Some aspect of diagnosis and type of clinical management and risk factors of age-related macular degeneration / Шинэ санаа Шинэ нээлт

Age-related macular degeneration (AMD) is the leading cause of severe visual loss in people aged 50 years or older. It estimates that 25-35 million people lost vision due to AMD in the world. Rapid increase of aging population, 33.2 million people was affected by AMD in 1994and there is estimation the number will reach 80 million by 2050. Prevalence of disease is different in countries it relates due to aging population and the ratio is higher in developed countries. The risk factors of AMD; race, nationality, life style, cigarette smoking, alcoholconsumption, UV exposure, diet, vitamin or food supplements consumption, drugs and high blood pressure. This study was to evaluate risk factors in age related macular degeneration because cigarette smoking, alcohol consumption and high blood pressure are high among elder Mongolians. Introduction of Optical Coherent Tomography /OCT/ in ophthalmology enables us to early diagnose and prevention. It will be basic data for developing AMD prevention policy and improving methods of diagnosis and management.

Decreased VEGF-A and sustained PEDF expression in a human retinal pigment epithelium cell line cultured under hypothermia

BACKGROUND: Previous reports have described a decrease in retinal temperature and clinical improvement of wet age-related macular degeneration (AMD) after vitrectomy. We hypothesized that the retinal temperature decrease after vitrectomy plays a part in the suppression of wet AMD development. To test this hypothesis, we evaluated the temperature dependence of the expression of vascular endothelial growth factor-A (VEGF-A) and in vitro angiogen-esis in retinal pigment epithelium (RPE). RESULTS: We cultured ARPE-19 cells at 37, 35, 33 and 31°C and measured the expression of VEGF-A, VEGF-A splicing variants, and pigment epithelium-derived factor (PEDF). We performed an in vitro tube formation assay. The dehydrogenase activity was also evaluated at each temperature. Expression of VEGF-A significantly decreased with decreased temperature while PEDF expression did not. VEGF165 expression and in vitro angiogenesis also were temperature dependent. The dehydrogenase activity significantly decreased as the culture temperature decreased. CONCLUSIONS: RPE cultured under hypothermia that decreased cellular metabolism also had decreased VEGF-A and sustained PEDF expression, creating an anti-angiogenic environment. This mechanism may be associated with a beneficial effect after vitrectomy in patients with wet AMD.

Retinal pigment epithelial and choroidal atrophy in wet age-related macular degeneration treated with multiple transpupillary themotherapy:A case report / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To report a case of wet age-related macular degeneration (AMD) treat with multiple transpupillary themotherapy (TTT) and choroidal neovascularization (CNV) disappeared but retinal pigment epithelial(PRE) and choroidal atrophy occurred with a low vision at the end point.METHODS: Clinical data including fundus hotographs, fundus fluorescein angiography (FFA), indocyanine angiography (ICGA) and optical coherence tomography(OCT) was reviewed.RESULTS: A 72-year-old man complained about blurred vision of his left eye and FFA revealed polypoidal choroidal vasculopathy (PCV) in the macula. His left eye had stable vision of 0.1 for 6 years without any treatment of CNV. About 2 years later, his right eye presented a piece of CNV. During the period of 3 years, the lesion remained more (3×5 PD) and less (1×2PD) in size with remarkable exudates and bleeding, and 7 sessions of TTT were applied with 80-280mW, 2mm of spot, and 60 seconds exposure and with the interval of 3 months or more. The CNV lesion finally disappeared, but there left a white area in the macula and vision decreased from 0.3 to 0.04.CONCLUSION: Although CNV lesion can be eliminated by TTT, obvious atrophy of RPE cells and the choroids can happen and this may not be of help for patient vision. It suggests that the parameters of TTT will be lower than 120 mW/mm and limited less two sessions if applicable, especially for Asia people.

The Study of Rhesus Retinal Pigment Epithelium Cells Transplantation / 医学研究杂志

Objective To investigate the retinal pigment epithelium cells(RPE) and makeit the base of clinical application for transplantation.Methods The cultured RPE cells labeled by BrdU was injected into the host's subretinal space by external transcleral.The structure and ultrastructure of the transplanted RPE cells were observed by microscope and transmission electron microscope.Results The transplanted cells had the normal structure as the host's cells.They attached to Bruch's membrane with basal infoldings and forming microvill on the surface of the cells.Conclusion The external transcleral is a practical method for RPE transplatation.The transplanted cells can vitalize and form some normal ultrastrcture.

The Effect of Glucose on Anoxia-induced Cell Damage in the Cultured Human Retinal Pigment Epithelial (RPE) Cell

PURPOSE: It is difficult to make the standard ischemic RPE culture model which is still not established. In ischemic model, oxygen and glucose are very important. To improve experimental model, we evaluate the effect of glucose on anoxia-induced human RPE cell damage. METHODS: Human RPE cells were incubated with 95% N2/5% CO2 and standard conditions (95% air/5% CO2) at 37degrees C, and various concentation of glucose were added to a glucose-free medium : no glucose, 0.2 mg/ml, 0.4 mg/ml, -2.0 mg/ml. On a daily basis, morphological and proliferation analysis was conducted using the inverted phase contrast microscope. The extent of cell damage was estimated through cell viability analysis. Cell viability was examined using PMS(phenazinemethosulphate)-MTS(3-(4.5 -dimethyl-thiazol-2-yl)-5-(3-caboxymethoxyphenyl)-2-(4-sulfo phenyl)-2H-tetrazolium, inner salt)assay after 24, 48, 72, and 96 hours. Single-stranded DNAs were detected with monoclonal antibody to prove cell apoptosis in cell damage. RESULTS: At slightly low glucose concentration(0.4 mg/ml), the cell viability of human RPE cells cultured at room air was maintained up to 96 hours, whereas that cultured at 95% N2 decreased after 48 hours. At the anoxic condition. the cell viability of human RPE cells cultured with the low glucose concentration (0.2 mg/ml) decreased after 24 hours, but those done with higher glucose concentrations (more than 0.8 mg/ml) were maintained up to 96 hours. In the cell death caused by the anoxic culture, apoptosis was not suggested by single-stranded DNA detection. CONCLUSIONS: Properly higher glucose concentration on culture medium improve cell viability and reduce the cell damage in human RPE culture in anoxic condition. This result helps to improve experimental ischemic model of RPE cell.

Degradation of phagosomes and diurnal changes of lysosomes in rabbit retinal pigment epithelium

Diurnal changes of lysosomes including ultrastructural changes of phagosomes and acid phosphatase reactions in phagosomes, as well as diurnal biochemical changes in cathepsin D activity, were studied in the retinal pigment epithelium (RPE) of the rabbit. The rabbit was maintained on a natural light-dark cycle over seven days in fall and was sacrificed at various times during the day and night. The number of lysosomes or phagosomes in the RPE was the highest at 1.5 hours after exposure to sunlight (8:00 AM), and thereafter decreased with time. Three types of phagosomes were observed and acid phosphatase reactions were different in each type of phagosome; the fresh phagosomes were negative or positive, lamellar bodies positive, and dense bodies partially positive. The biochemical activity of cathepsin D was the highest at 8:00 AM, and this was consistent with the time of peak in phagocytic activity in the RPE. This report shows that phagocytic activity in the RPE occurred in the early stage after exposure to sunlight, and that fresh phagosomes were sequentially degraded to lamellar or dense bodies. Cathepsin D activity also increased, and this was consistent with the phagocytic activity in the RPE.