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.
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.