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.
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.
Autosomal recessive Best disease (ARB) is a rare clinical fundus disease caused by BEST1 mutation. The critical features of ARB are the presence of multifocal subretinal yellowish lesions, which corresponding to the hyperfluorescent spots on FAF, scattered over the posterior pole of the retina, absent of typical vitelliform lesions in the macula. Imaging of OCT is often manifested as subretinal or intraretinal fluid, and cystoid macular edema, and hypereflective focus at RPE level. EOG shows an absent or severely reduced light rise (decreased value of Arden), which often accompanied by reduction and delay of the rod and cone ERG. Some patients with ARB show hyperopia, short axial length and shallow anterior chambers, with a corresponding high incidence of angle-closure glaucoma. Though there isn't any effective therapeutic methods of ARB at present, prevention and treatment for its complications such as angle-closure glaucoma and choroidal neovascularization should be considered. Present study about ARB mainly focus on some retrospective cases, and ARB is often misdiagnosed with Best vitelliform macular dystrophy, central serous chorioretinopathy and other fundus diseases in clinic. A detailed understanding of the clinical features and genetic characteristics of ARB might be helpful in clinical diagnosis and treatment. Research with larger sample size are expected to further investigate the different stages of ARB and its developing process, the potential pathological mechanism, the relationship between genotype and phenotype, so as to improve the understanding of the disease.
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.
Ultra-wide-field fluorescein angiography (UWFA) can obtain very wide retinal images (up to 200°), and is a very helpful tool to detect peripheral retinal lesions which cannot be found by other imaging methods. Analyzing the characteristics of the UWFA images may improve our understanding, treatment outcomes and management strategies of ocular fundus diseases. However this technology is still in its premature stage, there is still a lot of work to be done to improve its clinical application and study the characteristics and clinical meanings of these peripheral retinal lesions.
The prevention and treatment of retinopathy of prematurity (ROP) is an important strategic content of blindness prevention and treatment in China. Medical institutions including remote areas have strengthened the awareness of neonatal fundus screening, however, there are problems of vague screening standards, mainly manifested in expanding the scope of screening and even universal screening of newborns. At the same time, all kinds of fundus changes found in the examination cannot be correctly interpreted and handled, which increase the economic and psychological burden of children's families. In addition, with the wide application of intravitreal injection of anti-neovascular endothelial growth factor, problems such as improper grasp of indications and improper treatment of complications have become increasingly prominent. At this stage, it is urgent to strengthen the construction of ROP prevention and control network, which is suitable for China's national conditions, led by the government and coordinated participation of health and medical institutions at all levels.
Outer retinal tubulations (ORT) are tubular structures that are visualized on spectral domain optical coherence tomography in single B-scans as nonedematous circular or ovoid structures at the level of the outer nuclear layer. It is most commonly seen in exudative age-related macular degeneration and pseudoxanthoma elasticum, as well as in multifocal choroiditis, panuveitis, geographic atrophy, central serous chorioretinopathy, polypoid choroidal neovascularization, choroideremia and some other diseases related to outer retinal structural damage. ORT is the structure of dislocation junction of outer membrane and ellipsoid band in the process of self-repair after destroyed. Cystoid retinal edema, subretinal fluid and photoreceptor layer damage are important factors for ORT formation. Anti-vascular endothelial growth factor (VEGF) drugs cannot make ORT disappear, and distinguishing between ORT and retinal cystoid edema is helpful to avoid unnecessary anti-VEGF treatment. ORT has a certain predictive value for the prognosis of vision, and has guiding significance for clinical treatment. However, the mechanism of ORT formation and its relationship with clinical practice are not yet fully understood. More advanced imaging equipment and a large number of cases are needed to study the formation of ORT and its relationship with classical choroidal neovascularization, retinal fibrous scarring and retinal atrophy.