Jiwon Baek

Background/Objectives: Experimental studies implicate the gut microbiome in diabetic retinopathy (DR), but population-based data on probiotic supplementation and DR are lacking. We examined this association in Korean adults with diabetes. Methods: We analyzed 2071 adults with diabetes in the Korea National Health and Nutrition Examination Survey 2018–2021 with graded fundus photographs and a product-level dietary supplement interview. We used survey-weighted logistic regression (prespecified) and Poisson regression (added after the initial analysis) estimated odds ratios (ORs) and prevalence ratios (PRs), adjusted for age, sex, hypertension, smoking, and household income (Model 1), and additionally for diabetes duration and glycated hemoglobin (HbA1c) (Model 2, primary), with further adjustment for clinical, lifestyle, and dietary factors. Results: Probiotic supplements were used by 10.4% of participants. Weighted DR prevalence was 11.0% among users and 21.1% among non-users (Model 2 PR 0.57, 95% CI 0.36–0.90; OR 0.49, 95% CI 0.28–0.86; 27 exposed cases; fully adjusted PR 0.59, 95% CI 0.37–0.95). In exploratory analyses, compared with non-use, the PRs were 0.76 (95% CI 0.45–1.29; not statistically significant) for use of p = 0.024), a descriptive observation that does not demonstrate a protective effect. Use of any non-probiotic supplement was not associated with DR (PR 0.92), although vitamin C and vitamin A/lutein supplements showed inverse associations of similar magnitude. Conclusions: Probiotic supplement use was associated with a lower prevalence of DR among Korean adults with diabetes. These cross-sectional findings are consistent with, but do not establish, a role of the gut–retina axis in DR and require confirmation in prospective studies.

To evaluate and compare the clinical validity of synthetic ultra-widefield fluorescein angiography (UWFA) images generated from ultra-widefield fundus photography (UWFP) using generative adversarial networks (GANs) in patients with diabetic retinopathy (DR). Two GAN-based models, RegGAN and UWAFA-GAN, were trained to generate synthetic UWFA images from corresponding UWFP acquired using Optos California P200DTx. The dataset included 2084 image pairs (no DR: 124; nonproliferative DR: 795; severe NPDR: 770; proliferative DR: 395). Technical image similarity was assessed using peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM). Clinical similarity was assessed by expert graders using the DR severity scale, comparing the synthetic images with corresponding real UWFA images. Both models demonstrated acceptable performance in generating synthetic UWFA images from UWFP (F1-score range: 0.281–0.709; SSIM: 0.43–0.585; PSNR: 18.15–19.90). UWAFA-GAN achieved higher quantitative similarity metrics (SSIM and PSNR), indicating superior overall image fidelity, whereas RegGAN showed stronger clinical correlation with ground-truth UWFA, achieving higher diagnostic accuracy (66.7% vs. 49.2%) and more balanced precision, recall, and F1-scores across DR severity levels. This suggests that while UWAFA-GAN excels in pixel-level resemblance, RegGAN better preserves diagnostically relevant features. GAN models successfully generated UWFA images from UWFP in patients with DR. With further improvements, such models may serve as a complementary noninvasive imaging tool in selected clinical settings and may extend accessibility in resource-limiting settings. GAN-based synthetic angiography may serve as a noninvasive alternative to UWFA, particularly when conventional angiography is contraindicated or unavailable.

Background/Objectives: To comprehensively evaluate longitudinal retinal and choroidal vascular changes after phacoemulsification using automated optical coherence tomography angiography (OCTA) analysis and to investigate clinical factors influencing these changes. Methods: This retrospective study included 26 subjects (31 eyes) who underwent uncomplicated phacoemulsification. OCTA was performed at baseline and at 1 day, 1 week, 1 month, and 2 months postoperatively. Automated quantitative analysis was applied to assess vessel density- and structure-related parameters in the superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris, and Haller layer. Longitudinal changes were analyzed using repeated-measures analysis of variance, with time × clinical factor interactions evaluated for diabetes mellitus, anesthesia method, and sex. Inter-layer associations were assessed using Spearman correlation analysis. Results: Significant longitudinal changes were observed in retinal layers. In the SCP, vessel density increased from 42.59 ± 1.46 at baseline to 44.10 ± 1.44 at 2 months (p = 0.002), accompanied by increases in vessel length and node counts (all p < 0.001). In the DCP, vessel density increased from 34.66 ± 5.98 to 38.65 ± 4.83 (p < 0.001). In contrast, choriocapillaris-related parameters showed no significant overall time effect. In the Haller layer, mean vessel diameter decreased significantly over time (p < 0.001), while density-related metrics remained unchanged. ΔVAD demonstrated positive correlations between adjacent layers (SCP–DCP and DCP–choriocapillaris) and a negative correlation between choriocapillaris and Haller layers. Diabetes mellitus showed no significant longitudinal effect, whereas retrobulbar anesthesia and sex significantly modified selected choroidal trajectories. Conclusions: Automated and integrated OCTA analysis revealed layer-dependent retinal and choroidal vascular responses after phacoemulsification, with coordinated changes confined mainly to anatomically adjacent layers and selective modulation by clinical factors.

Purpose To analyze vascular morphologies of layers of the choroid and compare between acute and chronic central serous chorioretinopathy (CSC). Methods A total of 161 (79 acute and 82 chronic) CSC eyes followed up for 6 months were enrolled. Baseline optical coherence tomography (OCT) and OCT angiography (OCTA) data were collected, and choriocapillaris (CC), Sattler’s layer, and Haller’s layer en-face slabs were obtained from OCT and OCTA. Vessel parameter analysis was performed using the OCTA Vascular Analyzer. Results Acute CSC showed higher node numbers, vessel area density, and total vessel length at the CC along with reduced diameter variation, skew, and kurtosis when compared to chronic CSC (all P ≤ 0.032). Acute CSC showed reduced diameter, diameter variation, and skew at Sattler’s layer when compared to chronic CSC (all P ≤ 0.033). Finally, acute CSC showed reduced diameter kurtosis at Haller’s layer when compared to chronic CSC (P = 0.017). There were significant correlations noted among the above-mentioned parameters between each layer, with correlations being more prominent between Sattler’s and Haller’s layers. Conclusion CC change in chronic CSC involved decreased nodes, density, and greater diameter variation, which in turn led to increases in diameter and diameter variations of larger vessels.

Purpose To train generative adversarial network (GAN) models to generate predictive optical coherence tomography (OCT) images of central serous chorioretinopathy (CSC) at 3 months after observation using multi-modal OCT images. Methods Four hundred forty CSC eyes of 440 patients who underwent Cirrus OCT imaging were included. Baseline OCT B-scan images through the foveal center, en face choroid, and en face ellipsoid zone were collected from each patient. The datasets were divided into training and validation (n = 390) and test (n = 50) sets. The input images for each model comprised either baseline B-scan alone or a combination of en face choroid and ellipsoid zones. Predictive post-treatment OCT B-scan images were generated using GAN models and compared with real 3-month images. Results Of 50 generated OCT images, there were 48, 47, and 48 acceptable images for UNIT, CycleGAN, and RegGAN, respectively. In comparison with real 3-month images, the generated images showed sensitivity, specificity, and positive predictive values (PPV) for residual fluid in the ranges of 0.762–1.000, 0.483–0.724, and 0.583–0.704; for pigment epithelial detachment (PED) of 0.917–1.000, 0.974–1.000, and 0.917–1.000; and for subretinal hyperreflective material (SHRM) of 0.667–0.778, 0.925–0.950 and 0.700–0.750, respectively. RegGAN exhibited the highest values except for sensitivity. Conclusions GAN models could generate prognostic OCT images with good performance for prediction of residual fluid, PED, and SHRM presence in CSC. Implementation of the models may help predict disease activity in CSC, facilitating the establishment of a proper treatment plan.

To obtain a quantitative parameter for the measurement of choroidal vascular hyperpermeability (CVH) on ultra-widefield indocyanine green angiography (UWICGA) using an objective analysis method in macular choroidal neovascularization (CNV). A total of 113 UWICGA images from 113 subjects were obtained, including with 25 neovascular age-related macular degeneration (nAMD), 37 with polypoidal choroidal vasculopathy (PCV) (19 with thin-choroid and 18 with thick-choroid), 33 with pachychoroid neovasculopathy (PNV), and 18 age-matched controls. CVH was quantified on a gray image by the subtraction of 2 synchronized UWICGA images of early and late phases. The measured CVH parameter was compared with human graders and among CNV subtypes and correlated with choroidal vascular density (CVD) and subfoveal choroidal thickness (SFCT). The mean CVH values were 28.58 ± 4.97, 33.36 ± 8.40, 33.61 ± 11.50, 42.19 ± 13.25, and 43.59 ± 7.86 in controls and patients with nAMD, thin-choroid PCV, thick-choroid PCV, and PNV, respectively (p < 0.001). CVH was higher in thick-choroid PCV and PNV compared to the other groups (all p ≤ 0.006). The measured CVH value positively correlated with those reported by human graders (p < 0.001), CVD, and SFCT (p = 0.001 and p < 0.001, respectively). CVH can be measured objectively using quantitative UWICGA analysis. The CVH parameter differs among macular CNV subtypes and correlates with CVD and SFCT.