Objective To observe the inhibiting effects of alginate sodiumretinoic acid（AGS-RA）microspheres release system on the laser coagulationinduced subretinal proliferation.Methods RA were dissolved by absolute alcohol,then mixed with 1.5% AGS and made into AGSRA microspheres by a microcapsule electrostatic generator. The parameter of laser injury include irradiation time (0.20 s)，spot diameter (200 mu;ｍ) and output power (420 ｍＷ).Thirty pigmented rabbits were randomly divided into 3 groups (laser injury，experimental and control group).After laser coagulation,AGSRA or blank microspheres were immediately injected into the vitrous of experimental and control rabbits respectively.The height,width and area of 6 retinal spots of laser coagulation at each timepoint were analyzed histopathologically with serial retinal sections at 1,2,3,4,and 6 weeks after laser coagulation.Results Histopathological examination showed that there were morphological and distribution changes of retinal cells in all layers, and localized fibroblasts proliferation in the retina after laser injury. The laserinduced responses in experimental group were much milder（P＜0.01）, while the laser injury group and control group have same width（P＞0.05）and height/area of laser spots（P＞0.05）.Conclusion AGSRA release system can alleviate the subretinal proliferate after laser injury.
Objective To observe the expression of vascular endothelial growth factor A (VEGFA) and its receptors sFlt-1, kinase insert domain receptor (KDR) in lightinjured human retinal pigment epithelial (RPE) cells. Methods Cultured human RPE cells (8th - 12th generations) were divided into normal control group and light damage group. The cells of two groups were exposed to the 18 W cold white light (2200±300) Lux for 12 hours to induce light damage responses, but the cells of normal control group were packed by tinfoil with doubledeck high pressure disinfection. The VEGF-A, sFlt-1 and KDR mRNA and protein expressions were detected by reverse transcriptionpolymerase chain reaction (RT-PCR) and Western blot at 0, 6, 12, 24 hours after light damage. Results The VEGF-A mRNA and protein expressions in light damage group were significantly increased at 6 hours, and reached its peak at 12 hours after light damage which obviously higher than that in normal group (t=2.74, 2.93; P＜0.05), and then went down gradually. The sFlt-1 mRNA and protein expressions in light damage group reached its peak at 12 hours after light damage which obviously higher than that in normal group (t=4.32, P＜0.01), but obviously lower than that in normal group at 24 hours after light damage (t=2.41, P＜0.05). The KDR mRNA and protein expressions in light damage group were obviously higher than that in normal group at 24 hours after light damage （t=2.89, P＜0.05）,but there was no changes at 6, 12 hours after light damage (t=1.84, P＞0.05). Conclusions At 6, 12 hours after light damage, the expressions of VEGF-A and sFlt-1 increases significantly and KDR expression is stable in lightinjured RPE cells. At 24 hours after light damage, the expression of VEGF-A and sFlt-1 decreases, but KDR expression increases in light-injured RPE cells.
ObjectiveTo observe the effects of repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF) drugs on vitreous macular interface (VMI) in patients with exudative age-related macular degeneration (AMD).MethodsRetrospective study. Thirty-four exudative AMD patients who treated with intravitreal anti-VEGF drugs were included in this study. There were 26 males and 8 females. The age ranged from 50 to 80 years, with the average of (62.8±8.35) years. The eyes with at least 6 treatments during the 1-year follow-up were taken as the study eyes, and the eyes with no anti-VEGF drug treatment were the control eyes. Optical coherence tomography (OCT) examination was used to observe the VMI status of both eyes before treatment. Vitreous macular adhesion (VMA), macular epiretinal membrane (MEM), and complete vitreous detachment (C-PVD) were defined as abnormalities in VMI. The VMA was classified as focal (≤1500 μm) and broad (＞1500 μm) depending on the diameter of the vitreous and macular adhesions on the OCT images. Before treatment, there were 12 eyes with abnormal VMI in study eyes, including 8 eyes with broad VMA, 3 eyes with focal VMA, and 1 eye with MEM; 12 eyes with abnormal VMI in control eyes: broad VMA in 7 eyes, focal VMA in 2 eyes, C-PVD in 2 eyes, and MEM in 1 eye. The average follow-up time after treatment was 16.4 months. During the follow-up period, OCT was performed monthly in a follow-up mode. Comparing the changes on VMI between before and after treatment in both eyes of patients, respectively. The chi-square test was used to compare the difference on VMI. Because the number of samples was ＜40, Fisher's exact test was used for the analysis.ResultsAt the final follow-up, 12 eyes with abnormal VMI in the study eyes, including 5 eyes with broad VMA, 2 eyes with focal VMA, 3 eyes with C-PVD, and 2 eyes with MEM. There were 6 eyes altered comparing with baseline. In the control eyes, there were 13 eyes with abnormal VMI, including 5 eyes with broad VMA, 7 eyes with C-PVD, and 1 eye with MEM. A total of 6 eyes changed on VMI comparing with baseline. At the final follow-up, there was no significant difference on VMI changes between the study eyes and its corresponding control eyes (P=0.053). In all eyes, a total of 4 eyes changed from focal VMA to C-PVD at the final follow-up, accounting for 80.0% of the total focal VMA; 3 eyes changed from broad VMA to C-PVD, accounting for 21.4% of the total broad VMA.ConclusionsRepeated anti-VEGF treatment has little effect on VMI. Regardless of anti-VEGF therapy, eyes with focal VMA appears to be more prone to C-PVD than the broad one.
ObjectiveTo investigate the risk factors of postoperative vitreous hemorrhage after minimal vitrectomy without endotamponade for proliferative diabetic retinopathy (PDR).MethodsFrom June 2015 to June 2017, 103 eyes of 103 patients with PDR diagnosed and underwent minimalvitrectomy in Henan Provincial People's Hospital were enrolled in the study. There were 58 males and 45 females, with the average age of 58.37±10.14 years and diabetes duration of 8.7±7.2 years. Baseline systemic parameters including sex, age, diabetes duration, hypertension, HbA1c, creatinine, whether received anticoagulants, ocular parameters including whether combined with vitreous hemorrhage, whether finished panretinal photocoagulation (PRP), whether received treatment of anti-VEGF, whether combined with iris neovascularization (NVI), lens status preoperatively, whether hypotony postoperatively and intraoperative parameters including whether disc neovascularization (NVD) bleeding, whether fibrovascular membrane (FVM) residual, laser points, whether combined with cataract phacoemulsification were identified by multivariate logistic regression analysis.ResultsTwenty-nine of 103 eyes (28.15%) developed PVH in 1 day to 6 months after surgery, with self absorption of 18 eyes and reoperation of 11 eyes. Univariate analysis showed there were significant differences in age (t=2.124, P=0.036), anti-VEGF(χ2=7.105, P=0.008), NVD bleeding (χ2=10.158, P=0.001) and FVM residual(χ2=8.445, P=0.004) between patients with and without postoperative vitreous hemorrhage. Sex (χ2=0.021, P=0.884), diabetes duration (t=0.87, P=0.386), hypertension (χ2=2.004, P=0.157), HbA1c (t=1.211, P=0.229), creatinine (t=0.851, P=0.397), preoperative oral anticoagulants (χ2=0.985, P=0.321), preoperative vitreous hemorrhage (χ2=0.369, P=0.544), PRP (χ2=1.122, P=0.727), NVI (χ2=2.635, P=0.105), lens status (χ2=0.172, P=0.679), hypotony postoperatively (χ2=1.503, P=0.220), laser points (χ2=1.391, P=0.238) and combined phacoemulsification surgery (χ2=0.458, P=0.499) were not associated with PVH. Multivariate logistic regression analysis revealed the more PVH appeared in younger (OR=1.065, P=0.009) and NVD bleeding (OR=6.048, P=0.001) patients.ConclusionYounger age and NVD bleeding are the important risk factors for PVH after minimal vitrectomy without endotamponade in PDR.
Objective To investigate the causes of visual loss and failure of treatment after intraocular silicone oil removal. Methods Retrospective clinical analysis of the causes of loss of visual acuity of 15 eyes after silicone oil removal in patients with complicated retinal detachment which were successfully treated with vitreous and retinal microsurgery. Results Among the 15 eyes,retina failed to reattach in 11 eyes,secondary glaucoma occurred in 2 eyes and corneal opacity appeared in another two eyes.All of them were resulted in total loss of vision. Conclusion Retinal redetachment was the leading cause of final visual loss in the failing 15 cases(15 eyes) after intraocular silicone oil removal,and secondary glaucoma and corneal decompensation may also be the causes of visual loss. (Chin J Ocul Fundus Dis, 1999, 15: 230-231)
Objective To evaluate the effect of vitreoretinal surgery on tear film.Methods Ninety-seven patients (97 eyes) of retinal detachment undergoing surgical therapy including vitrectomy, scleral buckling or scleral encircling were included in this study. Uncomfortable eye symptoms were inquired and tear break-up time (BUT), Schirmer Ⅰ test (SⅠt), corneal fluorescein staining (CFS), tear meniscus height (TMH) were measured at three days before surgery and at six time-points after surgery (two, 14 days and one, two, three, six months). Thirty patients were randomly chosen to receive impression cytology of conjunctiva at three days before surgery and at four time-points after surgery (one, two, three, six months).Results Comparing with the preoperative results, at the first three time-points after surgery (two, 14 days, one month), uncomfortable symptoms (t=-25.082,-9.966, -4.718,P＜0.01) and CFS scores(t=-6.244,-3.716,-4.683, P＜0.01) increased, tear breakup time (BUT) shortened greatly (t=9.960, 5.627, 4.953; P＜0.01). SⅠt and TMH increased significantly（t=-25.931,-5.839;-25.345,-3.873;P＜0.01） at two and 14 days after surgery. The number of conjunctival goblet cell decreased significantly at one month after surgery（t=2.259, P＜0.05).All those tear film parameters returned to preoperative level at two months after surgery.Conclusion Vitreoretinal surgery influences tear film stability transiently, and the tear film function tends to restore in two months after the operation.
Objective：To observe the protective effect of ginkgo bilo ba extrac t (EGb 761), a free radical scavenger, on the photoreceptor cells after lighti nduced retinal damage. Methods：Seventytwo female SpragueDa wley (SD) rats we re randomly divided into 4 groups: normal control group, lightinduced retinal da m age model group, model+physiological saline group, and model+EGb 761 group, with 18 rats in each group. All of the rats except the ones in the control group were exposed to white light at (2740plusmn;120) lx for 6 hours after the dark adap tation for 24 hours to set up the lightinduced retinal damage model. Rats in m o del + physiological saline group and model+EGb 761 group were intraperitoneall y injected daily with physiological saline and 0.35% EGb 761 (100 mg/kg), respec tively 7 days before and 14 days after the light exposure. Apoptosis of photorec eptor cells was detected 4 days after light exposure; 7 and 14 days after light exposure, histopathological examination was performed and the layer number of ou ter nuclear layers (ONL) on the superior and inferior retina was counted. Results：Four days after light exposure, the apoptosis of photorecep tor cells was fou nd on ONL in model, model+ physiological saline and model+EGb 761 group, and w as obviously less in model + EGb 761 group than in model and model+physiologic al saline group. Seven days after light exposure, the layers of ONL on the super ior retina were 3 to 4 in model and model+physiological saline group, and 7 to 8 in model+EGb 761 group; the mean of the layer number of ONL in model+EGb 761 group (6.92plusmn;0.82) was less than that in normal control group (8.40plusmn;0.95) (t=-1.416, P＜0.05), but significantly more than that in model (5.96 plusmn;1.36 ) and model+physiological saline group (5.90plusmn;1.40）（t=1.024, 1.084; P＜0.05). Fourteen days after light exposure, the layers of ONL on the superior retina were 0 to 1 in model and model+physiological saline group, and 3 to 4 i n model+EGb 761 group. The mean of the layer number of ONL in model+EGb 761 group (5.5 2plusmn;1.06) was significantly more than that in model (3.44plusmn;2.15) and model + physiological saline group (3.37plusmn;1.91) (t=2.082, 2.146, P＜0.05). Conclusion：EGb 761 can partially inhibit the apoptosis of pho toreceptor cells, thus exert protective effect on photoreceptor cells.
ObjectiveTo observe the changes in physical properties of silicone oil after intraocular tamponade. MethodsThe silicone oil was removed from 99 patients (99 eyes) of primary retinal detachment with 23G vitreous cutter system. The upper silicone oil was collected after put the vitrectomy samples at room temperature for 3 days. According to the time of intraocular tamponade, the silicone oil samples were divide into six groups including group A (1 month, 12 samples), group B (2 months, 15 samples), group C (3 months, 25 samples), group D (6 months, 22 samples), group E (1-2 years, 13 samples) and group F (above 2 years, 12 sample). Fresh unused silicone oil was set as blank control group. Then the emulsion particles, kinematic viscosity, surface tension, density, transmittance and refractive index were measured. ResultsThe difference between group A-F and the control was statistical significant (P<0.05) in emulsion particles (F=89.337), kinematic viscosity (F=10.660), surface tension (F=11.810), density (F=13.497), transmittance of wavelengths (F=455.496, 566.105, 525.102, 767.573, 622.961, 601.539), but not statistical significant at refractive index (F=2.936, P>0.05). The number of silicone oil emulsion particles has no statistical difference between group A and the control (P>0.05), but was significantly different between group B-F (P<0.05). The kinematic viscosity of silicone oil has no statistical difference between group A, B and the control (P>0.05), but was significantly different between group C-F (P<0.05). The surface tension of silicone oil has no statistical difference between group A-D and the control (P>0.05), but is significantly different between group E and F (P<0.05). The density of silicone oil has no statistical difference between group A-D and the control (P>0.05), but was significantly different between group E and F (P<0.05). The transmittance of silicone oil has statistical difference between group A-F and the control(P<0.05). The refractive index of silicone oil has no statistical difference between all the groups and the controls significantly (P>0.05). ConclusionsThe physical properties of silicone oil will change during the intraocular tamponade. The emulsion particles number will increase and the transmittance will decrease after 2 months, the kinematic viscosity of silicone oil will decrease significantly after 3 months, and the density and surface tension will change significantly after 1 year of tamponade.
ObjectiveTo investigate the medium and long-term influence of silicon oil versus heavy silicone oil on rabbit retinas. Methods28 health standard rabbits were randomly divided into A, B and C groups, with 12, 12 and 4 rabbits respectively. All rabbits received routine vitrectomy and tamponade with silicone oil (group A), or heavy silicone oil (group B) or balanced salt solution (group C). After 4, 8, 12 and 24 weeks, the retinal b-wave amplitude was measured by ERG, posterior retinal thickness was measured by optical coherence tomography (OCT). Retinal ultrastructure and tissue morphology were observed by transmission electron microscopy and optical microscopy. ResultsCompare to group C, the b-wave amplitude decreased at 4 weeks after surgery, and decreased at 8 weeks after surgery for group B, and decreased at 8 weeks after surgery, and decreased at 24 weeks after surgery for group A. The decreases were greater in group B than group A at 8, 12, 24 weeks after surgery, the difference was statistically significant (P < 0.05). The posterior retinal thickness of group A and B was thinner than group C at 24 weeks after surgery (P < 0.05). The decreases were greater in group B than group A, the difference was statistically significant (P < 0.05). Transmission electron microscopy and optical microscopy revealed severe pathological changes of retinal ultrastructure and morphology in group A and B rabbit eyes, at 12 weeks and 8 weeks after surgery respectively. The changes were more severe in group B and group A, including edema and necrosis in cone/rod cells, in disk membranes, mitochondria, cytoplasm, nucleus and other organelles. The morphological changes were also more severe in group B and group A, including degenerations of ganglion cell layer, inner nuclear layer changes. Those changes became more severe when the tamponade time extended. ConclusionThe heavy silicone influence on visual function, ultrastructures, histomorphology of rabbit retinas is much worse than the silicon oil, and the effect is more significant with its time prolong.
Objective To investigate the refractive changes of ocular measurable factors due to scleral buckling surgery. Methods A total of 86 eyes of successful rhegmatogenous retinal detachment with a higher encircling scleral buckle underwent A-scan and keratometer examination before surgery as well as l week,4 and 12 weeks after surgery.The refractive factors included the depth of anterior chamber,thickness of lens,axial length of eye,corneal curvature and refraction of eye were detected pre- and post-operatively. Results Compared with preoperation,the depth of anterior chamber was decreased significantly at the lst,4th and 12th postoperative week(P＜0.05),while no significant change of the axial length of eye was observed.The thickness of lens was increased significantly and the refractive error was myopic shifted at the lst and 4th week after operation(P＜0.05),but no significant change was observed at the 12th postoperative week.Statistically significant difference was also observed in corneal curvature of central axis in the local bucklele;1 quadrant with encircling group between preoperation and the lst and 4th postoperative week. Conclusions With higher encircling scleral buckle,the refractive change after buckling surgery may be caused primarily by the shallowing of anterior chamber and thickening of lens. (Chin J Ocul Fundus Dis, 1999, 15: 227-229)