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 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)
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 observe the fundus characteristics of human immunodeficiency virus with acquired immune deficiency (HIV/AIDS). Methods A total of 1041 HIV/AIDS patients were enrolled in this study. The patients included 882 males (88.70%) and 159 females (11.30%). The patientsprime; ages ranged from 12 to 73 years, with a mean age of 41 years. The median time of HIV/AIDS diagnosis was 12 months, which ranged from one month to 10 years. HIV infection was acquired through sexual contact, intravenous drug use, blood transfusion or mother-to-child transmission in 475 patients (45.63%), 508 patients (48.80%), 44 patients (4.25%) and 14 patients (1.34%), respectively. Ocular examinations (vision acuity, slit lamp microscope and fundus examination) were performed on recruited patients with HIV/AIDS. Additional exams (intraocular pressure, fundus photography and fundus fluorescein angiography) were done if abnormal ocular fundus was found. The ocular manifestations were diagnosed according to clinic reference. Results Ocular manifestations of HIV/AIDS were detected in 247 patients (23.73%). Of 247 patients, the most common ocular manifestation was HIV retinopathy, which was present in 132 patients (53.44%); cytomegalovirus retinitis (CMVR) was second place, affecting 70 participants (28.34%). Clinic findings of HIV retinopathy included retina microaneurysm, hemorrhage along the blood vessel with cotton-wool spots, while irregular dry edge, granular appearing border, were present in CMVR, and the optic nerve may be affected. Fluorescein angiogram of HIV retinopathy demonstrated that hemorrhage was shown as sheltered fluorescence, with b fluorescence without leakage in center of hemorrhage. Fluorescein angiogram of CMVR demonstrated significant hemorrhage appearing as sheltered fluorescence with leakage and/or transparent fluorescence. The optic disk and lesioned area were stained with fluorescence. Conclusions There are various HIV/AIDS related ocular manifestation. HIV retinopathy and CMVR are common ocular manifestations. The main clinical findings of HIV retinopathy are hemorrhage and/or cotton-wool spots, while irregular granular appearing edges and hemorrhage were observed in CMVR.
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)