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Purpose: To investigate the changes in choroidal thickness (ChT), refractive status, and ocular dimensions in the mouse eye in vivo using updated techniques and instrumentation., Methods: High-resolution swept-source optical coherence tomography (SS-OCT), eccentric infrared photoretinoscopy, and custom real-time optical coherence tomography were used to analyze choroidal changes, refractive changes and ocular growth in C57BL/6J mice from postnatal day (P) 21 to month 22., Results: The ChT gradually increased with age, with the thickest region in the para-optic nerve head and thinning outward, and the temporal ChT was globally thicker than the nasal ChT. Retinal thickness remained stable until 4 months and subsequently decreased. The average spherical equivalent refraction error was -4.81 ± 2.71 diopters (D) at P21, which developed into emmetropia by P32, reached a hyperopic peak (+5.75 ± 1.38 D) at P82 and returned to +0.66 ± 1.86 D at 22 months. Central corneal thickness, anterior chamber depth, lens thickness, and axial length (AL) increased continuously before 4 months, but subsequently exhibited subtle changes. Vitreous chamber depth decreased with lens growth. ChT was correlated significantly with the ocular parameters (except for retinal thickness) before the age of 4 months, but these correlations diminished after 4 months. Furthermore, for mice younger than 4 months, the difference in the ChT, especially temporal ChT, between the two eyes contributed most to that of axial length and spherical equivalent refraction error., Conclusions: Four months could be a watershed age in the growth of mouse eyes. Large-span temporal recordings of refraction, ocular dimensions, and choroidal changes provided references for the study of the physiological and pathological mechanisms responsible for myopia.

Purpose: To describe choroidal thickness measurements using a sequential deep learning segmentation in adults who received childhood atropine treatment for myopia control., Design: Prospective, observational study., Methods: Choroidal thickness was measured by swept-source optical coherence tomography in adults who received childhood atropine, segmented using a sequential deep learning approach., Results: Of 422 eyes, 94 (22.3 %) had no previous exposure to atropine treatment, while 328 (77.7 %) had received topical atropine during childhood. After adjusting for age, sex, and axial length, childhood atropine exposure was associated with a thicker choroid by 32.1 μm (95 % CI, 9.2-55.0; P = 0.006) in the inner inferior, 23.5 μm (95 % CI, 1.9-45.1; P = 0.03) in the outer inferior, 21.8 μm (95 % CI, 0.76-42.9; P = 0.04) in the inner nasal, and 21.8 μm (95 % CI, 2.6-41.0; P = 0.03) in the outer nasal. Multivariable analysis, adjusted for age, sex, atropine use, and axial length, showed an independent association between central subfield choroidal thickness and the incidence of tessellated fundus (P < 0.001; OR, 0.97; 95 % CI, 0.96-0.98)., Conclusions: This study demonstrated that short-term (2-4 years) atropine treatment during childhood was associated with an increase in choroidal thickness of 20-40 μm in adulthood (10-20 years later), after adjusting for age, sex, and axial length. We also observed an independent association between eyes with thicker central choroidal measurements and reduced incidence of tessellated fundus. Our study suggests that childhood exposure to atropine treatment may affect choroidal thickness in adulthood., Competing Interests: Declaration of Competing Interest Dr Jost B. Jonas has disclosed European patent EP 3 271 392, JP 2021–119187, and US 2021 0340237 A1: Agents for use in the therapeutic or prophylactic treatment of myopia or hyperopia. Dr Audrey Chia has disclosed royalties from Myopine. Dr Leopold Schmetterer has disclosed consultancy fee from Thea Pharma., (Copyright © 2024. Published by Elsevier Inc.)

Aim: The study aims to compare choroidal thickness, deep and superficial retinal capillary plexuses, and foveal avascular zone (FAZ) parameters in elite martial arts athletes and a healthy sedentary control group., Methods: The study included martial arts athletes (32 individuals, 64 eyes) and healthy sedentary persons (43 individuals with healthy sedentary lifestyles, 86 eyes) aged 18-35 years. In this single non-repeated observational and cross-sectional study, choroidal thickness, superficial and deep retinal capillary plexuses, and FAZ measurements were measured using Swept-source optical coherence tomography angiography (SS-OCTA) and compared between groups., Results: No statistically significant differences were found (p > 0.05) in age, IOP, AL (axial length), and best-corrected visual acuity (BCVA) parameters between groups. There were no statistically significant differences between the groups in choroidal thickness, superficial and deep retinal capillary plexuses, and FAZ parameters determined by the OCTA method (p > 0.05)., Conclusion: In our study, we observed that the retinal and choroidal structures of martial art athletes and healthy sedentary individuals were similar. This observation implies that the putative microvascular effects on the choroid and retina in martial arts, especially those based on the anaerobic energy system, may reflect similar outcomes to those observed in individuals with sedentary lifestyles characterized by healthiness., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest and are fully responsible for the content and writing of this article., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Purpose: This study aims to introduce the coefficient of spatial variance of choroidal thickness to describe the choroidal variation and investigate its associated factors in healthy eyes., Methods: This retrospective cross-sectional study included 1031 eyes from 1031 subjects who received a swept-source optical coherence tomography examination. The mean choroidal thickness in the macular 6 × 6 mm region and 900 subregions of 0.2 × 0.2 mm were computed using the embedded algorithm. Before analysis, potential segmentation and magnification errors were corrected. The coefficient of spatial variance was defined as the standard deviation divided by the mean (multiplied by 100%) of the choroidal thicknesses across 900 grids. Potential factors associated with the coefficient of spatial variance were assessed using multiple linear regression., Results: The mean choroidal thickness of the entire 6 × 6 mm macular region was 204.50 ± 72.88 μm. The mean coefficient of spatial variance was 26.58 ± 8.24%, ranging from 11.00 to 61.58%. Statistical analysis revealed that the means choroidal thickness (β = - 0.08, R 2  = 0.42, p < 0.001) and anterior chamber depth (β = - 2.39, R 2  = 0.05, p = 0.06) were associated with the coefficient of spatial variance., Conclusion: Our study first incorporated the coefficient of spatial variance to represent the spatial variation of the choroidal thickness and observed that the greater thinning of the choroid is correlated with a more pronounced spatial variation., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

This study aimed to compare the dominant and non-dominant eyes of healthy individuals in terms of CT and CVI values to assess the effect of ocular dominance on choroidal morphology. Three hundred eyes of 150 individuals were included in this study. All patients underwent routine ophthalmological examinations and hole-in-the-card tests to determine the dominant eye. EDI-OCT was used to obtain choroidal images. Choroidal thickness (CT) was measured at three points on the choroid including the subfoveal region (subfoveal choroidal thickness (SFCT)), 1500 μm nasal (NCT) and temporal (TCT) to the fovea. Choroidal vascularity index (CVI), total choroidal area (TCA), luminal area (LA), and stromal area (SA) were measured at fovea-centered choroidal area by image binarization via Image J software. While 93(%62) participants were right-eyed, 57(%38) participants were left-eyed. We could not detect any difference in SFCT, NCT, TCT, TCA, LA, SA, and CVI measurements between the dominant and the non-dominant eyes. ( p  > 0.05 for all). We could not detect any effect of ocular dominance on choroidal structures. These results also support the use of randomized ocular data regardless of which eye is dominant when investigating CVI and CT in scientific research.

In this manuscript, the structure of the human choroid is reviewed with emphasis of the macro- and microscopic anatomy including Bruch's membrane, choriocapillaris, Sattler's and Haller's layer, and the suprachoroid. We here discuss the development of the choroid, as well as the question of choroidal lymphatics, and further the neuronal control of this tissue, as well as the pathologic angiogenesis. Wherever possible, functional aspects of the various structures are included and reviewed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Purpose: The purpose of this study was to evaluate the diurnal variation in choroidal parameters in a wide field area among healthy subjects and to identify correlations between choroidal luminal area and stromal area and various systemic factors., Methods: In this cross-sectional study, 42 eyes from 21 healthy participants (mean age = 32.4 ± 8.8 years) were examined using wide-field swept-source optical coherence tomography angiography (WF SS-OCTA, 24 mm × 20 mm). Measurements of choroidal parameters, including choroidal volume (CV), choroidal thickness (CT), choroidal vessel volume (CVV), and choroidal stromal volume (CSV), were taken at 8:00, 12:00, 18:00, and 22:00. Systemic factors, such as blood pressure and heart rate, were concurrently monitored., Results: Our study observed significant diurnal variations in the mean total CV, CT, CVV, and CSV, with minimum measurements around 12:00 (P < 0.001) and peak values at 22:00 (P < 0.001). Furthermore, changes in CV in specific regions were more closely associated with fluctuations in CVV than CSV in the same regions. No significant diurnal variations were found in systolic (P = 0.137) or diastolic blood pressure (P = 0.236), whereas significant variations were observed in the heart rate (P = 0.001)., Conclusions: Our study reveals diurnal variations in choroidal parameters and their associations, emphasizing that changes in choroidal volume relate more to the luminal than the stromal area in vessel-rich regions. This enhances our understanding of choroidal-related ocular diseases., Translational Relevance: Regions with higher choroidal vasculature observed greater choroidal volume changes.

Purpose: To determine whether light chromaticity without defocus induced by longitudinal chromatic aberration (LCA) is sufficient to regulate eye growth., Methods: An interferometric setup based on a spatial light modulator was used to illuminate the dominant eyes of 23 participants for 30 minutes with three aberration-free stimulation conditions: (1) short wavelength (450 nm), (2) long wavelength (638 nm), and (3) broadband light (450-700 nm), covering a retinal area of 12°. The non-dominant eye was occluded and remained as the control eye. Axial length and choroidal thickness were measured before and after the illumination period., Results: Axial length increased significantly from baseline for short-wavelength (P < 0.01, 7.4 ± 2.2 µm) and long-wavelength (P = 0.01, 4.8 ± 1.7 µm) light. The broadband condition also showed an increase in axial length with no significance (P = 0.08, 5.1 ± 3.5 µm). The choroidal thickness significantly decreased in the case of long-wavelength light (P < 0.01, -5.7 ± 2.2 µm), but there was no significant change after short-wavelength and broadband illumination. The axial length and choroidal thickness did not differ significantly between the test and control eyes or between the illumination conditions (all P > 0.05). Also, the illuminated versus non-illuminated choroidal zone did not show a significant difference (all P > 0.05)., Conclusions: All stimulation conditions with short- and long-wavelength light and broadband light led to axial elongation and choroidal thinning. Therefore, light chromaticity without defocus induced by LCA is suggested to be insufficient to regulate eye growth., Translational Relevance: This study helps in understanding if light chromaticity alone is a sufficient regulator of eye growth.

This research investigates the distribution, progressive changes, and contributing factors of macular choroidal and retinal thickness in Tibetan children utilizing swept-source optical coherence tomography (SS-OCT). The Lhasa childhood study recruited 1632 students from seven primary schools in Lhasa. These participants underwent OCT and ophthalmological evaluations, encompassing retinal and choroidal thickness measurements, refractive error, axial length (AL), and systemic examinations. The median age of the scholars was 8.57 ± 0.50 years with a median spherical equivalent (SE) of 0.19 ± 1.28D. Multivariate regression analysis revealed that thinner macular choroid thickness was correlated with lower value of SE, worse best-corrected visual acuity, higher mean arterial blood pressure (MABP) and boys, while retinal thickness was associated with better image quality and lower value of SE. The choroid and retina were significantly thinner in myopic children. SE was positively related to the thickness of all choroidal and full retinal subregions. In comparison to baseline data from 20 months prior, most regions of the full retina had significantly thinned. Choroidal thickness of Tibetan children is thinner than that of same-age children from other regions. Thinning of retina, the outer-sector GCC and GCIPL may be specified as a follow-up and prognostic indicator for myopia., (© 2024. The Author(s).)

Aim: This research was conducted to determine the normal values of choroidal thickness in healthy individuals and to evaluate the relationship between this thickness and age, gender, refraction, axial length and average macular thickness using OCT., Material and Method: In the study, the right eyes of 400 healthy individuals (234 women, 166 men) between the ages of 4 and 70 years, who applied to the Department of Ophthalmology outpatient clinic for examination, were evaluated., Results: Macular thickness, macular volume, and foveal thickness were found to be 249.12 ±21.32 µm, 9.98 ±0.5 µm3 and 280 ±13.45 µm, respectively. According to linear regression analysis, a negative correlation was detected between age and subfoveal choroidal thickness (p &lt; 0.05). It was determined that foveal thickness, retinal volume and average retinal thickness were higher in men, and foveal thickness increased with age (p &lt; 0.05)., Conclusion: As a result of the research, it was determined that age is an important factor affecting choroidal thickness. It is thought that, in future, improving in vivo imaging of the choroid and measuring choroidal thickness using OCT will facilitate understanding of the pathophysiological basis of many ophthalmological diseases.

Background and Objective: The Suprachoroidal Space (SCS) is a theoretical structure which can be demonstrated between the inner border of the sclera and the outer boundary of the choroid. SCS is being studied for its potential uses as a route for drug delivery and innovative surgical techniques for the treatment of many retinal diseases. Retinitis pigmentosa (RP) is a group of inherited eye disorders characterized by a gradual loss of photoreceptors, resulting in vision impairment, which typically presents as night blindness and progressive visual field loss. The purpose of the study is to define the morphology of outer choroidal margins by means of SS-OCT in RP., Material and Method: This is a retrospective observational study designed to evaluate the presence of SCS in RP. We performed Swept Source optical coherence tomography (SS-OCT) in a group of 55 patients affected by RP (26 males and 29 females, 110 eyes) with a mean age of 51.8 ± 13.7 years. In the control group, we included 28 healthy subjects (6 males and 22 females, 56 eyes) with a mean age of 48,8 ± 16,6 years., Results: OCT scans allowed the outer choroidal margin and inner scleral margin to be delineated with certainty in all 110 eyes. In the RP group SCS was detected in 47 of 110 eyes (42,7%), in the control group SCS was detected in 11 eyes (19,6%). Subjects with SCS visible (RP group) had reduced retinal thickness (168.4 µm) compared to those with not visible SCL (211.2 µm, P = .007)., Conclusions: SS-OCT can be successfully applied to assess the presence of SCS in RP and the high rate of SCS found in the RP patients is encouraging when considering future innovative therapies., (Copyright © 2023 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.)

Purpose: To analyze the choroidal thickness between patients with keratoconus undergoing cross-linking treatment and a healthy population, as well as to determine the factors that influence choroidal thickness., Methods: This was an observational, analytical, case-control study that was conducted from February 2021 to June 2021. Choroidal thickness was measured at different locations, including the subfoveal, nasal (1000 μm), temporal (1000 μm), superior (1000 μm) and inferior (1000 μm) locations using a Spectral-domain optical coherence tomography with enhanced depth imaging, which allowed us to obtain horizontal and vertical B-scans centered on the fovea., Results: This study included 21 patients with keratoconus (mean age, 21.86 ± 5.28 years) and 28 healthy patients (mean age, 24.21 ± 4.71 years). Choroidal thickness was significantly greater in patients with keratoconus than in healthy patients in each of the following measured locations: subfoveal (P < 0.001); nasal (1000 μm) (P < 0.001), temporal (1000 μm) (P < 0.001), superior (1000 μm) (P < 0.001) and inferior (1000 μm) (P < 0.001) locations. Variables such as age (ρ = - 0.09; P = 0.50) and refraction (ρ = 0.14; P = 0.34) were not found to be associated with choroidal thickness. In a stepwise multiple linear regression, the group was the single variable correlated with choroidal thickness (β = 0.88; P < 0.001)., Conclusion: Choroidal thickness is thicker in keratoconus patients treated with cross-linking than in the healthy population. This finding could be associated with inflammatory choroidal mechanisms in keratoconus patients, but more studies are needed. Age and refractive error do not seem to influence choroidal thickness., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

(1) Purpose: To evaluate the anatomy and perfusion of choroidal substructures in third-trimester pregnant women using optical coherence tomography (OCT) and OCT angiography (OCTA) imaging. (2) Methods: In this cross-sectional study, women in their third trimester of uncomplicated pregnancy and non-pregnant age-matched women were recruited. Participants underwent enhanced depth imaging (EDI) OCT and OCTA. Subfoveal choroidal thickness (SFCT), as well as choroidal sublayer perfusion, were compared between groups. (3) Results: In total, 26 eyes of 26 pregnant and 26 eyes of 26 non-pregnant women were included. The median age in both groups was 29 years. The median SFCT was 332 (211-469) µm in the pregnant group and 371.5 (224-466) µm in the non-pregnant cohort ( p = 0.018). The median choriocapillaris perfusion (CCP) was significantly lower in the pregnant group (46% vs. 48%, p = 0.039). Moreover, Haller's layer perfusion correlated significantly with mean arterial pressure in non-pregnant women (CC = 0.430, p = 0.028) but not in pregnant ones (CC = 0.054, p = 0.792). (4) Conclusions: SFCT was found to be thinner and CCP was lower in third-trimester pregnant women. Hormonal changes during pregnancy and consecutive impacts on autoregulation of small choroidal vessels might play an important role. Therefore, altered choroidal measurements during third-trimester pregnancy should be carefully evaluated as, to some extent, it could be a normal physiological change.

Purpose: To assess choroidal changes using enhanced depth imaging optical coherence tomography in coronavirus disease (COVID-19)., Methods: Thirty-two patients with moderate COVID-19 and 34 healthy subjects were included in the study. Choroidal thickness was measured at 3 points as follows: at the subfovea, 1500 mm nasal to the fovea, and 1500 mm temporal to the fovea. The total choroidal area, luminal area, stromal area, and choroidal vascular index were measured with Image-J. All the measurements were performed during the disease and at 4 months after remission., Results: In the patient group, the subfoveal, nasal, and temporal choroidal thicknesses were decreased as compared with those in the controls, but without statistically significant differences (p=0.534, p=0.437, and p=0.077, respectively). The mean total choroidal, stromal, and luminal areas and choroidal vascular index were statistically significantly decreased in the patient group (p&lt;0.001, p=0.001, p=0.001, and p=0.003; respectively). At 4 months after remission, the choroidal structural parameters and choroidal vascular index revealed statistically significant increases as compared with the baseline measurements in the patients with COVID-19 (all p&lt;0.001 and p=0.047, respectively)., Conclusion: The choroidal vascular and stromal parameters showed significant transient decreases during the disease course of COVID-19.

Purpose: The purpose of this study was to explore the age-related change in choroidal thickness (ChT) and test the hypothesis that baseline ChT is predictive of refractive error change in healthy young adults., Methods: Participants underwent spectral-domain optical coherence tomography (SD-OCT) imaging and autorefraction at 20 (baseline) and 28 years old. The enhanced depth imaging mode on the SD-OCT was used to obtain images of the choroid. Scans were exported from the SD-OCT and analyzed with a custom software that automatically measures the central ChT. The longitudinal change in subfoveal ChT and association between baseline subfoveal ChT and 8-year change in refractive error (spherical equivalent) were determined using linear mixed models., Results: In total, 395 eyes of 198 participants (44% men; 18-22 years at baseline) were included. Over 8 years, mean spherical equivalent decreased by 0.25 diopters (D) and axial length increased by 0.09 mm. Subfoveal choroid thickened by 1.3 µm/year (95% confidence interval [CI] = 0.6-2.0), but this was reduced by 0.9 µm/year (95% CI = 1.6-0.2) for every 1 mm increase in axial length. For every 10 µm increase in baseline ChT, average annual change in spherical equivalent and axial length reduced by 0.006 D/year and 0.003 mm/year, respectively., Conclusions: In a community-based cohort of young adults, the choroid continued to change during early adulthood. Choroidal thickening was less in eyes that were longer at baseline, and the choroid thinned in eyes that showed myopia progression. The association between baseline ChT and longitudinal changes in spherical equivalent and axial length supports the hypothesis that ChT may be predictive of refractive error development and/or myopia progression.

Although accumulating evidence suggests a higher prevalence of posterior vitreous detachment (PVD) in highly myopic eyes, the relation between ocular biometric features and PVD stages in such eyes remains unclear. Therefore, we enrolled 170 patients with high myopia (axial length ≥ 26.0 mm) to investigate the status of PVD regarding subfoveal choroidal thickness and axial length. Utilising swept-source optical coherence tomography, we classified the PVD status into five stages. The distribution of PVD grades increased as the choroidal thickness decreased and axial length increased (P < 0.01). On adjusting for age and sex, decreased choroidal thickness and increased axial length were associated with more advanced PVD stages: odds ratios with the highest vs. lowest groups were 0.31 (95% confidence interval [CI] 0.09-1.01; P trend  = 0.009) for choroidal thickness and 5.16 (95% CI 1.34-19.80; P trend  = 0.002) for axial length. The inverse association between choroidal thickness and PVD status seemed stronger in women than in men (P interaction  = 0.05). In conclusion, we firstly observed a significant trend of decreased choroidal thickness, along with increased axial length, with increased grade of PVD, particularly among women with highly myopic eyes, suggesting that advanced morphological myopic changes contribute to PVD in middle-aged adults., (© 2022. The Author(s).)

Background: Obesity is one of the major public health problems globally, especially among women. Obesity is associated with glaucoma, cataract, age-related macular degeneration and diabetic retinopathy. Although it is clear that the anatomy and physiologic functions of the choroid may be affected by obesity, data investigating the effect of obesity on the choroid is limited and/or unavailable for the Saudi population., Objective: To assess Choroidal Thickness (CT) changes in a sample of healthy Saudi Arabian women with different Body Mass Index (BMI) using Spectral-domain Ocular Coherence Tomography (SD-OCT)., Methods: A total of 140 healthy women aged 18-29 years (mean age ± standard deviation SD, 24.5 ± 1.7 years) with different BMI, axial length (AL) ≤ 24 ± 1.0 mm, and spherical equivalent refraction (SER) of ≤ ±2.0 dioptres were enrolled for the study. The participants were age and refractionmatched, and grouped into underweight (BMI ≤ 18.0 kg/m2) (n = 30), normal (control group) (18.5-24.9 kg/m2) (n = 43), overweight (25.0-29.9 kg/m2) (n=37), and obese study groups (≥ 30.0 kg/m2) (n = 30). SD-OCT imaging was performed on one eye of each participant. Comparisons among groups for all locations and the associations between CT and other variables were examined., Results: The mean CT at the subfoveal region (285 ± 31 μm, range: 203 μm to 399 μm) was significantly greater, and it was the lowest in the nasal region (248 ± 26 μm, range 154 to 304) compared with other locations, across all the groups (p < 0.05). Compared with the control, the subfoveal choroid was thinner in the obese group (mean difference: 22.6 μm, 95% Confidence Interval; CI: 8.6 μm to 36.6 μm; p = 0.02) and across all locations (p < 0.05) but thicker at the temporal location in the underweight group (12.4 μm, 95% CI: -23.7 μm to -1.04 μm; p = 0.01). No significant association of subfoveal CT with any of the measured parameters, including age (p-values ranged from 0.10 to 0.90), was found., Conclusion: BMI may have an influence on the CT of healthy individuals and could be a cofounder in research studies on CT. It is, therefore, recommended that BMI should be evaluated in the clinical diagnosis and management of conditions associated with choroid in healthy individuals., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Purpose: To determine the relationship between large-sized and medium-sized choroidal vessels and choriocapillaris using the three-dimensional choroidal vascularity index (3D CVI) and percentage of flow deficits (FD%)., Methods: Prospective observational study. The main outcome measures included choroidal volume parameters (3D CVI, mean choroidal thickness, total choroidal volume, choroidal luminal volume, and choroidal stromal volume), choriocapillaris parameters (FD%, average area of FD, and FD count), and age and axial length., Results: A total of 63 healthy individuals with an average age of 40.60 ± 12.32 years were included in this study. Univariate analysis showed that FD% (R = 0.295, P = 0.019) and area of FD (R = 0.276, P = 0.028) were significantly positively associated with 3D CVI, and FD count was negatively associated with 3D CVI (R = -0.297, P = 0.018). After adjusting for age and axial length, a significant correlation between FD% and 3D CVI (R = 0.264, P = 0.039) and between area of FD and 3D CVI remained (R = 0.267, P = 0.037). However, no significant correlation was found between FD count and 3D CVI after adjusting for axial length (R = -0.220, P = 0.085)., Conclusion: In healthy individuals, choroidal vessel dilatation as suggested by elevated 3D CVI may lead to decreased choriocapillaris perfusion, which was correlated with an enlarged area of FD in choriocapillaris.

The choroid provides nutritional support for the retinal pigment epithelium and photoreceptors. Choroidal dysfunction plays a major role in several of the most important causes of vision loss including age-related macular degeneration, myopic degeneration, and pachychoroid diseases such as central serous chorioretinopathy and polypoidal choroidal vasculopathy. We describe an imaging technique using depth-resolved swept-source optical coherence tomography (SS-OCT) that provides full-thickness three-dimensional (3D) visualization of choroidal anatomy including topographical features of individual vessels. Enrolled subjects with different clinical manifestations within the pachychoroid disease spectrum underwent 15 mm × 9 mm volume scans centered on the fovea. A fully automated method segmented the choroidal vessels using their hyporeflective lumens. Binarized choroidal vessels were rendered in a 3D viewer as a vascular network within a choroidal slab. The network of choroidal vessels was color depth-encoded with a reference to the Bruch's membrane segmentation. Topographical features of the choroidal vasculature were characterized and compared with choroidal imaging obtained with indocyanine green angiography (ICGA) from the same subject. The en face SS-OCT projections of the larger choroid vessels closely resembled to that obtained with ICGA, with the automated SS-OCT approach proving additional depth-encoded 3D information. In 16 eyes with pachychoroid disease, the SS-OCT approach added clinically relevant structural details, including choroidal thickness and vessel depth, which the ICGA studies could not provide. Our technique appears to advance the in vivo visualization of the full-thickness choroid, successfully reveals the topographical features of choroidal vasculature, and shows potential for further quantitative analysis when compared with other choroidal imaging techniques. This improved visualization of choroidal vasculature and its 3D structure should provide an insight into choroid-related disease mechanisms as well as their responses to treatment.

Abstract: Several macular pathologies are associated with choroidal vascular supply and thus require choroidal thickness evaluation. However, there is no standard subfoveal choroidal thickness (SFCT) measurement method. This study investigated a new method of SFCT measurement, using optical coherence tomography.This is a single-center observational study. Eighty-two senior medical students participated as observers and independently measured the SFCT on 5 standard optical coherence tomography images of healthy adults in a tertiary care setting. They used 3 different methods: the observer's own method, the conventional method, perpendicular to the retinal pigment epithelium, and the new method, along a virtual line connecting the umbo with the most elevated point of the ellipsoid. Additionally, the SFCT angle-the angle between the measurement line and the vertical line of the image-was measured and compared between methods. The intraclass correlation coefficient was used to determine interpersonal variability.The intraclass correlation coefficients for SFCT, measured using methods 1, 2, and 3, were 0.853, 0.880, and 0.896, respectively (P < .001 for all). Method 3 was the highest. The intraclass correlation coefficients of the SFCT angles were 0.647, 0.842, and 0.307, respectively (P < .001 for all).The new method showed the lowest interpersonal variability and could therefore be a reliable standard for SFCT measurement, even in foveae with a steep slope on optical coherence tomography.Trial registration: Not applicable., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: To evaluate short-term retinal and choroidal vascularity changes in the healthcare professionals after four hours of use filtering facepiece respirators (FFR)., Materials and Methods: This prospective study included 20 healthcare professionals. Oxygen saturation, pulse rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), mean ocular perfusion pressure (MOPP), and spectral domain optical coherence tomography (OCT) imaging were evaluated at baseline and after four hours wearing of FFP3 FFRs without an exhalation valve. Superior temporal artery (STA), inferior temporal artery (ITA), superior temporal vein (STV), and inferior temporal vein (ITV) diameter were measured from OCT images. The total subfoveal choroidal area (TCA), luminal area (LA), stromal area (SA) choroidal vascularity index [(CVI), the ratio of LA to TCA] were determined after binarization of enhanced depth imaging OCT (EDI-OCT) images of the choroid., Results: The mean age of the participants was 27.35 ± 2.80 years (range, 25-34). Eight of them were female and 12 were male. After wearing the FFR for four hours, a significant decrease was observed in the mean DBP ( p  = 0.018), MAP ( p  = 0.016), and MOPP ( p  = 0.007) when compared to base-line values. STV diameter ( p  = 0.019) and ITV diameter ( p  = 0.046) measurements were found significantly higher than baseline measurements. A significant increase in the choroidal vascularity was observed in the LA ( p  = 0.004) and TCA values ( p  = 0.043) after wearing the FFR for four hours., Conclusion: The current study shows that after four hours usage of FFR, in addition to systemic changes, retinal and choroidal vascularity might be affected significantly. With further studies, long-term effects and clinical significance of these short-term changes should be investigated on healthcare professionals.

Purpose : To assess the correlation between the choriocapillaris (CC) on optical coherence tomography (OCT) angiography and the inner choroid (IC) on structural OCT. Methods : In this prospective, cross-sectional, observational, pilot study, consecutive healthy subjects were imaged with a 6x6mm macular scan using OCTA PlexElite. Angiographic images of the CC were isolated using 10 μm-thick slab starting 21 μm posterior to the automatically segmented retinal pigment epithelium (RPE) band centerline. The structural en face OCT images of the IC were isolated using five 10 μm-thick slabs starting 11 to 51 μm posterior to the automatically segmented RPE band centerline. Retinal vessels masking was obtained by two methods: automated OCTA superficial vessel slab and automated structural OCT outer retina to CC (ORCC) slab. The en face OCT images were binarized for computation of the stromal index (SI). The flow deficits (FD) of the angiographic CC were correlated with the SI of the structural en face OCTs of the IC. Results : Twenty eyes of 20 subjects were enrolled. The strongest correlation was observed between the CC FD and the inner choroid SI of the 31-41 slab (IC SI 31-41 ) using the ORCC mask (R = 0.603, p = .005). Similar results were observed when the analysis was repeated when using IC SI 31-41 values obtained with the superficial vessels mask (R = 0.561, p = .01). Conclusions : The angiographic CC FD was significantly correlated with the structural inner choroidal stromal index. These findings suggest that there may be an opportunity to use structural OCT data to analyze the CC, which may allow longitudinal assessment from historical structural OCT datasets.

Purpose : The study aimed to investigate the relationship between iris thickness (IT) and choroidal thickness (CT) in healthy subjects. Materials and Methods : Forty-five healthy participants (24 women, 21 men) aged 18-62 years were included in the study. The iris thickness was measured by anterior segment optical coherence tomography (AS-OCT). The iris thickness was measured at 750 μm (IT750T) and 2000 μm (IT2000T) from the temporal scleral spur. The iris thickness was measured at 750 μm (IT750N) and 2000 μm (IT2000N) from the nasal scleral spur. Choroidal thickness was measured by optical coherence tomography. Choroid thickness was measured at 750 μm (CT750N, CT750T) and 2000 μm (CT2000N, CT2000T) from the center of the fovea on both the nasal and temporal sides. Results : There were significant correlations between CT750T and IT750T, IT750N, IT2000N ( r = 0.409, p =0.005; r = 0.396, p =0.007; r = 0.329, p =0.02, respectively). There were significant correlations between CT2000T and IT750T, IT750N, IT2000N ( r = 0.383, p =0.009; r = 0.478, p =0.001; r = 0.331, p 0=0.02, respectively). Conclusions : There was a significant correlation between CT and IT thicknesses at different points.

Purpose: To evaluate the degree of genetic influence on macular choroidal volume., Design: A cross-sectional twin and family study., Methods: In total, 353 Korean adults with healthy eyes from 78 households with 2 or more family members were included in the study. Macular choroidal volume was measured using spectral-domain optical coherence tomography with enhanced depth imaging at 9 macular subfields defined by the ETDRS. Demographics and clinical characteristics were investigated, including age, sex, axial length, hypertension, diabetes, drinking habits, and smoking status. The associations of these factors with macular choroidal volume were assessed using univariate and subsequent multivariate regression analyses while accounting for family structure. The heritability estimates of macular choroidal volume in total and at each of the 9 macular subfields were calculated after adjusting the covariates., Results: Patients who were younger, male, and had a shorter axial length showed associations with greater choroidal volume (P < .001 for all 3 independent variables). The covariates-adjusted heritability (±standard error) of the total macular choroidal volume was 0.76 ± 0.06, and the heritabilities of choroidal volume at each subfield ranged from 0.55 ± 0.09 (inner temporal subfield) to 0.77 ± 0.08 (inner superior subfield)., Conclusion: The macular choroidal volume is highly heritable., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this paper was to study the bilateral choroidal thickness (CT) symmetry and differences in healthy individuals using wide-field swept-source optical coherence tomography (SS-OCT)., Methods: All participants underwent a wide-field 16-mm 1-line scan using SS-OCT. CTs were measured at the following 12 points: 3 points at 900 µm, 1800 µm, and 2700 µm away from the nasal optic disc margin (nasal peripapillary area), 1 point at the subfovea, 6 points at 900 µm, 1800 µm, and 2700 µm away from the subfovea to the nasal and temporal areas (macular area), and 2 peripheral points at 2700 and 5400 µm from temporal point 3 (peripheral area). Bilateral CTs were measured; their correlations and differences in the corresponding regions were analyzed., Results: There were no statistically significant differences in CTs between the right and left eyes in all corresponding areas (all P > 0.05); they all showed significant positive correlation coefficients (r) (all P < 0.001). However, the nasal peripapillary and peripheral areas had relatively low correlation coefficients, compared to the macular areas. In addition, the bilateral CT differences were 32.60 ± 25.80 µm in the macular area, 40.67 ± 30.58 µm in the nasal peripapillary area, and 56.03 ± 45.73 µm in the peripheral area (all P < 0.001)., Conclusions: Overall, the CTs of each region were bilaterally symmetrical. However, the differences in CTs increased from the center to the periphery, which indicated that the anatomic variation of the nasal peripapillary and peripheral choroid was greater than that of the macula.

Clinical Relevance: Obesity has become one of the most important health problems of today with its increasing prevalence. With the development of retinal imaging systems, obesity has been observed to be associated with changes in outer retinal layers and choroid in women., Background: The aim of this study was to examine retinal layer parameters and their relationship with body mass index in obese women., Methods: The study included 197 eyes of 197 women, of whom 44 were normal-weight, 40 were overweight, 40 were class 1 obese, 38 were class 2 obese, and 35 were morbidly obese. The thickness of the choroid was measured manually using an enhanced-depth imaging optical coherence tomography scanning program., Results: The mean choroidal thickness values in five locations were lower than those of normal-weight, overweight, class 1, and class 2 obese women, in morbidly obese women (p < 0.05 for all). Subfoveal outer retinal layer thickness and specific sublayer thickness of the photoreceptor layer values were significantly lower in morbidly obese women than in normal-weight women, but there were no statistically significant differences between the groups in retinal pigment epithelium thickness and Bruch's membrane thickness (p = 0.001, p < 0.001, p = 1.00, and p = 0.101, respectively). Furthermore, there were significant negative relationships between body mass index and subfoveal choroidal thickness, subfoveal outer retinal layer thickness, and specific sublayer thickness of the photoreceptor layer values (r = -0.327, p < 0.001; r = -0.259, p < 0.001; and r = -0.281, p < 0.001, respectively)., Conclusions: Morbid obesity was associated with a thinner choroid, subfoveal outer retinal layer, and specific sublayer thickness of the photoreceptor layer in women. Furthermore, retinal hypoxia associated with morbid obesity may be related to a decrease in photoreceptor layer thickness. Thinning of the outer retinal layer may also lead to atrophy of the cone sheath.

We investigated the anatomical differences in the choroidal structure between pregnant women in the first trimester of pregnancy and age-matched healthy nonpregnant women using enhanced depth imaging optical coherence tomography (EDI-OCT) and choroidal binarization analysis. The main parameters measured in the two study groups, namely, pregnant women in the first trimester and healthy nonpregnant women, were choroidal thickness and the choroidal luminal area. Binarization of the EDI-OCT images from each patient was performed, and the choroidal vascularity index (CVI) was calculated. The correlations between the baseline characteristics of the subjects and the CVI were investigated using linear mixed model analysis. As a result, there was no statistically significant difference in the mean age, best-corrected visual acuity, axial length, central retinal thickness, subfoveal choroidal thickness, systolic blood pressure (BP), or diastolic BP between the two study groups. Conversely, a significant difference was observed in the CVI (P = 0.012) between the two groups. The multivariate analysis identified a significant correlation between the CVI and the systolic BP (P = 0.0044, linear mixed test). Taken together, a larger choroidal luminal area was associated with a higher systolic BP, especially in the first trimester of pregnancy. Our findings may provide further insight into the choroidal changes that occur during pregnancy.

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.

Purpose: To investigate the impact of oral isotretinoin therapy in choroidal thickness, central macular thickness (CMT), and retinal nerve fibre layer (RNFL) thickness using optical coherence tomography (OCT)., Patients and Methods: Choroidal thicknesses, CMT, and RNFL thickness of 64 eyes were evaluated at baseline and the end of the third month of isotretinoin therapy by spectral-domain OCT. For assessment of choroidal thickness, OCT measurements were obtained at the fovea with 6 additional measurements at adjacent locations (at 500-1000-1500 µm temporal to the fovea and 500-1000-1500 µm nasal to the fovea)., Results: There was not a statistically significant difference between the baseline and third-month follow-up measurements of choroidal thicknesses at seven distinct locations ( p  > 0.05). Similarly, RNFL thickness and CMT did not change with a mean dose of 30 (±6) mg per day isotretinoin therapy during follow-up (101.82 vs 102.24, p  = 0.079; 217.77 vs 217.25, p  = 0.731, respectively)., Conclusion: After the use of oral isotretinoin for 3 months, no significant side effects have been observed in choroidal thickness, CMT, and RNFL thickness by OCT.

Aim: This study aimed to determine the effects of strabismus surgery on choroidal thickness in paediatric patients with Spectral Domain-Optical Coherence Tomography (SD-OCT)., Material and Methods: Sixty eyes of 60 children with esotropia were included. The mean age was 9.5 ± 3.1 years. The choroidal thickness was measured using SD-OCT, which was performed before the surgery and 1 week, 1 month and 3 months postoperatively. At the same time, the patients' visual acuity was evaluated., Results: There were no statistically significant differences between the preoperative and postoperative values in terms of the visual acuity (P > 0.05). When compared to the preoperative values, decreases were found in the choroidal thicknesses in all of the areas measured during the first week evaluation (P < 0.05). In the postoperative first month, significant decreases were also found in the choroidal thicknesses in all the areas measured (P < 0.05); however, in the postoperative third month, there were no changes in any of the areas (P > 0.05)., Conclusions: We observed that there was a significant decrease in the choroidal thickness during the early postoperative period and no significant change in the late postoperative period in paediatric patients of double horizontal muscle surgery. Moreover, these early changes in the choroid in paediatric patients show that it does not cause a functional loss., Competing Interests: None

Purposes: To evaluate changes in ocular blood flow and subfoveal choroidal thickness in patients with symptomatic carotid artery stenosis after carotid artery stenting., Methods: We included 15 men (mean age, 63.6 ± 9.1 years) with symptomatic carotid artery stenosis and 18 healthy volunteers (all men; mean age, 63.7 ± 5.3 years). All participants underwent detailed ophthalmologic examinations including choroidal thickness measurement using enhanced depth-imaging optic coherence tomography. The patients also underwent posterior ciliary artery blood flow measurements using color Doppler ultrasonography before and after carotid artery stenting., Results: Patients lacked ocular ischemic symptoms. Their peak systolic and end-diastolic velocities increased to 10.1 ± 13.1 (p=0.005) and 3.9 ± 6.3 (p=0.064) cm/s, respectively, after the procedure. Subfoveal choroidal thicknesses were significantly thinner in patients with carotid artery stenosis than those in the healthy controls (p=0.01). But during the first week post-procedure, the subfoveal choroidal thicknesses increased significantly (p=0.04). The peak systolic velocities of the posterior ciliary arteries increased significantly after carotid artery stenting (p=0.005). We found a significant negative correlation between the mean increase in peak systolic velocity values after treatment and the mean preprocedural subfoveal choroidal thickness in the study group (p=0.025, r=-0.617)., Conclusions: In patients with carotid artery stenosis, the subfoveal choroid is thinner than that in healthy controls. The subfoveal choroidal thickness increases after carotid artery stenting. Carotid artery stenting treatment increases the blood flow to the posterior ciliary artery, and the preprocedural subfoveal choroidal thickness may be a good predictor of the postprocedural peak systolic velocity of the posterior ciliary artery.

Purpose: To determine the effects of narrowband light exposure on choroidal thickness and the pupil response in humans., Methods: Twenty subjects, ages 21 to 43 years, underwent 1 hour of exposure to broadband, short wavelength "blue," or long wavelength "red" light, or darkness. Choroidal thickness, imaged with spectral domain optical coherence tomography, axial length, determined from biometry, and rod/cone- and intrinsically photosensitive retinal ganglion cell-driven pupil responses were measured before and after exposure. Pupil stimuli were six 1 second alternating red (651 nm) and blue (456 nm) stimuli, 60 seconds apart. Pupil metrics included maximum constriction and the 6 second post-illumination pupil response (PIPR)., Results: Compared with before exposure, the choroid significantly thinned after broadband light, red light, and dark exposure (all P < 0.05), but not after blue light exposure (P = 0.39). The maximum constriction to 1 second red stimuli significantly decreased after all light exposures (all P < 0.001), but increased after dark exposure (P = 0.02), compared with before exposure. Maximum constriction and 6-second PIPR to 1 second blue stimuli significantly decreased after all light exposures compared with before exposure (all P < 0.005), with no change after dark exposure (P > 0.05). There were no differences in axial length change or 6-second PIPR to red stimuli between exposures., Conclusions: Narrowband blue and red light exposure induced differential changes in choroidal thickness. Maximum constriction, a function of rod/cone activity, and the intrinsically photosensitive retinal ganglion cell-mediated PIPR were attenuated after all light exposures. Findings demonstrate differing effects of short-term narrowband light and dark exposure on the choroid, rod/cone activity, and intrinsically photosensitive retinal ganglion cells.

Purpose: Spectral-domain optical coherence tomography (SD-OCT) is the most useful tool to measure choroidal thickness (CT). CT may be increased in ocular and systemic diseases. However, there are concerns relating reproducibility and external validity of OCT. The aim of this study was to assess the inter-observer and intra-observer variability of manual OCT measurements., Methods: CT was manually measured in the central choroid of 40 eyes from 21 subjects (11 healthy and 10 with ankylosing spondylitis) using RTVue-100 OCT (Optovue Inc., Fremont, CA, EE.UU.). Measurements were performed by 9 independent ophthalmologists from 6 different centers. To assess the inter-observer variability, the intra-class correlation coefficient (ICC) method was calculated. Also, intra-observer variability was assessed in 2 of the ophthalmologists., Results: The mean subfoveal CT was 364.9±85.1μm (range, 170 to 572). The inter-observer ICC was 0.823 (CI 95%, 0.749 to 0.888, p<0.001). The intra-observer ICCs were 0.885 (CI 95%, 0.783 to 0.939, p<0.001) and 0.925 (CI 95%, 0.859 to 0.960. p<0.001)., Conclusions: In this study, manual measurements of CT with OCT showed a good concordance. These results suggest that manual OCT is a valid tool for multicenter studies., (Copyright © 2020 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.)

Purpose: To examine the choroidal thickness (ChT) response to short-term with-the-rule (WTR) and against-the-rule (ATR) simple myopic astigmatic defocus, with the response to spherical myopic defocus and clear vision used as control conditions., Methods: The left eye of 18 healthy adults aged 28 ± 6 years was exposed to clear vision, +3 D spherical myopic defocus, +3 D × 180 WTR, or +3 D × 90 ATR astigmatic defocus for 60 minutes, over four randomly ordered visits, while their right eye was optimally corrected. The macular ChT was measured with optical coherence tomography along the vertical and horizontal meridians before and after 20, 40, and 60 minutes of defocus., Results: After 60 minutes of defocus, ChT increased by +8 ± 5 µm (P < 0.001) with spherical myopic defocus, but varied with simple myopic astigmatic defocus, depending on the axis of astigmatism (P < 0.001), increasing by +5 ± 6 µm (P = 0.037) with WTR and decreasing by -4 ± 5 µm (P = 0.011) with ATR astigmatic defocus. These changes were similar across the vertical and horizontal meridians (P = 0.22). The ChT changes were greater than the change during the clear vision control condition (-1 ± 4 µm) for WTR (+5 ± 5 µm, P = 0.002) but not ATR (-4 ± 6 µm, P = 0.09) astigmatic defocus., Conclusions: These results provide insights into the human ChT response to short-term astigmatic defocus and highlight a potential difference in the myopiagenic signal associated with the orientation of astigmatic blur.

We aimed to determine the effect on choroidal thickness of daily 5 mg tadalafil use in patients with erectile dysfunction (ED) and to evaluate agreement between short form of International Index of Erectile Function (IIEF 1-5, 15) scores and choroidal thickness during follow-up. Enhanced depth imaging spectral domain-optical coherence tomography (EDI-OCT) was used to measure full choroidal thickness in the subfoveal area, choroidal thickness (CT) and small-choroidal-vessel-layer (SCVL) thickness. Thirty of the 45 patients included complete their follow-ups and exhibited medication continuity. Patients were divided into two groups, five (16.7%) with ED at any level at third-month follow-up, and 25 (83.3%) with no ED, and subgroup analysis was then performed. Median changes in SCVL thickness at first- and sixth-month follow-ups were 20.5 µm versus 9.0 μm (p = .001) and 23.5 µm versus 12.5 µm (p = .005) in patients without and with ED respectively. The SCVL thickness increased by 20 μm compared with the baseline level, indicating an improvement in the patient's complaints of erectile dysfunction. The level of increase in SCVL thickness can be a useful and objective guide to clinicians if they cannot be present when the IIEF questionnaire is administered., (© 2020 Blackwell Verlag GmbH.)

Purpose: To describe the choroidal thickness (ChT) in a large sample of young adults with the aim of establishing a normative ChT profile reference in this demographic cohort and explore its association with best-corrected visual acuity (BCVA)., Design: Cross-sectional study., Methods: From a single center, 741 young adults (19-30 years of age, 49% male) were recruited to undergo a comprehensive ophthalmic examination, including BCVA measurement, post-cycloplegic autorefraction, ocular biometry, tonometry, and spectral-domain optical coherence tomography (SD-OCT) imaging. The enhanced depth imaging mode on the SD-OCT was used. The main outcome measure was the central macular ChT (0.5-mm radius around the fovea). The ChTs at the inner (between 0.5-mm and 1.5-mm radius) and outer macular rings (between 1.5-mm and 2.5-mm radius) were also measured., Results: The median central macular ChT was 370 μm (interquartile range 312-406 μm). The choroid was thickest at the superior-inner, inferior-inner, and central macular regions (370-373 μm) and thinnest nasally at the outer macular region (median 256 μm). Decreased central macular ChT was associated with younger age, female sex, nonwhite ethnicities, and myopia (P ≤ .013). There was a significant association between better BCVA and increased central macular ChT (P < .001), after adjusting for age, sex, ethnicity, and ocular measures. His relationship was only apparent in eyes with central macular ChTs <300 μm (P = .019) and absent in eyes with ChTs >300 μm., Conclusions: The central ChT of young adults was 370 μm. There was a significant association between worse BCVA and thinner choroids below a threshold of 300 μm, raising the possibility that ChT could be predictive of visual function., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background and Objectives : Despite the growing number of new research publications, normative references for children's optical coherence tomography (OCT) parameters are still not completed. We chose to explore this topic because of the lack of normative parameters that is due to an improvement in different technologies and instruments. Our aim was to determine referential rates of retinal nerve fiber layer (RNFL) thickness and flow deficits (FD%) in the macular choriocapillaris (CC) in normal eyes of ophthalmologically healthy children. Materials and Methods : Ophthalmologically healthy 8- to 14-year-old individuals participated ( n = 75) in this study. OCT images were taken using an swept-source-OCT (SS-OCT) instrument (DRI-OCT Triton, Topcon, Tokyo, Japan). The early treatment diabetic retinopathy study (EDTRS) grid (6 × 6 mm) divided the RNFL into the thickness maps. The FD% values of the CC were calculated on the 3 × 3-mm scans in a 1-mm circle (C 1 ), 1.5-mm rim (R 1.5 ), and the entire 2.5-mm circle (C 2.5 ), and on the 6 x 6-mm scans in a 1-mm circle (C 1 ), 1.5-mm rim (R 1.5 ), the entire 2.5-mm circle (C 2.5 ), 2.5-mm rim (R 2.5 ), and 5-mm circle (C 5 ). Results : Both scan quantifications of FD% in the C 1 , C 2.5 , and R 1.5 sectors were similar, but the 6 × 6-mm scan measurements were statistically significantly smaller than the 3 × 3-mm ones. Significant moderate correlations were found between axial length (AxL) and FD% in the 6 × 6-mm scans, namely C 1 ( r = -0.347, p = 0.002), C 2.5 ( r = -0.337, p = 0.003), R 1.5 ( r = -0.328, p = 0.004), R 2.5 ( r = -0.306, p = 0.008), and C 5 ( r = -0.314, p = 0.006). Conclusions : The thinnest RNFL layers were on the temporal and nasal sides. FD% values in the C 1 , C 2.5 , and R 1.5 sectors were similar between the 3 × 3-mm and 6 × 6-mm scans. The negative moderate correlations between AxL and FD% were found in all C 1 , C 2.5 , C 5, R 1.5 , and R 2.5 sectors of the 6 × 6-mm scans. Further prospective studies are needed to determine more accurate normative references for children's OCT parameters.

Purpose: To clarify the changing characteristics of choroidal thickness over time within different age ranges and among different refractive statuses of children aged 6 to 18 years., Design: Prospective cohort study., Methods: Data of axial length, cycloplegic refraction, and choroidal thickness (using swept-source optical coherence tomography) were collected at baseline and at a 1-year follow-up for 756 participants. One-year change in choroidal thickness and its association with age and refraction were analyzed., Results: Significantly greater attenuation of choroidal thickness was observed in younger children aged 6-9 years for all participants (-9 ± 25 μm) and for those with a myopic shift (-12 ± 25 μm), whereas there was a larger increase in adolescents aged 10-13 years for those without a myopic shift (9 ± 23 μm). There was a marked decrease in the choroidal thickness for newly developed myopic patients compared with persistent-nonmyopic patients and persistent-myopic patients (P < .01). The association between changes in axial length and choroidal thickness was less strong in persistent-myopic patients (β = -15.4, P = .022) than that in persistent-nonmyopic patients (β = -30.4, P < .001) and newly developed myopic patients (β = -33.7, P = .001), whereas among the persistent-myopic patients, the association was less strong in the baseline mild-myopic patients (β = -10.4, P = .193) than that in the baseline moderate-to high-myopic patients (β = -31.4, P = .026)., Conclusions: Changes in choroidal thickness varied by age. There was an increased rapid thinning of the choroid among newly developed myopic patients, and a nonsignificant association between changes in choroidal thickness and axial length in the early stages of myopia., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess topographic variations of choroidal thickness (CT) in the fovea and beyond in healthy eyes., Methods: This cross-sectional study included healthy subjects ≤ 55 years of age with axial lengths (22-26 mm) and refractive error margins (-4D, +4D) in normal ranges. Images were acquired using swept-source optical coherence tomography angiography (OCT-A). Corneal thickness (CT) maps from 12 × 12-mm radial scans and 9 × 9-mm OCT-A B-scans were analyzed., Results: The study included 64 eyes of 33 subjects (mean age, 37 years). Mean CT was >300 µm in all locations except the nasal outer macula. The subfoveal CT was >395 µm in 30% of cases; in 38.7% of cases, >50% of the CT map was thicker than 395 µm. The mean thickest choroidal point was 395.2 µm (range, 164-548 µm), located superior and temporal to the macula in 72.2% of cases and subfoveally in 1.8% of cases. The CT pattern was symmetrical (58%) or asymmetrical (42%) along a horizontal axis correlating with choroidal vein distribution. Half of the asymmetrical patterns were thicker in the inferior quadrants, with an oblique temporal watershed of venous drainage, and the other half were thicker superiorly. The mean vascularity index was ∼75% regardless of the mean CT., Conclusions: One-third of healthy eyes of patients younger than age 55 had a thick choroid (>395 µm). In these normal eyes, the thickest choroidal point was not subfoveal, CT symmetry above and below the fovea depended on choroidal vein distribution, and choroidal vascularity index was independent from CT. No patients demonstrated fundus autofluorescence abnormalities, and the choriocapillaris remained visible even in thick choroids. These features could be interesting when differentiating normal versus pathological states.

Purpose: To assess the association between clinical and perinatal characteristics and subfoveal choroidal thickness in 9-year-old children., Methods: The study included data from the population-based Generation R cohort, whose participants underwent cycloplegic refractometry, ocular biometry, height, weight and subfoveal choroidal thickness measurements using a swept-source optical coherence tomography (SS-OCT) instrument. Birth parameters were obtained using medical records. Statistical analyses were performed using multivariate regression models adjusted for age, ethnicity and sex., Results: A total of 1018 children (52.5% girls, 47.5% boys) with a mean age of 9.9 ± 0.3 years and a mean cycloplegic spherical equivalent refraction of 0.80 ± 1.1 D in boys and 0.81 ± 1.4 in girls were eligible for analysis. The subfoveal choroid was 17 μm thicker in girls (298 ± 60.6 μm) than in boys (281 ± 55.0 μm; p < 0.001), a difference of 9.1 μm persisting after adjustment for age, ethnicity and axial length (p = 0.017). Subfoveal choroidal thickness decreased with increasing ocular axial length (-16.2 μm/mm, 95% CI -21.2 to -12.4, p < 0.001) and with increasing myopic refraction (-10.0 μm/D, 95% CI 6.8-13.1; p < 0.001, adjusted for age, ethnicity, axial length and sex) while it increased with increasing body height (1.3 μm/cm, 95% CI 0.8 to 1.9, p < 0.001). Additionally, choroidal thickness increased with increasing birthweight (13.0 μm/kg; 95% CI 0.006-0.020; p < 0.001) and increasing size for gestational age (8.2 μm/kg; 95% CI 4.6-11.8; p < 0.001). Smoking up until the time that pregnancy became known was associated with a thinner choroid (p = 0.016). There was no detectable effect of alcohol consumption. The distributions of axial length, refraction and choroidal thickness were narrower than in older populations., Conclusion: The subfoveal choroid was thicker in girls than in boys, and higher body height, higher birthweight and larger size for gestational age were associated with a thicker subfoveal choroid. The implications of these findings for myopia development need further evaluation in longitudinal studies., (© 2019 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Significance: This study demonstrated that a semiautomated segmentation method could help inexperienced practitioners to obtain choroidal thickness as good as experienced practitioners., Purpose: The purpose of this study was to compare choroidal thickness measurements obtained by semiautomated and manual segmentation methods., Methods: Optical coherence tomography images of 37 eyes from 37 healthy young subjects acquired by a spectral-domain optical coherence tomography device were reviewed retrospectively. Two naive examiners measured choroidal thickness using manual and semiautomated methods, whereas two experienced examiners used only the semiautomated method. The semiautomated method referred to a fully automated segmentation program customized based on MATLAB and followed manual verification. After highlighting the inner and outer choroidal boundaries through automated segmentation, examiners reviewed these boundaries in each B-scan and conducted manual revisions if segmentation errors occurred. After selecting points where correct boundary was located, the software used a spline fit to blend the corrected region with the rest of the boundary. All measurements were summarized in a 6-mm Early Treatment Diabetic Retinopathy Study grid. Operation time spent to complete retinal and choroidal segmentation on each eye was recorded. Between-examiner agreements, that is, intraclass correlation coefficient and coefficient of reproducibility (CoR), were calculated among four sets of semiautomated measurements, and within-examiner agreements were comparisons between manual and semiautomated results from the same naive examiners. Eyes with thin or thick choroids were also analyzed separately., Results: The between-examiner and within-examiner agreements were excellent with intraclass correlation coefficient of 0.976 or greater. Pairwise within-examiner CoRs ranged from 17.4 to 47.1 μm. Pairwise between-examiner CoRs were between 13.0 and 38.9 μm. Eyes with thin choroid had better agreements than those with thick choroids. On average, naive examiners saved 3 to 5 minutes per eye using the semiautomated method., Conclusions: With the help of a dedicated software, inexperienced practitioners could obtain choroidal thickness measurements with accuracy similar to experienced practitioners. Processing time with the semiautomated method was also reduced.

The purpose of the study is to propose choroidal spatial distribution indexes (CSDIs) to represent choroidal topographic features, establish a normative database for CSDIs, and identify factors associated with CSDIs in healthy eyes. Retrospective data analysis of 363 healthy eyes from a single-center, prospective, cross-sectional, non-interventional study. Subjects were evaluated using spectral domain OCT with enhanced depth imaging. Choroidal volume and average thickness were measured with OCT in nine macular subfields defined by the Early Treatment Diabetic Retinopathy Study. Vertical CSDI was defined as the natural logarithm of superior choroidal volume divided by inferior choroidal volume. Horizontal CSDI was defined as the natural logarithm of temporal choroidal volume divided by nasal choroidal volume. The overall distributions of vertical and horizontal CSDIs was analyzed. Linear regression analyses were used to identify ocular and systemic factors associated with vertical and horizontal CSDIs. The average vertical CSDI was 0.062 ± 0.206, and average horizontal CSDI was 0.138 ± 0.226. Both vertical and horizontal CSDIs followed normal distribution. Increasing age was significantly associated with greater vertical CSDI (choroidal volume distribution tilted toward the superior region), and longer axial length and thinner subfoveal choroidal thickness were significantly associated with greater horizontal CSDI (choroidal volume distribution tilted toward the temporal region).

Purpose: To assess the reproducibility of retinal and choroidal measurements in the macular and peripapillary areas using swept-source optical coherence tomography in patients with Parkinson's disease., Methods: A total of 63 eyes of 63 patients with idiopathic Parkinson's disease were evaluated using a three-dimensional protocol of swept-source optical coherence tomography. The following layers were analyzed: full retinal thickness, retinal nerve fiber layer, ganglion cell layer, and choroid. The coefficient of variation was calculated for every measurement., Results: In the macular area, the mean coefficients of variation of retinal thickness, ganglion cell layer + thickness, and choroidal thickness were 0.40%, 0.84%, and 2.09%, respectively. Regarding the peripapillary area, the mean coefficient of variation of the retinal nerve fiber layer thickness was 2.78. The inferior quadrant showed the highest reproducibility (coefficient of variation= 1.62%), whereas the superonasal sector showed the lowest reproducibility (coefficient of variation= 8.76%)., Conclusions: Swept-source optical coherence tomography provides highly reproducible measurements of retinal and choroidal thickness in both the macular and peripapillary areas. The reproducibility is higher in measurements of retinal thickness versus choroidal thickness.

Objectives: We investigated the effects of topical phenylephrine 2.5% instillation on choroidal thickness (CT), peripapillary choroidal thickness (pCT) and retinal nerve fibre layer (RNFL)., Methods: Healthy control patients underwent enhanced depth imaging (EDI) by spectral-domain optical coherence tomography (OCT) before and 30 min after phenylephrine instillation, using eye-tracking and follow-up software. Changes in 14 different locations of CT, 2 locations of pCT and RNFL were assessed., Results: The study included 119 eyes of 62 patients (19 males and 43 females), with a mean age of 59.8 ± 15.3 years (range: 26-88 years). Within 30 min after instillation, the mean subfoveal CT both in vertical and horizontal scan were significantly thinned (p = 0.005 and p  = 0.018, respectively). In total, 1500, 1000 and 500 µm temporal CT measurements showed also a significant thinning (p = 0.021, p  = 0.037 and p = 0.020, respectively), as well as 500 µm both superior (p  = 0.045) and inferior (p  = 0.009). 1500, 1000 and 500 µm nasal CT, and 1500 and 1000 µm CT superior and inferior measurements showed no significant thinning after phenylephrine instillation. pCT was significantly thinned after phenylephrine in both superior (p = 0.016) and inferior (p = 0.050) measurements. RNFL analysis did not significantly change after phenylephrine instillation (p =  0.209)., Conclusions: A significant thinning of CT and pCT occurred following phenylephrine instillation. Future studies analysing CT and pCT should detail if this mydriatic agent was used or not.

Purpose: The purpose of the study was to evaluate the choroidal and retinal thicknesses in singleton versus twin pregnancies., Materials and Methods: This study included 20 single and 20 twin pregnant women in their 3 rd trimester with 20 age-matched healthy nonpregnant women as a control group. All participants underwent a detailed ocular examination. Cirrus enhanced depth imaging-optical coherence tomography was used for choroidal thickness (CT) with frame enhancement software. The study was divided into three groups: Group 1 - singleton pregnancy, Group 2 - twin pregnancy, and Group 3 - healthy nonpregnant controls. CT was measured from nasal, subfoveal, and temporal fields., Results: Regarding CT, the twin pregnancy group had the thickest choroid followed by the singleton pregnancy group and control group. There was a statistically significant difference between Group 2 and Group 3 in terms of nasal, subfoveal, and temporal CTs ( P = 0.002, P = 0.001, and P = 0.003, respectively). There was a statistically significant difference between Group 1 and Group 3 regarding just subfoveal CT ( P = 0.028). Regarding retinal thickness, there was a statistically significant difference between Group 1 and Group 3 regarding the mean macular volume and ganglion cell-inner plexiform layer thicknesses ( P < 0.05). Furthermore, regarding mean retinal nerve fiber layer thickness, there was a statistically significant difference between Group 1 and Group 2 and between Group 2 and Group 3 ( P = 0.004, P = 0.003, respectively)., Conclusion: Our study is the first one which evaluates choroidal and retinal thicknesses in twin pregnancies. We found that there was an increase in CT in the 3 rd trimester of pregnancies and it was prominent in twin pregnancies., Competing Interests: There are no conflicts of interest., (Copyright: © 2019 Middle East African Journal of Ophthalmology.)

The analysis of the choroid in the eye is crucial for our understanding of a range of ocular diseases and physiological processes. Optical coherence tomography (OCT) imaging provides the ability to capture highly detailed cross-sectional images of the choroid yet only a very limited number of commercial OCT instruments provide methods for automatic segmentation of choroidal tissue. Manual annotation of the choroidal boundaries is often performed but this is impractical due to the lengthy time taken to analyse large volumes of images. Therefore, there is a pressing need for reliable and accurate methods to automatically segment choroidal tissue boundaries in OCT images. In this work, a variety of patch-based and fully-convolutional deep learning methods are proposed to accurately determine the location of the choroidal boundaries of interest. The effect of network architecture, patch-size and contrast enhancement methods was tested to better understand the optimal architecture and approach to maximize performance. The results are compared with manual boundary segmentation used as a ground-truth, as well as with a standard image analysis technique. Results of total retinal layer segmentation are also presented for comparison purposes. The findings presented here demonstrate the benefit of deep learning methods for segmentation of the chorio-retinal boundary analysis in OCT images.

Purpose: We describe changes in choroidal thickness from age 11 to 16 years and its association with ocular biometrics and body development., Method: In this longitudinal, population-based observational study, choroidal thickness was measured subfoveally and 1- and 3-mm temporal thereof using enhanced depth imaging spectral domain optical coherence tomography. Analyses were stratified by sex and adjusted for age and the time of day that the scan was performed., Results: The study included 687 participants (304 boys). Median (interquartile range [IQR]) age was 11.5 (0.6) years at baseline and 16.6 (0.3) years at follow-up. Mean increase in choroidal thickness was 33, 27, and 11 μm at the three respective locations. The subfoveal choroid thickened less in eyes whose axial length increased more (boys, β = -85 μm/mm; 95% confidence interval [CI], -104 to -66, P < 0.0001; girls, β = -105 μm/mm; 95% CI, -121 to -89, P < 0.0001) and in eyes with a more negative refractive development (boys, 11 μm/diopters [D]; 95% CI, 4.0 to 18, P = 0.0022; girls, 22 μm/D; 95% CI, 16 to 27, P < 0.0001). Subfoveal choroidal thickness increased less in girls who underwent early puberty (Tanner stage 4 vs. 1; -39 μm' 95% CI, -72 to -5.9, P = 0.021) and who had a longer baseline axial length (β = -8.6 μm/mm; 95% CI, -15 to -2.7, P = 0.0043), and more in girls who grew taller (β = 0.9 μm/cm; 95% CI, 0.1 to 1.7, P = 0.026)., Conclusions: The choroid increased in thickness from age 11 to 16 years. The increase was greater in girls with later sexual maturation and smaller in eyes that added more axial length and had a relatively negative refractive development.