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Choroidal imaging biomarkers
摘要： The choroid is the vascular coat of the eye,and its role has been studied in multiple chorioretinal disorders. The recent advancements in choroidal imaging techniques including enhanced depth imaging optical coherence tomography (EDI-OCT), swept source (SS-OCT), enface OCT and OCT angiography have facilitated an in-depth analysis of choroid. The gradual shift from manual to automated segmentation and binarization methods have led to precise and reproducible measurements of choroidal parameters. These qualitative and quantitative parameters, called choroidal imaging biomarkers, have evolved over the past decade from a simple linear subfoveal choroidal thickness to more complex 3 dimensional (3-D) choroidal reconstruction thus widening the spectrum encompassing multiple parameters. These biomarkers have provided a better understanding of the pathogenesis, are helpful in diagnostic dilemmas, and in future may also help to devise treatment options. The lack of normative data, absence of standardized parameters and limitations of the imaging techniques, however, have led to ambiguity and difficulty in the interpretation of these variables. We attempt to address these lacunae in the literature and provide a basic understanding of the choroid in both health and disease using these choroidal biomarkers.
关键词： Optical coherence tomography angiography (OCTA),En-face OCT,Swept source optical coherence tomography (SS-OCT),Choroidal thickness,Choroidal vascularity index (CVI),Choroidal imaging biomarkers,Choroidal volume
更新于2025-09-23 15:21:21
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Prospective evaluation of changes in choroidal vascularity index after half-dose photodynamic therapy versus micropulse laser treatment in chronic central serous chorioretinopathy
摘要： Purpose To assess whether treatment of chronic central serous chorioretinopathy (cCSC) with photodynamic therapy (PDT) and high-density subthreshold micropulse laser (HSML) results in choroidal vascularity index (CVI) changes that may account for the treatment effect. Methods Patients with cCSC were prospectively included and analyzed. Patients received either half-dose PDT or HSML treatment. CVI of the affected and unaffected eye was obtained before treatment, 6 to 8 weeks after treatment, and 7 to 8 months after treatment. Results At baseline, 29 eyes (29 patients) were included both in the PDT and in the HSML group. The mean (± standard deviation) CVI change in the HSML group between before PDT and 6 to 8 weeks after PDT was ? 0.009 ± 0.032 (p = 0.127), whereas this was 0.0025 ± 0.037 (p = 0.723) between the visit before PDT and final visit. The patients in the PDT group had a CVI change of ? 0.0025 ± 0.037 (p = 0.723) between the visit before PDT and first visit after PDT, and a mean CVI change of ? 0.013 ± 0.038 (p = 0.080) between the visit before PDT and final visit. There was no significant correlation between CVI and BCVA at the measured time points, in both the HSML group (p = 0.885), and in the PDT group (p = 0.904). Moreover, no significant changes in CVI occurred in the unaffected eye at any time point. Conclusions PDT and HSML do not significantly affect CVI, and therefore a CVI change may not be primarily responsible for the treatment effect. The positive treatment effect of both interventions may rely on other mechanisms, such as an effect on choriocapillaris and/or retinal pigment epithelium function.
关键词： Choroidal vascularity index,Photodynamic therapy,Central serous chorioretinopathy,Micropulse laser
更新于2025-09-23 15:19:57
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Choroidal structure in subtypes of polypoidal choroidal vasculopathy determined by binarization of optical coherence tomographic images
摘要： Importance: Chorodial structure in subtypes of polypoidal choroidal vasculopathy. Background: To evaluate choroidal vascularity in the eyes of patients with polypoidal choroidal vasculopathy (PCV) with and without choroidal vascular hyperpermeability (CVH). Design: A hospital-based retrospective study. Participants: Fifty-eight PCV patients (28 with CVH; 30 without CVH) and 30 normal controls were included in this study. Methods: All study subjects underwent spectral-domain optical coherence tomography with enhanced depth imaging, and the choroidal images were binarized into the luminal area and stromal area. Main outcome measures: Choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT). Results: Compared to normal controls, patients with PCV showed no obvious difference in SFCT (p = 0.510), but significantly lower CVI (p = 0.003). Among PCV patients, the CVI in eyes with CVH was significantly greater than that in those without CVH (65.78 ± 4.70 vs. 62.28 ± 3.90; p = 0.002), and a significant difference in SFCT was also found between the two subtypes of PCV (340.8 ± 89.2 vs. 250.4 ± 67.7; p < 0.001). Conclusions and Relevance: PCV eyes with CVH have a greater CVI and a thicker SFCT than those without CVH. The significant differences in choroidal vascularity between the two subtypes of PCV may broaden our understanding of the pathogenesis of this disease and contribute to significant improvements in treatment.
关键词： polypoidal choroidal vasculopathy,choroidal thickness,optical coherence tomography,choroidal vascular hyperpermeability,Choroidal vascularity index
更新于2025-09-19 17:15:36
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Choroidal structural analysis in eyes with diabetic retinopathy and diabetic macular edema—A novel OCT based imaging biomarker
摘要： To evaluate structural changes in the choroid among patients with diabetic macular edema (DME), with varying grades of diabetic retinopathy (DR), using enhance depth imaging spectral domain optical coherence tomography (EDI SD-OCT) scans. A cross-sectional study was conducted on 82 eyes with DR and DME and 86 healthy control eyes. Eyes with DME were classified according to the severity of DR as per the international DR severity scale. Sub foveal choroidal thickness (SFCT)was obtained using EDI SD-OCT scans. These scans were binarized into luminal and stromal areas, to derive the choroidal vascularity index (CVI). CVI and SFCT were analyzed between the study and control group using paired-T test. Tukey’s test was used to correlate the differences in CVI and SFCT between different grades of DR. Further analysis was done to look for the effect of DR severity and type of DME on CVI as well as SFCT using correlation coefficient and linear regression analysis. SFCT was significantly increased in eyes with DME as compared to the controls (334.47 ±51.81μm vs 284.53±56.45μm, p<0.001), and showed an ascending trend with worsening of DR, though this difference was not statistically significant [mild non-proliferative diabetic retinopathy (NPDR) = 304.33±40.39μm, moderate NPDR = 327.81±47.39μm, severe NPDR = 357.72±62.65μm, proliferative DR (PDR) = 334.59±47.4μm, p-0.09]. CVI was significantly decreased in DME with DR eyes as compared to controls (63.89±1.89 vs 67.51 ±2.86, p<0.001). CVI was also significantly decreased with worsening DR (mild NPDR = 66.38±0.3, moderate NPDR = 65.28±0.37, severe NPDR = 63.50±0.47, PDR = 61.27±0.9, p<0.001). SFCT and CVI are dynamic parameters that are affected by DME. Unlike CVI, SFCT is also affected by ocular and systemic factors like edema and hypertension. CVI may be a more accurate surrogate marker for DME and DR and can potentially be used to monitor the progression of DR.
关键词： choroidal vascularity index,diabetic macular edema,subfoveal choroidal thickness,optical coherence tomography,diabetic retinopathy
更新于2025-09-04 15:30:14