Objective To observe the location of the watershed zones of the choroidal blood supply relative to the optic disc in glaucoma by indocyan ine green angiography, and to investigate the mechanisms in the development of glaucomatous neuropathy. Method Simultaneous ICGA and FFA were performed on 31 eyes of 31 patients with glaucoma (17 of POAG, 14 of NTG) and 37 eyes of 37 control subjects. The watershed zones were classified into three types according to their location relative to the optic disc: by type I, no water shedzone around the optic disc; type II, the optic disc surrounded partially by watershed zone; type III, the optic disc surrounded completely by watershed zone. Each of the watershed zone types was scored (i.e., type I=1, type II=2, type III=3). Results In 87.1% of the glaucomatous eyes , the watershed zones included or partially included the optic disc. However, the figure in the control group was 56.8%. The glaucoma group had a higher score of watershed zone type than the control group. Conclusions The mechanisms in the development of glaucomatous neuropathy are correlative to the choroidal blood supply around the optic disc. (Chin J Ocul Fundus Dis,2004,20:218-220)
Objective To monitor the release of amino acids of the whole retina during and after experimental glaucoma by increasing the intraocular pressure (IOP). Methods Experimental glaucoma was induced in one of the two eyes of rabbits by increasing IOP at 120 mm Hg for 45 min under infusion of saline in anterior chamber;then the pressure was released and the needle inserted into the anterior chamber was removed,this state was maintained for another 45 min.Every 15 min during the experiment 5 rabbits were killed and experimental eyes were enucleated.Aliquots(20 μl)of the retinal extracts(see below)were mixed with ophthaldialdehyde reagent and analysed for amino acid content by the HPLC method of Wangwei,using a 150 mm×4.6 mm,5 μm C18 column. Results A large increase in the release of glutamate,but not of the other three amino acids monitored,occurred during initial experimental ocular hypertension.It reached peak value of(111.73±17.46)10-5 mmol/g at 15 min of hypertension.15 min after release of intraocular pressure,again,immediately large and specific increase in the concentration of glutamate was reached to(102.96±51.91)10-5 mmol/g.In eyes subjected to paracentesis of anterior chamber,no difference was found between experimental eyes and controls. Conclusion These results suggest that glutamate is triggered by increasing the IOP,and it releases not only during the period of experimental ocular hypertension,but also afterwards. (Chin J Ocul Fundus Dis, 2002, 18: 146-148)
Objective To evaluate the diagnosis of blue-on-yellow perimetry and macular threshold perimetry in early primary glaucoma. Methods Humphrey II 750 automatic perimetry was used to test 60 eyes of 60 cases in normal control group and 63 eyes of 63 cases in early primary glaucoma group with white-on-white perimetry (W/W), blue-on-yellow perimetry (B/Y),and macular threshold perimetry (M TP). The results of the visual field defects detected by the three perimetries were compared and analyzed.Results The differences of mean sensibility of W/W, B/Y and MTP between the two groups had statistical significance[t=-3 .01, P=0.0054 (W/W); t=-2.95, P=0.006 3 (B/Y); t=-2.59,P=0. 0150 (MTP)]. In the diagnosis of early primary glaucoma, the sensitivity of MTP was the highest (83%), B/Y was the second (65%), and W/W was the lowest (48%). When B/Y and MTP were combined, the sensitivity was improved to 94% using parallel testing, and the specificity was improved to 87% using serial testing.Conclusions B/Y and MTP are valuable in diagnosis of early primary glaucoma, and the sensitivity and specificity of the diagnosis can be improved when B/Y and MTP are combined. (Chin J Ocul Fundus Dis,2003,19:102-105)
ObjectiveTo observe the differences in scleral lamina curvature (SLC) of patients with pseudoexfoliation glaucoma (PXG), primary open-angle glaucoma (POAG), and primary chronic angle-closure glaucoma (CPACG) were compared and analyzed and their significance was analyzed.MethodsA retrospective clinical study. From June 2017 to December 2020, 30 PXG (PXG group), POAG (POAG group) and CPACG patients (CPACG group) diagnosed at Eye Center of Cangnan County people's Hospital of Zhejiang Province (Cangnan Hospital Affiliated to Wenzhou Medical University) were included in the study. The age difference between the three groups of patients was statistically significant (t=17.925, P=0.001); gender composition ratio (χ2=2.158, P=0.276), intraocular pressure (t=4.993, P=0.078), and axial length (t=1.956, P=0.532), central corneal thickness (t=1.407, P=0.724), average visual field defect (t=2.725, P=0.496), optic disc retinal nerve fiber layer thickness (t=2.185, P=0.492) in comparison, the differences were not statistically significant (P>0.05). The frequency-domain optical coherence tomography deep-enhanced imaging (OCT EDI) technology was used to measure the average and 0°, 30°, 60°, 90°, 120°, 150° SLC of the affected eyes, and calculate the SLC index (SLCI) and SL curve depth (SLCD). Quantitative data comparison between groups used independent sample t test. Count data comparison used χ2 test. Univariate and multivariate logistic regression analysis were used for correlation analysis.ResultsThe results of OCT EDI examination showed that the SLC of eyes with PXG and CPACG was significantly steep, while the SLC of eyes with POAG was relatively flat. Except for the angle of 150°, the other 6 angles of SLCI and SLCD in the PXG group and CPACG group were higher than those in the POAG group, and the differences were statistically significant (P<0.05). However, there was no statistically significant difference between PXG group and CPACG group for 7 angles of SLCI and SLCD (P>0.05). Logistic regression analysis showed that the average SLCI [odds ratio (OR)=1.498, 95% confidence interval (CI) 1.137-2.018, P=0.001], age (OR=1.074, 95%CI 1.019-1.143, P=0.016) was significantly correlated with PXG; mean SLCI (OR=1.625, 95%CI 1.192-1.997, P=0.001), intraocular pressure (OR=1.383, 95%CI 1.106-1.993, P=0.012) was significantly correlated with CPACG. POAG group (β=0.143, 95%CI 0.032-0.208, P=0.016), CPACG group (β=0.132, 95%CI 0.079-0.315, P=0.043) intraocular pressure was correlated with mean SLCI; all factors of PXG group were correlated with SLCI without correlation (P>0.05).ConclusionCompared with POAG, the SLC of eyes with PXG and CPACG is steeper and related to disease occurrence.
Objective To evaluate the effects of cold provoca tion on optic dise blood flow and retinal light sensitivity of primary open-angle glaucoma (POAG) patients,and explore the relationship between the changes of optic disc blood flow and retin al light sensitivity. Methods A total 33 POAG patients (33 eyes)and 13 normal controls (13 eyes) were tested by usin g th e Heidelberg retinal flowmetry (HRF) and Topcon automatic perimeter,and the optic disc blood flow and retinal light sensitivity of POAG patients and normal cont rols were measured at normal conditions and after cold provocation. Results The mean optic disc blood flow,volume and the mean retinal light sensitivity of POAG patients decreased significantly (Plt;0.05) after cold provocation.There was a linear and significant relationsh ip between the decrease of mean optic disc blood flow and mean retinal light sen sitivity of POAG patients (r=0.615,P<0.001). The optic disc blood flow of POAG patients with a history of migraine were more likely to r educe in response to cold provocation and reduced much more than those without such history (Plt;0.05). Conclusion Cold provocation can significantly reduce both the optic disc blood flow and retinal light sensitivity in POAG patients.A close correlation was fo und between the amount of mean optic disc blood flow decrease and the volume of mean retinal light sensitivity decline. (Chin J Ocul Fundus Dis, 2001,17:37-40)
ObjectiveTo explore the effects of vitrectomy on neovascular glaucoma combined with vitreous hemorrhage.MethodsSeven eyes of 7 patients with neovascular glaucoma combined with vitreous hemorrhage underwent vitrectomy combined with phacoemulsification, panretinal photocoagulation, and trabeculectomy. The preoperative visual acuity ranged from light perception to 0.2, and the mean preoperative intraocular pressure was 54 mm Hg (38-64 mm Hg)(1 mm Hg=0.133 kPa). The mean follow-up was 8 months (6-15 months).ResultsThe postoperative visual acuity ranged from light perception to 0.4, and the mean postoperative intraocular pressure was 17 mm Hg (10-30 mm Hg) which was significantly lower than preoperative one (Plt;0.05). The postoperative complications mainly included fibrosis exudates in anterior chamber (7 eyes), intraocular pressure elevation 1-2 weeks after the operation (2 eyes), and postoperative suprachoroidcavity hemorrhage (2 eyes).ConclusionVitrectomy combined with phacoemulsification, panretinal photocoagulation, and trabeculectomy may be effective procedures for some cases of neovascular glaucoma combined with vitreous hemorrhage.(Chin J Ocul Fundus Dis, 2005,21:148-149)
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.