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.
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.