The activities and distributions of succinate dehydrogenase(SDH),malic dehydrogenase(MDH),lactic dehydrogenase(LDH),acid phosphatase(ACP) and alkaline phosphatase(AKP) in retinal vessels were studied and observed with enzymatic histochemical techniques. The retinal vessels showed a b LDH activity, moderate SDH and MDH activity. The dehydrogenase activity described above was evenly and equally distributed in the microvasculature between arterioles and venules, and was the best in arteries. AKP showed predominant activity in the endothelial cells of capillaries and arterioles which were stained bly. No activity for ACP observed in the retinal vessels. The observations above indicate that the retinal vessels are metabolically active and have a great capacity for glycolysis. （Chin J Ocul Fundus Dis,1992,8:6-9）
Purpose To observe the clinical features and visual acuity of the eyes with idiopathic macular holes. Methods We reviewed the clinical materials of 23eyes of 18 patients with idiopathic macular holes and the follow up results from 6 to 120 months. Results In the initial examinations of 22 eyes,the numbers of eyes with stagesⅠ-Ⅳ macular holes were5,4,10,3 eyes respectively,and funds fluorescein angiography showed there were focal transmission of choroidal fluorescein in 17 eyes (stagesⅡ～Ⅳ).Macular hole ocurred in one eyes during follow up.At the final examination of 23 eyes,the numbers of eyes with stages Ⅰ～Ⅳ macular holes were 2,2,9,8 eyes respectively .Full-thickness macular hole of 2 eyes closed naturally after posterior vitreous detachment.The time interval of the subjective visual loss on stage Ⅰ was 5-8 months,stageⅡ8-20 months,stageⅢ12-126 months ,and the average visual acuity on stageⅠwas 0.7,stage 0.55,stageⅢ0.08,and stage Ⅳ0.08 Conclusion Approximately 60% of impending (stage Ⅰ) hole progress to full thickness holes, the full thickness holes were usually enlarged and the visual acuity of affected eyes decreased as the natural course was prolonged . (Chin J Ocul Fundus Dis,1998,14:222-223)
Objective To investigate the risk factors associated with neovascular glaucoma (NVG) after pars plana vitrectomy (PPV) in eyes with proliferative diabetic retinopathy (PDR). Methods Retrospective study. One hundred and thirty-seven patients (137 eyes) with PDR who underwent PPV were recruited. There were 85 males and 52 females. The average age was (60.1±8.8) years old. The duration of diabetes was (10.2±3.6) years. There were 49 patients with ipsilateral carotid artery stenosis. Fifty-three eyes underwent intravitreal ranibizumab or conbercept injection before PPV. All eyes were treated with 23G standard three-port PPV. The average follow-up time after PPV was 11.5 months. Fundus fluorescein angiography (FFA) was conducted in postoperative 4-6 weeks to observe non-perfused retinal areas. Risk factors, such as ipsilateral carotid artery stenosis, the presence of non-perfusion in retina after PPV and the application of anti-vascular endothelial growth factor (VEGF) drugs before PPV, were identified by logistic regression. Results Twenty of 137 patients (14.6%) developed postoperative NVG after PPV. Ipsilateral carotid artery stenosis [odds ratio (OR) =5.048, 95% confidence interval (CI) 2.057-12.389,P=0.000] and the presence of non-perfusion in retina after PPV (OR=4.274, 95%CI 1.426-12.809,P=0.009) were significant risk factors for postoperative NVG, while the application of anti-VEGF drugs was not (OR=1.426, 95%CI 0.463-4.395,P=0.536). But the time from PPV to the onset of NVG varies significantly between the two groups of injection of anti-VEGF drugs or not (t=−4.370,P=0.000). Conclusions Risk factors associated with NVG after PPV in eyes with PDR included ipsilateral carotid artery stenosis and the presence of non-perfusion in retina after PPV. The application of anti-VEGF drugs before PPV can delay the onset of NVG in PDR eyes after vitrectomy.
ObjectiveTo observe the expression of Rap1, guanosine triphosphate-Rap1 (GTP-Rap1), vascular endothelial growth factor (VEGF) and β-catenin in experimental choroidal neovascularization (CNV).MethodsForty-two brown Norwegian rats were randomly divided into a blank control group (7 rats) and a model group (35 rats). Both eyes were enrolled. The CNV model was established by holmium ion laser photocoagulation in the model group. At 3, 7, 14, 21, and 28 days after photocoagulation, fluorescein fundus angiography (FFA) and choroidal vascular smear were performed to observe the degree of fluorescein leakage and CNV area in rats; Western blot and real-time quantitative polymerase chain reaction (RT-PCR) were used to detect the expression of Rap1, GTP-Rap1, VEGF, β-catenin and mRNA in CNV.ResultsThe results of FFA examination showed that a large disc-shaped fluorescein leaked in the photo-condensation spot 14 days after photocoagulation. Laser confocal microscopy showed that compared with 7 days after photocoagulation, CNV area increased at 14, 21, 28 days after photocoagulation, and the difference were statistically significant (t=3.725, 5.532, 3.605;P＜0.05). Western blot showed that there was no significant difference in the relative expression of Rap1 protein in CNV at different time points after photocoagulation between the two groups (P=0.156). Compared with the blank control group, the relative expression of GTP-Rap1 protein was significantly decreased, the relative expression of VEGF and β-catenin protein were significantly increased in the model group (P=0.000). The results of RT-PCR showed that there was no significant difference in the relative expression of Rap1 mRNA at different time points after photocoagulation between the two groups (P=0.645), but there were significant difference in the relative expression of β-catenin mRNA (P=0.000). At 7, 14, 21 and 28 days after photocoagulation, there were significant difference in the relative expression of GTP-Rap1 and VEGF mRNA between the two groups (P=0.000).ConclusionsThe expression of GTP-Rap1 in experimental CNV is significantly lower than that in normal rats.