PURPOSE:To discuss the clinical characteristics and differential diagnosis of peripapillary subretinal hemorrhage(PPSRH). METHOD:Retrospective analysis of the clinical documents including mainly the ocular manifestations and the findings of fundus fluorescein angiography(FFA)of 37 patients (38 eyes)with PPSRH. RESULTS:In all of these 37 patients,36 were myopes, 31 were young persons ,the average age was 21 years old,and 36 were affected unilaterally. The subretinal hemorrhage revealed itself in 4 types :PPSRH (5 eyes),PPSRH with disc iaemorrhage (21 eyes),PPSRH with vitreous hemorrhage (2 eyes), and PPSRH with disc hemorrhage and vitreous hemorrhage (10 eyes). In the FFA, the hemorrhages showed blocked fluorescence and the optic discs showed irregular hyperfluorescence at the late phase. All of the hemorrhages were absorbed within 3 weeks to 3 months without any treatment. CONCLUSIONS:According to the manifestation of the optic discs in FFA PPSRH might be complicatton of the buried optic disc drusen. （Chin J Ocul Fundus Dis,1997,13: 143-145 ）
PURPOSE:To evaluate the activitv of protein kinase C(PKC) in response to retinal photochemical insult in rat. Furthermore, to investigate the effect of dexamethasone(DXM ) on PKC activity. METHODS :The experiments were performed on 48 SI') rats whieh were separated into two groups,control and treated groups,and the latter received daily intraperitoneal injections of DXM (1 mg/kg)for 5 consecutive days,starting 3 days before light exposure. The animals were continually exposed to green fluorescent light (510nm~560nm) with an illuminance level of (1 900plusmn;106.9)lx for 24 hrs.The retinal enzyme activity of PKC was tested at 6 hrs,1 day,3 days,7 days,and 14 days after light exposure respectively. RESULTS:In animal models,PKC activity showed a transient increase in both groups at 6 hrs after light exposure and then decrease persistently there alter. The activity of PKC was unresponsive to DXM intervention. CONCLUSIONS :These results suggested that the persistent lower PKC activity might result in disturbance of retinal function in rat retinal photochemical injury. （Chin J Ocul Fundus Dis,1997,13: 78-80）
PURPOSE:The changes of expression level of rhodopsin mRNA and its relationship with the morphology in light damaged rat retinas were studied. METHODS:The changes of expresson level of rhodopsin mRNA in light damaged rat retinas and the changes on retinal morphology were observed through the technique of in situ hybridization and electron microscopy. RESULTS:The hybridization signals of rhodopsin mRNA mainly distributed in the photoreceptor layer of retina,relatively b in the inner and outer segments. As the increase of light exposure time,the expression level of rhodopsin mRNA in retinas greatly decreased before the changes on morphological injury of retina. For the same eye globe of the same rat at the same time,the hybridization signals at the upper and posterior region of the retina decreased more obviously than the lower and peripheral region of the retina. CONCLUSIONS:It was demonstrated for the first time that the expression of rhodopsin mRNA was located at the photoreceptor layer of the retina. Continuous exposure to light could greatly decrease the expression of rhodopsin mRNA and the decreases differ regionally. It might be the early signals of retinal photic injury.It is a good method to study the expression level of retina mRNA through the in situ hybridization. （Chin J Ocul Fundus Dis,1997,13: 228-210）
Eighteen SD rats with streptozotocin-induced diabetes were observed for the influence of magnesium in glycolytic pathway in their retinal tissue.The diabetic rats were divided into 3 groups:6 of them drank 0.5% Mgso4 solution every day,6 received intramuscular Mgso4 (0.05/kg)in half month interval,and the another 6 drank tape water every day.Six normal rats were employed as employed as nondiabetic control.The activity of the three crucial rate-limiting enzymes ralating to glycolytic pathway-hexokinase,phosphofructokinase and pyruvate kinase in retinal tissue of the rats was investigated after a period of 30days.The results revealed that the levels of the enzymes were significantly depressed in diabetic rats not taking magnesium,while the enzyme levels maintained nearly the same in diabetic rats taking magnesium,while the enzyme levels maintained nearly the same in diabetic rats taking magnesium as in the control group.This suggested that the glycolytic pathway in retinal tissue was disturbed in early stage of diabtes,and magnesium might play an important role in maintaining the normal metabolism of glucose. （Chin J Ocul Fundus Dis,1993,9:81-83）
Tweenty-one SD rats with streptozotocin-induced diabetes were investigated for the influence of magnesium in cAMP level in the retina of the diabetic rats. The diabetic rats were divided into 3 groups: group 1, drinking tap hehwater; group 2, drinking 0.5% MgSO4 solution and group 3, receiving intramuscular MgSO4(0.1g/kg) once a month. In addition, group 4, a controlgroup of normal nondiabetic rats fed with tap water. In aperiod of 5 months examination, the growth and health conditions of diabetic rats were found to be nearly normal in group 2, 3 and 4, manifested by gaining weight and soft, smooth hairs on the skin, in contrast with loss in weight, rough hairs and even dying of infection in 2 of the diabetic rats in group 1. furthermore, the level of cAMP content in retina was found significantly higher in the diabetic rats taking Mg++ in spite of the route of administration(group 2, 3), as well as in the control group(group 4) than that of the diabetic rats which were fed with tap water. These results demonstrated that Mg++ might play an important role in improving the metabolism of diabetic rats including the retinal tissue by influencing the level of cAMP content, which is necessary in nuclear acid metabolism, protein synthesis, proliferation and differentiation, and other intracellular metabolic processes. （Chin J Ocul Fundus Dis,1992,8:141-143）
The retina of SD rats was incubated in four types of the Eagle solution respectively. The results showed the cAMP level of retinas was the lowest in the hGnMg(high glucose with normal magnesium) solution but the cAMP level was significantly increased in the hGhMg(high glucose with high magnesium) and higher than that of normal control group. The cAMP level was the highest in the nGhMg(normal glucose with high magnesium). The results suggested that magnesium might play an important role in maintaining the normal metabolism of glucose of the retinal tissue. （Chin J Ocul Fundus Dis,1992,8:138-140）