregulation may play the main role in the long term. Occlusion of one vortex vein has little influence on the hemodynamic and structural status of the choroid.

Choroidal structure as a biomarker for visual acuity in intravitreal aflibercept therapy for polypoidal choroidal vasculopathy

PURPOSE

To investigate the relationship between choroidal structure and visual acuity after intravitreal aflibercept therapy for polypoidal choroidal vasculopathy (PCV).

METHODS

We conducted a retrospective, single-centre and observational study including 18 eyes of 18 patients with PCV (73.8 ± 10.2 years of age) who were treated with three monthly intravitreal aflibercept injections followed by additional treatments in a treat-and-extend protocol. The cross-sectional images of the macula were obtained with enhanced depth imaging optical coherence tomography at baseline, at 3 months, and at 12 months. The choroidal layer was divided into luminal or stromal segments by applying binarization processing to calculate these areas. The relationships between age, spherical equivalent, best-corrected visual acuity (BCVA), baseline value, or changes in the luminal or the stromal areas, and the BCVA change at 12 months were analysed using multiple regression analyses and model selection procedures.

RESULTS

Both stromal and luminal areas were decreased at 3 and 12 months compared to baseline areas (5% and 9% at 3 months, 6% and 12% at 12 months, p < 0.0001, p < 0.0001, p < 0.0001 and p < 0.0001, respectively). Greater improvement of visual acuity (VA) at 12 months was significantly associated with younger age, greater spherical equivalent, worse baseline BCVA, greater baseline luminal area, and smaller baseline stromal area.

CONCLUSIONS

Choroidal structure might be useful as a new biomarker for potential Visual outcomes after intravitreal aflibercept therapy for PCV.

Choroidal vascularity index in type-2 diabetes analyzed by swept-source optical coherence tomography

The relationships between changes in choroidal vasculature and the severity of diabetic retinopathy (DR) remain unclear. We assessed choroidal changes in diabetic patients by measuring choroidal vascularity index (CVI) in conjunction with DR stage. In this study, patients with diabetes and healthy controls were retrospectively analyzed. Subjects were divided into seven groups as follows: Healthy controls, no DR, mild/moderate non-proliferative DR (NPDR), severe NPDR, proliferative DR (PDR), panretinal photocoagulation-treated DR, and clinically significant macular edema. The mean CVI values in the above groups were 69.08, 67.07, 66.28, 66.20, 63.48, 65.38, and 66.28, respectively. The eyes of diabetic patients exhibited a significantly lower CVI value than those of healthy controls even without DR. The PDR group exhibited a significantly lower CVI value than the healthy control, no DR, and mild/moderate NPDR groups. Age, sex, disease duration, glycated hemoglobin, fasting blood sugar, or intraocular pressure had no correlation with CVI. In multivariate regression analysis, thicker subfoveal choroid and thinner central retina were significantly associated with higher CVI values. These findings carefully suggest that changes in choroidal vasculature could be the primary event in diabetes even where there is no DR.