Complications of proliferative diabetic retinopathy have become the major indications of vitrectomy. The surgery, however, is not basically a causative therapy. The visual function after operation depends on the degree of retinal ischemia and damage induced. The surgery itself has a potential for severe complications. Therefore it is important to better understand the pathology and to master surgical strategy and techniques in order to improve surgical outcomes and reduce the surgical complications. (Chin J Ocul Fundus Dis,2007,23:234-237)
Refractory macular hole (MH) has lower surgical anatomical closure rate and poor recovery of visual acuity due to its clinical characteristics. Refractory macular hole includes unclosed MH, reopening MH, large MH, high myopic MH, traumatic MH and secondary MH. Some modified surgeries were employed to improve the surgical results. Inverted internal limiting membrane flap, autologous transplantation of the internal limiting membrane, laser photocoagulation, extended internal limiting membrane peeling, arcuate retinotomy, lens capsular flap transplantation and mesenchymal stem cell transplantation can improve the prognosis partially. Loosening MH traction, providing a scaffold for Müller cell proliferation and promoting photoreceptor reconstruction will be the key points in future.
Familial exudative vitreoretinopathy (FEVR) is a hereditary retinal vascular dysplasia. So far, 6 genes have been found to be associated with FEVR: Wnt receptor Frizzled Protein 4, Norrie's disease, co-receptor low-density lipoprotein receptor-related protein 5, tetraspanin 12, zinc finger protein 408, and kinesin family members 11 genes. Its clinical manifestations, pathological processes and genetic patterns are diverse, and it shows the relationship between gene polymorphism and clinical manifestation diversity. It is characterized by different symptoms between the same individual, the same family, and the same gene mutation; different clinical stages and gene mutation types of parents or unilateral genetic children; different clinical characteristics and gene mutation patterns of full-term and premature infant; combined with other eye disease and systemic diseases; double gene mutations and single gene mutations have different clinical manifestations and gene mutation characteristics. A comprehensive understanding of the different clinical manifestations and diverse genetics of FEVR can provide better guidance for the treatment of FEVR.
With the continuous advancement of technology, the field of retinal surgery is poised to witness an increasing array of innovations and breakthroughs. The innovation in retinal surgery plays a pivotal role in enhancing the success rate of operations, reducing the risk of complications, and improving patient prognosis and quality of life. This encompasses innovations in vitrectomy systems, the novel application of vitrectomy in treating other ocular diseases, advancements in retinal surgical techniques, technological and conceptual innovations, as well as multidisciplinary collaboration, all of which contribute to the ongoing development in the treatment of retinal diseases. Therefore, innovations in retinal surgery should receive significant attention from ophthalmologists specializing in retinal diseases with the best service to patients.
There are many topics in clinical studies of diabetic retinopathy (DR). The current hot topics include the relationship between DR and systemic diseases, major factors for initiation and progression of DR, early DR screening strategies, DR prevention strategies and how to improve the therapeutic effects of DR. However, due to the complexity of DR pathogenesis, multiple risk factors, long cycle of DR prevention and control, it is difficult to exclude all the confounding factors in the DR clinical research. From the long-term perspective, delaying the occurrence and progression of DR and establishing an efficient and practical prevention and control system is the focus of the future DR research in China.
ObjectiveTo observe the influence of human umbilical cord mesenchymal stem cells (hUCMSC) transplantation into vitreous cavity of diabetic rats on the retinal morphology, and the expression of glial fibrillary acidic protein (GFAP) and rhodopsin (RHO). Methods78 male Sprague-Dawley rats were used. 70 rats were injected with streptozotocin by tail vein injection at a dose of 40 mg/kg to establish the diabetes mellitus model, and another 8 rats were injected with 0.1 mol/L pH 4.0 citric acid buffer at the same dose as the normal control group. After 6 weeks of modeling, 10 rats were taken as the control group of diabetic model. hUCMSC suspension was injected into the right eye vitreous cavity of the remaining 60 rats, and the same volume of Dulbecco's modified Eagle/F12 medium was injected into the left vitreous cavity as control eyes. 1, 2 and 4 weeks after transplantation, follow-up experiments were performed. The experimental eyes were labeled as U1, U2, and U4 groups, while the control eyes were recorded as D1, D2, D4, and each group consisted of 20 eyes. After paraffin section and hematoxylin-eosin staining, the structure of the retina was observed by optical microscopy and the thickness of the outer nuclear layer and the inner nuclear layer (INL) were measured. The distribution and migration of hUCMSC in rat retina were observed by frozen section-tissue immunofluorescence assay. The mRNA and protein expression of GFAP and RHO in the retina were detected by real-time quantitative polymerase chain reaction (PCR) and Western blot assays. ResultsThe results of optical microscope observation showed the normal structure of retina in normal control group. The retinal nerve fiber layer (NFL) was thinned and the number of retinal ganglion cells (RGC) in the control group of diabetic rats was decreased. The decreased number and disorder arrangement of RGC were observed as well in U1, D1 rats. The RGC number of U2, U4, D2, D4 rats was gradually decreased. Compared with D4 group, the thickness of INL in U4 group was significantly increased (P < 0.05). Tissue immunofluorescence assay showed that hUCMSC were distributed along the inner limiting membrane in the retina of the U1 group, while the number of hUCMSC in the U2 group was gradually decreased, mainly in the NFL and ganglion cell layers. Real-time PCR and Western blot data indicated that the relative expression of GFAP mRNA and protein in the diabetic retina was significantly increased, and the relative expression of RHO mRNA and protein decreased gradually in the diabetic model group and the D1, D2, D4 groups. Compared with D2 and D4 groups, the mRNA and protein expression of GFAP in U2 and U4 groups were decreased, and the relative expression of RHO mRNA and protein were all increased (P < 0.01). ConclusionhUCMSC could migrate and integrate into the retina, after the transplantation into the vitreous cavity of diabetic rats, which reduced the expression of GFAP, but enhanced the expression of RHO.