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)
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 determine the effects of lensspecific overexpression of OSM on the eye development. Methods A truncated mouse OSM c DNA (661 bp) was linked to the αA-crystallin promoter. Transgenic mice were characterized by routine histological and immunohistochemical techiniques. TUNEL assays were used to de tect cell death. The mRNA expression of caspase-3 was detected by in situhybridization, Rabbit anti-cleavage caspase-3 antibody was used to detectactive capase-3. Results At embryonic day (E) 14.5 and 17.5, expression of the OSM transgenic protein was detected specifically in lens fiber cells. The onset of retinal degeneration in the mid portion of the transgenic retinae was observed started from E17.5. By the time of birth 50% or more of the retinal cells were missing. The OSM transgenic retinal cells underwent apoptosis indicated by TUNEL assays. Most strikingly, activation of caspase-3 protein were observed throughout the transgenic retinas. Conclusions Lens-specific overexpression of OSM activate caspase-3, leading to abnormal eye development,apoptosis and widespread retinal degeneration. (Chin J Ocul Fundus Dis，2003，19：201-268)
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.
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.
ObjectiveTo observe the effect of lysophosphatidylcholine acyltransferase-1 (LPCAT1) deficiency on the structure and electrophysiology of the murine retina. MethodsRd11 mice (Lpcat1 homozygous mutant, n=60) and wild-type C57BL/6J mice (n=60) were used in this study. Immunohistochemistry was performed to determine the expression of LPCAT1 in the mouse retina. Retinas of rd11 mice and age-matched control mice at postnatal 3, 6, 9-day and 2, 4, 6, 8-week were paraffin embedded,sectioned and hematoxylin eosin stained, and full-field electroretinograms (F-ERG) were also recorded at these time points. Statistics were based on independent samples t-test. ResultsLPCAT1 was absent in rd11 mice retina. In wild-type C57BL/6J mice retina, LPCAT1 was expressed most strongly in the inner segment of photoreceptor cells, weak in the ganglion cell layer. Rd11 mouse exhibited retinal degeneration and eventual photoreceptor cell loss. Retinas of rd11 mice showed nearly half of the photoreceptor cells missing around postnatal week 4,and by 6-week after birth only two layers of nuclei remained. At postnatal week 8,nearly all photoreceptor cells were lost. Dark-adapted F-ERG showed reduced rod-driven response at 2 and 4 weeks of age, which was flattened by 6 and 8 weeks of age. By 2 weeks of age, no significant difference was found in b-wave amplitude between rd11 eyes [(72.8±15.6) μV] and C57BL/6J eyes [(105.2±21.1) μV] (t=-2.760, P=0.025). Compared with age-matched control mice [(231.8±32.0)μV], rod response of rd11 mice [(20.6±6.4) μV] decreased obviously at postnatal week 4 (t=-14.471, P=0.000). Cone response was nearly normal at 2 and 4 weeks of age but substantially reduced at 6 weeks of age, which was flattened by 8 weeks of age. At 2 and 4 weeks after birth, no significant difference was found in b-wave amplitude between rd11 eyes [(46.8±7.2), (78.0±8.2) μV] and C57BL/6J eyes [(42.8±6.4), (91.4±9.4) μV] (t=0.930, -2.401; P=0.379, 0.043). Compared with age-matched control mice [(116.2±12.9) μV], cone response of rd11 mice [(17.2±2.0) μV] decreased obviously at postnatal week 6 (t=-17.008, P=0.000). ConclusionThe layers of photoreceptor cells nuclei in rd11 mice decreases with age, and its F-ERG reflection is unusual.
Objective To observe the effect of laser photocoagulation of the peripheral retinal holes and/or degeneration in high myopia. Methods Full fundus examination for high myopic patients was made before keratorefractive surgery with binocular indirect ophthalmoscopy.Peripheral holes,degeneration and vitreous traction were found in 206 eyes of 135 patients,and all of them were treated with laser photocoagulation. Results No retinal detachment occurred after keratorefrative operation within 1 year follows up. Conclusions Retinal laser photocoagulation is an effective and safety method before keratorefractive operation for prevention of the retinal detachment in high myopia at least in short-term observation. (Chin J Ocul Fundus Dis, 1999, 15: 135-136)
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.