Objective To observe the levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) in aqueous humor of patients with macular edema secondary to central retinal vein occlusion (CRVO). Methods Forty eyes of 40 consecutive patients with macular edema secondary to CRVO (CRVO group) were enrolled in this study. The patients included 25 males and 15 females. The patient age ranged from 38 to 76 years. The control group was 20 patients with senile cataract who underwent phacoemulsification, including 10 males and 10 females. The levels of VEGF165, VEGF165b, IL-6 and MCP-1 in aqueous humor were determined by enzymelinked immunosorbent assay. The correlation of VEGF, and IL-6, and MCP-1 were analyzed. Results The median aqueous level of VEGF165, IL-6 and MCP-1 were 1089.0, 165.6, 1253.0 pg/ml respectively in CRVO group, which were higher than the control group's results (168.2, 4.7, 216.4 pg/ml respectively), the differences were statistically significant (Z=-4.549, -6.008, -5.343;P＜0.001). The VEGF165b in CRVO group and control group were 834.0, 915.9 pg/ml respectively, the difference was not statistically significant (Z=-0.207，P＞0.05). The ratio of VEGF165b to VEGF165 in CRVO group and control group were 2.71, 7.28 respectively, the difference was statistically significant (t=-3.007，P＜0.05). There was a highly positive correlation between IL-6 and VEGF in CRVO group (r=0.526,P=0.001) and also mild positive correlation in control group (r=0.425，P=0.070). No correlation between MCP-1 and VEGF was observed in both groups (CRVO group: r=0.211,P＞0.05. Control group: r=-0.019,P＞0.05). Conclusions VEGF165, IL-6 and MCP-1 levels were increased in CRVO patients while the VEGF165b was normal. The ratio between VEGF165b and VEGF165 in aqueous humor of patients with macular edema secondary to CRVO was decreased.
Macular edema (ME) secondary to central retinal vein occlusion（CRVO) often cause severe visual impairment. Intravitreal anti-vascular endothelial growth factor agents and steroids can effectively eliminate ME and improve visual function, but the visual outcome is affected by multiple factors. Retinal blood flow, especially the macular microcirculation, has significant correlation with visual outcome. Ischemic CRVO, especially patients with severe damage in the deep and superficial vascular layer of the macular zone, usually have poor visual outcome. In addition, the integrity of the multi-layer retinal structure closely correlates with the visual outcome. Patients with intact ellipsoid zone, external limit membrane beneath the fovea have good visual recovery. Additionally, good baseline visual acuity, positive response to treatment in early phase, young age and timely treatment usually brings about better visual outcome.
ObjectiveTo compare the one year efficacy of intravitreal injection with ranibizumb for macular edema (ME) secondary to ischemic and non-ischemic central retinal vein occlusion (CRVO).MethodsA total of 88 patients (88 eyes) with ME secondary to CRVO were enrolled in this retrospective study. The best corrected visual acuity (BCVA) was detected by the Early Treatment Diabetic Retinopathy Study Chart. The optical coherence tomography was used to measure the foveal retinal thickness (CRT) and macular edema volume. The patients were divided into non-ischemic group and ischemic group, 44 eyes of 44 patients in each group. There was no significant differences in age (t=0.650, P=0.517) and gender (χ2=0.436, P=0.509) between the two groups. Compared with the ischemic group, the CRT was significantly decreased in the non-ischemic group (t=−2.291, P=0.024), and the edema volume in the macular area was significantly reduced (t=−2.342, P=0.022). All eyes were treated with continuous intravitreal injection of ranibizumab three times, and repeated injections were performed as needed. The patients without obvious ME regression after treatment were combined with triamcinolone acetonide injection. The patients with peripheral retinal non-perfusion area were combined with peripheral retinal laser photocoagulation. The follow-up was 1 year. The number of injections was counted. The changes of BCVA, CRT and edema volume in the macular area were compared between the two groups.ResultsDuring the 1-year follow-up period, 88 eyes were injected 1 to 10 times, with the mean of 4.51±2.33. The number of injections in the ischemic group and non-ischemic group were 4.55±1.59 and 4.48±2.91, respectively. There was no significant difference in the average number of injections between the two groups (t=0.136, P=0.892). The number of acetonide injections and laser treatment in the ischemic group was significantly higher than that in the non-ischemic group (t=3.729, 9.512; P＜0.001). At the last follow-up, compared with the ischemic group, the BCVA was increased (t=8.128), the CRT was decreased (t=−7.029) and the edema volume in the macular area was decreased (t=−7.213) in the non-ischemic group (P＜0.001).ConclusionCompared with ME secondary to ischemic CRVO, intravitreal injection of ranibizumab for ME secondary to non-ischemic CRVO has the better outcome of vision improvement and edema regression as well as less frequent of acetonide injections and laser treatment.
At present, intravitreal injections of anti-VEGF agents is the main method for the treatment of macular edema secondary to retinal vein occlusion (RVO), which can significantly inhibit neovascularization, release macular edema and improve the vision of patients. However, VEGF is a survival factor of vascular endothelial cells, whether it can lead to the progress of retinal ischemia and it has an effect on retinal capillaries deserves our clinical attention. Most scholars currently think that the anti-VEGF agents will not aggravate the occlusion of retinal capillaries in the treatment of macular edema secondary to RVO from the aspects of the changes of perifoveal capillary arcade, the quantification of foveal avascular zone area, retinal nonperfusion area and retinal vascular density of the superficial and deep capillary plexus In addition, the changes of these indicators may be related to the number of times patients need treatment, visual prognosis and so on. In the future, with the gradual popularization of OCT angiography and the prolongation of the number and time of anti VEGF drug treatment, we look forward to the study of larger samples and longer follow-up time to further analyze the influence of the retinal capillary after anti-VEGF therapy in patients with macular edema associated with RVO.