Objective To observe the change of diffusion upper limit of macromol ecules through pathological retina and the difference between the layers of retina. Methods Retinal edema was emulated by establishing branch retinal vein occlusion (RVO) model in miniature pig eyes under photodynamic method. Two days later, the retinas of both eyeballs were peeled off. The diffusion test apparatus was designed by ourselves. FITC-dextrans of various molecular weights (4.4, 9.3, 19.6, 38.9, 71.2 and 150 kDa) and Carboxyfluorescein (376 Da) were dissolved in RPMI1640 solutions and diffused through inner or outer surface of retina. The rate of transretinal diffusion was determined with a spectrophotometer. Theoretical maximum size of molecule (MSM) was calculated by extrapolating the trend-linear relationship with the diffusion rate. In separate experiments to determine the sites of barrier to diffusion, FITC-dextrans were applied to either the inner or outer retinal surface, processed as frozen sections, and viewed with a fluores cence microscope. Results FITC-dextrans applying to inner retinal surface, 4.4 kDa dextrans were largely blocked by inner nuclear layer (INL); 19.6,71.2 kDa dextrans were blocked by the nerve fiber layer (NFL) and inner plexiform layer; 15.0 kDa dextrans were blocked by NFL. FITC-dextrans applying to outer retinal surface, most dextrans with various molecular weights were blocked before outer nuclear layer (ONL). No matter applying to the inner or outer surface, Carboxyfluore scein can diffuse through the whole retina and aggregate at INL and ONL. After RVO, the inner part of retina became edema and cystoid, loosing the barrier function. Compared with the normal retina, the MSM in RVO tissues increased (6.5plusmn;0 39nm Vs 6.18plusmn;0.54nm, t=4.143, P=0.0001). Conclusions A fter RVO, the barrier function of inner part of retinal is destroyed and the upper limit of diffusion macromolecule size increased, which is nevertheless limited. ONL acts as bottle-neck barriers to diffusion, if the outer part of retina is damaged, the change of the diffusion upper limit will be prominent. （Chin J Ocul Fundus Dis，2008，24：197-201）
Objective To investigate the method and effect of krypton laser photocoagulation for neovascularization in retinal vein occlusion . Methods Tweenty eight eyes of 27 patients with retinal vein occlusion with neovascularization were photocoagulated by krypton green and red laser.The fundus changes were observed by fundus fluorescein angiography after photocoagulation. Results The neov ascularization disappeared completely in 20 eyes and became smaller in 6 eyes,re mained no change in 2 eyes,and the visual acuity improved in 17 eyes (60.7%) after 6 monthes to 2.5 years of follow-up. Conclusion Krypton laser photocoagulation is obviously effective on regression of n eovascularization and prevenion of vitreous hemorrhage in retinal vein occlusion . (Chin J Ocul Fundus Dis, 2001,17:12-14)
Objective To measure the macular function of the fellow eye in patients with unilateral retinal vein occlusion (RVO). Methods A total of 24 cases of unilateral RVO were diagnosed by fundus fluorescein angiography (FFA), and multifocal ERG (mfERG) was recorded by RETI scan. The mfERG data of 24 fellow eyes of those RVO patients, and 18 normal control eyes were analyzed and compared. The parameters included the amplitude density, latency of the P1 and N1 wave in 6 concentric circles and 4 quadrants of the mfERG graphics. Results The amplitude densities of P1 and N1 wave in first and second concentric circles of RVO fellow eyes were significantly lower than normal eyes (t=4.520, 2.147; P＜0.05). There was no significant difference (P＞0.05) of P1/N1 latency in any concentric circles or quadrants between RVO fellow eyes and normal eyes. Conclusion The central fovea of the RVO fellow eyes was functionally impaired.
Objective To investigate the changes of ocular hemodynamics in patients with retinal vein occlussion(RVO)． Methods The hemodynamic parameters(PSV,EDV,PI,Vmax)of central retinal artery(CRA)and central retinal vein(CRV)were measured in the involved eyes(n=48) with RVO and the contralateral clinically healthy eyes(n=39) and in the control eyes(n=40) by color Doppler imaging (CDI)(ATLHDI3000). Results Peak systolic velocity (PSV) and end diastolic velocity (EDV) were significantly lower in the CRA of involved eyes and clinically healthy eyes of patients with RVO compared with control eyes,and pulsatility index(PI)was significantly higher in the CRA of involved eyes of patients with RVO compared with control eyes．PSV were significantly lower in the CRA of involved eyes of patients with RVO compared with their clinically healthy eyes．Pulsatility index(PI)was significantly higher in the CRA of involved eyes of patients with RVO compared with their clinically healthy eyes．Maximun vein velocity (Vmax) was significantly lower in the CRV of involved eyes and clinically healthy eyes of patients with RVO compared with control eyes． Conclusion The changes of hemodynamics in CRA,CRV of involved eyes of patients with RVO may invade their clinically healthy eyes．CDI may be helpful to early diagnosis for RVO． (Chin J Ocul Fundus Dis,1998,14:111-113)
ObjectiveTo observe serum homocysteine (Hcy) levels in retinal vein occlusion (RVO) patients with different ages and types. MethodsA total of 79 patients (79 eyes) diagnosed with RVO were enrolled. There were 33 females and 46 males, the mean age was (57.00±9.29) years. Eighty-two age-and sex-matched patients (82 eyes) without retinal vascular disease were included as controls. There were 32 females and 50 males, the mean age was (60.00±10.15) years. Among RVO patients, there were 24 patients younger than 50 years old (young patients) and 55 patients older than 50 years old (elderly patients); 35 patients with central RVO (CRVO) and 44 patients with branch RVO (BRVO). Fasting plasma Hcy, serum vitamin (Vit) B6, B12 and folate levels were measured in all patients. The relationship of high Hcy, low VitB6, low folate and RVO with different age were analyzed. ResultsHcy level was significantly higher in RVO patients than control subjects (t=2.946, P<0.01). Blood concentration of folate and VitB6 were significantly lower in RVO patients than control subjects (t=2.641, 2.889; P<0.01). Blood level of VitB12 was significantly different in RVO patients from control subjects (t=1.665, P>0.05). Concentrations of Hcy, folate, VitB12 and VitB6 were not different between patients with CRVO and BRVO (t=0.756,1.306,0.682,1.306;P>0.05). Hcy level was significantly higher in the young RVO patients than in the elderly RVO patients (t=2.394, P<0.05). Blood concentration of folate and VitB6 were lower in the young RVO patients than in the elderly RVO patients, but the difference were not significant(t=1.318, 1.694; P>0.05). The number of patients with high Hcy [χ2=13.67,odds ratio (OR)=3.327,95% confidence interval (CI)=1.742-6.354], low VitB6 (χ2=5.28,OR=2.068,95%CI=1.103-3.878) and low folate status (χ2=8.642,OR=2.546,95%CI=1.349-4.806) in RVO patients were more than control subjects (P=0.0001, 0.023, 0.004). ConclusionsHigh Hcy, low folate and low VitB6 were risk factors for the onset of RVO. Hcy may play more important role in young patients with RVO. Hcy, folate and VitB6 levels were similar in CRVO and BRVO patients.
Objective To evaluate the effectiveness of repeated intravitreal conbercept injection in patients with macular edema (ME) of retinal vein occlusion (RVO), guided by optic coherence tomography (OCT). Methods It is a retrospective case study. Forty patients (40 eyes) diagnosed as ME secondary to RVO were enrolled in this study. There were 19 males (19 eyes) and 21 females (21 eyes), with the mean age of (53.58±13.19) years and the mean course of 1.5 months. The best corrected visual acuity (BCVA), indirect ophthalmoscopy, fundus fluorescein angiography (FFA) and OCT were performed. The mean baseline of BCVA, central macular thickness (CMT) were 0.25±0.18 and (509.48±170.13) μm respectively. All the patients were treated with 10.00 mg/ml conbercept 0.05 ml (including conbercept 0.5 mg). Follow-up of these patients was 1 to 6 months after treatments, the BCVA, fundus manifestations, OCT were retrospectively observed by every month, the FFA was retrospectively observed by every 3 months. When there was retinal edema or CMT ≥50 μm by OCT during follow-up, those patients were retreated with intravitreal conbercept injection. The changes of the BCVA, CMT were evaluated before and after treatment. Meanwhile, complications in eyes related to medicine and treatment methods were evaluated too. Results At the 6 months, the BCVA was improved (increase≥2 lines) in 25 eyes (62.50%), stabilized (±1 line) in 13 eyes (32.50%) and decreased 2 lines in 2 eyes (5.00%). Retinal hemorrhage and exudates were absorbed in most patients. FFA showed no fluorescein leakage in 11 eyes (27.50%), minor fluorescein leakage in 26 eyes (65.00%), and retinal capillary non-perfusion in 3 eyes (7.50%). OCT showed absorption of the subretinal fluid. The mean CMT were (235.20±100.44) μm at 6 months. Intravitreal injection of conbercept was applied for 4 times in 8 eyes (20.00%), 3 times for 18 eyes (45.00%), and 2 times for 14 eyes (35.00%). The mean number of intravitreal injection was 2.85 times. There were no ocular or systemic adverse events observed in all patients. Conclusion Intravitreal conbercept injection is an efficacy and safe treatment for the patients with ME of RVO guided by OCT. It can stabilize and improve the visual acuity.
Retinal vein occlusion (RVO) is a serious retinal vascular disease, often accompanied by systemic cardiovascular and cerebrovascular diseases, the eye changes include macular edema, retinal ischemia, and even neovascularization, etc. As a common chronic disease of the fundus, it seriously affects patients' vision and quality of life. With the development of optical coherence tomography, the role of choroid in the occurrence and development of RVO has become a research hotspot. The research on the changes of the choroid layer of the eye with RVO has expanded from a simple two-dimensional thickness analysis to a more comprehensive multidimensional observation index such as three-dimensional volume, blood flow density and velocity. In addition, some cutting-edge research combines artificial intelligence algorithm techniques to improve the accuracy and depth of analysis. In the future, it is still necessary to further improve the data of the choroid layer of the eye with RVO, enhance the overall understanding of RVO, and provide new ideas for clinical prevention and treatment of RVO.
ObjectiveTo observe the clinical therapeutic effects of radial optic neurotomy (RON) for central retinal vein occlusion (CRVO).MethodsThe clinical data of 12 patients (12 eyes) with CRVO who had undergone RON were retrospectively analyzed. The patients were examined by visual acuity and fundus examination, photography, fundus fluorescein angiography, and optical coherence tomography (OCT). The visual acuities of all of the 12 eyes with severe hemorrhage and retinal edema were less than 0.1. A microvitreoretinal blade or CRVO knife was penetrate into the nasal side of the optic disk, and the incision reached the cribriform plate and even the back, and then dissected at the nasal side of the cribriform plate. The postoperative follow-up period lasted 2 to 15 months with the mean of 6.5 months, and the visual acuity, the condition of visual field and ocular fundus of the eyes undergone the surgery were observed.ResultsIn 12 eyes undergone RON successfully, the visual acuity after the surgery improved more or less in 9 (75%), and more than or up to 0.1 in 6. The results of the examinations showed that the retinal edema and hemorrhage disappeared gradually, varicosity mitigated, retinal serous detachment mitigated or disappeared, and macular cystoid edema faded; macular fovea recovered in 3 eyes, optic nerve had a hemorrhage during the operation in 3 eyes, and the dissected part of optic nerve became atrophic afterward in 4.ConclusionsRON performed at the edge of the nasal side of the optic disc is safe and effective, which may improve the visual acuity of the eyes with CRVO and mitigate retinal hemorrhage and edema.(Chin J Ocul Fundus Dis, 2005,21:10-12)
Retinal vein occlusion (RVO) is characterized by obstruction of retinal vein blood flow, distended flexion, retinal hemorrhage, edema, and neovascularization, and its pathogenesis is not completely clear. Recent studies have found that endothelin (ET)-1, ETA receptor and ETA signaling pathways in the ET system may be involved in the occurrence and development of RVO by stimulating vasoconstriction to increase retinal vein pressure and inducing the expression of pro-inflammatory factors such as TNF-α, IL-6 and IL-1β. In-depth understanding of the correlation between the ET system and the occurrence and development of RVO can provide new ideas for further research on the pathogenesis of RVO.
Objective The present study focus on the macular branch retinal vein occlusion (MBRVO) with and without laser treatment,and evaluate prospectively whether laser treatment is useful in improving the visual acuity and reducing the macular edema. At the same time to learn the difference of macular light sensitivity before and after laser treatment.Methods Forty-five eyes of forty-five patients with MBRVO and macular edema were randomized to laser treatment and no laser treatment. Follow up examinations were performed every 3 months. We compared the difference of visual improvement, resolution of macular edema between the two groups. The central 30°visual field of 20 patients with MBRVO were examined at pretreatment and 3 months after laser treatment. A comparison of light sensitivity at fovea ，central 10°and 11~30°eccentricity were done between before and after laser treatment. Results Comparison of visual improvement and resolution of macular edema showed a statistical difference between laser treatment and no laser treatment. The mean reduction of macular light sensitivity at the fovea and 11~30°3 months after the treatment has no statistical difference between before and after treatment (Pgt;0.05). But the mean light sensitivity at central 10°eccentricity were significantly decreased 3 months after photocoagulation (Plt;0.05).Conclusion The laser treatment might promote or accelerate visual acuity recovery and reduce the macular edema. There is no significant difference about the efficiency on macular function after laser treatment.(Chin J Ocul Fundus Dis，2003，19：201-268)