Objective To observe the expression of erythropoietin (EPO) and EPO receptor (EPOR) in detached retina in rat model. Methods Fourty-eight male SD rats were randomly divided into control group and retinal detachment (RD) groups (1 hour, 3, 6, 12, 24, 48, and 72 hours group) with 6 rats (12 eyes) in each group. 1.4% hyaluronic acid was slowly injected into the subretinal space to induce the detachment of the upper retina to set up the RD model. The expression levels of mRNA and protein of EPO and EPOR were measured by RT-PCR and western-blotting analysis. Meanwhile, the locations of EPO and EPOR in retina were checked by immunohistochemistry. Results Both of the mRNA and protein levels of EPO and EPOR increased after RD, and reached the peak at the 48th hour after RD. The mRNA levels of EPO and EPOR were significantly higher in the 6 and 12 hours group than that in the control group（Plt;0.05）. The protein levels of EPO and EPOR were significantly higher in 3 hours group than that in the control group（Plt;0.05）. Immunohistochemistry indicated weak expression of EPO from ganglion cell layer to inner and outer segment of photoreceptor cells, and b expression in the corresponding location was found 48 hours after RD. Expression of EPOR from ganglion cell layer to inner segment of photoreceptor cells in the normal retina was detected, and b expression in the corresponding location was found 48 hours after RD. Conclusion The expression of EPO and EPOR in retina increases gradually after RD, and reaches the peak at the 48th hour; most of the layers of neural retina can express EPO and EPOR.
ObjectiveTo evaluate the incidence of retinal re-detachment and possible risk factors after removal of silicone oil. MethodsThe clinical data of 821 patients (858 eyes) who underwent removal of silicone oil in General Hospital of PLA during 2008-2012 were retrospectively analyzed. The patients included 518 males and 303 females. The age was ranged from 1 to 79 years old, with an average of 44.03 years. All patients underwent removal of silicone oil after vitrectomy combined with silicone oil tamponade (the tamponade period was ranged from 40 days to 13 years, with an average of 6.82 months). The incidence, time and causes of retinal re-detachment were analyzed. ResultsRetinal re-detachment occurred in 43 patients (44 eyes, 5.13%). Among these retinal re-detachment in 44 eyes, 23 eyes (52.27%) occurred in 1 week, 13 eyes (29.55%) in 1-4 weeks, 4 eyes (9.08%) in 4-8 weeks, 2 eyes (4.55%) in 8-12 weeks, and 2 eyes (4.55%) more than 12 weeks after silicone oil removal. Possible reasons of retinal re-detachment included activated original retinal holes (7 eyes), residual peripheral vitreous (3 eyes), traction of epiretinal proliferative membrane (18 eyes), new retinal hole (9 eyes), non-closure of original retinal holes (5 eyes) and traction of retinal incarceration in the scleral incision (2 eyes). ConclusionsThe incidence of retinal re-detachment after silicone oil removal is 5.13%. The incidence reduced gradually with the extension of time after removal silicone oil.