The choroidal vascular index (CVI) is the ratio of the luminal area to the total choroidal area. It can not only reflect the changes in the vascular composition of the choroid, but also serve as an observation index for follow-up treatment effects. CVI is a new biometric tool, which is gradually applied to the observation of choroidal structure in various eye diseases. It has great application prospects in the study of pathophysiological mechanisms, disease process monitoring and efficacy evaluation such as central serous chorioretinopathy, polypoid choroidal vascular disease, age-related macular degeneration, diabetic retinopathy,etc. Understanding the research progress of CVI in various eye diseases can provide reference for clinical research of CVI.
Leber hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disease. It is clinically recognizable by painless, bilateral loss of vision, and the prognosis of vision is generally poor. In recent years, the information provided by optical coherence tomography (OCT) and OCT angiography (OCTA) has greatly improved people's understanding of LHON, and new progress has been made in the intervention and treatment of LHON. A detailed understanding of the structural changes of retina and choroid under OCT and OCTA of the natural course and after treatment of LHON, may provide reference for revealing the pathogenesis, prediction of onset time, differential diagnosis, follow-up of treatment effect and prognosis of LHON.
Ras homolog family (Rho)/ Rho-associated coiled-coil kinase (ROCK) signaling pathway widely exists in human and mammal cells, which is closely related to inhibition of repair after optic nerve damage. The expression level of Rho/ROCK signaling pathway-related proteins is up-regulated in glaucoma, and related with the death of retinal ganglionic cell (RGC) and the axon activity. ROCK inhibitors can protect the surviving RGC and promote axon extension with a dose-dependent manner. ROCK inhibitors also can inhibit glial scar formation, lower intraocular pressure and inhibit inflammatory response to some degrees. Rho/ROCK signaling pathway correlates with the optic nerve disease progression, and ROCK inhibitors hope to become a new therapeutic drug.
Leber hereditary optic neuropathy (LHON) is a blinding disease caused by mutations in mitochondrial DNA. It is a classic disease model for studying mitochondrial abnormalities. Its main mutation sites are m11778G.A, m.3460G.A and m.14484T.C. LHON cell models are mainly produced by lymphoblasts, fibroblasts, cell hybrids and induced pluripotent stem cells, while LHON animal models are mainly mice, which are produced by rotenone and ND4 mutants. Although the research on the LHON model has achieved good results, there are still many difficulties in constructing an ideal experimental model, which severely limit the exploring to the pathogenesis and therapeutic drugs of LHON. A detailed understanding of the application and characteristics of existing models in LHON will help improve experimental design and construct new models.
Adult Coats disease is characterized by abnormal expansion of retinal capillaries, often accompanied by massive lipid exudation and exudative retinal detachment. Unlike Coats disease in young children, adult Coats disease is mostly limited to peripheral retina, with slow progress and better prognosis. Adult Coats disease should be identified with Coats-like diseases such as exudative age-related macular degeneration, diabetic retinopathy, obsolete retinal vein occlusion, idiopathic macular telangiectasia 1, obsolete posterior uveitis, retinal vasculitis, or acute retinal necrosis. Because the pathogenesis of Coats disease is not clear, it lacks specific treatment measures for the cause of disease. The purpose of simple or combined laser photocoagulation, freezing, vitreous intravitreal injection against vascular endothelial growth factor drugs or triamcinolone and surgery is to eliminate abnormal blood vessels and exudation, maintain visual function, which can also improve retinal detachment and prevent neovascular glaucoma and other complications. To explore the similarities and differences of adult Coats disease with Coats disease in young children, to further promote the study of the pathogenesis of adult Coats disease and to provide new targets for its treatment are the direction of future research.
Ultra-wide field fundus autofluorescence (FAF) imaging is a new noninvasive technique with an imaging range of about 200 °. It can detect peripheral retinal lesions that cannot be found in previous FAFs and more objectively reflect intracellular content and distribution of lipofuscin in the retinal pigment epithelium (RPE) and RPE cell metabolic status. The ultra-wide field FAF can find the abnormal autofluorescence (AF) in the peripheral retina of the eyes of age-related macular degeneration (AMD), and different AF manifestations may have an impact on the diagnosis and treatment of the different AMD subtypes. It is helpful to evaluate subretinal fluid in the eyes of central serous choroidal retinopathy and can accurately detect the changes in the outer retina of the eyes without subretinal fluid. It can help to determine the type of uveitis and fully display the evolution of the disease. It can also assess the peripheral photoreceptor cell layer and RPE in patients with retinal dystrophy and retinitis pigmentosa, and comprehensively evaluate their retinal function and monitor the progress of disease. It can also assist in the evaluation of the short-term efficacy and RPE cell function after the scleral buckling surgery for patients with rhegmatogenous retinal detachment. In the future, ultra-wide field FAF may change the knowledge and intervention strategy of ocular fundus diseases and promote the clinical and scientific research in this field.
Retinal leakage is not only a very common pathological phenomenon but also a common pathological feature of many retinal diseases, its pathogenesis is very complex. The application of ultra-wide-angle fluorescein angiography is one of the main means to observe and evaluate retinal leakage. Leakage index is a new index for evaluating retinal leakage. Studies have explored its correlation in diabetic retinopathy, retinal vein occlusion, uveitis and other diseases, evaluating treatment effects and predicting prognosis. However, the number of related studies is small and the conclusions are inconsistent. In the future, it is still necessary to further advance the quantitative analysis of leakage, the application of leakage in more diseases, and the clinical trials of leakage rate to explore its role in predicting and evaluating treatment effects in retinal diseases.