Objective To observe the expression of p53, bcl-2 genes, vascular endothelial cell growth factor（VEGF）, basic fibroblast growth factor（bFGF）, insulin-like growth factor-I （IGF-I）, and the receptors of these factors of retinal vascular endothelial cells (VECs) of 1- to 20-week diabetic rats, and the relationship between the expressions and cell cycle arrest.Methods Retinal sections of diabetic rats induced by alloxan were immunohistochemically stained and observed by light microscopy (LM) and electron microscopy (EM). Dot blotting and Western blotting were used to determine the expression of mRNA, proteins of p53 and bcl-2. Results Under LM, immunohistochemical positive expression of p53 and bcl-2 were found on the vessels of ganglion cell layer and inner nuclear layer of retinae of 8- to 20-week diabetic rats; under EM, these substances were observed depositing in VECs. The retinal VECs also expressed VEGF, bFGF, IGF-I and their receptors. There was no positive expression of other cell types in these retinae, all cell types of retinae in control group, or all cells of retinae of diabetic rats with the course of disease of 1 to 6 weeks. The result of dot blotting revealed that retinal tissue of 20-week diabetic rat expressed p53 and bcl-2 mRNA, and the result of Western blotting revealed that they also expressed p53 and bcl-2 proteins. But retinal tissues of control group did not. Positive expression of bax was not found in the retinae in control group or 1- to 20-week diabetic rats. Conclusion p53, bcl-2 may introduce cell cycle arrest of VECs of retinae in 8- to 20-week diabetic rats. High glucose might stimulate the expression of VEGF, bFGF, IGF-I and their receptors, and the growth factors may keep VECs surviving by self-secretion. (Chin J Ocul Fundus Dis，2003，19：29-33)
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）
OBJECTIVE :To investigate ocular vessel flow velocity in normal eyes by color Doppler imaging(CDI). METHODS: Ninety people (180 normal eyes)had flow velocity measured by CDI in three vessels,ophthalmic artery (OA),central retinal artery(CRA) and posterior ciliary artery (PCA),and the relations between velocity and affecting factors were analysed. RESULT: The diastolic and systolic velocity of OA,CRA and PCA were (31.7plusmn;10.9)cm/s, (7.2plusmn;2.6)cm/,s, (10.2plusmn;3.4)cm/s, (2.8plusmn;1.2)cm/s and (11.3plusmn;3.6)cm/s, (3.2plusmn;1.4)cm/s respectively. The velocity of OA had possitive correl-ativity with RBC,HCT and negative correlativity with age,while it revealed no relationship with sex, laterality of right or left eye,and normal IOP. CDI of ocular vessels in normal eyes is a triangle with three peaks and double sunkens in its frenquency spectum, revealed highly resistant,and both the pulsatility and resistive indexes were relatively high. The width of each frequency band basically was the same,and there was no obvious frequency window. CONCLUSION: The ocular application of CDI might lay the foundation of a comparatively comprehensive knowledge of the ocular hemodynamics. （Chin J Ocul Fundus Dis,1997,13: 99-101）
目的 探讨视网膜微血管直径与2型糖尿病(DM2)并发症糖尿病视网膜病变(DR)的关系。 方法 选取2009年1月-11月住院确诊DM2患者200例，根据眼底彩色照相结果将患者分为DR组和NDR组，测量视网膜血管直径、测定生化指标及血压，用非条件Logistic回归分析糖尿病视网膜病变发生的危险因素。 结果 V1扩张10 μm时，DM2患者并发DR危险性增加(OR 1.75，95% CI 1.14～3.04，Plt;0.05)；空腹血糖水平增加1 mmol/L，DM2患者并发DR的危险性增加(OR 1.87，95% CI 1.43～2.81，Plt;0.05)； 糖化血红蛋白增加1个单位，DM2患者并发DR的危险性增加(OR 1.08，95% CI 1.02～1.13，Plt;0.05)；DM病程增加1年，DM2患者并发DR的危险性增加(OR 1.41，95% CI 1.18～1.70，Plt;0.05)。 结论 在DM2患者中，视网膜静脉直径大小、空腹血糖水平、糖化血红蛋白水平、糖尿病病程是DR发生的危险因素。
Objective To investigate the clinical characteristics of prepapillary and preretinal vascular loops. Methods The clinical manifestation, results of the fundus fluorescein angiography, and the prognosis of 20 cases(24 eyes) with prepapillary and preretinal vascual loops were analyzed retrospectively. Results 66.7% of prepapillary and preretinal vascular loops were involved in one eye, and 95.8% of vascular loops were located within one optic disc diameter. There were different configuration types of the vascular loops. Among 20 cases(24 eyes) of the vascular loops, 70.8%(17 eyes) were arterial, 12.5%(3 eyes) were venous, and 16.7%(4 eyes) were both arterial and venous. 62.5% of eyes with prepapillary and preretinal vascular loops were associated with other congenital and developmental anomalies of retinal vascular vessels. Conclusion Most PRVL are arterial and superior to the optic disc. The serious distortion of the vascular loops may result in disturbance of blood flow in artery and retinal hemorrhage, which cause visual loss. (Chin J Ocul Fundus Dis, 1999, 15: 9-11)
The existing retinal vessels segmentation algorithms have various problems that the end of main vessels are easy to break, and the central macula and the optic disc boundary are likely to be mistakenly segmented. To solve the above problems, a novel retinal vessels segmentation algorithm is proposed in this paper. The algorithm merged together vessels contour information and conditional generative adversarial nets. Firstly, non-uniform light removal and principal component analysis were used to process the fundus images. Therefore, it enhanced the contrast between the blood vessels and the background, and obtained the single-scale gray images with rich feature information. Secondly, the dense blocks integrated with the deep separable convolution with offset and squeeze-and-exception (SE) block were applied to the encoder and decoder to alleviate the gradient disappearance or explosion. Simultaneously, the network focused on the feature information of the learning target. Thirdly, the contour loss function was added to improve the identification ability of the blood vessels information and contour information of the network. Finally, experiments were carried out on the DRIVE and STARE datasets respectively. The value of area under the receiver operating characteristic reached 0.982 5 and 0.987 4, respectively, and the accuracy reached 0.967 7 and 0.975 6, respectively. Experimental results show that the algorithm can accurately distinguish contours and blood vessels, and reduce blood vessel rupture. The algorithm has certain application value in the diagnosis of clinical ophthalmic diseases.