Choroidoscleral Interface Research Articles

PERIPHERAL EXUDATIVE HEMORRHAGIC CHORIORETINOPATHY-A NEW ADDITION TO THE SPECTRUM OF PACHYCHOROID DISEASE?

Purpose: To demonstrate choroidal vascular changes and report a novel choroidal thickness contour in eyes with peripheral exudative hemorrhagic chorioretinopathy (PEHCR). Methods: Retrospective, observational, comparative case series. Fourteen eyes of nine patients with PEHCR and 14 eyes of 14 age-matched and sex-matched controls underwent swept-source optical coherence tomography. Choroidal thickness was measured from posterior edge of the retinal pigment epithelium–Bruch membrane to choroidoscleral interface at 11 points 1,000 µm apart. Large choroidal vessel thickness was also measured. Results: In PEHCR group, the choroid was thinnest at 3 mm nasal to fovea (mean 95.3 ± 33.5 µm) and thickest at 7 mm temporal to fovea (mean 272.7 ± 80.2 µm), with gradual increase in choroidal thickness from nasal to temporal periphery. The choroid was thickest subfoveally (259.7 ± 63.8 µm) in the control group. The choroid was significantly thicker in temporal periphery in PEHCR eyes as compared to controls (P = 0.0002). The mean large choroidal vessel thickness was 202.4 ± 50.8 µm in the PEHCR group and 160.6 ± 40.5 µm in the control group (P = 0.0235). Conclusion: Peripheral exudative hemorrhagic chorioretinopathy eyes showed progressively increasing choroidal thickness toward the temporal periphery, compared with age-matched and sex-matched controls. This gave rise to a club-shaped choroidal contour compared with the bowl-shaped contour seen in control eyes. Thicker choroid and pachyvessels favor inclusion of PEHCR in the pachychoroid disease spectrum.

Distribution of Choroidal Thickness and Choroidal Vessel Dilation in Healthy Japanese Individuals: The Nagahama Study.

PurposeTo report fundamental epidemiologic data for choroidal parameters such as choroidal thickness and index of choroidal vascularity in Japanese individuals and to evaluate their correlations with age, sex, systemic parameters, and other ocular parameters.DesignPopulation-based cohort study.ParticipantsA total of 9850 individuals participated in the first follow-up of the Nagahama Prospective Cohort for Comprehensive Human Bioscience (the Nagahama Study) conducted between 2013 and 2016.MethodsAll participants underwent standardized ophthalmic examinations, including OCT with enhanced depth imaging (EDI; RS-3000 Advance; Nidek). We manually segmented the choroidoscleral interface to measure subfoveal choroidal thickness (SFCT) and calculated the normalized choroidal intensity obtained with EDI (NCIEDI) and choroidal vascularity index (CVI). These are indices of choroidal brightness in OCT and reportedly represent the dilation of choroidal vessels. After summarizing the age-sex stratified distributions of SFCT, NCIEDI, and CVI, their associations with age, sex, axial length (AL), and spherical equivalent (SE) were evaluated using linear regression analysis with adjustments for possible confounders.Main Outcome MeasuresDistribution of SFCT, NCIEDI, and CVI in the healthy Japanese population and their characteristics.ResultsAge-sex standardized SFCT, NCIEDI, and CVI were 291.2 μm, 0.653, and 66.88%, respectively. In both men and women, SFCT was associated negatively with age (P < 0.001) and NCIEDI was associated positively with age (P < 0.001). Although both SFCT and NCIEDI did not differ significantly between men and women overall (P = 0.87 and P = 0.21, respectively), among younger participants (35–50 years of age), men showed significantly greater SFCT than women (P < 0.001). Only in men was CVI associated positively with age (P < 0.001). In the multivariable analysis, SFCT was associated significantly with age, sex, AL, SE, and the interaction term of age and sex (P < 0.001). Independent of SFCT, NCIEDI and CVI were associated significantly with age (P < 0.001).ConclusionsWe report normative Japanese SFCT, NCIEDI, and CVI data using a large general Japanese cohort. The association analysis of SFCT with NCIEDI and CVI suggested that younger individuals have a more lumen-rich choroid for their choroidal thickness than older individuals.

Choroidal Differences between Spectral and Swept-source Domain Technologies

ABSTRACT Purpose of the study To assess differences in healthy eyes in volume (CV) and choroidal thicknesses (CT) across all macular Early Treatment Diabetic Retinopathy Study (ETDRS) areas measured by swept source (SS)-OCT and spectral domain (SD)-OCT with enhanced depth imaging (EDI). Materials and Methods One hundred and fifty healthy eyes were studied in patients aged between 21–68 years. All of these patients underwent an ophthalmic examination that included axial length (AL), a fast macula protocol with EDI by Spectralis SD-OCT, and a 3D macular cube by DRI-Triton SS-OCT. CT and CV values were measured after a manual segmentation with SD-OCT and automatically with SS-OCT. Results The values obtained by SD-OCT were statistically higher than the values obtained by SS-OCT in all ETDRS areas. To determine the differences that were related to total CV or AL, the eyes were divided depending on their total CV and AL values into two groups. There were persistent differences between the two devices that were not related to the total CV. In subjects with a higher AL, these differences were not present in either the total CV or the subfoveal CT. In longer eyes, the differences diminished, and there were no statistical differences between the devices in the subfoveal area, temporal quadrants, inferior inner ring, or CV. Conclusions The choroidal values obtained with the SD-OCT are statistically higher than those measured by SS-OCT. Both techniques are able to clearly visualize the choroidoscleral interface and provide different values that are highly correlated. These differences are smaller in eyes with a longer AL and are not related to the total CV.

En-face choroidal vascularity in central serous chorioretinopathy.

To evaluate the choroidal vascularity index of eyes for acute and chronic central serous chorioretinopathy patients using swept-source optical coherence tomography generated en-face scans. This was a retrospective study, in which slabs of en-face optical coherence tomography scans, at 5 μm intervals, spanning from the retina to choroid, were binarized using a validated algorithm to calculate choroidal vascularity index. The choroidal vascularity index was defined as the ratio between the choroidal vascular luminal area and the total choroidal area. Choroidal vascularity index was calculated for all the slabs of every subject in both the groups. A total of 30 eyes for each acute and chronic central serous chorioretinopathy groups were recruited. The mean choroidal vascularity index of the acute group was 45.21% ± 2.25% at the choriocapillaris, which increased to the maximal value of 48.35% ± 2.06% at 75% depth of the choroidal thickness and 45.31% ± 3.27% at the choroidoscleral interface; whereas for the chronic group, the mean choroidal vascularity index was 44.76% ± 2.60% at the choriocapillaris, which maximized at 50% choroidal depth (48.70% ± 1.32%) and then returned to 45.41% ± 6.02% at the choroidoscleral interface. For both groups, the choroidal vascularity index increased from choriocapillaris to maximum values at mid-choroid and returned to almost the choriocapillaris value at the choroidoscleral interface.

Choroidoscleral Interface Irregularity Index: A novel optical coherence tomography-based parameter in patients with epiretinal membrane

This study aimed to assess the regularity of the choroidoscleral interface (CSI) using a novel parameter, CSI irregularity index, before and after epiretinal membrane (ERM) surgery. This study included 36 patients with idiopathic ERM who underwent pars plana vitrectomy and ERM removal. All subjects underwent ocular examinations at baseline and at 1, 2, 4, and 6 months after surgery. The regular contour of the CSI was found in 14 patients (38.9%); mean CSI irregularity index was 14.84 ± 11.01 in this group. The irregular contour of the CSI was found in 22 patients (61.1%); mean CSI irregularity index was 33.96 ± 20.64 in this group. The CSI irregularity index decreased gradually after ERM surgery, and was correlated with postoperative best-corrected visual acuity. The CSI irregularity index could serve as a surrogate marker to quantitatively represent the CSI morphology. We observed the gradual decrease of the CSI irregularity index after ERM surgery in quantitative manner. This study showed correlations between the CSI irregularity index and visual outcomes after ERM surgery. Our results suggest that the CSI irregularity index might be an intuitive anatomic indicator of the CSI and might be useful as a possible prognostic marker for patients undergoing ERM surgery.

En-face choroidal vascularity map of the macula in healthy eyes.

To report the en-face choroidal vascularity index in healthy eyes. Thirty eyes of 30 healthy individuals were studied. Multiple high-density cross-sectional swept source optical coherence tomography scans were obtained to create a volume scan. The choroid was segmented for the whole volume scan and choroidal inner boundaries were flattened. Subsequently, multiple en-face scans separated by 25 µm were obtained and binarized. Choroidal vascularity index was calculated at level of choriocapillaris, medium, and large choroidal vessels. The mean age of the study cohort was 35.6 ± 8.8 years. The overall mean en-face choroidal vascularity index was 54.25 ± 0.55%. There was a statistically significant difference of choroidal vascularity index in choriocapillaris (53.16 ± 0.43%), medium choroidal vessel (51.38 ± 0.27%), and large choroidal vessel (55.69 ± 0.87%) (p < 0.01). Choroidal vascularity index analysis in three subgroups based on subfoveal choroidal thickness (low: <300 µm, medium: 300-400 µm, high: >400 µm) showed a statistically significant difference (p = 0.001). Choroidal vascularity index showed a significant correlation with subfoveal choroidal thickness (r = 0.441; p = 0.015), whereas there was no significant correlation of age (p = 0.21), refraction (p = 0.20), and gender (p = 0.67) with en-face choroidal vascularity index. En-face choroidal vascularity index shows a significant variation at the level of choriocapillaris, medium choroidal vessel, and large choroidal vessel in normal eyes. Choroidal vascularity index reaches a nadir at the level of medium choroidal vessel and reaches the maximum value at large choroidal vessel near choroidoscleral interface. En-face choroidal vascularity index shows a significant physiological variation and appears to increase with increase in subfoveal choroidal thickness.

Wide-field choroidal thickness profile in healthy eyes

The introduction of wide field optical coherence tomography (WF-OCT) has provided newer insights in the imaging of peripheral choroid. We evaluated choroidal thickness (CT) and large choroidal vessel thickness (LCVT) of 20 eyes in horizontal and vertical meridians using WF-OCT. A high-definition line scan through the fovea in both horizontal and vertical meridian was captured in primary and extremes of gaze to obtain scans up to mid-equator. CT and LCVT measurements were done across predefined points in macular area and all quadrants. LCVT was calculated after identifying a large choroidal vessel near choroidoscleral interface. The main outcome measures were differences in CT and LCVT in macular and four quadrants. Mean CT (331.23 ± 76.34 µ) and LCVT (201.46 ± 54.31 µ) in vertical macular segment were significantly more than CT (245.79 ± 55.38 µ; p = 0.0002) and LCVT (150.48 ± 52.58 µ; p = 0.004) in horizontal macular segment. CT at peripheral points in all quadrants was significantly reduced as compared to subfoveal CT (all p values < 0.05) with maximum reduction in inferior quadrant (64.5%). Using linear regression, only quadrant had a significant effect on CT and LCVT (both p < 0.001). CT and LCVT are highest at the macular area with reduction towards the periphery. The contribution of LCVT to CT is less at the fovea compared to other peripheral points.

Morphologic Features of the Choroidoscleral Interface in a Healthy Population Using Swept-Source Optical Coherence Tomography

To analyze the morphologic features of the choroidoscleral interface in a healthy population using swept-source optical coherence tomography (SS OCT). Retrospective data analysis of a subgroup of eyes from a previous single-center, prospective, cross-sectional, noninterventional study. A total of 276 healthy eyes from 154 subjects were evaluated using SS OCT. Inclusion criteria were best-corrected visual acuity between 20/20 and 20/25, spherical equivalent between ±3 diopters, and no systemic or ocular diseases. Two independent investigators analyzed the morphologic features of the choroidoscleral interface in a masked fashion, classifying the contour and shape as concave (bowl-shaped) or inflective (S-shaped contour with ≥1 inflection point). The presence of a temporal choroidoscleral interface inflection was identified in 12.8% of the eyes. The mean choroidal thickness was 372.1 ± 76.8μm and the average distance from the inflection point to the fovea was 4427.3 ± 627.9μm. Nine patients showed an inflective profile in both eyes. No changes in the retinal profile were found in any of these cases. The mean age of the patients with an inflective profile was 16 ± 19 years (range 4-82) vs 36 ± 25 years (range 3-95) in the group with a concave contour (P= .001). The temporal choroidal thickness at 4000 and 5000μm from the fovea was thicker in the group with a concave contour. Temporal choroidoscleral interface inflection or S-shaped profile of the choroidoscleral interface with focal thinning of the choroid can be considered a normal variation without clinical significance, especially in younger populations.

Choroidal Analysis in Healthy Eyes Using Swept-Source Optical Coherence Tomography Compared to Spectral Domain Optical Coherence Tomography

To compare analyses of choroidal thickness and volume in healthy eyes measured concurrently with prototype long-wavelength swept-source optical coherence tomography (OCT) and commercially available spectral-domain optical coherence tomography (OCT) with and without enhanced depth imaging (EDI). Prospective cross sectional study. The study included 19 healthy subjects (19 eyes), who were prospectively recruited to undergo 2 consecutive imaging sessions on the same randomly selected eye using spectral domain OCT and a prototype long-wavelength swept-source OCT. On spectral domain OCT, 2 line scans, 1 with and 1 without EDI, and 1 volumetric scan were obtained. On swept-source OCT, 1 line scan and 1 volumetric scan were obtained. Scan patterns on swept-source OCT were created to simulate those available on Cirrus HD-OCT to keep the time of image acquisition constant. Swept-source OCT volumetric scans were motion corrected using a novel registration algorithm. Choroidal thickness and volume were analyzed. The choroidoscleral interface was clearly visualized in 19/19 (100%) of eyes imaged by swept-source OCT, compared to 14/19 (73.6%) and 13/19 (68.4%) eyes imaged by spectral domain OCT, with and without EDI, respectively. There was no significant difference in choroidal thickness measurements on the line scans obtained on either system (P = 0.10). Choroidal volume could not be assessed on volumetric scans from spectral domain OCT. Mean choroidal volume from swept-source OCT volumetric scans was 11.77 ± 3.13 mm(3) (6.43 mm(3)-17.15 mm(3)). This is the first study that compares simultaneously a prototype long-wavelength swept-source OCT to a commercially available spectral domain OCT for a detailed analysis of choroid in healthy eyes. Swept-source OCT shows potential for better choroidal analysis. Studies using swept-source OCT in diseased eyes will further define this new technology's utility in chorioretinal diseases.

Enhanced Visualization of the Choroido-Scleral Interface Using Swept-Source OCT

An accurate analysis of the thickness and volume of choroid using optical coherence tomography (OCT) requires precise visualization of the choroido-scleral interface. Results of studies that use spectral-domain OCT (SD-OCT) to look at the percent visualization of the choroido-scleral interface for accurate analysis of choroidal thickness show varying success rates. This study assessed the visualization of choroido-scleral interface in 19 healthy participants (19 eyes) prospectively recruited for consecutive high-definition raster scanning with an SD-OCT system with and without enhanced depth imaging (EDI) and a prototype long-wavelength swept-source OCT (SS-OCT) system. Choroido-scleral interface was visualized in all eyes imaged on SS-OCT, compared with 13 of 19 (68.4%) and 14 of 19 (73.6%) eyes imaged on SD-OCT without EDI (P = .009) and with EDI (P = .02), respectively. The prototype long-wavelength SS-OCT system, with its higher acquisition speed and deeper tissue penetration, may have better clinical utility in determining the involvement of choroid in various chorioretinal diseases.

Analysis of Morphological Features and Vascular Layers of Choroid in Diabetic Retinopathy Using Spectral-Domain Optical Coherence Tomography

Diabetic retinopathy (DR) is characterized by microaneurysms, capillary nonperfusion, and ischemia within the retina, ultimately leading to neovascularization and/or macular edema. Evidence suggests that choroidal angiopathy may coexist with retinal vascular damage. Recent advances in spectral-domain optical coherence tomography (SD-OCT) permit an efficient visualization of the choroid. To analyze the morphological features and vascular layers of the choroid in patients with DR using SD-OCT. A cross-sectional retrospective review identified patients with DR and healthy (control) subjects who underwent 1-line raster scanning from February 1, 2010, through June 30, 2012. Patients were classified into the following 3 groups: nonproliferative DR without macular edema (9 eyes), proliferative DR without macular edema (PDR) (10 eyes), and diabetic macular edema (DME) (14 eyes). Two independent raters experienced in analyzing OCT images evaluated the morphological features and vasculature of the choroid. New England Eye Center. Thirty-three eyes of 33 patients with DR and 24 eyes of 24 controls. Diabetic retinopathy. Choroidal morphological features and vasculature analysis. The choroidoscleral interface had an irregular contour in 8 of 9 eyes with nonproliferative DR (89%), 9 of 10 eyes with PDR (90%), and 13 of 14 eyes with DME (93%) compared with 0 of 24 controls. The thickest point of the choroid was displaced from under the fovea, and focal choroidal thinning was observed in eyes with DR. Mean subfoveal choroidal thickness and mean subfoveal medium choroidal vessel layer and choriocapillaris layer thickness were significantly reduced in eyes with PDR (P < .05) and DME (P < .05) compared with controls. Choroidal morphological features are altered in patients with moderate to severe DR. The subfoveal choroidal thickness and the subfoveal medium choroidal vessel layer and choriocapillaris layer thicknesses are significantly reduced in patients with PDR and DME. To our knowledge, this is the first study to analyze the morphological features and vasculature of the choroid in DR using SD-OCT. These findings may be clinically useful in predicting the progression of DR.