Diabetic macular edema (DME) is the most common retinopathy that seriously threatens the visual function of diabetic patients, and it represents a major cause of blindness especially among people in working age. Ocular VEGF inhibitors are most often used as a first line therapy for DME, and have revolutionary significance in improving visual outcomes. However, there remain 30%-50% patients who fail to respond to anti-VEGF treatment, and the need for frequent injections brings a substantial treatment burden to patients and society. Novel therapeutic strategies include improving efficacy and duration of anti-VEGF drugs, targeting inflammation, the plasma kallikrein–kinin system, the angiopoietin-Tie2 system, neurodegeneration and other alternative pathways, as well as using subthreshold and targeted laser therapy. It is still challenging in the individualized management of DME to identify non-responders to anti-VEGF drugs and to establish a standardized regimen for the switch from anti-VEGF therapy to anti-inflammatory or other alternative treatment. Further research and development of new therapies, as well as preventive and screening strategies, are needed to reduce the impact of diabetic retinopathy and DME on public health.
The concept of “Microbe-gut-eye axis” holds that metabolites of the gut microbiota are involved in the pathogenesis of various eye diseases. The composition and diversity of gut microbiota in diabetic retinopathy (DR) patients are significantly different from those in non-DR patients. Metabolites of the gut microbiota such as lipopolysaccharide, short-chain fatty acid, bile acids and branched-chain amino acid aggravate or attenuate the progression of DR by regulating the release of inflammatory cytokines, mitochondrial function, insulin sensitivity, immune response, and autophagy of retinal cells. Therefore, gut microbiota and their metabolites play a role in the occurrence and development of DR through multiple pathways. The participation of gut microbiota may open up a new way to prevent and treat DR in the future.
Objective To observe the subfoveal choroidal thickness (SFCT) in eyes of patients with diabetic macular edema (DME). Methods Twenty patients (32 eyes) with DME were enrolled in this crosssectional observational study. The patients included 12 males and eight females, with a mean age of (47.3plusmn;10.2) years. All the patients were examined documenting best corrected visual acuity (BCVA), spectraldomain optical coherence tomography (OCT) and ophthalmological examination. According to OCT DME morphology, samples are divided into diffuse macular edema, cystoid macular edema, serous retinal detachment and hard exudate groups. The SFCT was measured by a Cirrus HD-OCT with enhanced depth imaging (EDI) and was compared with the average SFCT (286.84plusmn;28.80) mu;m of same age group. Correlation between SFCT and age, diopter, diabetic duration, fasting blood glucose, BCVA and central retinal thickness were analyzed by Pearson Analysis. SFCT of different DME types were analyzed by ANOVA Analysis. Results The mean SFCT of 32 eyes was (223.81plusmn;43.74) mu;m (ranging from 120.50 to 361.50 mu;m), which was lower by 63.03 mu;m (95% confidence interval, -78.80 to -47.26 mu;m, P＜0.01) from normal SFCT. SFCT was independent of age (r=0.124), diopter (r=0.277), diabetic duration (r=0.286), fasting blood glucose (r=0.408), BCVA (r=0.087), and central retinal thickness (r=0.036). There was no significant difference of SFCT between different DME types (F=0.042，P＞0.05). Conclusion SFCT is thinner in eyes with DME as compared to normal eyes of the same age.
O-linked N-acetylglucosamine (O-GlcNAc) glycosylation is an important form of post-translational protein modification, mainly intracellular. It is closely related to cellular signaling pathways, and is involved in signal transduction, gene transcription and other important biological processes. Studies have found that O-GlcNAc glycosylation is directly related with diabetic retinopathy (DR), further studies may help us to uncover the DR mechanism, and develop new strategies for the diagnosis and treatment of this disease.
The Evidence-based guidelines for diagnosis and treatment of age-related macular degeneration in China (2023) is the first evidence-based clinical practice guidelines for the diagnosis and treatment of age-related macular degeneration (AMD) in China that strictly follows the WHO guideline formulation and international guideline standards. Based on the latest evidence-based medical evidence and the rapid development of ocular fundus imaging technology, the new version of the guidelines has been updated in the diagnosis, treatment and follow-up of AMD. Based on the origin and presence of neovascularization in retinal tissue, the macular neovascularizations are divided into type 1, type 2 and type 3 macular neovascularization (MNV). Optical coherence tomography (OCT) plus OCT angiography is recommended as the useful diagnostic method in neovascular AMD patients. Antioxidant vitamins, zinc, lutein, zeaxanthin, or a mix of antioxidant vitamins and minerals are recommended to prevent the progression of early to intermediate AMD. Intravitreal administration of anti-vascular endothelial growth factor (VEGF) agents is the first-line treatment for neovascular AMD, and once a month for the first 3 months plus treatment and prolonged administration regimen shows benefit to a certain extent. For poor response and non-response neovascular AMD patients, the clinician should decide the next treatment plan based on comprehensive consideration. Close observation is recommended for non-exudative MNV, and anti-VEGF therapy should be used promptly once non-exudative MNV transfer to exudative MNV. It is hoped that this guideline will improve the diagnosis, treatment, prevention and follow-up of AMD in China.
Based on the current situation of patients with retinal diseases in China and the clear requirements of the "14th Five-Year Plan for Eye Health (2021-2025)" to strengthen the construction of the prevention and control system for retinal diseases, experts in the field of retinal diseases in China have conducted in-depth and comprehensive thematic discussions, and used the modified Delphi method for collective decision-making and opinion solicitation, ultimately forming consensus and consistent guidance suggestions for the management of chronic diseases of retinal diseases that are in line with China's national conditions. This consensus includes key content such as definitions, treatment plans, and follow-up frequency for the management of chronic diseases of the fundus. It clearly proposes relevant measures to improve the management process of chronic diseases of the fundus, and elaborates on the advantages and feasibility of establishing an online remote platform for the management of chronic diseases of the fundus, in order to assist doctors in formulating personalized treatment plans and ensure that patients receive standardized treatment and follow-up. This consensus will provide guidance and reference for the management of chronic diseases and long-term standardized diagnosis and treatment of major fundus diseases in China.
Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus (DM), and its pathogenesis remains incompletely understood. Research has identified inflammation as a key factor in the onset and progression of DR. As a group of systemic metabolic disorders, the dysregulation of polyunsaturated fatty acid (PUFA) metabolism induced by DM is closely related to the inflammatory mechanisms in DR. Recent metabolomic studies have revealed that in various stages of DR and in diabetic animal models, most upregulated PUFAs and their derivatives act as pro-inflammatory mediators, while downregulated PUFAs and their derivatives are predominantly anti-inflammatory. In the progression of DR, some PUFAs may exert anti-inflammatory effects by inhibiting microglial activation, reducing the expression of inflammatory proteins, antagonizing the pro-inflammatory effects of arachidonic acid, and suppressing the activation of inflammasomes and the migration of neutrophils. Conversely, other PUFAs may promote inflammation through mechanisms such as the formation of pro-inflammatory mediators resembling prostaglandins, facilitating leukocyte adhesion, and inducing oxidative stress responses. PUFAs play a complex dual role in the inflammatory mechanisms of DR. A deeper understanding of these mechanisms not only aids in elucidating the pathogenesis of DR but also provides potential targets for developing new therapeutic strategies.
Objective To compare the efficacy of 23G and 20G vitrectomy for diabetic retinopathy. Methods Thirty-eight eyes of 33 patients with diabetic retinopathy who underwent primary vitrectomy were enrolled in this study. Twenty eyes of 18 patients underwent 23G microincision vitrectomy (23G group). Eighteen eyes of 15 patients underwent 20G vitrectomy (20G group). The followup ranged from 6 to 12 months. The surgical time, number of iatrogenic retinal tears, times of coagulation for hemorrhage, instrumental change for fibromembrane removal, intraocular pressure (IOP) at 1st, 2nd and 3rd days after surgery, postoperative complications, anatomic success rate, and best corrected visual acuity (BCVA) were observed. Results The mean surgical times were (63.5±21.7) and (83.9±27.5) minutes in 23G and 20G group which was a significant difference (t=2.55, P=0.02). The numbers of iatrogenic retinal tears were six and 14, while the mean times of coagulation were 71 and 104 in 23G and 20G group respectively. There were three and 12 eyes needing instrumental change for fibromembrane removal in 23G and 20G group with significant difference (χ2=10.58, P=0.001). At the 1st, 2nd and 3rd days after surgery, IOP were (10.2±2.0), (13.4±2.5), and (14.9±2.3) mm Hg (1 mm Hg=0.133 kPa) in 23G group, (16.5±2.9), (19.3±2.4), and (20.1±2.9) mm Hg in 20G group. Compared with each other, the differences were statistically significant (t=7.71, 7.41, 6.18; P＜0.01). There was one eye with intraocular hemorrhage, one eye with neovascular glaucoma (NVG), and one eye with retinal detachment (RD) in 23G group. There were two eyes with intraocular hemorrhage, two eyes with NVG, and one eye with RD in 20G group. Compared with each other, the differences were not statistically significant (χ2=0.49, 0.49, 0.01; P＞0.05). The anatomic success rates were 950% and 94.4% in 23G and 20G group without significant difference (χ2=0.01, P=0.94). There were no complications such as endophthalmitis or choroidal detachment. In 23G group, BCVA was ＜0.05 in one eye, 0.05 – 0.09 in five eyes, 0.1 -0.2 in 10 eyes, ≥0.3 in two eyes. In 20G group, BCVA was ＜0.05 in one eye, 0.05 - 0.09 in nine eyes, 0.1 -0.2 in six eyes, ≥0.3 in two eyes. Compared with each other, the differences were not statistically significant (χ2=2.70, P＞0.05). Conclusion 23G microincision vitrectomy is beneficial to shorten the operation time, reduce instrumental changes, decrease intraoperative complications, and enhance visual rehabilitation.