Purpose
To evaluate differences in the pattern of optic disc and retinal nerve fiber layer (RNFL) damage in normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) patients.
Methods
We enrolled 49 eyes of 49 patients:30 NTG (IOP≤21 mm Hg,1 mm Hg=0.133 kPa), 19 HTG(IOP≥25 mm Hg). Mean age was 59.2±12.3 (range, 36-75) for HTG patients, and 59.6±8.6(range, 39-71) for NTG patients. All patients underwent complete ophthalmic examination, achromatic automated perimetry (AAP), scanning laser ophthalmoscopy (SLO), scanning laser polarimetry (SLP), optical coherence tomography (OCT) and Heidelberg retinal tomography (HRT). All patients had glaucomatous optic nerve damage and abnormal AAP.
Results
There were no differences in mean deviation on AAP between NTG and HTG eyes (P=0.37), while the corrected pattern standard deviation was larger in NTG than in HTG eyes (P=0.014). Cup∶disc area ratios in global (P=0.03) and three sectors (Plt;0.05) except nasal sector were significantly larger in the NTG group, whereas rim area in global (P=0.03) and three sectors (Plt;0.05) except nasal quadrant obtained by SLO were smaller in NTG than in HTG eyes. The other numerical parameters obtained by three imaging technologies could not detect differences in the optic disc or RNFL anatomy between the two groups.
Conclusions
Cup∶disc area ratio was larger in patients with NTG than in those with HTG, whereas significant thinning of rim was associated with NTG eyes. The measurement of retinal nerve layer thickness in global and each quadrant was similar between two groups. More focal or segmental analysis of the data contained within SLO, SLP and OCT images are needed to detect localized differences in eyes with varying levels of IOP.
(Chin J Ocul Fundus Dis, 2002, 18: 109-112)
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 measure optic disc parameters in Mongolian and Han healthy subjects with or without family history of glaucoma, to explore the causes of the differences and their significance in the diagnosis of early glaucoma. Methods Fifteen healthy Mongolian individuals (30 eyes), 30 healthy Han individuals (60 eyes) with a family history of open-angle (30 eyes) or angle-closure (30 eyes) glaucoma, and 45 healthy Han individuals (90 eyes) without a family history of glaucoma were enrolled in this study. The 45 healthy Han individuals without a family history of glaucoma included three age-groups: 20 to 29 years old group, 30 to 39 years old group and 40 to 49 years old group, each group have 15 subjects (30 eyes). Thirteen parameters were measured by Heidelberg retina tomography (HRT) for all subjects, including disc area, cup area, rim area, cup volume, rim volume, cup/disc area ratio, linear cup/disc ratio, mean cup depth, maximum cup depth, cup shape, disc height variation contour, mean retinal nerve fiber layer (RNFL) thickness and optic nerve fiber layer crosssectional area. The results were analyzed and compared between the above groups. Results There was no statistically significant (t=0.791,P=0.132) of the height variation contour between Mongolian and Han without a family history of glaucoma (20 to 29 years old) group. The other parameters of Mongolian were smaller than Han without a family history of glaucoma (20 to 29 years old) group, but the difference was not statistically significant (t=-1.039, -0.799, -0.840,-1.108, -0.956, -0.695, -0.931, -1.099, -1.074, -0.580, -0.204, -1.425; P＞0.05). The parameters in Han with a family history of open-angle glaucoma group were bigger than Han without a family history of glaucoma (30 to 39 years old) group. The differences were statistically significant for disc area, cup area, rim area, cup volume, rim volume, cup area ratio, linear cup/disc ratio, mean cup depth, cup shape measure, nerve fiber layer cross-sectional area (t=4.758, 3.187, 2.544, 2.674, 1.798, 3.676, 2.721, 2.715, 2.510, 2.373; P＜0.05), but were not statistically significant for maximum cup depth, disc height variation contour and mean RNFL thickness (t=1.649, 1.565, 0.767; P＞0.05). Most parameters in Han with a family history of angle-closure glaucoma group were the same as that in Han without a family history of glaucoma (40 to 49 years old) group, including cup area, rim area, cup volume, rim volume, cup/disc area ratio, linear cup/disc ratio, mean optic cup depth, maximum cup depth, cup shape, disc height variation contour, mean RNFL thickness, optic nerve fiber layer cross-section (t=1.201, 1.697, 1.000, 0.516, 0.740, -0.172, -0.070, -0.972, 1.530, -0.390, -0.091, 0.659; P＞0.05); but the difference of disc area between these 2 groups was statistically significant (t=2.224,P＜0.05). Conclusions The family history of glaucoma can change the optic disc parameters of healthy individuals, especially those with a family history of open-angle glaucoma. There is no difference of optic disc parameters between healthy Mongolian and Han subjects.
Objective
To determine the difference of global indices of retinal thickness at posterior pole in primary and suspected glaucoma.
Methods
Forty-five global indices of analysis on retinal thickness at posterior pole in every case, including 12 cases of primary open-angle glaucoma and 11 cases of suspected glaucoma were obtained by advanced retinal thickness analyzer. Every index was also compared.
Results
There were significant differences between primary and suspected glaucoma in foveal shape deviation (FSD), foveal corrected thickness deviation (FCTD), foveal fixation corrected thickness deviation (FFD), foveola thickness deviation (VTD), corrected foveola thickness deviation (CVTD), peri-foveal abnormally thin area (PFATN), posterior-pole pattern deviation (PPPD), and posterior-pole abnormally thin area (PPATN).
Conclusion
There are significant difference of morphologic indices of retinal thickness at posterior pole between primary and suspected glaucoma.
(Chin J Ocul Fundus Dis, 2002, 18: 113-115)
Objective
To evaluate glaucoma and anterior chamber angle changes after intravitreal silicone oil injection(SOI).
Methods
The intraocular pressure(IOP) and anterior chamber angles of 34 e yes(33 patients)undergone pars plana vitrectomy and SOI were observed.
Results
Glaucoma occurred in 9 eyes(26%),in which silicone oil glaucoma(SOG) accounted for 77%(7/9).The changes of the superior part of anterior chamber angle were peripheral anterior synechiae in 11 eye(32%) and SO emulsification droplets in 22 eyes(64%) in 1～4.5 months after surgeries.Glaucoma occurred in 6 eyes of 7 eyes undergone peripheral iridectomy at the inferio r part of the iris after the closure of iridectomy holes (plt;0.05).
Conclusion
High incidence of glaucoma was found in this series of patients after intravitreal silicone oil injection,and the main causes of SOG were closure of the inferior iridecomy hole and silicone emulsification.
(Chin J Ocul Fundus Dis, 2001,17:105-107)
Glaucoma is one of blind causing diseases. The cup-to-disc ratio is the main basis for glaucoma screening. Therefore, it is of great significance to precisely segment the optic cup and disc. In this article, an optic cup and disc segmentation model based on the linear attention and dual attention is proposed. Firstly, the region of interest is located and cropped according to the characteristics of the optic disc. Secondly, linear attention residual network-34 (ResNet-34) is introduced as a feature extraction network. Finally, channel and spatial dual attention weights are generated by the linear attention output features, which are used to calibrate feature map in the decoder to obtain the optic cup and disc segmentation image. Experimental results show that the intersection over union of the optic disc and cup in Retinal Image Dataset for Optic Nerve Head Segmentation (DRISHTI-GS) dataset are 0.962 3 and 0.856 4, respectively, and the intersection over union of the optic disc and cup in retinal image database for optic nerve evaluation (RIM-ONE-V3) are 0.956 3 and 0.784 4, respectively. The proposed model is better than the comparison algorithm and has certain medical value in the early screening of glaucoma. In addition, this article uses knowledge distillation technology to generate two smaller models, which is beneficial to apply the models to embedded device.
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)
The lamina cribrosa (LC) is a complicated collagenous meshwork of trabeculae and laminar pores contain capillaries, nerves and neurogliocytes, which provides structural and nutrient support to the retinal ganglion cell axons as they exit the eye. The intraocular pressure causes direct damage or deformation and remodeling of LC, leads to axoplaxmic transport and blood supply disturbance. The preponderance of evidence suggests that LC is the principal site of glaucomatous damage. The development of optic coherence tomography (OCT) technology has improved the imaging quality of deep structures of the optic nerve head and makes it possible to detect LC. The quantitative research indexes of LC structure include LC depth, laminar curvature, laminar thickness, prelaminar tissue, laminar pore, laminar defect and hemodynamics. To improve the understanding of LC structure, explore the characteristics of LC and understand the biomechanical and hemodynamic pathogenesis of glaucoma, which would be contribute to the application of big data research in the diagnosis and treatment of glaucoma.
Objective To evaluate the efficacy of intravitreal injection with Bevacizumab for iris neovascularization (INV) which caused by proliferative dia betic retinopathy (PDR) or central retinal vein occlusion (CRVO). Methods The clinical data of 39 patients (47 eyes) with INV who undergone intravitreal injection with Bevacizumab from 12,2006 to 3,2007 in Department of Ophthalmology, Peopleprime;s Hospital of Peking University were retrospectively analyzed. The patients (22 males and 17 females, 23 left eyes and 24 right eyes) aged from 28 to 82 years with the average of （57.77plusmn;13.0）years. 26 cases (34 eyes) were PDR and 13 cases (13 eyes) were CRVO. All of patients underwent intravitreal injection with 1.25 mg/0.05 ml Bevacizumab. Follow-up time was 1 day, 3 days, 1 week, 3 week s and 6 weeks after the treatment. The visual acuity, changes of intraocular pre ssure and changes of INV before and after the treatment were observed and analyzed. Results In patients with PDR, the visual acuity was improved in 19 eyes (55.9%), was stable in 15 eyes (44.1%) and none decreased. In patients with CRVO, the visual acuity was improved in 4 eyes (30.8%), was stable in 9 eyes (69.0%) and none decreased. Among neovascular glaucoma (NVG), decreas e of IOP was noticed in 16 eyes with PDR (80%) and 6 eyes with CRVO (667%). Re gression of INV was noticed in 97.1% PDR patients and 84.6% CRVO patients. Conclusions Intravitreal injection with Bevacizumab is very effective in treating INV. Further researches still needs to explore long term efficacy, safety and complications of this t reatment. （Chin J Ocul Fundus Dis，2008，24：176-179）
ObjectiveTo compare the choroidal thickness (CT) of macular and peripapillary area among malignant glaucoma(MG), chronic primary angle-closure glaucoma (CPACG) and normal control eyes. And to investigate the correlation between CT and MG.
Methods Sixteen subjects (32 eyes) with MG, 31 (31 eyes) with CPACG and 32 (32 eyes) normal controls were collected. MG eyes and the fellow non-MG eyes were included in the MG group. CT of all subjects was measured in the fovea, 1mm and 3mm to the fovea and peripapillary area using enhanced-depth imaging technique of optical coherence tomography (OCT-EDI). The average of CT in fovea by horizontal and vertical macular scan was defined as the average CT in fovea. The average of temporal, superior, nasal and inferior CT in 1 mm and 3 mm to the fovea were measured respectively. The average of temporal, superior, nasal and inferior CT was defined as the average CT in peripapillary area. The differences of CT among MG, CPACG and normal controls were compared. And the differences of CT between MG eyes and the fellow non-MG eyes were compared.
ResultsAfter eliminating the influence of age, the average CT of MG in the fovea, 1mm and 3mm to the fovea was significantly thicker than that of CPACG and normal controls (P < 0.05). And the average CT of CPACG in the fovea, 1mm and 3mm to the fovea was significantly thicker than that of normal controls (P < 0.05). In peripapillary area, the temporal, superior and inferior CT of MG was significantly thicker than that of CPACG and normal controls (P < 0.05). There was no significant difference of CT in peripapillary area between CPACG and normal controls (P > 0.05). In the fovea, 1mm and 3mm to the fovea and peripapillary area, there was no significant difference of CT between MG eye and the fellow non-MG eye in MG group (t=－1.029~－0.130, P > 0.05).
ConclusionsThe choroid thickness of macular and peripapillary area in MG eyes is thicker than that of CPACG and the normal controls. An increased CT of macular and peripapillary area may be one of the risk factors for MG.
