Retinal degeneration mainly include age-related macular degeneration, retinitispigmentosa and Stargardt’s disease. Although its expression is slightly different, its pathogenesis is photoreceptor cells and/or retinal pigment epithelial (RPE) cel1 damage or degeneration. Because of the 1ack of self-repairing and renewal of retinal photoreceptor cells and RPE cells, cell replacement therapy is one of the most effective methods for treating such diseases.The stem cells currently used for the treatment of retinal degeneration include embryonicstem cells (ESC) and various adult stem cells, such as retinal stem cells (RSC), induced pluripotent stem cells (iPSC). and mesenchyma1 stem cells (MSC). Understanding the currentbasic and clinical application progress of ESC, iPSC, RSC, MSC can provide a new idea for the treatment of retinal degeneration.
Pyroptosis is a newly discovered form of cell death. Through the activation of inflammasome complexes, pyroptosis induces the production of interleukin (IL) -1β and IL-18, and the osmotic swelling of cells, thus induces cellular rupture and death. It plays a role in the pathological process of a variety of human diseases. The death of retinal cells including photoreceptor cells and retinal pigment epithelium (RPE) cells is the main reason leading to visual dysfunction in the pathogenesis in ocular fundus diseases. Researches have demonstrated that pyroptosis is closely related to the onset and progression of various retinal diseases. In age-related macular degeneration, pyroptosis directly causes apoptosis of RPE cells and upregulation of pro-inflammatory factors, enhancing toxic effect of lipofuscin. For retinitis pigmentosa, pyroptosis is the leading manner of death of secondary cone photoreceptor cells. In cytomegalovirus retinitis, pyroptosis is the main responding way to infection. This review presented the molecular mechanism of pyroptosis and its role in age-related macular degeneration, retinitis pigmentosa and cytomegalovirus retinitis and other retinal diseases.
ObjectiveTo investigate the relationship between optic disc hemorrhage and localized retinal never fiber layer defects (RNFLDs) in norma l tension glaucoma.MethodsIn 83 patients with normal-tension glaucoma, the cumulative frequency and quadrantal distribution of optic disc hemorrhages were retrospectively analyzed. The neighboring relation between optic disc hemorrhages and RNFLDs in a same quadrant and the changes of correspondin gretinal never fiber layer (RNFL) after the occurrence of optic disc hemorrhages were observed by tridimensional photochromy of ocular fundus.Results(1) The occurrences and distribution of optic disc hemorrhages: 29of83(34.94%) patients (33 eyes) had totally 58 occurrences, including 39 in infer iotemporal area, 14 in superiotemporal area, and 5 in other area. (2) The relati onship of neighborhood between optic disc hemorrhages and RNFLDs: in the availab le tridimensional photochrome, 23 occurrences in 15 patients (16 eyes) were foun d with cuneiform RNFLDs in the same quadrant, in which 22 was near the border of cuneiform RNFLDs. (3) The changes of corresponding retinal never fiber layer (R NFL) after the occurrence of optic disc hemorrhages: the photochromes of 24 occurrences in 20 patients (21 eyes) were kept well in the initial and the 2-year follow-up periods, while the changes of RNFL were found in each region correspon ding to the 19 occurrences (in inferiotemporal or superiotemporal area) in the initial photochrome, including 7 cuneiform defects with various sizes, and 12 developed localized RNFLDs next to the initial hemorrhages in the optic disc. No obvious localized RNFL corresponding to the other 5 occurrences (1 in inferiotempo ral, 1 in superiotemporal, and 3 in other areas) were found in the follow up period.ConclusionOptic disc hemorrhages in normal-tension glaucoma occur mostly in inferiotemporal area, and secondly in superiotemporal area of optic disc, and the appearance of optic disc hemorrhages may suggest that the localized RNFLDS would develop in the associated regions.(Chin J Ocul Fundus Dis，2004，20：339-342)
Familial exudative vitreoretinopathy (FEVR) is a hereditary disease with high geneticheterogeneity, including autosomal dominant inheritance, autosomal recessive inheritance, snd X-linked recessive inheritance. So far, six genes have been found to be associated with FEVR: Wnt receptor fizzled protein (FZD4), Norrie disease (NDP), co-receptor low-densitylipoprotein receptor-related protein 5 (LRP5), and tetrasin 12 (TSPANI2), zinc finger protein408 (ZNF408), kinesin family member 11 (KIF11) gene. Among them, FZD4, NDP, LRPS, TSPANI2 and other four genes play an important role in the Norrin/Frizzled 4 signaling pathway. In retinal capillary endothelial cells, Norrin specifically controls the occurrence of ocular capillaries by activating the Norrin/Frizzled 4 signaling pathway. ZNF408 and KIF11 are newly discovered pathogenic genes related to FEVR in the past 5 years. ZNF408 encodes the transcription factor that plays an important role in retinal angiogenesis. KIF11 plays a role in eye development and maintenance of retinal morphology and function.