Purpose To investigate the development of embryonic stem cells (ESC)in the subretinal space． Methods ESC were cultivated in suspension for 4 days till they developed into cell aggregates,i.e.embryonic body(EB).ESC as well as EB combined with or without RA were respectively transplanted into vitreous cavity and subretina1 space in SD rats,and the subretinal transplanted eyes,transient ischemia-reperfusion injuries were made by ligating the ophthalmic artery for 40 seconds before the transplantation .The experimental eyes were enucleated for histological and immunohistochemical assays after 14～28 d. Results The EB was found to develope into photoreceptors induced by RA in the subretinal space under an ischemia-reperfusion condition，and EB transplantation without RA induction induced multiple differentiations in the subretinal space.The single injection of RA without EB induced hyperplasia of the neural retinal cells.ESC transplanted into vitreous cavity rapidly proliferated and developed into atypical hyperplastic mass. Conclusion EB derived from ESC can differentiate into photoreceptors induced by RA in the host subretinal space under an ischemia-reperfusion condition. (Chin J Ocul Fundus Dis，2000，16：213-284)
ObjectiveTo observe the histopathological changes in peripheral retinal lesions under intraoperative optical coherence tomography (iOCT). Methods A retrospective case series study. Eighty-eight patients (194 eyes) who underwent vitreoretinal surgery in the Department of Ophthalmology at the East Ward of the First Affiliated Hospital of Zhengzhou University from October 2021 to May 2022 in 94 eyes were included in the study. Among them, 49 cases were male and 39 cases were female, with the mean age of (50.93±17.55) years. Ninety-four eyes included 32 eyes with retinal detachment, 6 eyes with proliferative diabetic retinopathy, 28 eyes with vitreous hemorrhage, 8 eyes with ocular trauma, 14 eyes with the macular lesion, 1 eye with uveitis, 1 eye with family exudative vitreoretinopathy (FEVR), 1 eye with acute retinal necrosis (ARN), and 3 eyes with lens dislocation. All affected eyes were examined with iOCT during vitreoretinal surgery. The iOCT scanning of the peripheral retina was performed with the help of episcleral pressure. The pre-equatorial and serrated edge anterior and posterior of retinas were scanned according to the characteristics of different fundus diseases. Various abnormal fundus manifestations were recorded. Results In 94 eyes, 53 eyes (56.38%, 53/94) have different types of retinopathy in the peripheral retina. Of these, 7 eyes (7.45%) have retinal cystoid degeneration; 19 eyes (20.21%) have lattice degeneration; and 8 eyes (8.51%) have pigment degeneration; 9 eyes (9.57%) have pavement-like degeneration; 7 eyes (7.45%) have small occult holes; 1 eye (1.06%) has familial exudative vitreoretinopathy (FEVR) serrated edge "dyke-like" proliferative degeneration; 4 eyes (4.26%) have vitreous and retinopathy adhesions; and one eye (1.06%) has ARN. Conclusion With clear refractive media, iOCT can provide clear scans of different peripheral retinal lesions.
Optogenetics is a novel technique which combines optics with genetics. Using genetic means, a selected opsin protein is ectopically expressed in target neurons, which are then stimulated by light to moderate the neuronal circuit, as a consequence to regulate the animal's behaviors. Retinal degeneration like retinitis pigmentosa and aged macular degeneration causes visual impairment and eventual blindness. Optogenetics techniques have opened the door to creating artificial photoreceptors in the remaining retinal circuits of retinal degeneration retinas via gene therapy. However, there are still limitations in optogenetics technique, for example, potential risk in virus infection, the choice of target cells and the low visual resolution of the experiment animal. It has been reported that vision was successfully restored to a certain extent in animal model using optogenetics technique. With higher photosensitivity of opsin protein, longer activation kinetics and higher transfection efficiency of virus vector, optogenetics techniques' application in ophthalmology will be improved.
Inherited retinal degeneration (IRD) is a group of fundus diseases characterized by a high degree of genetic heterogeneity and clinical heterogeneity, and more than 300 genetic mutations have been identified in association with IRD. Dysregulation of the intracellular second messenger cyclic guanosine monophosphate (cGMP) plays an important role in the development of IRD. cGMP participates in phototransduction process in photoreceptors. Abnormally elevated cGMP over-activate protein kinase G and cyclic nucleotide-gated channel, causing protein phosphorylation and Ca2+ overload, respectively, and these two cGMP-dependent pathways may individually or collectively drive photoreceptor degenerative lesions and death; therefore, reducing cGMP synthesis and blocking downstream signaling can be considered as treatment strategies. Investigating the molecular mechanisms of cGMP dysregulation in photoreceptor degeneration may provide a more comprehensive picture of the pathogenesis of IRD, as well as ideas for finding new therapeutic targets and designing therapeutic programs.
Objective To investigate the clinical characteristics of retinal degeneration (RD) with retinal holes and the therapeutic effect of argon laser therapy. Methods The data of argon laser therapy in 210 RD patients (224 eyes) with retinal holes who underwent the treatment in our department were retrospectively analyzed, which was compared with the data of argon laser therapy in 173 RD patients (198 eyes) without retinal holes. Results In RD patients with retinal holes, 89.7% of the patients were less than 60 years old (53.3% males and 46.7% females). Grid-like degeneration was found in 65.6% of the patients in whom 87.5% had the range of degeneration less than 1 quardrant. There were oval-shaped holes in 60.7% of the patients and accompanied with limited rhegmatogenous retinal detachment (LRRD) in 23.7%. Compared with RD patients without retinal holes, the ratio of patients with the age ofge;35 years, cystic degeneration, retinal lengthways small plica, and subjective symptoms was higher in RD patients with retinal holes; while the therapeutic effect of argon laser therapy on patients with LRRD was obviously less than whom without retinal holes (Plt;0.01 ). Conclusions RD with retinal holes often occurs in youth, most of whom have grid-like degeneration with the range of le;1 qua drant. The major types of retinal holes are oval-shaped degeneration without retinal detachment. There was no sex difference in RD patients with retinal holes and most of the patients have no subjective symptoms. The therapeutic effect of prophylactic argon laser therapy on RD patients with retinal holes but no retinal detachment is satisfying. (Chin J Ocul Fundus Dis, 2006, 22: 39-41)
Objective To investigate the degenerative changes in the inner rat retina after photic injury.Methods After 24 hour-dark adaptation, sixty Lewis rats were exposed in a ventilated green plexiglass chamber that transmitted continuous green light between 480-520 nm with an intensity of 900～1 000 lx. After 24 hour exposure, the rats stayed in darkness and were sacrificed after 1 day, 3,7 or 14 days. The neurons in the inner retina were marked by immunohisto chemical technique and observed by light and electronic microscope.Results The apoptotic photoreceptor cells were noted after photic injury. The degeneration and decreasing number of rod bipolar cells were found after 3 days; the edema of horizontal cells occurred after 1 day but ameliorated gradually; decreasing number of amacrine cells was found after 1 day; sustained edema of ganglion cells and prolifeeration of the Müller cells were found after photic injury. Pyknotic and edematous neruronal degenerations of inner retina were found in ultrastructural study.Conclusion The neurons in the inner retina as well as Müller cells are involved in the degeneration after photic injury. Different neurons manifest different patterns of degeneration.(Chin J Ocul Fundus Dis，2003，19：201-268)