Objective To explore the effect of oxygen inhalation on the retinae of newborn rats and its mechanism.Methods We mimicked the retinopathy of prematurity(ROP) by putting the newborn rats in high concentrated oxygen. One-day old rats were put into the oxygen box with the oxygen concentration of 80% for continuous 7 days; then in air condition for 7 days. The arterial blood oxygen pressure, retinal superoxide dismutase (SOD), and malondialdehyde (MDA) of the rats (1,2,4,7,8,9,11,14 days old) were examined. The diameter of retinal vessels′main branch and the coverage rate of peripheral vessels were measured in 7- and 14-day-old rats by ink perfusion. The retinal neovascularization of rats (8,9,11, 14 days old) were observed by HE staining. The rats of the same age fed in air condition were in the control group.Results The differential pressures of blood oxygen of rats (1,2,4,7 days old) in study group were significantly higher than those in the control group (P＜0.01), while the differential pressures of blood oxygen of rats (8,9,11,14 days old) in study group were lower than those in the control group (P＞0.05). The contents of SOD of the retinae in the rats ( 1,2,4,7,8 days old) were significantly lower than those in the control group(P＜0.01, P＜0.05 ), while the contents of MDA were significantly higher than those in the control group (P＜0.01,P＜0.05). The diameter of retinal vessels′main branch in 7-day rats was 75% of the control group, and the coverage rate of peripheral vessels was 22% of the control group; and was 61% and 73% respectively in 14-day-old rats. The neovascularization could be seen in 16.7% of the rats in the study group and nought in the control group.Conclusion The damage of free radical of the retina in high concentrated oxygen and hypoxia situation after oxygen supply may be one of the most important mechanism of ROP. (Chin J Ocul Fundus Dis，2003，19：269-332)
ObjectiveTo observe the correlation between the changes of area foveal avascular zone (FAZ), central foveal thickness (CFT), the thickness of the macular ganglion cell-inner plexiform layer (GCIPL) and the BCVA in type 2 diabetic mellitus patients with different fundus lesions.MethodsA prospective clinical study. Eighty-three eyes of 51 patients with type 2 diabetic mellitus were collected in Shengjing Hospital of China Medical University from January 2018 to January 2019, including 31 males and 20 females. The average age was 53.4±7.8 years. According to the diabetic retinopathy international clinical staging criteria, the patients were divided into the non-diabetic retinopathy (NDR) group with 17 patients (31 eyes), and the non-proliferative diabetic retinopathy (NPDR) group with 34 patients (52 eyes). And 13 control eyes of 8 age- and sex-matched healthy physical examination subjects (control group) were selected in this study. The BCVA examination was performed using the international standard visual acuity chart, which was converted into IogMAR visual acuity. OCT was used to measure the CFT, the mean and the minimum thickness of GCIPL. OCT angiography (OCTA) examination was applied to obtain blood flow density scan images in macular area of 3 mm × 3 mm size. The superficial FAZ area was measured by Photoshop software. The differences of the superficial FAZ area, BCVA, CFT, the mean and the minimum thickness of GCIPL in each group were statistically analyzed, and to explore the correlation between the parameters. Analysis of variance was used to compare measurement data among three groups, and chi-square test was used for the comparison of counting data among three groups. The statistical correlation was evaluated using Pearson’s correlation coefficient.ResultsThe average area of superficial FAZ area in the control group, NDR group and NPDR group were 0.314±0.103, 0.349±0.102, 0.416±0.148 mm2; the mean logMAR BCVA were 0.015±0.038, 0.029±0.059, 0.129±0.133; the mean CFT were 247.46±13.35, 244.13±25.09, 263.12±24.96 μm; the mean GCIPL thickness were 89.00±4.98, 86.06±4.43, 82.61±14.32 μm; the mean minimum GCIPL thickness were 84.85±3.18, 80.68±5.39, 71.19±19.94 μm, respectively. The superficial FAZ area, logMAR BCVA, CFT and the minimum thickness of GCIPL showed significant differences (F=4.660, 11.708, 6.891, 6.333; P=0.012, 0.000, 0.002, 0.003) among these three groups. Correlation analysis showed that the logMAR BCVA was positively correlated with the superficial FAZ area (r=0.335, P=0.001), negatively correlated with the mean GCIPL thickness (r=－0.348, P=0.001) and the minimum GCIPL thickness (r=－0.416, P=0.000), no significant correlated with the CFT (r=0.171, P=0.095). The superficial FAZ area was negatively correlated with the CFT (r=－0.262, P=0.010) and the minimum GCIPL thickness (r=－0.213, P=0.037), no significant correlated with the mean GCIPL thickness (r=－0.179, P=0.081).ConclusionsWith the aggravation of fundus lesions in patients with type 2 diabetic mellitus, the superficial FAZ area gradually expands, the minimum GCIPL thickness gradually becomes thinner and the BCVA gradually decreases. Both the superficial FAZ area and the GCIPL thickness are correlated with BCVA. The superficial FAZ area is correlated with CFT and the minimum GCIPL thickness.
Objective To observe the concentration of vancomycin and the changes of pharmacokinetic parameters in rabbit vitreous with endophthalmitis in different pathological conditions.Methods Eighty-one adult healthy rabbits were randomly divided into endophthalmitis with lens group (group A), aphakic endophthalmitis group (group B), aphakic endophthalmitis and vitrectomy group (group C), 27 rabbits in each group. The right eyes of all rabbits received intravitreal injection of 1 ml (10 mg/ml) vancomycin. Three rabbits from each group were sacrificed at 0.5, 2.0, 4.0, 6.0, 12.0, 24.0, 48.0, 72.0, 84.0 hours after the injection. The eyes were harvested to collect the vitreous. The vitreous concentrations of vancomycin in all the groups were detected by high performance liquid chromatography (HPLC-UV). The pharmacokinetic parameters including the area under the curve (AUC) of the concentration-time graph, clearance rate (CL), half-life period (t1/2) and peak concentration (Cmax) were calculated by 3p 97 pharmacokinetic software. Results The concentrations of vancomycin in the group A were always higher than the therapeutic drug levels after injection. In the group B and C, the concentrations of vancomycin remained significantly high at 0.5, 2.0, 4.0, 6.0 and 12.0 hours after injection, decreased quickly at 24 and 48 hours after injection, below the minimal inhibitory concentrations at 72 hours after injection. The differences were statistically significant among group A, B and C (t=4.968, 5.232;P＜0.05), but not statistically significant between group B and C (t=1.279, P＞0.05). The AUC were 15 790.61,7643.94, 7443.44 mu;g/(ml?h), CL were 0.063, 0.131, 0.134 ml/h, t1/2 were 13.49, 7.15, 6.93 hours and Cmax were 711.56, 648.45, 667.74 mu;g/ml in the group A, B and C, respectively. In the group A, the CL was lower (t=2.963, 3.097; P＜0.05) and t 1/2 was longer (t=3.315, 3.481; P＜0.01) than those in the group B and C, but there was no significant difference on Cmax (t=1.687,1.214;P＞0.05). Conclusion The pharmacokinetic parameters of vancomycin in rabbit vitreous with endophthalmitis varied between different pathological conditions
ObjectiveTo explore the inhibition effect of Cysteine-rich 61(CCN1;Cyr61) specific siRNA expression vector on RNV in a mouse model of oxygen-induced retinopathy (OIR). MethodsOne hundred and twenty healthy C57BL/6J mice were chosen and randomly divided into the experimental group and control group, with 60 mice in each group. The experimental group was intravitreously injected with CCN1siRNA recombinant plasmids. The control group was injected with vector plasmids. Adenosine diphosphate-ase stained retina flat-mounts was performed to assess the retinal vascular profiles, retinal section with HE staining was applied to count the number of new vascular cell nuclei and the protein and mRNA expression of CCN1 and vascular endothelial growth factor (VEGF) were detected by immunohistochemistry, Western blot and Real-time RT-PCR. ResultsCompared with control group, regular distributions, good branches and reduced density of retinal neovascularization were observed in the experimental group. The number of nucleus of vascular endothelial cells breaking through the inner limiting membrane was obviously less in the experimental group than that in the control group (t=8.756, P < 0.05). The expression of CCN1 and VEGF were obviously decreased in the experimental group compared with the control group (all P < 0.05). ConclusionThe development of RNV of ROP can be markedly inhibited by RNA interference targeting CCN1, and CCN1siRNA may provide an effective method for preventing vascular proliferative retinopathy.
Epigenetic mechanisms influence gene expression and function without modification of the base sequence of DNA and may generateagenetic phenotype. Epigenetic modifications include DNA methylation, histone modifications, and deployment of noncoding RNA. There is growing evidence that epigenetic mechanisms could playacrucial role in the development of diabetic retinopathy (DR). Molecular biological methods which could maintain mitochondrial homeostasis through the regulation of epigenetic mechanisms may prevent the development of DR. Epigenetic-related treatment modalities will become the new direction of targeted therapy for DR.
Objective To evaluate the efficacy and safety of intravitreal bevacizumab (IVB) as a preoperative adjunct to vitrectomy for prevention of postoperative vitreous hemorrhage (VH) in proliferative diabetic retinopathy (PDR) patients.Methods This was a meta analysis of randomized controlled trials (RCT). A computerized search was conducted in the Medline, Embase, Cochrane Library, Chinese Biomedical Database and Chinese Journal Full text Database combined with manually searching of bibliographies of pertinent articles, journals and literature reference proceedings. RCT on IVB as a preoperative adjunct to vitrectomy for prevention of postoperative VH in PDR were selected according to inclusion and exclusion criteria. After the data extraction, methodological quality assessment of RCT that were included using the Jadad scale. The outcome measures included the incidence of postoperative VH, postoperative best corrected visual acuity (BCVA), the incidence of postoperative retinal reattachment and postoperative complications. The statistical analysis was performed by Stata/SE 11.2. The weighted mean difference (WMD) with 95% confidence interval (CI) was calculated for continuous variable, and odds ratio (OR) with 95% CI for dichotomous variable. Results In total, seven RCT that fulfilled the eligibility criteria were included in the metaanalysis involving 170 patients in IVB group and 161 patients in control group. According to the Jadad scale, one RCT scored 5 points, one RCT scored 3 points and the other 5 RCT scored 1 point. The results suggested that IVB group achieved lower incidence of postoperative VH than control group both within four weeks after surgery (OR=3.28, 95% CI: 1.58-6.82,P=0.00), and over four weeks after surgery (OR=2.51, 95% CI1.21-5.22,P=0.01). There was no significant differences in incidence of postoperative VH between IVB and control group either at postoperative 3 months (OR=2.52, 95% CI: 0.74-8.57,P=0.14), or at postoperative 6 months (OR=3.26, 95% CI: 0.50-21.45,P=0.22). The results suggested that IVB group achieved better postoperative BCVA than control group (WM1=0.29, 95% CI: 0.13-0.44,P=0.00), but no significant differences were found between IVB and control group on the incidence of postoperative retinal reattachment (OR=0.39, 95% CI:0.10ndash;1.59,P=0.19), postoperative retinal re-detachment (OR=2.36, 95% CI: 0.74- 7.56, P=0.15) and postoperative neovascular glaucoma (OR=1.47, 95% CI: 0.28ndash;7.71,P=0.65). Conclusions IVB as a preoperative adjunct to vitrectomy could prevent postoperative VH in PDR effectively, and be relatively safe. However, a high-quality, multicenter, large sample, long-term RCT is warranted to be further investigated.