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 assess the efficacy and safety of a dorzolamide/timolol combination versus latanoprost in the treatment of open-angle glaucoma. Method We searched for randomized control trials concerning a dorzolamide/timolol combination versus latanoprost in the treatment of open-angle glaucoma,in electronic databases , and handsearched some related journals. The quality was evaluated and meta-analysis was conducted using the software RevMan 5.0. Results Six randomized control trials involving 361 patients and 361 eyes were identified. The Meta-analysis showed that at the end of study, there was a statistically significant difference between the two study groups with WMD – 0.49, and 95%CI – 1.06 to 0.07 ( P=0.09) in lowering intraocular pressure; there was no statistically significant difference between the two groups with WMD 1.43 and 95%CI 0.49 to 4.21 (P=0.53); and there was no statistically significant differences between the two groupswith WMD 0.40 and 95%CI 0.13 to 1.26 (P=0.12) in incidence of headache. Conclusion Compared with latanoprost, dorzolamide-timolol combination have increased efficacu in lowering intraocular pressure (IOP).If we want a more reliable result ,we need a large number of multi-centre,double-blinded randomized control trials.
ObjectiveTo compare the lamina cribrosa parameters between primary open angle glaucoma (POAG) and chronic primary angle closure glaucoma (CPACG) eyes.
MethodsA total of 73 POAG eyes (73 subjects), 64 CPACG eyes (64 subjects), and 40 normal control eyes (40 subjects) with matched ages were included in this cross-sectional observational study. No significant difference was found in sex (χ2=2.07) and age (F=0.38) among three groups (P > 0.05). The intraocular pressure, average retinal nerve fiber layer (RNFL) thickness and average visual field defect were not significantly different between POAG and CPACG patients (F=15.67, 21.15, 44.40, 27.99; P < 0.05). All subjects underwent spectral-domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI). The optic nerve head was scanned radially at the angle of 20; six high resolution B-scan images were obtained from each eye. The center and para-center lamina cribrosa thickness (LCT) and anterior lamina cribrosa surface depth (ALCSD) were measured in each image. The mean LCT and ALCSD were recorded as the average of the LCT and ALCSD of the 6 images and compared among POAG, CPACG and normal control eyes.
ResultsThe average LCT of normal control eyes were (211.48±12.07) μm, while those of the POAG eyes were (145.43±34.33) μm, CPACG eyes were (156.79±33.66) μm. The mean LCT of the POAG and CPACG eyes were thinner than those of the control eyes (t=-11.76, -9.88; P < 0.01). All LCT of the POAG eyes were significantly thinner than those of the CPACG eyes (t=-1.96, P=0.03).The average ALCSD of normal control eyes were (390.73±84.40) μm, while those of the POAG eyes were (558.51±176.66) μm, CPACG eyes were (539.39±177.30) μm, respectively. The average ALCSD of the POAG and CPACG eyes were deeper than those of the control eyes (t=5.65, 4.96; P < 0.01). But no significantly different ALCSD was shown between POAG and CPACG eyes (t=0.63, P=0.49).
ConclusionsPOAG and CPACG eyes have thinner LCT and deeper ALCSD than normal eyes. POAG eyes have thinner LCT than CPACG eyes when their visual field defect and damage of RNFL were in the same degree.
There are so many biomechanical risk factors related with glaucoma and their relationship is much complex. This paper reviewed the state-of-the-art research works on glaucoma related mechanical effects. With regards to the development perspectives of studies on glaucoma biomechanics, a completely novel biomechanical evaluation factor -- Fractional Flow Reserve (FPR) for glaucoma was proposed, and developing clinical application oriented glaucoma risk assessment algorithm and application system by using the new techniques such as artificial intelligence and machine learning were suggested.
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)
