Large Choroidal Vessel Layer Thickness Research Articles

Wide-field choroidal vascular analysis in central serous chorioretinopathy.

To report the wide-field choroidal vessel analysis in central serous chrorioretinopathy (CSCR) and their fellow eyes. Wide-field optical coherence tomography (WF-OCT) images (55°) were obtained using Spectralis HRA + OCT (Heidelberg Engineering, Germany) in extremes of gazes in all quadrants and manual montages were created to obtain wide field images up to equator. Choroidal thickness (CT), large choroidal vessel layer thickness (LCVT), and choroidal vascularity index (CVI) were calculated in macular segment (twice the disc to fovea distance) and all four quadrants. Regression analysis was performed to identify the factors influencing CVI. Thirty-one patients of CSCR including 39 eyes of CSCR (32 chronic, 7 acute) and 23 fellow eyes were analyzed. CT and LCVT were significantly higher in submacular choroid than all extramacular segments in both CSCR and fellow eyes (all p values <0.01). CVI varied significantly in different segments in horizontal (p < 0.01 in both) and vertical meridian (p < 0.01 and p = 0.01 respectively) in CSCR and fellow eyes. Both CSCR and fellow eyes had highest CVI in nasal segment with minimum CVI in macular segment. Age (p = 0.85), gender (p = 0.39), chronicity of the disease (acute vs chronic, p = 0.57), axial length (p = 0.67), SBP (p = 0.81), and DBP (p = 0.94) were not significantly correlated to CVI. CVI shows significant regional variation with macular segment showing the lowest CVI whereas nasal segments have highest CVI in both CSCR and their fellow eyes. On the contrary, submacular segment has highest CT and LCVT with taper towards periphery in both CSCR and fellow eyes.

Choroid structure analysis following initiation of hemodialysis by using swept-source optical coherence tomography in patients with and without diabetes.

We aimed to evaluate choroid structural changes using swept-source optical coherence tomography (SS-OCT) following hemodialysis initiation in diabetic and nondiabetic patients with end-stage kidney disease (ESKD). In this multicenter, prospective, cross-sectional study, diabetic (DM group; 30 eyes; 16 patients) and nondiabetic patients (NDM group; 30 eyes; 15 patients) with ESKD were evaluated after hemodialysis initiation. SS-OCT findings were analyzed using a manual delineation technique and binarization method before the first and last hemodialysis sessions, conducted approximately 2 weeks apart. Subfoveal choroidal thickness changes and mean large choroidal vessel layer thickness were significantly greater in the DM group (-13.3% ± 2.5% and -14.5% ± 5.2%, respectively) than the NDM group (-9.5% ± 3.1% and -9.2% ± 3.4%, respectively; p = 0.049 and p = 0.02, respectively). Binarized SS-OCT analysis revealed that the mean subfoveal choroidal area was significantly larger in the DM group (-21.9% ± 6.5%) than the NDM group (-17.2% ± 5.9%; p = 0.032). The change ratio in mean luminal area values was significantly greater in the DM group (-27.7% ± 8.7%) than the NDM group (-17.7% ± 5.8%; p = 0.007). The DM group exhibited substantial changes in the choroidal layer, possibly reflecting choroidal vascular disorders caused by diabetes.

Clinical and angiographic characterization of choroidal neovascularization in diabetic retinopathy.

To report the clinical and angiographic characteristics of choroidal neovascularization in patients with diabetic retinopathy. Patients of type 2 diabetes mellitus with presence of choroidal neovascularization in at least one eye were retrospectively analyzed. The study eyes were divided into three groups based on presence (active or scarred) or absence of choroidal neovascularization (fellow eyes). Imaging characteristics of active choroidal neovascularization were recorded using optical coherence tomography, fluorescein, and indocyanine angiography. Central macular thickness, subfoveal choroidal thickness, and large choroidal vessel layer thickness were compared at baseline and final visit. Our study reports the prevalence rate of choroidal neovascularization in eyes with diabetic retinopathy (0.27%; 36 out of 13,382 eyes). A total of 64 eyes of 32 patients (age, mean ± standard deviation: 68.5 ± 9.3 years) with baseline visual acuity of 0.69 ± 0.69 logarithm of minimum angle of resolution (Snellen equivalent 20/100) were included. Nonproliferative diabetic retinopathy (57 eyes) comprised the majority followed by proliferative diabetic retinopathy (7 eyes). Eyes with choroidal neovascularization (36, 56.25%) included both active (25) and scarred (11) choroidal neovascularization, with bilateral choroidal neovascularization in 4 patients. Type 1 choroidal neovascularization was the most common subtype of choroidal neovascularization on optical coherence tomography. Common etiologies for active choroidal neovascularization included age-related macular degeneration (3; 12%), myopia (1; 4%), and inflammatory choroidal neovascularization secondary to chorioretinitis (1; 4%). In the remaining 20 eyes, choroidal neovascularization formation was primarily due to diabetic choroidopathy. The prevalence of choroidal neovascularization in eyes with diabetic retinopathy is very low, with a lower prevalence of age-related macular degeneration. Diabetic choroidopathy plays a significant role in formation of choroidal neovascularization in eyes with diabetic retinopathy.

Low incidence of pachydrusen in central serous chorioretinopathy in an Indian cohort.

Purpose:The aim of this study is to report the prevalence, clinical and swept-source optical coherence tomography (SS-OCT) characteristics of pachydrusen in eyes with central serous chorioretinopathy (CSCR) and their fellow eyes.Methods:A total of 264 eyes of 132 patients with a diagnosis of CSCR (acute/persistent/recurrent/chronic/inactive) in atleast one eye, were analyzed in this retrospective, cross-sectional study. SS-OCT parameters including choroidal thickness (CT), large choroidal vessel layer thickness (LCVT) at fovea and the site of pachydrusen were recorded. Paired t test and analysis of variance (ANOVA) was used to compare CT in eyes with CSCR (subfoveal and site of pachydrusen) and multiple groups respectively.Results:The mean age of the study patients was 42.9 ± 9.5 years with 119 males (90.15%). Bilateral CSCR was present in 31 patients. Nine eyes (chronic, 4; persistent, 2; and inactive/resolved CSCR, 3) showed presence of pachydrusen with an overall prevalence of 6.82% (9 eyes of 9 patients out of 132 patients). There was no significant difference of subfoveal CT (SFCT) in eyes with CSCR (422.4 ± 107.8 μ) vs fellow eyes (407.0 ± 96.5 μ) and eyes with CSCR associated with pachydrusen (413.7 ± 101.5 μ) vs fellow eyes of CSCR eyes with pachydrusen (431.6 ± 188.8 μ) (P = 0.71). LCVT as a percentage of CT was higher at the site of pachydrusen compared to SFCT (69.8% vs. 50.8%).Conclusion:CSCR can be associated with pachydrusen with a lower prevalence rate than previously reported. Whether the thickened large choroidal vessels at site of pachydrusen play any role in formation in pachydrusen needs further evaluation.

Identifying central serous chorioretinopathy biomarkers in coexisting diabetic retinopathy: a multimodal imaging study

BackgroundTo describe clinical and imaging characteristics of patients presenting with diabetic retinopathy (DR) with coexisting acute or chronic central serous chorioretinopathy (CSCR).MethodsThis was a cross-sectional study which included 54 eyes...

Evaluation of Choroidal Layer Thickness in Central Serous Chorioretinopathy.

Purpose:To evaluate medium and large choroidal vessel layer thickness (MCVT and LCVT, respectively) in eyes with acute and chronic central serous chorioretinopathy (CSC) in comparison with age-matched controls.Methods:The study included 96 eyes of 96 patients with CSC, including 53 eyes with acute CSC, 43 eyes with chronic CSC, and 30 eyes of 30 age-matched normal subjects. Manual measurements of subfoveal choroidal thickness (SFCT), MCVT, and LCVT at subfoveal and 750 μm nasal and temporal to the fovea locations were made on enhanced depth imaging optical coherence tomography (EDI-OCT) of the macula in all subjects using ImageJ software (National Institutes of Health, Bethesda, MD, USA).Results:SFCT in acute CSC was significantly larger than that in healthy eyes (P = 0.0001). SFCT in acute CSC did not differ significantly from that in chronic CSC eyes. Subfoveal LCVT and MCVT in acute CSC eyes were greater than those in healthy eyes (P = 0.02 and P = 0.03, respectively). Mean SFCT and MCVT in chronic CSC eyes were significantly larger than those in control eyes (P = 0.01 and P = 0.04, respectively). No significant difference in LCVT was observed between chronic and control eyes.Conclusion:Choroidal vasculature is altered in both acute and chronic CSC. SFCT, MCVT, and LCVT are higher in eyes with acute CSC. The thickening of medium choroidal vessels is still detectable in chronic CSC compared to control eyes.

Pachydrusen in polypoidal choroidal vasculopathy in an Indian cohort.

Purpose:To report the prevalence of pachydrusen and their relationship with subfoveal choroidal thickness (SFCT) and large choroidal vessel layer thickness (SF-LCVT) in eyes with polypoidal choroidal vasculopathy (PCV) and their fellow eyes.Methods:The case records of 50 patients (99 eyes; 59 PCV and 40 fellow eyes) were retrospectively analyzed for the presence of pachydrusen and other drusen types such as soft drusen. The diagnosis was established using colour fundus photography and optical coherence tomography (OCT). SFCT and SF-LCVT were measured and correlated with the different types of drusen.Results:The mean age of the study cohort was 62.26 ± 10.67 years and included 27 males and 23 females. Pachydrusen and soft drusen were seen in 14 (PCV: 8 and fellow eyes: 6) and 8 eyes (PCV: 2 and fellow eyes: 6) respectively. The mean SFCT and SF-LCVT in the eyes with and without pachydrusen was not significanty different (280.29 ± 103.11 μ vs. 292.63 ± 87.17 μ; P = 0.63 and 180.57 ± 59.20 vs. 173.73 ± 54.86 μ; P = 0.67, respectively). The pachydrusen were most commonly located near the vascular arcades and showed scattered distribution pattern. Though SFCT and SF-LCVT was lower in the eyes with soft drusen compared to eyes with pachydrusen, it failed to reach statistical significance (SFCT, P = 0.1 and SF-LCVT, P = 0.06).Conclusion:The prevalence of pachydrusen in PCV and their fellow eyes is lower in Indian population suggestive of ethnic variations. SFCT and SF-LCVT was not noted to vary signifcantly in eyes with and without pachydrusen in this study cohort.

Differences in Choroidal Structures Between Idiopathic and Steroid-Induced Central Serous Chorioretinopathy

Purpose: The purpose of this article is to investigate the differences in intrachoroidal structures between eyes with idiopathic central serous chorioretinopathy (CSC) and those with steroid-induced CSC. Methods: Thirty eyes of 30 patients with idiopathic CSC and 17 eyes of 15 patients with steroid-induced CSC were studied. Cross-sectional swept-source optical coherence tomography images of eyes with idiopathic and steroid-induced CSC were retrospectively analyzed by the manual layer delineation technique and by the binarization technique. Results: The mean subfoveal choroidal thickness (SCT) was not significantly different between the eyes with idiopathic CSC (408.0 ± 106.6 µm) and those with steroid-induced (389.9 ± 105.4 µm; P = .67) CSC. Manual layer delineation showed that the mean ratio of the large choroidal vessel layer thickness to the SCT was significantly higher in eyes with idiopathic CSC (0.874 ± 0.070) than in eyes with steroid-induced CSC (0.828 ± 0.083; P = .02). The binarization method showed that the mean ratio of the luminal areas to the choroidal areas centered at the fovea was significantly higher in eyes with idiopathic CSC (0.747 ± 0.064) than in eyes with steroid-induced CSC (0.701 ± 0.046; P = .01). Conclusion: The intrachoroidal structures in steroid-induced CSC were different from those in idiopathic CSC. These findings suggest different pathophysiologic mechanisms may be involved in the pathogenesis of these 2 entities.

Choroidal Haller's and Sattler's Layers Thickness in Normal Indian Eyes.

AIM:This study aims to study normative choroidal thickness (CT) and Haller's and Sattler's layers thickness in normal Indian eyes.MATERIALS AND METHODS:The choroidal imaging of 73 eyes of 43 healthy Indian individuals was done using enhanced depth imaging feature of spectralis optical coherence tomography. Rraster scan protocol centered at fovea was used for imaging separately by two observers. CT was defined as the length of the perpendicular line drown from the outer border of hypereflective RPE-Bruch's complex to inner margin of choroidoscleral junction. Choroidal vessel layer thickness was measured after defining a largest choroidal vessel lumen within 750 μ on either side of the subfoveal CT vector. A perpendicular line was drawn to the innermost border of this lumen, and the distance between the perpendicular line and innermost border of choroidoscleral junction gave large choroidal vessel layer thickness (LCVLT, Haller's layer). Medium choroidal vessel layer thickness (MCVLT, Sattler's layer) was measured as the distance between same perpendicular line and outer border of hypereflective RPE-Bruch's complex.RESULTS:The mean age of individuals was 28.23 ± 15.29 years (range 14–59 years). Overall, the mean subfoveal CT was 331.6 ± 63.9 μ. Mean LCVLT was 227.08 ± 51.24 μ and the mean MCVLT was 95.65 ± 23.62 μ. CT was maximum subfoveally with gradual reduction in the thickness as the distance from the fovea increased.CONCLUSION:This is the first study describing the choroidal sublayer thickness, i.e., Haller's and Sattler's layer thickness along with CT in healthy Indian population.

The Effect of Change in Intraocular Pressure on Choroidal Structure in Glaucomatous Eyes.

PurposeChoroidal thickness increases linearly with intraocular pressure (IOP) lowering. We studied the relationship between the change in size of the choroidal vasculature and IOP lowering after glaucoma procedures.MethodsThirty eyes of twenty-nine patients were examined pre- and postoperatively for up to 6 months with standard clinical assessment, enhanced depth imaging spectral-domain optical coherence tomography (OCT), and axial length measurement. Each enhanced depth imaging spectral-domain OCT image was analyzed using three separate methods to determine the choroidal thickness, choroidal vessel thickness, choroidal interstitial thickness, large choroidal vessel layer thickness, medium choroidal vessel layer thickness, and light-dark ratio. Bivariate linear regression analysis was completed with largest change in IOP as the independent variable. The dependent variables included choroidal thickness, choroidal vessel thickness, and choroidal interstitial thickness, at the largest change in IOP. Multivariable regression analysis using a generalized estimating equation to account for multiple measurements per eye was also completed.ResultsMean choroidal vessel thickness increases 1.5 μm for every 1 mm Hg decrease in IOP (P < 0.0001; 95% confidence interval [CI], 0.8, 2.1) and choroidal interstitial thickness increases 1.3 μm for every 1 mm Hg change in IOP (P < 0.0001; 95% CI, 0.8, 1.8). There was no significant association between change in IOP and change in large choroidal vessel layer temporally (P = 0.13), nasally (P = 0.20), or subfoveally (P = 0.18). There was also no association between IOP and the light-dark ratio (P = 0.16).ConclusionsThe increase in choroidal thickness at lower IOP is associated with approximately equal increases in its intravascular and extravascular compartments.

Choroidal Morphology and Vascular Analysis in Eyes With Neovascular Age-Related Macular Degeneration Using Spectral-Domain Optical Coherence Tomography.

To describe morphology and vascular layer thickness of the choroid in eyes with neovascular age-related macular degeneration (AMD) using spectral-domain optical coherence tomography (SD-OCT). Cross-sectional, retrospective analysis of 15 eyes with neovascular AMD and 11 healthy age-matched eyes that underwent single horizontal, high-definition raster line imaging using high-definition SD-OCT. Two independent graders assessed choroid morphology and measured the thickness of individual vascular layers of the choroid beneath the fovea. Normal concave choroidal contour was found in 13.3% of eyes with neovascular AMD and 100% of healthy eyes. The thickest point of the choroid was located beneath the foveal center in 20% of eyes and focal thinning was observed in 40% of eyes with neovascular AMD, compared to 91% and 0% of healthy eyes, respectively. Subfoveal total choroidal thickness, large choroidal vessel layer thickness, and the medium choroidal vessel/choriocapillaris layer thickness were reduced in eyes with neovascular AMD compared to healthy eyes (205.7 µm ± 17.08 µm versus 281.3 µm ± 19.29 µm, P = .007; 174.1 µm ± 16.34 µm versus 244.5 µm ± 19.51 µm, P = .01; and 31.53 µm ± 3.67 µm verus 51.9 µm ± 1.94 µm, P = .0002, respectively). Choroidal morphology is altered in eyes with neovascular AMD as assessed on SDOCT. Choroidal thinning in neovascular AMD involves all its vascular layers. These morphological and vascular changes may have clinical implications in the diagnosis and monitoring of eyes with neovascular AMD. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:618-625.].

Morphology and Vascular Layers of the Choroid in Stargardt Disease Analyzed Using Spectral-Domain Optical Coherence Tomography

To analyze total thickness, morphology and individual vascular layers of the choroid in eyes with Stargardt disease using spectral-domain optical coherence tomography (SD OCT). Cross-sectional retrospective review. Twenty-eight patients with Stargardt disease (53 eyes) with a mean age of 46 (15-79) years and 30 healthy subjects (30 eyes) with a mean age of 49 (22-79) years who underwent 1-line raster scanning with SD OCT were identified. Diagnosis of Stargardt disease was based on ophthalmic history and complete ophthalmic evaluation. The healthy subjects had best-corrected visual acuity of 20/20 or better with no chorioretinal pathology. Two independent raters assessed the total thickness, morphology, and the individual vascular layers of the choroid. The choroid was irregularly shaped in 26 of 41 eyes (64%) with Stargardt disease when compared to 0 of 30 healthy eyes (0%). Mean subfoveal total choroidal thickness and mean subfoveal large choroidal vessel layer thickness were significantly reduced in eyes with Stargardt disease when compared to healthy eyes (272.8 ± 32.8μm vs 225.4 ± 69.9μm; P= .03 and 219.5 ± 30.6 vs169.2 ± 70.1; P= .04, respectively). The maximal choroidal thickness was subfoveal in 9 of 41 eyes (22%), focal choroidal thinning was observed in 21 of 41 eyes (51%), and attenuation of large choroidal vessel layer was observed in 8 of 41 eyes (20%) with Stargardt disease. There was no association of the best-corrected visual acuity with any choroidal morphologic feature, except that it was better by a mean of 0.61 ± 0.21 in eyes that had preservation of large choroidal vessel layer (33 of 41, 80%) when compared to those that had attenuation of large choroidal vessel layer (P= .007). This study shows alterations in the total thickness, morphology, and the individual vascular layers of the choroid in eyes with Stargardt disease on SD OCT. These findings may potentially contribute to the clinical staging and monitoring of Stargardt disease.

An Optical Coherence Tomography-Based Analysis of Choroidal Morphologic Features and Choroidal Vascular Diameter in Children and Adults

To analyze choroidal sub-layers and vascular diameter in children, and to compare these choroidal features with those of adults. Retrospective observational study. This study included 96 eyes from 48 healthy children and 54 eyes from 27 healthy adults. The subfoveal choroidal thickness, large choroidal vessel layer thickness, medium choroidal vessel layer-choriocapillaris layer thickness, and large choroidal vessel diameter were estimated. The ratio of thickness of the large choroidal vessel layer to total choroidal thickness was calculated. The association between subfoveal choroidal thickness and large choroidal vessel layer, as well as ratio of thickness of the large choroidal vessel layer to total choroidal thickness, was analyzed. Furthermore, the ratio and choroidal vascular diameter were compared between children and adults. The mean age was 6.7 ± 1.9 years and 30.7 ± 4.3 years in children and in adults, respectively. In children, the mean ratio was 0.71 ± 0.08 and the mean choroidal vascular diameter was 103.1 ± 16.0 μm. In adults, the values were 0.73 ± 0.08 and 122.5 ± 20.7 μm, respectively. The subfoveal choroidal thickness in children was significantly associated with the ratio (P < .001), whereas the association was not significant in adults (P = .173). The choroidal vascular diameter was significantly greater in adults than in children (P < .001). However, the ratio was not different between the 2 groups (P = .391). Choroidal morphologic features are generally comparable between children and adults. Some differences between the 2 groups may reflect changes in choroidal morphology associated with aging.

ANALYSIS OF THE THICKNESS AND VASCULAR LAYERS OF THE CHOROID IN EYES WITH GEOGRAPHIC ATROPHY USING SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY

To analyze the total choroidal thickness and thickness of the individual vascular layers of the choroid in eyes with geographic atrophy (GA), using spectral-domain optical coherence tomography. A cross-sectional retrospective review identified 17 patients with GA (17 eyes) and 14 age-matched healthy subjects (14 eyes), who underwent high-definition raster scanning at New England Eye Center, Boston, MA. Patients were diagnosed with GA based on clinical examination and investigations. Two independent raters evaluated the thickness and vascular layers of the choroid. Mean choroidal thickness was significantly lower in eyes with GA when compared with age-matched healthy eyes (P < 0.0001). Subfoveal choroidal thickness in eyes with GA was significantly less when compared with healthy eyes (158.1 ± 23.65 μm versus 267.5 ± 19.27 μm, P = 0.001). Subfoveal large choroidal vessel layer thickness and medium choroidal vessel layer/choriocapillaris layer thickness were significantly reduced in eyes with GA when compared with healthy eyes (P = 0.001 and P < 0.0001, respectively). The choroid is significantly thinner in eyes with GA involving the fovea when compared with healthy eyes. Choroidal thinning in GA involves all its vascular layers. Further studies involving prospective correlation of choroidal vascular changes to the quantitative progression of GA is expected to provide further insight on the choroidal angiopathy associated with GA.

Analysis of Choroidal Morphologic Features and Vasculature in Healthy Eyes Using Spectral-Domain Optical Coherence Tomography

To analyze the morphologic features and vasculature of the choroid in healthy eyes using spectral-domain (SD) optical coherence tomography (OCT). Cross-sectional retrospective review. Forty-two healthy subjects (42 eyes) with no ocular disease who underwent high-definition scanning with Cirrus high-definition OCT (Carl Zeiss Meditec, Inc., Dublin, CA) at the New England Eye Center, Boston, Massachusetts, between November 2009 and September 2010. The SD OCT images were evaluated for morphologic features of the choroid, including the shape of the choroid-scleral border, location of the thickest point of choroid, and regions of focal choroidal thinning. Total choroidal thickness and large choroidal vessel layer thickness were measured by 2 independent observers experienced in analyzing OCT images using the Cirrus linear measurement tool at the fovea, 750 μm nasal and temporal to the fovea. Custom software was used to calculate the ratio of choroidal stroma to the choroidal vessel lumen. Qualitative assessment of the choroidal morphologic features, quantitative analysis of choroidal vasculature, and use of novel automated software to determine the ratio of choroidal stromal area to the area of choroidal vessel lumen. The 42 subjects had a mean age of 51.6 years. All subjects (100%) had a so-called bowl or convex shape to the choroid-sclera junction, and the thickest point of the choroid was under the fovea in 88.0% of the subjects. The mean choroidal thickness was 256.8 ± 75.8 μm, mean thickness of the large choroidal vessel layer was 204.3 ± 65.9 μm, and that of the medium choroidal vessel layer-choriocapillaris layer was 52.9 ± 20.6 μm beneath the fovea. The ratio of large choroidal vessel layer thickness to the total choroidal thickness beneath the fovea was 0.7 ± 0.06. The software-generated ratio of choroidal stromal area to the choroidal vessel lumen area was 0.27 ± 0.08, suggesting that choroidal vessel lumen forms a greater proportion of the choroid than the choroidal stroma in healthy eyes. This is the first study to describe the morphologic features and vasculature of the choroid in healthy eyes from 1-line raster scans obtained using SD OCT. The method described holds promise and has immediate clinical usefulness in recognizing subtle changes in choroidal morphologic features and the role of choroidal angiopathy in various disease states that, in the future, may inform new treatment methods. Proprietary or commercial disclosure may be found after the references.

Analysis of the Morphology and Vascular Layers of the Choroid in Retinitis Pigmentosa Using Spectral-Domain OCT

To analyze choroidal morphology and vascular layers in eyes with retinitis pigmentosa (RP) using spectral-domain optical coherence tomography. Cross-sectional, retrospective analysis of 14 patients (14 eyes) with RP and 33 healthy subjects (33 eyes) who underwent high-definition one-line raster scanning at a single center. Two independent raters evaluated the morphology, thickness, and vascular layers of the choroid in both groups. The choroid had an irregular shape in 11 of 14 eyes (79%) with RP. The thickest point of choroid was not subfoveal as in healthy eyes, and exaggerated nasal thinning of the choroid was observed in nine of 14 eyes (65%) with RP. Mean subfoveal total choroidal thickness and large choroidal vessel layer thickness were significantly lower in eyes with RP (P = .04 and P = .02, respectively) than in healthy eyes. Choroidal morphology is altered and an exaggerated thinning of the large choroidal vessel layer is observed in eyes with RP. Further studies involving correlation of disease stage and severity with choroidal changes may provide further insight into the involvement of choroid in RP and other inherited retinal dystrophies.