Optical coherence tomography (OCT) is widely used to detect and classify retinal diseases. However, OCT-image-based manual detection by ophthalmologists is prone to errors and subjectivity. Thus, various automation methods have been proposed; however, improvements in detection accuracy are required. Particularly, automated techniques using deep learning on OCT images are being developed to detect various retinal disorders at an early stage. Here, we propose a deep learning-based automatic method for detecting and classifying retinal diseases using OCT images. The diseases include age-related macular degeneration, branch retinal vein occlusion, central retinal vein occlusion, central serous chorioretinopathy, and diabetic macular edema. The proposed method comprises four main steps: three pretrained models, DenseNet-201, InceptionV3, and ResNet-50, are first modified according to the nature of the dataset, after which the features are extracted via transfer learning. The extracted features are improved, and the best features are selected using ant colony optimization. Finally, the best features are passed to the k-nearest neighbors and support vector machine algorithms for final classification. The proposed method, evaluated using OCT retinal images collected from Soonchunhyang University Bucheon Hospital, demonstrates an accuracy of 99.1% with the incorporation of ACO. Without ACO, the accuracy achieved is 97.4%. Furthermore, the proposed method exhibits state-of-the-art performance and outperforms existing techniques in terms of accuracy.

Increasing evidence suggests that exosomes are involved in retinal cell degeneration, including their insufficient release; hence, they have become important indicators of retinopathies. The exosomal microRNA (miRNA), in particular, play important roles in regulating ocular and retinal cell functions, including photoreceptor maturation, maintenance, and visual function. Here, we generated retinal organoids (ROs) from human induced pluripotent stem cells that differentiated in a conditioned medium for 60 days, after which exosomes were extracted from ROs (Exo-ROs). Subsequently, we intravitreally injected the Exo-RO solution into the eyes of the Royal College of Surgeons (RCS) rats. Intravitreal Exo-RO administration reduced photoreceptor apoptosis, prevented outer nuclear layer thinning, and preserved visual function in RCS rats. RNA sequencing and miRNA profiling showed that exosomal miRNAs are mainly involved in the mitogen-activated protein kinase (MAPK) signaling pathway. In addition, the expression of MAPK-related genes and proteins was significantly decreased in the Exo-RO-treated group. These results suggest that Exo-ROs may be a potentially novel strategy for delaying retinal degeneration by targeting the MAPK signaling pathway.

This study investigated the therapeutic effects of exosomes derived from human-induced pluripotent stem cell (hiPSC)-derived retinal organoids (ROs) on corneal epithelial wound healing. Exosomes were isolated from the culture medium of the hiPSC-derived ROs (Exo-ROs) using ultracentrifugation, and then they were characterized by a nanoparticle tracking analysis and transmission electron microscopy. In a murine model of corneal epithelial wounds, these exosomes were topically applied to evaluate their healing efficacy. The results demonstrated that the exosome-treated eyes showed significantly enhanced wound closures compared with the controls at 24 h post-injury. The 5-ethyl-2′-deoxyuridine assay and quantitative reverse transcription polymerase chain reaction revealed a substantial increase in cell proliferation and a decrease in inflammatory marker contents in the exosome-treated group. The RNA sequencing and exosomal microRNA analysis revealed that the Exo-RO treatment targeted various pathways related to inflammation and cell proliferation, including the PI3K-Akt, TNF, MAPK, and IL-17 signaling pathways. Moreover, the upregulation of genes related to retinoic acid and eicosanoid metabolism may have enhanced corneal epithelial healing in the eyes treated with the Exo-ROs. These findings suggest that hiPSC-derived RO exosomes could be novel therapeutic agents for promoting corneal epithelial wound healing.

Purpose: To evaluate the efficacy of intravitreal brolucizumab in polyp regression of treatment-naive polypoidal choroidal vasculopathy (PCV) patients and its effect on 1-year treatment outcome.Methods: Medical records of 31 treatment-naive PCV patients, who received three monthly intravitreal brolucizumab injections followed by as-needed injections for at least a year, were retrospectively reviewed. Visual and anatomical outcomes were evaluated at 3, 6, and 12 months. Complete polyp regression rate and percentage change of vascular lesion and polyp area were evaluated after three monthly injections of brolucizumab. The effect of complete polyp regression and the impact of vascular lesion and polyp reduction rate on 1-year treatment outcome were also evaluated.Results: In terms of visual outcome, best-corrected visual acuity significantly improved after 12-month follow-up (p < 0.001). In terms of anatomical outcome, central macular thickness (CMT) and central choroidal thickness significantly decreased after 12-month follow-up (p < 0.001). Complete polyp regression was observed in 23 patients (74.2%) after three monthly injections. Group with complete polyp regression had a higher rate of achieving dry macula at 3 months (p = 0.026) and fewer number of injections (p < 0.001) compared to the group without complete polyp regression. Higher polyp reduction rate was significantly associated with higher CMT change from baseline at 3 months (p = 0.048) while higher vascular lesion reduction rate was significantly associated with higher CMT change from baseline at 12 months (p = 0.031) and fewer number of injections (p = 0.012).Conclusions: Intravitreal brolucizumab injection effectively improved visual and anatomical outcomes and achieved significant polyp regression in treatment-naive PCV patients. Complete polyp regression and the reduction rate of vascular lesion size and polyp size after loading injection significantly influence the treatment outcome of PCV patients. However, careful monitoring and preoperative warning is warranted due to occurrence of brolucizumab-related IOI.

X-linked juvenile retinoschisis (XLRS) is a hereditary retinal degeneration affecting young males caused by mutations in the retinoschisin (RS1) gene. We generated human induced pluripotent stem cells (hiPSCs) from XLRS patients and established three-dimensional retinal organoids (ROs) for disease investigation. This disease model recapitulates the characteristics of XLRS, exhibiting defects in RS1 protein production and photoreceptor cell development. XLRS ROs also revealed dysregulation of Na/K-ATPase due to RS1 deficiency and increased ERK signaling pathway activity. Transcriptomic analyses of XLRS ROs showed decreased expression of retinal cells, particularly photoreceptor cells. Furthermore, relevant recovery of the XLRS phenotype was observed when co-cultured with control ROs derived from healthy subject during the early stages of differentiation. In conclusion, our in vitro XLRS RO model presents a valuable tool for elucidating the pathophysiological mechanisms underlying XLRS, offering insights into disease progression. Additionally, this model serves as a robust platform for the development and optimization of targeted therapeutic strategies, potentially improving treatment outcomes for patients with XLRS.

The role of the mitogen-activated protein kinase (MAPK) pathway in choroidal neovascularization (CNV) remains unclear. This study investigates the involvement of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 pathways in CNV development, as well as the therapeutic potential of sprouty 2 (SPRY2), an MAPK inhibitor, in a laser-induced mouse model. The expressions of ERK, JNK, and p38 proteins were analyzed using Western blotting and immunostaining. Immunofluorescence imaging revealed increased p-ERK and p-JNK expression in the retina, retinal pigment epithelium (RPE), and choroid up to day 7. Co-immunostaining showed p-ERK colocalized with CD31, CD11b, F4/80, cytokeratin, and GFAP in the retina, while p-JNK and p-p38 were associated with angiogenesis and inflammation throughout the retina and choroid. Compared to aflibercept, SPRY2 administration significantly inhibited CNV lesions, endothelial proliferation, fibrosis, and apoptosis, while better-preserving RPE integrity. SPRY2-treated mice showed a stronger reduction in CNV-related inflammation, epithelial–mesenchymal transition, and photoreceptor apoptosis. These results highlight the MAPK pathway’s role in CNV pathogenesis, with ERK primarily mediating Müller cell gliosis and JNK, contributing to angiogenesis and inflammation. SPRY2 effectively suppressed CNV lesions, supporting its potential as a therapeutic target for CNV treatment via MAPK pathway modulation.