| Background:Diabetic retinopathy (DR) and diabetic macular edema (DME) are the most common microvascular complications of DM, which may cause visual acuity (VA) declined sharply and even blindness. DME is one of the common manifestations of DR and the main reason of impired VA in DR patients. It is characterized by swelling of the central part of the retina, when the swelling region involving the range about an optic disc diameter from the fovea, the impact on VA is more serious. There are some defects of traditional treatments including macular focal or grid photocoagulation, intravitreous injection of triamcinolone acetonide and vitrectomy. It had been confirmed that the VEGF staining was significantly higher in retina of the DM patient than normal person, it is clear that VEGF is one of most important endogenous mediators in the pathogenesis of DME, so anti-VEGF treatment for DME has become one hot research, for example, intravitreous anti-VEGF drugs including Bevacizumab and Ranibizumab. The short-term efficacy and safety have been confirmed by numerous studies at home and abroad, but there were some shortcomings, for example, relapse after treatment, need repeated injections, the effect of some patients is not ideal, the potential risks of off-lable and lack of observational studies on its long-term effects. Therefore, optimization of treatment options, including change the frequency of injection and the structure of drugs to improve bioavailability become a hot research for clinicians. Ranibizumab is a humanized anti-VEGF monoclonal antibody fragment, which has smaller molecular weight and could better penetrate the retina so that the vitreous bioavailability is up to 50~60%. It is the only drug for the treatment of eye diseases approved by the U.S. FDA, its effectiveness, safety, and the way of intravitreous injection have been confirmed in the studies of AMD. The effectiveness and safety of Ranibizumab for the treatment of DME have been confirmed in abroad studies, but it is still need long-term, large-scale randomized controlled clinical trials to confirm the best treatment programs and long-term safety of intravitreous injection. At present, there is lack of such studies at home. Therefore, it is the focus of clinicians to develop large-scale, prospective and randomized controlled trials, in accordance with the principles of medical consultation, in order to choose more scientific treatment and maximum the improvement of visual function.1. Observation of clinical cases of intravitreous injection with Bevacizumab for diabetic macular edemaObjective:To investigate the clinical therapeutic effects of intravitreous injection of Bevacizumab for diabetic macular edema (DME). Methods:Retrospective analysis the clinical datas of sixty-six eyes of 65 patients with DME who were diagnosed as diabetic macular edema in the Department of Ophthalmology, Xijing Hospital, from January 2008 to August 2010, and initially received intravitreous injection with Bevacizumab.Best-corrected visual acuity (BCVA), the grade of macular edema and the type of leakage, central retinal thickness (CRT) and total macular volume (TMV) were performed before and after the injection. These indicators before treatment, after treatment 2 weeks, 6 weeks, and 12 weeks of 38 patients (41 eyes) who received single intravitreous injection treatment in the first three months were analyzed.Results:The mean BCVA letters, CRT and TMV of 65 patients were 39.81±17.18, (514.11±247.43)μm, (11.70±2.37) mm~3 and 43.45±14.38, (455.47±193.34)μm, (10.64±2.13) mm~3 before treatment and at the last follow-up visit, respectively. Before treatment, the mean BCVA letters of 38 patients (41 eyes) who received single intravitreous injection treatment in the first three months was 45.09±12.68. This improved significantly (P<0.05) to 52.45±13.67, 59.09±12.31 and 50.36±11.72 at 2 weeks, 6 weeks, and 12 weeks after treatment, respectively. The mean CRT at 2 weeks, 6 weeks, and 12 weeks after treatment were (348.91±209.76), (327.93±127.60) and (444.00±193.61)μm, which also significantly (P<0.05) improved from (503.95±246.79)μm. The mean TMV were (11.07±2.23), (10.25±1.81), (9.76±2.01) and (9.92±1.49) mm~3 before treatment and at 2 weeks, 6 weeks, and 12 weeks after treatment. No serious adverse events were observed.Conclusion:Intravitreous injection with Bevacizumab may be effective in reducing DME and enhancing VA in limited period, but the duration of efficacy was limited and the efficacy of single injection can be maintained around 8~12 weeks, and need repeated injections or combined with other therapies to control the edema recurrence and stable the existing vision. Therefore the long-term curative effects and complications should be further observed through mulit-center clinical trial.2. Randomized controlled phaseⅢclinical trial of intravitreous injection with Ranibizumab for diabetic macular edemaObjective:Confirm the efficacy and safety of ranibizumab as adjunctive therapy when added to laser photocoagulation and/or mono-therapy in patients with visual impairment due to diabetic macular edema (DME). Methods:In accordance with a randomized, double-masked, multicenter, laser-controlled phase III study, there are 11 DME patients who meet the inclusion and exclusion criterias were randomly assigned to accept one of the treatments: Ranibizumab and active laser or single Ranibizumab or single laser treatment, follow-up period is 12 months all together. Analysis the changes of best-corrected visual acuity (BCVA), the absorption of macular edema and the type of leakage, central retina thickness (CRT) and total macular volume (TMV) were performed before and after the injection.Results:Compared with before the treatment, all 11 patients, the number of BCVA letters improved>5, improved or declined<5 and declined>5 were 8, 2 and 1, respectively; CRT decreased>150μm, decreased<150μm and increased were 8, 2 and 1, respectively; TMV decreased>1mm~3, decreased<1mm~3 and increased were 9, 1 and 1, respectively; From the Fundus color photos, the exudative or hemorrhage in macular was obviously absorbed in 9 patients, the macular edema aggratated in 2 patients; FFA showed that macular leakage significantly reduced in 6 patients, after treatment the edema leakage increased were 4 patients, 1 patients have no significant changes in macular leakage. Conclusion:Intravitreous injection with Ranibizumab or laser treatment may be effective in reducing DME and enhancing VA in limited period. However, the number of cases is limited in our study, the long-term efficacy and safety should be verified by the conclusions of this multi-center clinical trial.In summary, the retrospective observation and randomized, controlled phaseⅢclinical trial have confirmed the short-term efficacy and safety of intravitreous injection of anti-VEGF drugs for the treatment of DME, but still need repeated injections or combined with other therapies based on the specific conditions of patients to stable the ideal long-term vision and control edema of most patients. Moreover, studies had confirmed that there are a low incidence of adverse events related to the drugs and intravitreous injection, but ocular complications caused by diabetes itself can not be ignored. With the results of this prospective clinical study, it can provide more effective clinical evidence and deepen our understanding of the pathogenesis of the disease. |
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