Photodynamic therapy is the first treatment confirmed to be effective in the treatment of exudative age-related macular degeneration in 2000, which had been introduced to China in the same year. The pathological new vessels were destructed by the singlet oxygen and oxygen free radical released by activated photosensitizer. In the next 12 years, it has been widely applied for the treatment of subfoveal and parafoveal choroidal neovascularization caused by all kinds of chorioretinal diseases. More than a treatment, it also help us to explore the pathogenesis of fundus disease, the capability to embolize the capillaries within the treating area let us not only understand the mechanism of central serous chorioretinopathy and polypoidal choroidal vasculopathy, but also make it a effective cure for them. However, there are still a lot of unsolved questions such as the mechanism of photodynamic therapy, the relationship with human genomic difference, and even the development of angiogenesis. Besides with the more novel medications and strategies available, we also face the appropriate application for indications, selection of combined therapy and optimization of treatment regimens. Further investigations about the photodynamic therapy and disease and their relations from both basic and clinical study will guide us the treatment in clinic and also reveal the truth of related fundus diseases deep under the surface.
With the renovations of modern retinal imaging modality, such as video ophthalmoscopy, fundus photography, fundus fluorescein angiograph and spectral domain optical coherence tomography, it is possible to get high resolution and reproducible in vivo imaging of retina from neonates to improve the diagnosis and treatment of pediatric retinal disease. Now we have a better tool to investigate the early development of human retina, the pathogenesis and progression of pediatric retinal diseases, and to monitor the treatment efficacy and prognosis of these diseases. To expand these technologies in the diagnosis and treatment of pediatric retinal disease, we need simple, safe, comprehensive and objective applications which can only be achieved through multi-disciplinary cooperation.
Retinopathy of prematurity, familial exudative vitreoretinopathy and Coats disease are the most common neonates and infants retinal vascular diseases, which may lead to severe visual damage because of either tractional retinal detachment caused by the proliferation of pathogenic neovascularization, or exudative retinal detachment due to the extremely leakage from abnormal retinal vessels. Classic treatment is retinal laser photocoagulation which could destroy these abnormal vessels or reduce non vascular areas to diminish the growth of new vessels, however the side effects induced by laser it self such as visual field damage, hemorrhage, retinal tear, fail to control the progression of the disease make the laser treatment hard to improve the vision of these young patients. Anti-vascular endothelial growth factor (VEGF) agents have been widely applied in various adult retinal and choroidal vascular diseases, they are even possible to replace the pan retinal photocoagulation in proliferative diabetic retinopathy, while there are still many unsolved problems in the applying in neonates and infants retinal vascular diseases, like dosage, timing, retreatment and systemic side effects. We should realize the importance of selecting the laser photocoagulation and anti-VEGF for neonates and infants retinal vascular diseases.
Familial exudative vitreoretinopathy (FEVR) is a severe inherited vitreoretinal disorder. Recently, mutations in genes encoding frizzled 4 (FZD4), low density lipoprotein receptor-related protein 5 (LRP5), norrie disease protein (NDP), tetraspanin 12 (TSPAN12), zinc fmger protein 408 (ZNF408), kinesin family member 11 (KIF11) have so far been identified to cause FEVR. The former four genes have been shown to participate in the Wnt and Norrin-β-catenin signal pathway, which perform a crucial role for this pathway in ocular and vascular development. The primary clinical feature of FEVR is incomplete retinal vascular development on the temporal side of the peripheral retina, with or without abnormal retinal vascular differentiation. The clinical manifestations of this disease differ greatly among patients, from asymptomatic to complete retinal detachments with blindness. Fundus angiography and genetic screening are the main diagnostic methods for this disease and the early screening is extremely important in the treatment and prognosis. The progress can be controlled by laser treatment at the initial stage. Scleral buckling surgery and vitrectomy can be performed with advanced retinal detachment, but the prognosis is poor. The effect of anti-vascular endothelial growth factor drugs on new blood vessels may play a certain role in its treatment. With the in-depth study of pathogenesis, selective targeted treatment of FEVR pathogenic genes will become a new direction of treatment for some kinds of phenotype. This article reviews the recent advances of FEVR.
Familial exudative vitreoretinopathy (FEVR) is a serious hereditary retinal vascular disease. The clinical manifestations vary, and the severity of the patients' condition is different. In severe cases, it may lead to bilateral blindness. The pathogenic mechanism of FEVR is also complex. At present, more than ten classical and candidate pathogenic genes have been found: NDP, FZD4, LRP5, TSPAN12, CTNNB1, KIF11, ZNF408, RCBTB1, LRP6, CTNNA1, CTNND1, JAG1, ATOH7, DLG1, DOCK6, ARHGP31 and EVR3 region. These pathogenic genes are involved in Wnt/β-catenin signaling pathway, norrin/β-catenin pathway and Notch pathway. They regulate and affect the development of retinal blood vessels, hyaloid vascular system regression, endothelial cell connections, and blood retinal barrier homeostasis, ultimately leading to the occurrence and development of FEVR disease.