Choroidal Thickness Measurements Research Articles

Differences in imaging biomarkers between patients with intermediate and advanced non-neovascular age-related macular degeneration (AMD) in the University of Colorado AMD registry.

To quantify and compare the different prevalence rates of specific retinal imaging biomarkers in patients with intermediate AMD (iAMD) and advanced non-neovascular AMD (nnAMD). Cross-sectional study of patients with iAMD and advanced nnAMD. Imaging studies were reviewed for qualitative imaging biomarkers. Choroidal thickness measurements were obtained subfoveally and in 1000 um and 2000 um intervals away from the fovea. The Chi-squared test and Fisher's exact test were used to compare rates of imaging biomarkers among the two cohorts. P-value of <0.05 was considered significant. 376 eyes of 197 patients with iAMD and 187 eyes of 97 patients with advanced nnAMD were recruited. There were significantly lower rates of the following imaging biomarkers in the iAMD compared with the advanced nnAMD cohorts: soft drusen (66.0% vs. 84.2%, p = 0.001), calcified drusen (4.3% vs. 40.0%, p < 0.0001), RPD (26.2% vs. 53.3%, p < 0.0001), ORT (0.5% vs. 46.9%, p < 0.0001), RP (1.1% vs. 46.3%, p < 0.0001), pigment migration (53.2% vs. 100%, p < 0.0001), and iRORA (17.9% vs. 80.2%, p < 0.0001). In the iAMD cohort, choroidal thickness was significantly greater at 188 µm (SD: 60) and 194 µm (SD: 69), compared to the advanced nnAMD with measurements of 153 µm (SD: 68), and 161 µm (SD: 76). This difference was statistically significant (p < 0.0001 and p = 0.0002). Our results highlight significant differences in imaging biomarkers between both cohorts. Key biomarkers, such as iRORA, RPD, pigment migration, and thinner choroidal thickness, were associated with advanced nnAMD. Identifying these biomarkers early may help target patients who could benefit from new treatments, potentially delaying vision loss.

Optical coherence tomography choroidal enhancement using generative deep learning

Spectral-domain optical coherence tomography (SDOCT) is the gold standard of imaging the eye in clinics. Penetration depth with such devices is, however, limited and visualization of the choroid, which is essential for diagnosing chorioretinal disease, remains limited. Whereas swept-source OCT (SSOCT) devices allow for visualization of the choroid these instruments are expensive and availability in praxis is limited. We present an artificial intelligence (AI)-based solution to enhance the visualization of the choroid in OCT scans and allow for quantitative measurements of choroidal metrics using generative deep learning (DL). Synthetically enhanced SDOCT B-scans with improved choroidal visibility were generated, leveraging matching images to learn deep anatomical features during the training. Using a single-center tertiary eye care institution cohort comprising a total of 362 SDOCT-SSOCT paired subjects, we trained our model with 150,784 images from 410 healthy, 192 glaucoma, and 133 diabetic retinopathy eyes. An independent external test dataset of 37,376 images from 146 eyes was deployed to assess the authenticity and quality of the synthetically enhanced SDOCT images. Experts’ ability to differentiate real versus synthetic images was poor (47.5% accuracy). Measurements of choroidal thickness, area, volume, and vascularity index, from the reference SSOCT and synthetically enhanced SDOCT, showed high Pearson’s correlations of 0.97 [95% CI: 0.96–0.98], 0.97 [0.95–0.98], 0.95 [0.92–0.98], and 0.87 [0.83–0.91], with intra-class correlation values of 0.99 [0.98–0.99], 0.98 [0.98–0.99], and 0.95 [0.96–0.98], 0.93 [0.91–0.95], respectively. Thus, our DL generative model successfully generated realistic enhanced SDOCT data that is indistinguishable from SSOCT images providing improved visualization of the choroid. This technology enabled accurate measurements of choroidal metrics previously limited by the imaging depth constraints of SDOCT. The findings open new possibilities for utilizing affordable SDOCT devices in studying the choroid in both healthy and pathological conditions.

In-vivo characterization of scleral rigidity in myopic eyes using fundus-pulsation optical coherence elastography

The sclera plays an important role in the structural integrity of the eye. However, as myopia progresses, the elongation of the eyeball exerts stretching forces on the posterior sclera, which typically happens in conjunction with scleral remodeling that causes rigidity loss. These biomechanical alterations can cause localized eyeball deformation and vision impairment. Therefore, monitoring scleral rigidity is clinically important for the management and risk assessment of myopia. In this study, we propose fundus pulsation optical coherence elastography (FP-OCE) to characterize posterior scleral rigidity in living humans. This methodology is based on a choroidal pulsation model, where the scleral rigidity is inversely associated with the choroidal max strain obtained through phase-sensitive optical coherence tomography (PhS-OCT) measurement of choroidal deformation and thickness. Using FP-OCE, we conducted a pilot clinical study to explore the relationship between choroidal strain and myopia severity. The results revealed a significant increase in choroidal max strain in pathologic myopia, indicating a critical threshold beyond which scleral rigidity decreases significantly. Our findings offer a potential new method for monitoring myopia progression and evaluating therapies that alter scleral mechanical properties.

Evaluating the Effect of Childhood Obesity on Choroidal Structures

Aim: To evaluate the effect of childhood obesity on choroidal structures with spectral-domain optical coherence tomography (SD-OCT). Material and Methods: A total of 80 children (20 children per each group; healthy, overweight, obese, and morbid-obese) were included in the study. Accompanying comorbidities such as insulin resistance, dyslipidemia, and metabolic syndrome were recorded. The subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) measurements were obtained from SD-OCT images and compared between groups. Results: No notable differences were found between groups regarding the means of age and axial length (p=0.504, and p=0.805, respectively). The SFCT medians (min-max) of healthy, overweight, obese, and morbid-obese children were 398.5 (319.0-453.5) μm, 299.0 (274.7-387.0) μm, 295.5 (257.0-385.0) μm, and 304.5 (272.2-386.0) μm respectively. Overweight and obese children had thinner choroid than non-obese healthy children (p=0.032). Besides, no significant correlation was observed between the severity of obesity and SFCT (p=0.722). In terms of CVI, total choroidal area, luminal area, and stromal area; no significant differences were found between groups (p=0.710, p=0.452, p=0.221, and p=0.863, respectively). Obese children with dyslipidemia had thinner SFCT than those not have dyslipidemia (292.0 (166-431)μm vs 348.0(173-491)μm, p=0.003), while insulin resistance and metabolic syndrome had no effect on SFCT (p=0.336, and p=0.211, respectively). Conclusion: Childhood obesity and accompanying dyslipidemia led to a decrease in SFCT without any significant change in the CVI. However, the severity of obesity and having insulin resistance or metabolic syndrome had no effect on either SFCT or CVI. The thinning in the SFCT may be related to microvascular disorders due to childhood obesity and dyslipidemia

Assessing acute nicotine impact on choroidal thickness: a randomized, double-blinded study comparing smoking cessation aids, including nicotine gum and electronic cigarettes.

To explore whether differences in choroidal thickness arise from nicotine consumption in healthy young individuals, specifically comparing the effects of nicotine gum to electronic cigarette (vaping), while maintaining a consistent 4mg nicotine dosage. In a randomized double-blinded prospective cross-sectional study, 20 healthy participants (mean age ± standard deviation: 23 ± 2.36years) were randomly assigned to either the nicotine gum or vaping group. Choroidal thickness (ChT) measurements were conducted using optical coherence tomography (OCT) (Topcon 3D OCT-1 Maestro System) at baseline, 30, and 60min after ingesting 4mg of nicotine, with ChT measurements taken from five different horizontal areas. Neither the nicotine delivery method (gum or vaping) demonstrated a statistically significant impact on ChT mean scores among subjects in the five measured areas at baseline, 30, and 60min (p > 0.05). However, significant differences were observed in ChT mean scores within subjects across the five areas (F (1.83, 72) = 36.43, p < 0.001), regardless of other study factors such as group, time, and visit (p > 0.05). A statistically significant interaction was identified between the factors of area and time concerning participants' ChT mean scores when stratified by the type of smoking (tobacco, vaping, and dual) (p = 0.003). The results of this study revealed that nicotine, up to particular concentration of 4mg, does not have a statistically significant vasoconstrictive effect on choroidal thickness, regardless of the delivery method, within the examined group. These findings offer valuable insights into the relationship between nicotine intake and choroidal dynamics in young adults.

Ophthalmologic profile of patients with systemic sclerosis.

To study the ophthalmologic manifestations of systemic sclerosis (SSc) and its correlation with autoantibody profile. A cross-sectional study on 200 eyes of 100 consecutive adult patients diagnosed with SSc was performed at a tertiary care center in Northern India. The examination of ocular adnexa, anterior segment, and posterior segment with slit-lamp biomicroscopy, tear film break-up time (TBUT), Schirmer's II test, and choroidal thickness measurement by swept-source ocular coherence tomography was done. Autoantibody profile was available for 85 patients, and its statistical association with the ocular examination findings was analyzed. In total, 100 patients (93 females and 7 males) were included. The mean age was 45.11 ± 11.68 years, and the mean disease duration was 6.93 ± 3.68 years. Meibomian gland disease was more commonly found in patients with the diffuse subtype of SSc (P = 0.037). Choroidal thickness was increased in 34% and decreased in 7% (reference range = 307 ± 79 mm) patients. Reduced TBUT, meibomian gland dysfunction, and eyelid stiffness had a statistically significant association with the presence of anti-Scl-70 antibody (P = 0.003, <0.0001, and 0.004, respectively). These patients had ocular fatigue, foreign body sensation, and burning sensation. No significant association was noted with the presence of SS-A/Ro and SS-B/La antibodies. This study highlights the need for an active comprehensive ophthalmic evaluation. Approximately 75% of the patients in our cohort had ocular involvement to varying extent. An isolated presence of anti-Scl70 antibody was also found to have a positive association with dry eye disease.

Relationship between automated choroidal thickness measurements and retinal sensitivity using microperimetry in patients with myopia and different stages of myopic maculopathy

PurposeTo assess the relationship between macular choroidal thickness (CT) measurements and retinal sensitivity (RS) in eyes with myopia and different stages of myopic maculopathy.MethodsA masked, cross-sectional, and consecutive study involving patients with emmetropia/myopia (control group) and high myopia (HM) eyes. Automated choroidal thickness (CT) and manual outer retinal layer (ORL) thickness were acquired using swept-source optical coherence tomography, while retinal sensitivity (RS) assessed by microperimetry (MP3) in all regions of the macular Early Treatment Diabetic Retinopathy Study (ETDRS) grid. Comparisons were made between groups, and correlations were performed among these measurements, demographic and ocular parameters and myopic maculopathy classification.ResultsA total of 37 (74 eyes) patients were included in the study. The mean age was 39 ± 13 years, and 28 patients (76%) were female. HM eyes exhibited inferior best-corrected visual acuity and a more advanced myopic maculopathy classification compared to the control group. The mean macular CT were 255 and 179 μm in the control and HM eyes (P < 0.001), respectively. In the HM eyes, superior ETDRS region presented the greatest values. Mean RS in control and HM groups was 28 and 24 dB (P = 0.001), respectively. Inner temporal followed by superior, were the regions of higher RS. Mean ORL thickness was 83 and 79 μm (P < 0.001), in the control and HM groups, respectively. The inner temporal ETDRS region presented the thickest measure. CT correlated significantly with RS (r = 0.41, P < 0.001) and ORL thickness, (r = 0.58, P < 0.001), which also correlated with RS (r = 0.40, P < 0.001). Spherical equivalent, axial length and myopic maculopathy stage were the parameters that most correlated with CT, RS and ORL thickness. For every 100 μm increase in thickening of CT there was an average increase of 3.4 μm in ORL thickness and 2.7 dB in RS. Myopic maculopathy classification demonstrated influence only with CT.ConclusionMyopia degree is related to ORL and choroidal thinning and deterioration of retinal sensitivity in some ETDRS regions of the macula. Choroidal thinning is associated to with a decline of retinal sensitivity, thinning of ORL, and worsening of myopic maculopathy classification, so new treatments are necessary to prevent myopia progression.

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Assessing the impact of internal carotid artery stenosis on choroidal thickness using Cirrus optical coherence tomography

Aims: The choroid, one of the body's most highly vascularized tissues, receives its blood supply from the ophthalmic and posterior ciliary arteries, which stem from the internal carotid artery. The utilization of spectral-domain optical coherence tomography (SD-OCT) for both qualitative and quantitative assessment of the retina is increasing. The recent introduction of enhanced depth imaging OCT (EDI-OCT) has offered a novel approach to evaluate the choroid using commercially accessible SD-OCT devices. EDI-OCT enables the in vivo examination and measurement of the choroid. The main objective of our study is to evaluate choroidal thickness using EDI-OCT in patients with unilateral significant carotid stenosis; the secondary objective is to observe whether hemodynamic changes affect choroidal thickness. Methods: The study is prospectively designed as a cross-sectional, controlled, and single-blind study, encompassing patients who underwent neck computed tomographic angiography within a one-year period due to any disease. Included patients had carotid stenosis of 50% or more on one side and less than 50% on the other side. The eyes on the side with higher carotid stenosis constituted the study group, while the other side formed the control group. Anterior and posterior segment examinations of the patients, visual acuity according to Snellen Chart, and choroidal thickness were measured. Results: A total of 30 eyes of 15 patients were evaluated. Of the patients included in the study, 9 were men and 6 were women; the average age was 67.9 years (49-85). In the study group, the average choroidal thickness measurements were 211 µm in the nasal, 221 µm in the central and 209 µm in the temporal; in the control group, they were measured as 223 µm in the nasal, 243 µm in the central, and 231 µm in the temporal, respectively. Despite the choroidal thickness being thinner in the study group, the difference did not reach statistical significance. Conclusion: Additional research is required to pinpoint the factors contributing to the dynamics of choroidal thickness and to delineate its significance in carotid artery stenosis more comprehensively.

Mean Amplitude of Diurnal Variation of Sub-Foveal Choroidal Thickness among Adults with Healthy Eyes Visiting Outpatient Department of a Tertiary Eye Care Centre.

The choroid, particularly the choroidal vasculature, plays an important role in the pathophysiology of various ocular diseases. Diurnal variation in the thickness of the choroid has been reported in previous studies. This study aimed to find the mean amplitude of diurnal variation of sub-foveal choroidal thickness among adults with healthy eyes visiting the outpatient Department of a tertiary eye care centre. A descriptive cross-sectional study was conducted among adults with healthy eyes presenting to the outpatient Department of a tertiary eye care centre from 1 February 2023 to 3 June 2023 after obtaining ethical approval from the Institutional Review Committee. After a comprehensive medical eye examination, sub-foveal choroidal thickness measurement was performed using enhanced depth imaging optical coherence tomography at the baseline and subsequent interval afterwards. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. Among 60 eyes, the mean amplitude of the diurnal variation of subfoveal choroidal thickness was 35.16±14.08 microns (31.59-38.72, 95% Confidence Interval). The mean amplitude for the right eye was 36.30±14.08 microns, and for the left eye, it was 34.23±14.08 microns. The amplitude of diurnal variation of subfoveal choroidal thickness from this study was found to be similar to other studies done in international settings. choroid; circadian rhythm; cross-sectional study; Ophthalmology.

Effect of adalimumab on choroidal thickness and choroidal vascularity index in eyes with non-infectious uveitis using enhanced-depth imaging optical coherence tomography.

To evaluate the effect of adalimumab (ADA) on choroidal thickness (ChT) and choroidal vascularity index (CVI) in eyes with non-infectious uveitis (NIU). Thirty-seven eyes with NIU including Behçet disease (BD), sarcoidosis, ankylosing spondylitis (AS), juvenile idiopathic arthritis and idiopathic arthritis, 38 eyes of non-uveitic (NU) patients including BD, AS and rheumatoid arthritis, and 40 healthy control eyes were included. ADA was used for anti-TNF-naive adult (80 mg) or paediatric (40 mg) patients with refractory NIU, then 40 mg every 2-week (20 mg in children<30 kg) with controls at weeks 1, 4, 12, and 24. Images were used to measure central, nasal, and temporal ChT, and the luminal area (LA), stromal area, and total choroidal area (TCA) were analysed using enhanced-depth imaging optical coherence tomography (EDI-OCT) by ImageJ software. The CVI was then calculated as the ratio of LA to TCA. Mean ages were similar between the groups. Mean (SE) subfoveal ChT measurements for each location were also similar (for each, p > 0.05). However, calculated CVI values in eyes with NIU (0.63 ± 0.007) were significantly (p < 0.001) lower than NU eyes (0.66 ± 0.006) and controls (0.70 ± 0.007) (p < 0.001). Moreover, CVI was significantly lower in NU eyes compared to controls (p < 0.001). There were no significant CVI changes between the consecutive visits after ADA therapy in eyes with NIU (for each, p > 0.05). Decreased CVI in NIU and NU eyes indicates that systemic inflammation affects the choroidal vasculature and perfusion both in the presence and absence of ocular involvement. Although CVI may be used as a possible novel tool in monitoring ocular involvement and progression of NIU, CVI does not seem to be a biomarker for treatment monitoring in NIU.

Impaired brachial flow-mediated dilation may predict choroidal and retinal nerve fibre layer thickness changes in people with obesity

ABSTRACT Clinical relevance Choroidal thickness and peripapillary retinal nerve fibre layer (RNFL) changes are known to occur in obesity. Endothelial dysfunction and systemic atherosclerosis may play a role in the pathophysiology of these differences. Background Flow-mediated dilation (FMD) is reduced in patients with endothelial dysfunction, and the ankle-brachial index is a surrogate marker for atherosclerosis. This study was conducted to examine the relationship between systemic vascular parameters (FMD, and ankle-brachial index), subfoveal choroidal thickness, and peripapillary RNFL thickness in obese individuals. Methods This observational, cross-sectional study involved 108 total participants who were divided into two groups. One group consisted of 54 obese subjects who each had a body mass index of 30 kg/m2 or more. The other control group contained 54 participants who each had a body mass index of 25 kg/m2 or less but higher than 20 kg/m2 . For each participant, only one eye was examined in this study. Subfoveal choroidal thickness, RNFL thickness, ankle-brachial index, and ultrasound measurement of the brachial artery FMD were performed. FMD was categorised according to receiver operating characteristic analysis, and endothelial dysfunction was defined as an FMD ≤ 7.29%. Results Subfoveal choroidal and RNFL thicknesses in the temporal quadrant were significantly lower in the obese group (p < 0.05). Lower mean values of subfoveal choroidal and RNFL thicknesses in the temporal and inferior quadrants were observed in subjects with an FMD ≤ 7.29% (p < 0.05). In people with obesity, FMD was positively correlated with subfoveal choroidal thickness (r = 0.322, p = 0.001), inferior RNFL thickness (r = 0.259, p = 0.007), and temporal RNFL thickness (r = 0.297, p = 0.002). However, the ankle-brachial index was not correlated with obesity. Conclusions Impaired FMD was associated with reduced subfoveal choroidal and RNFL thicknesses in the temporal and inferior quadrants of people with obesity.

Assessment of macular choroidal and retinal thickness: a cohort study in Tibetan healthy children

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.

Choroidal thickness measurement in central serous chorioretinopathy using swept source optical coherence tomography: an observational study

Background: Central serous chorioretinopathy (CSCR) is a common retinal condition with an increased risk of recurrence. Traditional approaches have made choroidal visualization challenging, but recent advances in optical coherence tomography (OCT) innovation have permitted the collection of more accurate choroidal visualizations. This study aimed to measure choroidal thickness in eyes with active CSCR as well as in the unaffected opposite eyes of these same individuals. Methods: This research was conducted at the ophthalmology division in Ghazi Al-Hariri hospital from the 1st of October 2019 until the 31th of March 2020. A total of 49 people, corresponding to 65 eyes, were included in the study. Among these participants, 16 individuals presented with central serous chorioretinopathy (CSCR), affecting a total of 32 eyes. The CSCR individuals were further split into two groups: "group A" consisted of 20 eyes with active CSCR, and "group B" encompassed the remaining 12 unaffected opposite eyes. Additionally, 33 individuals who were age and gender-matched served as controls assigned as "group C". Results: The choroid exhibited a substantial rise in thickness across each of the nine sectors in group A as compared to group C. Similarly, group B showed a significant increase in choroidal thickness in relation to group C. The mean subfoveal choroidal thickness (SFCT) was measured as follows: 474.55μm, 437.5μm, and 292.03μm among groups A, B, and C, correspondingly. These differences were identified as clinically significant for both A vs. C and B vs. C. Conclusions: This study's findings indicate a thickening of the choroid in both eyes exhibiting active CSCR, as well as in the unaffected opposite eyes of those with the disease.

Short-term effects of cyclopentolate and tropicamide eye drops on macular choroidal thickness in myopic children.

To investigate the short-term effects of cyclopentolate and tropicamide eyedrops on choroidal thickness (ChT) in myopic children using placebo or low-dose atropine eyedrops. The analysis included 242 myopic individuals (7-19 years) enrolled in two randomised placebo-controlled clinical trials of low-dose atropine eyedrops. Cycloplegia was induced using either one drop of 1% cyclopentolate (n = 161), two drops of 1% cyclopentolate (n = 32) or two drops of 1% tropicamide (n = 49). ChT measurements were taken using swept-source optical coherence tomography before and 30 min after administering the cycloplegic eye drops. A subset of 51 participants underwent test-retest measurements prior to cycloplegia. Mean changes in subfoveal ChT after two drops of tropicamide and one and two drops of cyclopentolate were -2.5 μm (p = 0.10), -4.3 μm (p < 0.001) and -9.6 μm (p < 0.001), respectively. Subfoveal ChT changes after one and two drops of cyclopentolate were significantly greater than the test-retest changes (test-retest mean change: -3.1 μm; p < 0.05), while the tropicamide group was not significantly different (p = 0.64). Choroidal thinning post-cyclopentolate was not significantly different between atropine and placebo treatment groups (p > 0.05 for all macular locations). The coefficient of repeatability (CoR) in the tropicamide group (range: 8.2-14.4 μm) was similar to test-retest (range: 7.5-12.2 μm), whereas greater CoR values were observed in the cyclopentolate groups (one drop: range: 10.8-15.3 μm; two drops: range: 12.2-24.6 μm). Cyclopentolate eye drops caused dose-dependent choroidal thinning and increased variation in pre- to post-cycloplegia measurements compared with test-retest variability, whereas tropicamide did not. These findings have practical implications for ChT measurements when cyclopentolate is used, particularly for successive measurements.

An Open-Source Deep Learning Algorithm for Efficient and Fully Automatic Analysis of the Choroid in Optical Coherence Tomography.

To develop an open-source, fully automatic deep learning algorithm, DeepGPET, for choroid region segmentation in optical coherence tomography (OCT) data. We used a dataset of 715 OCT B-scans (82 subjects, 115 eyes) from three clinical studies related to systemic disease. Ground-truth segmentations were generated using a clinically validated, semiautomatic choroid segmentation method, Gaussian Process Edge Tracing (GPET). We finetuned a U-Net with the MobileNetV3 backbone pretrained on ImageNet. Standard segmentation agreement metrics, as well as derived measures of choroidal thickness and area, were used to evaluate DeepGPET, alongside qualitative evaluation from a clinical ophthalmologist. DeepGPET achieved excellent agreement with GPET on data from three clinical studies (AUC = 0.9994, Dice = 0.9664; Pearson correlation = 0.8908 for choroidal thickness and 0.9082 for choroidal area), while reducing the mean processing time per image on a standard laptop CPU from 34.49 ± 15.09 seconds using GPET to 1.25 ± 0.10 seconds using DeepGPET. Both methods performed similarly according to a clinical ophthalmologist who qualitatively judged a subset of segmentations by GPET and DeepGPET, based on smoothness and accuracy of segmentations. DeepGPET, a fully automatic, open-source algorithm for choroidal segmentation, will enable researchers to efficiently extract choroidal measurements, even for large datasets. As no manual interventions are required, DeepGPET is less subjective than semiautomatic methods and could be deployed in clinical practice without requiring a trained operator. DeepGPET addresses the lack of open-source, fully automatic, and clinically relevant choroid segmentation algorithms, and its subsequent public release will facilitate future choroidal research in both ophthalmology and wider systemic health.

Choroidal thickness measurements in young Saudi adult population: a cross-sectional study.

To determine the choroidal thickness (CT) in young healthy Saudi adults using spectral-domain optical coherence tomography (SD-OCT) with an automated CT segmentation software. Fifty-eight young adults (total of 116 eyes), 39 males and 19 females participated in this study between the ages of 18 and 38y (mean 22.65±3.9y). All participants underwent ophthalmic screening examination, including the SD-OCT for measurements of CT in each quadrant egmented into five eccentric regions starting from the foveal region up to 4.5 mm towards the periphery. The choroid was thickest in the foveal region (central 1 mm, 300±60 µm) and began to progressively thinner beyond the parafovea (1.5-2.5 mm, 284±67 µm) towards the peripheral region (3.5-4.5 mm from the fovea, 254±83 µm). The superior choroid showed the thickest profile (309±57 µm), while the nasal choroid exhibited the thinnest (229±76 µm). The rate of the thinning with increasing eccentricity was more predominant in the nasal choroid, which thinned from the foveal region (294±58 µm) to the peripheral region (158±55 µm). The superior and inferior choroid did not show a statistically significant thinning with eccentricity (all P>0.05). There was no statistically significant difference in the CT between gender, age, and laterality of the eyes (all P>0.05). A significant association of myopia with thinner subfoveal choroid was observed (Pearson's, r=0.37), and regression analysis showed that a 10.3 µm choroidal thinning for each diopter increase of myopia. CT profile depends on eccentric and the quadrant. The CT profile across the measured area in the young Saudi adult population is comparable to other previous reports. Refractive error is critical for CT evaluation.

Evaluation of an Automated Choroid Segmentation Algorithm in a Longitudinal Kidney Donor and Recipient Cohort.

To evaluate the performance of an automated choroid segmentation algorithm in optical coherence tomography (OCT) data using a longitudinal kidney donor and recipient cohort. We assessed 22 donors and 23 patients requiring renal transplantation over up to 1year posttransplant. We measured choroidal thickness (CT) and area and compared our automated CT measurements to manual ones at the same locations. We estimated associations between choroidal measurements and markers of renal function (estimated glomerular filtration rate [eGFR], serum creatinine, and urea) using correlation and linear mixed-effects (LME) modeling. There was good agreement between manual and automated CT. Automated measures were more precise because of smaller measurement error over time. External adjudication of major discrepancies was in favor of automated measures. Significant differences were observed in the choroid pre- and posttransplant in both cohorts, and LME modeling revealed significant linear associations observed between choroidal measures and renal function in recipients. Significant associations were mostly stronger with automated CT (eGFR, P < 0.001; creatinine, P = 0.004; urea, P = 0.04) compared to manual CT (eGFR, P = 0.002; creatinine, P = 0.01; urea, P = 0.03). Our automated approach has greater precision than human-performed manual measurements, which may explain stronger associations with renal function compared to manual measurements. To improve detection of meaningful associations with clinical endpoints in longitudinal studies of OCT, reducing measurement error should be a priority, and automated measurements help achieve this. We introduce a novel choroid segmentation algorithm that can replace manual grading for studying the choroid in renal disease and other clinical conditions.

Evaluation of the retinal nerve fiber layer and choroidal thickness with optical coherence tomography in patients with psoriasis

BackgroundTo evaluate the retinal nerve fiber layer (RNFL), central retinal thickness (CRT), and choroidal thickness (CT) in patients with psoriasis. MethodsThe study included 43 patients diagnosed with psoriasis not receiving systemic treatment and 41 healthy volunteers. Spectral domain optical coherence tomography was used for retinal and choroidal thickness measurements. The mean RNFL, quadrant RNFL (superior, inferior, nasal, temporal), and CRT values were recorded. The choroidal thickness measurements were taken from the subfoveal area, towards the temporal and nasal directions from the fovea at distances of 500, 1000, and 1500 µm. ResultsThe RNFL was determined to be thinner in the superior quadrant (p=0.025), and the CT was thicker at all the measurement points (p < 0.05) in the patients with psoriasis. The CRT values were similar in both groups (p > 0.05). No correlation was determined between the parameters measured and disease duration or severity. ConclusionsThinning of the RNFL and increased CT may be a sign of choroidal microvascular changes and ganglion cell damage due to psoriasis.

Characteristics of the retina and choroid in fibromyalgia patients and their correlation with disease severity and quality of life

BackgroundTo evaluate retinal and choroidal characteristics of fibromyalgia (FM) patients using spectral-domain optical coherence tomography (SD-OCT), to compare them with healthy controls, and to determine the correlation of these measurements with disease severity and quality of life. MethodsThirty-nine eyes of 39 patients with FM and 44 eyes of 44 age‐ and sex‐matched healthy subjects were enrolled. The retinal nerve fiber layer (RNFL), central macular thickness (CMT), and choroidal thickness (CT) measurements of the subjects were obtained using SD-OCT (Maestro, Topcon Co. Tokyo, Japan), choroidal vascular index (CVI) was calculated by using the binarization method and the results were compared. Disease duration (DD), widespread pain index (WPI), symptom severity scale (SSS), visual analog scale (VAS), ocular pain assessment survey (OPAS), FM impact questionnaire (FIQ), European Quality of Life-5 Dimensions-3 level (EQ-5D-3 L), European Quality VAS score (EQ-VAS) and use of pregabalin were recorded. Correlations between the SD-OCT results and the FM parameters were evaluated. ResultsNo significant difference was found in terms of age and gender (p = 0.612, p = 0.244 respectively). Patients in the FM group had significantly thinner RNFL superior quadrant and CT (p = 0,009 and p < 0.001, respectively). CVI was significantly higher in the FM group (p < 0.001). There was an inverse correlation between OPAS and CT (r = -0.379, p = 0.027) and between VAS and CVI (r = -0.398, p = 0.020). The use of pregabalin had no effect on SD-OCT (p > 0.05). ConclusionPatients with FM demonstrated reduced RNFL superior quadrant and CT and increased CVI. Ocular and general body pain in FM was found to be associated with SD-OCT.