Diabetic retinopathy (DR) is a leading cause of vision impairment in the working-age population worldwide. Various modes of photoreceptor cell death contribute to the development of DR, including apoptosis and autophagy. However, whether ferroptosis is involved in the pathogenesis of photoreceptor degeneration in DR is still unclear. High-glucose (HG)-stimulated 661W cells and diabetic mice models were used for in vitro and in vivo experiments, respectively. The levels of intracellular iron, glutathione (GSH), reactive oxygen species (ROS), lipid peroxidation (MDA), and ferroptosis-related proteins (GPX4, SLC7A11, ACSL4, FTH1, and NCOA4) were quantified to indicate ferroptosis. The effect of ferroptosis inhibition was also assessed. Our data showed the levels of iron, ROS, and MDA were enhanced and GSH concentration was reduced in HG-induced 661W cells and diabetic retinas. The expression of GPX4 and SLC7A11 was downregulated, while the expression of ACSL4, FTH1, and NCOA4 was upregulated in the 661W cells cultured under HG conditions and in the photoreceptor cells in diabetic mice. Furthermore, the administration of the ferroptosis inhibitor ferrostatin-1 (Fer-1) obviously alleviated ferroptosis-related changes in HG-cultured 661W cells and in retinal photoreceptor cells in diabetic mice. Taken together, our findings suggest that ferroptosis is involved in photoreceptor degeneration in the development of the early stages of DR.

Ultra-wide field (UWF) retinal imaging can improve the detection rate of retinal hemorrhage as compared with conventional fundus images. However, hemorrhages in UWF retinal images can also become smaller and more widely distributed, which can be time consuming and labor intensive. With the development of computer technology, automatic segmentation techniques can assist physicians in diagnosis. However, the lack of publicly available UWF retinal hemorrhage segmentation datasets has limited the development of automatic hemorrhage segmentation techniques in UWF retinal images. We present a large-scale high-quality UWF retinal hemorrhage segmentation dataset, named UWF-RHS Dataset, for public use. To the best of our knowledge, we are the first team to make the UWF retinal hemorrhage segmentation dataset publicly available. In addition, we propose a multi-scale attention subtraction network (MASNet) for UWF retinal hemorrhage segmentation. Specifically, highly focused lesion features are extracted by using the proposed multi-scale attention subtraction (MAS) module at the progress of the skip-connection. Several comparative experiments and ablation experiments were performed at the UWF-RHS Dataset, and all experiments state that our proposed method is effective in diagnosing retinal hemorrhages with state-of-the-art results. The proposed UWF-RHS dataset and MASNet will greatly facilitate the development of automated segmentation techniques for UWF retinal hemorrhages. Links to the UWF-RHS dataset and the MASNet model code are available from https://github.com/wurenkai/UWF-RHS-Dataset-and-MASNet .

Objective. To determine the influence of phacoemulsification on choroidal vasculature in patients with diabetic retinopathy (DR) undergoing cataract surgery using swept-source optical coherence tomography (SS-OCT). Methods. The study was conducted in 23 eyes of 23 cataract patients with mild/moderate nonproliferative diabetic retinopathy (NPDR) without diabetic macular edema (DME) and 23 age-matched controls. Choroidal thickness (CT) and choroidal vascularity index (CVI) were measured at baseline and 1 week, 1 month, and 3 months after surgery. Results. The baseline CVI in the DR group was significantly lower than that in the control group ( $P=0.001$ ). CVI in DR patients after surgery significantly increased compared with preoperative values (all $P<0.001$ for 1 week, 1 month, and 3 months after surgery). Postoperative increase of CVI and CT in the DR group was more than in the control group, and the difference was significant 1 month and 3 months after surgery (all $P<0.05$ ). Conclusion. Patients with mild/moderate NPDR have reduced CVI compared with nondiabetic patients at baseline; diabetic cataract surgery tended to induce more increase in CVI and CT as compared with nondiabetic patients. This trial is registered with NCT04499768.