Epigenetic modifications such as DNA methylation, histone post-translational modifications, non-coding RNA are reversible, heritable alterations which are induced by environmental stimuli. Major risk factors of diabetes and diabetic complications including hyperglycemia, oxidative stress and advanced glycation end products, can lead to abnormal epigenetic modifications in retinal vascular endothelial cells and retinal pigment epithelium cells. Epigenetic mechanisms are involved in the pathogenesis of macular edema and neovascularization of diabetic retinopathy (DR), as well as diabetic metabolic memory. The heritable nature of epigenetic marks also playsakey role in familial diabetes mellitus. Further elucidation of epigenetic mechanisms in DR can open the way for the discovery of novel therapeutic targets to prevent DR progression.
To perform a meta-analysis of single nucleotide polymorphism needs to calculate gene frequency. This paper employs allele model as an example to introduce how to calculate gene frequency and display the process of a meta-analysis of single nucleotide polymorphism data using Review Manager 5.3 software.
The suprachoroidal space is a potential space between the sclera and choroid. Suprachoroidal spacedrug delivery is becoming an applicable method to the ocular posterior segment diseases. Because it targets the choroid, retinal pigment epithelium and retina with high bioavailability and safety, while maintaining low levels elsewhere in the eye. In recent years, new discoveries has been carried out in different areas of interest, such as drug delivery methods, pharmacokinetics and clinical trials. Clinical trials with suprachoroidal space injection of triamcinolone acetonide are executed with promising findings for patients with noninfectious uveitis and diabetic macular edema. Suprachoroidal space triamcinolone acetonide injectable suspension is the first and currently the only agent specifically approved for uveitic macular edema by Food and Drug Administration. Nowadays, many clinical trails with suprachoroidal space drug delivery have been explored, although there are still many risks and uncertainties. With the development of technology in the future, suprachoroidal space drug delivery appears to be a promising treatment modality for ocular posterior segment diseases.
Vascular endothelial growth factor (VEGF) is a multifunctional factor that promotes blood vessel formation and increases vascular permeability. Its abnormal elevation plays a key role in common retinal diseases such as wet age-related macular degeneration and diabetic macular edema. Anti-VEGF therapy can inhibit angiogenesis, reduce vascular leakage and edema, thereby delaying disease progression and stabilizing or improving vision. Currently, the clinical application of anti-VEGF drugs has achieved satisfactory therapeutic effects, but there are also issues such as high injection frequency, heavy economy burden, potential systemic side effects, and non-responsiveness. To address these issues, current research and development mainly aim on biosimilars, multi-target drugs, drug delivery systems, oral anti-VEGF drugs, and gene therapy. Some drugs have shown great potential and are expected to turn over a new leaf for anti-VEGF treatment in ophthalmology.
Uric acid (UA) is the final product of human purine metabolism. As one of the main antioxidants in the body, it can scavenge oxidative radicals. Under the action of oxidative-antioxidant shuttle mechanism, the antioxidant activity of UA can be reversed, causing inflammation and oxidative stress of vascular endothelial cells. Hyperuricemia (HUA) is considered to be one of the major risk factors for diabetes and diabetic nephropathy. The study of HUA in diabetic retinopathy (DR) is also a hot topic. UA can cause retinal vascular sclerosis, and affect the occurrence and development of DR by promoting oxidative stress and inducing neovascularization.
Microparticles are small vesicles that are released by budding of the plasma membrane during cellular activation and apoptotic cell breakdown. A spectrum of cell types can release microparticles including endothelial cells, platelets, macrophages, lymphocytes and tumor cells. Biological effects of microparticles mainly include procoagulant activity, inhibition of inflammation and cancer progression. The present study shows that vitreous microparticles isolated from proliferative diabetic retinopathy (PDR) stimulated endothelial cell proliferation and increased new vessel formation, promoting the pathological neovascularization in PDR patients. Oxidative stress induces the formation of retina pigment epithelium-derived microparticles carrying membrane complement regulatory proteins, which is associated with drusen formation and age related macular degeneration. Microparticles from lymphocyte (LMP) play an important role in anti-angiogenesis by altering the gene expression pattern of angiogenesis-related factors in macrophages. Besides, LMP are important proapoptotic regulators for retinoblastoma cells through reduction of spleen tyrosine kinase expression and upregulation of the p53-p21 pathway which ultimately activates caspase-3. However, how to apply the microparticles in the prevention and treatment of retinal diseases is a major challenge, because the study of the microparticles in the fundus diseases is still limited. Further studies conducted would certainly enhance the application of microparticles in the fundus diseases.
Lattice retinal degeneration is a common peripheral retinal degenerative condition and is widely recognized as a significant precursor to retinal detachment, resulting in severe visual loss. Recent advances in deep learning technologies have driven the development and adoption of automated screening systems for lattice retinal degeneration using ultra-widefield fundus imaging. These systems have demonstrated notable success in large-scale screening of peripheral retinal diseases, offering valuable support for the early identification and risk stratification of lattice degeneration. Currently, retinal laser photocoagulation remains the mainstay treatment for lattice degeneration. This intervention effectively mitigates the risk of rhegmatogenous retinal detachment. However, controversies persist regarding the optimal selection of treatment candidates and the evaluation of therapeutic efficacy. In the future, the continuous evolution of imaging analysis techniques and artificial intelligence holds promise for the development of personalized and precision-based intervention strategies. Such advancements are expected to provide more robust evidence to guide the diagnosis and treatment of lattice retinal degeneration, ultimately improving patient outcomes.
Cilia are hair-like protuberance on cells of the human body that play a vital role in organs generation and maintenance. Abnormalities of ciliary structure and function affect almost every system of the body, such as the brain, eyes, liver, kidney, bone, reproductive system and so on. Retinal photoreceptor cells are one of sensory neurons which convert light stimuli into neurological responses. This process, called phototransduction, takes place in the outer segments (OS) of rod and cone photoreceptors. OS are specialized sensory cilia, and disruptions in cilia genes, which are causative in a growing number of non-syndromic retinal dystrophies, such as retinitis pigmentosa, Leber’s congenital amaurosis. These syndromes are genetically heterogeneous, involving mutations in a large number of genes. They show considerable clinical and genetic overlap. At present, there are few researches on retinal ciliopathies and clinical treatment strategy. This review shows a comprehensive overview of ciliary dysfunction and visual development related diseases, which contributes to understand the characteristics of these diseases and take early intervention in clinic.
Transsynaptic retrograde degeneration of optic neuropathy (TRDON) refers to the degeneration and/or apoptosis of presynaptic neurons (retinal ganglion cells) caused by damage to the lateral geniculate body and post-geniculate visual pathway. At present, the pathogenesis of TRDON is secondary apoptosis of Pβ-type retinal ganglion cells, resulting in the atrophy of optic tract, thinning of the retinal nerve fiber layer and retinal ganglion cell layer thickness and declining of retinal microvascular density, which are consistent with the visual field defect attributed to the primary disease. Of which, the thinning of the retinal ganglion cell layer thickness is considered as the characteristic of TRDON. Now, there is little understanding and related research on TRDON in China. Clinicians should pay attention to the characteristics and severity, occurrence time and location of the above structural changes in these patients through optical coherence tomography, and monitor the activity and progress of the lesions, so as to determine the cut-off point for drug intervention and the drug targets for developing new treatment methods, and bring benefits for patients in partial visual function recovery and disability reduction.
Objective To assess the efficacy and safety of tacalcitol and calcitriol on vitiligo. Methods?We searched the MEDLINE (1966 to June 2008), Cochrane Central Register of Controlled Trials (The Cochrane Library, issue 4, 2008), OVID (1978 to June 2008), EMbase (1980 to June 2008), CBM (1978 to June 2008), CNKI (1979 to June 2008) to collect randomized controlled trials (RCTs). We also hand searched relevant journals and conference proceedings. The language was confined to English and Chinese. We screened the retrieved studies according to the predefined inclusion and exclusion criteria, evaluated the quality of included studies, and performed meta-analyses by using the Cochrane Collaboration’s RevMan 4.2 software. Results?Ffiteen trials involving 120 patients in 5 self-control trials and 793 patients in other 10 randomized controlled trials were included and assessed. The time of repigmentation onset of good responders and normal responders in the side treated with a combination of topical talcitol and NB-UVB was shorter than that in the control group [WMD= –?75, 95%CI (–?93.93, –?56.07); WMD= –?48, 95%CI (–?76.36, –?19.64)]. The mean number and cumulative dose of excimer light exposures for initial repigmentation in the side treated with tacalcitol and 308-nm monochromatic excimer light were less than those in the control group [WMD= –?0.78, 95%CI (–?1.02, –?0.54; WMD= –?1.06, 95%CI (–?1.36, –?0.76)]. The mean number of UVA exposures for initial repigmentation and complete repigmentation in the side treated with calcipotriol and PUVA were less than those in the control group [WMD= –?2.67, 95%CI (–?3.06, –?2.28); WMD= –?2.67, 95%CI (–?3.42, –?1.92)], and the cumulative UVA dose for iniitial and complete repigmentation in the combination group were also lower than those in the control group [WMD= –?25.68, 95%CI (–?29.44, –?21.92); WMD= –?27.14, 95%CI (–?34.80, –?19.48)]. The mean time of initial pigmentation was much shorter in the group treated with calcipotriol and corticosteroid was shorter than that in the control group [WMD= –?3.87, 95%CI (–?5.45, –?2.29)]. Conclusion?The limited evidence indicated that combination of topical tacalcitol with NB-UVB or monochromatic excimer light, or the combination of topical calcipotriol with PUVA or corticosteroid shortened the time of repigmentation and decreased the cumulative irradiation dose. The side effects were limited. No obvious effect was seen on re-pigmentation degree.