Objective To investigate the effect of proanthocyanidins (PC) on retina of rats with acute ocular hypertension. Methods The SpraqueDawley (SD) rats were randomly divided into the normal group, the model group and PC high or lowdosage group. The PC high or low dose group received 300mg/kg.d or 100mg/kg.d of PC in suspension solution for 5 days respectively. The normal group and the model group fed with distilled water for 5 days. Then acute ocular hypertension was induced in the model group and all PC groups, and after 48h of ocular hypertension the eyeballs were analyzed by electron microscope and UV spectrophotometer to measure the levels of superoxide dismutase(SOD), malonaldehyde (MDA), nitrogen monoxidum (NO), glutamic acid (Glu) and calcium ion(Ca2+). Results PC could raise the activity of SOD and reduced the levels of MDA,NO,Glu and Ca2+ in retina tissue. Electron microscope examination revealed that PC reduced retinal edema and ganglion cell apoptosis. PC also enhanced the SOD activity and suppressed the levels of MDA, NO, Glu and Ca2+. Conclusions PC can protect retina from acute ocular hypertension. The main mechanism might relate to anti-free radical oxidation, antagonizing calcium overloading, reducing toxicity of NO and Glu on the retina.
At present, there are few in vivo experimental studies on anterior chamber flow field, and the relevant technologies are not mature. This study explores the experimental method and key techniques of particle image velocimetry (PIV) for the in vivo measurement of anterior chamber flow field with slow flow velocity in the rabbit with acute intraocular hypertension. The experimental process can be divided into three parts: model construction of rabbit eye with acute intraocular hypertension, in vivo eyeball preparation, and PIV setup. The following key techniques were mainly investigated: the optimal injection strategy of fluorescent particles and the correction strategy for image acquisition errors caused by the effects of image refraction and respiration. The results showed that the best injection method was that 15 μL of fluorescent particles solution was slowly injected into the anterior chamber through the lower part of iris and then the rabbit was released and waited for 13 h. In this way particles were completely distributed in the anterior chamber with the help of the aqueous humor circulation, and then in vivo PIV experiment could be performed. The eyeball should be covered with a square flume filled with ultrasonic coupling gel for the sake of imaging during the experiment. The Maximal Information Coefficient algorithm could be applied to correct the measured results before post-processing calculation. The results indicated that feasible injection strategy of fluorescent particles and the correction strategy for image acquisition are critical to obtain nice experiment effects for the in vivo PIV measurement of anterior chamber flow field in the rabbit with acute intraocular hypertension.
Objective To investigate the factors associated with short-term elevation of intraocular pressure after ranibizumab intravitreal injection. Methods 292 eyes of 292 patients who were diagnosed retinopathy and suitable to receive ranibizumab intravitreal injection were enrolled in this prospective clinical study. There were 157 males and 135 females. 193 patients diagnosed with age-related macular degeneration and 99 other retinopathy patients. Mean age of patients was 62.75±13.74 years. All subjects underwent systemic and comprehensive ophthalmology examinations. The mean BCVA was 0.68±0.47 logMAR. Mean basal intraocular pressure was 18.1 mmHg (1 mmHg=0.133 kPa). All patients received intravitreal injection with 0.05 ml of ranibizumab (0.5 mg). The intraocular pressure were measured by non-contact tonometer at 10, 30, 120 minutes and 1 day after injection in a sitting position. The patients were grouped by the changes of intraocular pressure 10 minutes after injection. The elevation was more than 10 mmHg as elevation group and less than 10 mmHg as stable group. Analyze the possible related factors with elevation of intraocular pressure after ranibizumab intravitreal injection by comparing the different datum of two groups. Results The mean intraocular pressure were 23.8, 20.5, 19.9 and 17.4 mmHg at 10, 30, 120 minutes and 1 day after injection. The significant elevation level were 5.8, 2.4, 1.8, −0.7 mmHg compared with basal intraocular pressure. Among 292 eyes, intraocular pressure elevation in 68 eyes and stabled in 224 eyes. The age (Z=−0.732), gender (χ2=1.929), right or left eye (χ2=2.910), BCVA (Z=−0.039), diseases (χ2=2.088) were no significant difference between two groups (P＞0.05). The injection number (Z=−2.413, P=0.001), basal intraocular pressure (Z=−3.405, P=0.016) and elevations after injection (Z=−11.501, −8.366, −5.135, −3.568; P＜0.01) were significantly different comparing two groups (P＜0.05). By logistic regression analysis, basal intraocular pressure was positively correlated with the elevation of intraocular pressure 10 minutes after injection (B=−0.844, OR=0.43, 95%CI 0.24−0.76, P=0.004). Patients with higher basal intraocular pressure may occur intraocular pressure elevation after ranibizumab intravitreal injection much probably. Conclusions The factors associated with short-term elevation of intraocular pressure after ranibizumab intravitreal injection were basal intraocular pressure. The higher basal intraocular pressure, the higher risk to gain elevation of intraocular pressure after injection.
Objective To observe the clinical characteristics of steroid-induced ocular hypertension (SIOH) in patients with uveitis, and explore the relationship between its clinical phenotype and gene polymorphism. Methods A retrospective case-control study. From July 2019 to December 2020, 576 patients with uveitis who were treated with glucocorticoid eye drops in Tianjin Medical University Eye Hospital were included in the study. Among them, there were 175 confirmed glucocorticoid responders (SRs) and 401 glucocorticoid non-responders (NRs). Seventy cases of SRs (age ≥18 years) using 1% prednisone acetate eye drops were selected as the experiment group and 64 cases of NRs were selected as the control group. The polymorphism of rs2523864 and rs3873352 of human leukocyte antigen complex group (HCG) 22 gene were detected by Sanger sequencing. To observe the clinical characteristics of SIOH after the use of glucocorticoid eye drops, and the correlation between rs2523864 and rs3873352 and the occurrence of SIOH. Differences among groups were compared with the Chi-square test or Fisher's exact test. The correlation between the occurrence of SIOH and the range of intraocular pressure increases after glucocorticoid use and the rs2523864 and rs3873352 loci were compared using the odds ratio (OR) and its 95% confidence interval (CI). Results SIOH occurred in 175 (30.4%, 175/576) of 576 patients. Among them, there were 96 males (54.9%, 96/175) and 79 females (45.1%, 79/175); the average age was 33.64±17.40 years. Steroid high responders (HRs) and steroid moderate responders (MRs) were 58 (33.1%, 58/175) and 117 (66.9%, 117/175) cases. The medication time for the increase in intraocular pressure in MRs that was 33 (19, 56) days, and in HRs that was 28 (14, 36) days, the difference of which was significant (Z=－1.999, P=0.046). No differences were found in daily doses of ocular hypertension induced by 1% prednisone acetate eye drops between MRs which was 4.24 (3.46, 4.66) drops/day and HRs that was 4.32 (3.84, 5.36) drops/day (Z=－1.676, P=0.094). The genotype and allele frequency distribution of the rs3873352 locus in the case group and HRs group were significantly different from those in the control group (P＜0.05). The intraocular pressure with rs3873352 GG genotype after the medication was higher than that with GC and CC genotype (Z=2.855, 2.628; P=0.013, 0.026), whereas there was no significant difference between different genotypes of rs2523864 (Z=3.580, P＞0.05). Genetic model analysis revealed the risk of SIOH in rs3873352 G allele carriers (GG+GC) was 2.048 times that of non-G allele carriers (OR=2.048, 95%CI: 1.027-4.081, P=0.041). The genotype and allele frequency of rs2523864 locus showed no significant difference between different group (P＞0.05). Conclusions After the use of glucocorticoid eye drops, HRs have an earlier increase in intraocular pressure than MRs. HCG22-rs3873352 gene polymorphism is related to the occurrence of SIOH, GG genotype increases the risk of SIOH, and G allele is a risk gene for SIOH.
Objective To observe the effects of minocycline to the viability and apoptosis of ratprime;s retinal neuron cells (RNC) under pressure, and to investigate the neuroprotective mechanisms of minocycline against the RNC damage. Methods Establish a model of ratprime;s RNs under pressure cultured in vitro, the protective effect of minocycline is observed by different methods, including observing the morphology of the cells, evaluating the cellsprime; viability by methyl thiazolyl tetrazolium (MTT) colorimetry assay, and detecting the cellular apoptosis with acridine orange/ethidium bromide (AO/EB) double staining by fluorescence microscopy. Immunocytochemistry was used to detect the expression of iNOS and caspase-3 in the cells. Results Obvious morphology changes of RNC were found in cells under pressure compared with the control; the viability of RNC decreased and cellular apoptosis was found in 53.93% cells. The cellular morphology improved in the cells treated by 20 mu;mol/L minocycline, the cellular viability significantly increased, and the cellular apoptosis was found in 17.29% cells. In addition, the expression of iNOS and caspase3 in the treated cells decreased compared with which in the pressured group. Conclusion Minocycline with a certain concentration can effectively inhibit pressureinduced damage and apoptosis of RNC of rats, and the inhibitory effect on expression of iNOS and capases-3 may be the underlying mechanism.
Objective To observe the effect of lowering intraocular pressure(IOP) treatment on ocular hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy (NAION). Methods A total of 68 patients with NAION (68 eyes) were enrolled in this study. The patients were randomly divided into treatment group (38 eyes of 38 patients) and control group (30 eyes of 30 patients). All the patients were received methylprednisolone pulse therapy (200 mg, three days), vasodilator therapy with intravenous infusion of Xueshuantong solution (300 mg), optic nerve nutritional therapy with mouse nerve growth factor (30 mu;g) and acupoint injection in temporal with compound anisodine (2 ml). The total course was 10 days. The patients of treatment group received IOP lowering treatment to reduce the IOP to ge;8 mm Hg (1 mm Hg=0.133 kPa) or in a 30% reduction. The patients of control group received no IOP lowering treatment. The peak systolic velocity (PSV), pulsatility index (PI) and resistance index (RI) of ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (PCA) before and after treatment were comparatively analyzed by color doppler flow imaging. Results The differences of PSV (t=1.023, 1.145, 0.569), PI (t=0.679, 0.956, 1.634) and RI (t=0.816, 1.657, 0.998) of OA, CRA and PCA before treatment in treatment group and control group were not statistically significant (P＞0.05). Compared with before treatment, PSV (t=3.150, 7.650, 3.520) and PI (t=2.420, 5.430, 7.650) of OA, CRA and PCA increased obviously (P＜0.05), RI of OA, CRA and PCA decreased obviously (t=5.320, 9.640, 18.360;P＜0.05) after treatment in treatment group. In control group, the differences of PSV (t=2.090, -2.550, -2.100) and PI (t=-2.310, -2.230, -4.490) of OA, CRA and PCA between before and after treatment were not statistically significant (P＞0.05); but the differences of RI of OA, CRA and PCA between before and after treatment was statistically significant (t=2.970, 2.160, 2.690;P＜0.05). Compared with control group, PSV (t=2.632, 2.135, 5.364) and PI (t=3.251, 2.432, 4.243) of OA, CRA and PCA increased obviously (P＜0.05), RI of OA, CRA and PCA decreased obviously (t=3.664, 2.938, 4.324;P＜0.05) after treatment in treatment group. Conclusion Lowering intraocular pressure treatment can improve the ocular hemodynamics in NAION patients.
Objective:To observe the changes of the thickness of reti nal nerve fiber layer (RNFL) of optic disc in rats with chronic glaucoma continuously dete cted by optic coherence tomography (OCT). Methods:A total of 48 Wist ar rats (24 males and 24 females) were randomly divided into 3 groups with 16 ra ts (32 eyes) in each group. The right eyes were the photocoagulation eyes and the left ones were as the control. Laser photocoagulation with the wavelength of 532 nm was perfo rmed on the trabecular network of the right eyes to induce the chronic middlelevel oc u lar hypertension. The changes of the intraocular pressure (IOP) were observed. O pticdisc linear scanning of OCT was performed 3, 6, and 9 weeks after IOP incr e ased, and the thickness of RNFL of optic disc was detected by the computer. Eight rats in each group were killed and retinal histology slic es were used to detect the thickness of RNFL. The flatmount s of retina from the right eyes of the other 8 rats in each group were stai ned by 1% toluidine blue. The density of retinal ganglion cells (RGC) was calcul ated and the results were compared and analyzed. Results:IOP o f the rats increas ed chronically and moderately after photocoagulation. IOP of the experimental ey e 3,6, and 9 weeks after photocoagulation was obviously higher than which of the control eyes, respectively （P＜0.001）. The results of OCT showed that the thickness of the RNFL of the experimental eyes was (67.39plusmn;5.91) mu;m, (53.4 2plusmn;5.64) mu;m，and (44.35plusmn;5.76) mu;m 3, 6, and 9 weeks after photocoagulation, and the corresponding thickness in the control eyes was（80.32plusmn;5.87）, （79.69plusmn;5.69）, and （80.78plusmn;5.84）mu;m, respectively. The thickness of the retinal fiber layer detecte d by histological method was （64.38plusmn;6.54）, （51.47plusmn;6.4）, and （42.10 plusmn;6.10）mu;m in the experimental eyes 3, 6, and 9 weeks after photocoagulation, and (76.23plusmn;6.78), (78.64plusmn;6.15), and (77.64plusmn;6.63) mu;m in the control eyes. Regression analysis of the thickness detected by the two methods was made, and the regression coefficients was 0.932（P＜0.001）.The differ ence of the ave rage density of RGC between the two groups was significant (P＜0.05）. Conclusi on:Glaucoma model in Wistar rats may successfully set up b y photocoagulating the trabecular meshwork. The thickness of retinal nerve fiber layer of the optic disc in rats with chronic glaucoma detected by OCT and obser ved by the light m icroscope is accordant. The changes of the thickness of RNFL in rats with chroni c glaucoma could be continuously detected by OCT to investigate the progress of the glaucomatic retinopathy in rat model.