Fullfield electroretinalgraphy (ffERG) is an indispensablemeans in assessment of retinal disease; it is invasive, effective, objective, quantifiable, and reproducible. Currently ffERG has been extensively applied domestically, but it also has disadvantages such as too few detected diseases, nonstandardised methodology, and inaccurate description of the results. It is important to place more emphasis on the internationalization, standardisation, and normalization of the application; obtaining the differences of indication, detection techiniques, and description of the results among ffERG, multifocal ERG and pattern ERG; expanding the new fields and methods of clinical applications. So that ffERG could play an more important role in the diagnosis and management for the patients with retinal disease.
There are over 8 million blind patients in China, 1/3 of them are suffered from retinal degeneration diseases. Stem cells transplantation can delay the photoreceptor cell degeneration or replace the dead photoreceptor cells, provides hopes for these patients. How to make enough seed cells is the major barrier for cell therapy. Good seed cells should be safe and with great pluripotency, and can be made from a wide range of sources, easy to be standardized and industrialized. Seed cells made from three-dimensional embryonic stem cells cultures can reach the above criteria, thus three-dimensional embryonic stem cell culture is a new strategy for making seed cells for cell treatment of blind diseases.
Objective To observe the distribution and concentration of 125I-nerve growth factor (NGF) in rabbitsprime; eyes after intravitreal injection and posterior juxtascleral injection.Methods Intravitreal injection(group A) and posterior juxtascleral injection (group B) were performed with the dosage of 30mu;g/100mu;l 125I-NGF on left and right eyes in 45 white rabbits respectively. The gamma;-counts and the concentration of 125I-NGF (％ID/g) of each ocular tissue was determined 15 and 30 minutes, and 1,3,6,12,24,and 48 hours after injection. Results The 125I-NGF diffusion in group A was faster in ocular content and ocular inner wall. The vitreous content of 125I-NGF decreased gradually in group A, the curve changes in other eye tissues were normal. The concentration of 125I-NGF reached the peak 3 hours after injection in aqueous humor, iris and ciliary body, retina, and choroids, but 6 hours after injection in sclera and 8 hours in cornea. The changes of concentration of 125I-NGF in group B showed normal curve change. The peak time in group B were all 6 hours in all the tissues except aqueous humor (3 hours). Except the high concentration in vitreous body caused by intravitreal injection, the concentration of 125I-NGF in retina was the highest in group A. Conclusion Intravitreal injection of 125I-NGF can gain higher concentration in each ocular tissue than posterior juxtascleral injection, especially in retina. So intravitreal injection of NGF is a better ocular delivery method to treat the ocular fundus diseases.
Objective To observe the mutifocal electroretinogram (mfERG) characteristics of rod and cone cells in patients with retinitis pigmentosa (RP) and to evaluate the function of photosensory cell.Methods The mfERG recording technique for rod cell in eight normal subjects (eight eyes) were established and the influence of different brightness lightstimulus in P1 wave amplitude were analyzed. The cone and rod cells mfERG of 38 eyes in 19 patients were recorded and then calculated positive ratio from local signalnoise ratio. The average visual acuity and P1 wave amplitude density of cone mfERG in different types were compared and statistically analyzed. Meanwhile, the changes in P1 wave amplitude of cone and rod mfERG in four quadrants also compared and analyzed. Results Rod cell mfERG in normal subjects can be recorded stably by using blue flashes with low light intensity as 0.04 cd/m2. In patients with RP, the cone and rod cells mfERG can be detectd 65.79% and 10.51% respectively. P1 wave amplitude density in type I of cone cell mfERG was significantly higher than that in type II (t=5.21,P=0.000). There were no differences in average visual acuity (t=1.15, P=0.612). P1 wave amplitude density in type I was negatively related to logMAR visual acuity （r=-0.48，P=0.04）.The comparison of rod and cone cells mfERG in local wave characteristics showed that P1 wave amplitude densities had spatial relationship in each area. Conclusions The results suggested highly variable central responses in cone cell in RP patients, higher positive recorded ratio in cone cell than rod cell and spatial correspondence between the function of reserved cone and rod cells.
Objective To observe the image characteristics of autofluorescence (AF) in central serous chorioretinopathy (CSC). Methods A total of 85 eyes of 72 patients with CSC were examined by Headberg HRA2 laser scanning fundus fluorescein angiography (FFA), redfree light photography, and Kowa fundus colorizedphotography. The grey AF images were obtained with 488 nmwave-length laser and comparatively analyzed with results of fundus colorized photography, redfree light photography and FFA. Results In 85 eyes, single faint AF of the CSC focus was in 14 (16.5%); faint AF pool containing b lamellar focus was in 39 (45.9%); faint AF pool combining with mottling focus was in 25 (29.4%); local dense or scattered mottling AF at the posterior pole was in 7 (8.2%). FFA fluorescein leakage point or abnormal fluorescence were in accordance with abnormal AF in 60 eyes (70.6%); the changes of ocular fundus, results of FFA, and changes of AF were not accordance in 25 eyes (29.4%). AF of CSC focus during different disease course was different, which showed single platelike faint AF pool and b mottling AF complex focus in and out of the faint AF in the period of onset of the disease, while b mottling combining with faint mottling AF and various multiinfection fields in the period of chronicity. Conclusions The AF of CSC mainly demonstrates single faint AF, b mottling combining with faint mottling AF and multiinfection AF in macular fields. AF examination associates with fundus colorized photography and FFA can be mutually complemented in observing the images of CSC.
ObjectiveTo explore the distribution and features of the optic cup stem cells in embryonic rat at tailbud stage.MethodsThe distribution of optic cup stem cells in optic cup tissue in 12.5-embryonic-day-old rats was observed by immunohistochemistry. The separated cells from optic cup were cultured with serum-free media, and immunofluorescence technique was used to detect the ability of hyperplasia of stem cells and expression of CHX10 antigen and specific antigens of mature retinal cells before and after differentiation.ResultsThe optic cup stem cells in embryonic rat at tailbud stage were mainly located at inner, outer, and marginal layer of optic cup. No expression of specifically marked protein of mature retinal cells was detected. The cells separated from optic cup had the ability of single-cell clone, positive expression of CHX10 and expression of several specific antigens of mature retinal cells after the inducement, including Thy1.1, glial fibrillary acidic protein (GFAP), protein kinase C (PKC) α, and rhodopsin.ConclusionOptic cup of 12.5-embryonic-day-old rats composes of undifferentiated cells, and the stem cells are mainly located in optic cup inner and marginal. High ability of hyperplasia of the optic cup stem cells cultured in vitro is found. The cells, which are retinal stem cells, can express several specifically marked proteins of mature retinal cells after inducement and differentiation.(Chin J Ocul Fundus Dis, 2005,21:159-162)
Objective To describe cultured human retinal pigment epithelial (RPE) cells transdifferentiation and investigate the effects of human vitreous fluid on the morphologic and cytoskeleton changes of RPE cells in vitro. Methods Cytoskeleton characteristics in the 2nd, 5th, 8th passage of RPE cells in normal culture, which included cytokeratin 18 (CK18) and α-smooth muscle actin (α-SMA) were analyzed by Western blot. RPE cells were cultured in human vitreous-conditioned medium (VCM) at the concentration of 1∶4 for 6 days, morphologic changes were examined by light and electron microscopy, and cytoskeleton characteristics were analyzed by imunocytochemistry and Western blot. Results During culture in vitro, RPE cells lost epithelial characteristics and aquired fibroblast-like phenotype. The expression of CK18 was the highest at the 5th passage, and it decreased in the following passage, but α-SMA increased gradually. The morphologic transdifferentiation from epithelial to fibroblast-like cells of RPE was accelerated by VCM. Ultrastructural changes such as decreased microvilli and gradually increased rough endoplasmic reticulum and Golgi complex were found during the cultivation. CK18 produced by RPE cells decreased in VMC (P＜0.05), and α-SMA increased (P＜0.01). Conclusion Morphologic changes in epithelialmesenchymal transdifferenetiation of RPE cells are stimulated by VCM and accomplied by the shift of cytoskeleton proteins, The results imply that cells migration may be decreased and contraction may be enhanced in VCM. It may suggest that vitreous accelerates the pathogenesis of PVR and RPE cells play an important role. (Chin J Ocul Fundus Dis, 2002, 18: 289-292)