Wet age-related macular degeneration (wAMD) is caused by choroidal neovascularization (CNV), which occurs when the choroidal new capillaries reach the RPE layer and photoreceptor cell layer through the ruptured Bruch membrane, leading to neovascularization bleeding, leakage, and scarring. In view of the important role of VEGF in the development of CNV, targeted therapy with various intraocular anti-VEGF drugs is the first-line treatment for wAMD. However, the efficacy of anti-VEGF drugs in the treatment of wAMD is affected by a variety of factors, and some patients still have problems such as unresponsiveness, drug resistence, tachyphylaxis, long-term repeated injections, and severe adverse effects. It is the direction of future researches to deeply explore the physiological and pathological process of wAMD, find the cause of CNV formation, and seek better therapies.
The therapeutic effect of anti-vascular endothelial growth factor (VEGF) for neovascular age-related macular degeneration (nAMD) was determined by a number of factors. Comprehensive thorough analysis of clinical features, imaging results and treatment response can predict the potential efficacy and possible vision recovery for the patient, and also can optimize the treatment regime to make a personalized therapy plan. Precise medicine with data from genomics, proteomics and metabolomics study will provide more objective and accurate biology basis for individual precise treatment. The future research should focus on comprehensive assessment of factors affecting the efficacy of anti-VEGF therapy, to achieve individualized precise diagnosis and treatment, to improve the therapeutic outcome of nAMD.
Objective To observe the inhibitory effects and characteristics of intravitreal injection with bevacizumab on laser induced choroidal neovascularization (CNV).Methods Twelve male brown norway（BN）rats were divided into the bevacizumab group and control group with six rats in each group. One eye of rats were received a series of 8 diode laser esions around optic disc to induce CNV,then the rats in bevacizumab group and control group underwent intravitreal injection with 2 mu;l bevacizumab and ringer's lactate.On days 7,14,and 21，the morphology and leakage of CNV were observed by fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA).On day 21 after photocoagulation,the photocoagulated eyes were enucleated and processed for histopathologic examination, including hematoxylin and eosin (Hamp;E) staining and immunohistochemistry staining for vascular endothelial growth factor（VEGF）.Results On day 7 after photocoagulation,ICGA showed that CNV developed in the bevacizumab group and the control group. FFA showed that leakage intensity in the bevacizumab group was significantly lower than that in the control group，but the bevacizumab group gradually increased over time. The mean thickness of CNV significantly decreased in the bevacizumab group.The CNV in the bevacizumab group were negative for VEGF according to the result of immmuohistochemistry staining.Conclusions Early intravitreal injection with 2 mu;l bevacizumab can reduce the thickness of CNV and inhibit the leakage of CNV. However, bevacizumab could neither block the formation of CNV, nor suppress the permeability permanently. Combined other therapies with bevacizumab may be more potential to treat CNV effectively.
Anti-vascular dndothelial growth factor (VEGF) drugs have open up a new treatment channel for ocular neovascular diseases. A lots of clinical data has proved that anti-VEGF drugs are effective and safe. But we should also notice that long-term and excessive usage of anti-VEGF drugs brings some new problems and complications, and even affect the normal ocular physiological process of the angiogenesis and retinal blood flow. So, it is necessary to pay attention to the problems and potential risks of excessive usage of anti-VEGF therapies for ocular neovascular disease.
Objective To evaluate the efficacy and safety of photodynamic therapy (PDT) combined with intravitreal injection of bevacizumab for choroidal neovas cularization (CNV) caused by age-related macular degeneration (AMD). Methods A total of 21 eyes of 21 patients with AMD, which was diagnosed by examination of visual acuity, intraocular pressure, ocular fundus, fundus color photography, fundus fluorescein angiography(FFA), indocyanine green angiography(ICGA)and optic coherence tomography(OCT), were underwent PDT combined with intravitreal injection of Bevacizumab. The patients, 15 males (15 eyes) and 6 females (6 eyes), aged from 56 to 78 years, with the average of 68.6 years. The best corrected visual acuity：counting fingers/10cm0.9, logMAR was 1.04 plusmn; 0.41.CNV located in below or side central fovea of macula. There was obvious leakage of fluorescein which examined by FFA and ICGA. The average of retinal thickness of macular foveal was （258.91 plusmn; 78.66）mu;m. The treatment method of PDT has to according to the way of PDT for TAP and Verteporfin PDT for VIP. Intravitreal infection with 1.5mg bevacizumab was performed after three days under surface anesthesia. Follow-up time was 1, 3, 6, 12 months after the treatment. Results At last visit, the best-corrected visual acuity：counting fingers/10 cm 1.5, logMAR was 1.04plusmn;0.41, and the differences are statistically significant compared with before. The BCVA improved four or more lines in 6 eyes (28.57%), improved two to four lines in 9 eyes (42.86%), stabilized (plusmn;1 line or no change) in 6 eyes (28.57%) and decreased in none. The average intraocular pressure was （15.20plusmn;2.41）mmHg after surgery, and the differences was not statistically significant compared with before（P＞0.05）. FFA and ICGA showed CNV complete closure in 13 eyes (61.90 %), partial closure in 8 eyes (38.10%). The average of retinal thickness of mac ular foveal was（127.38plusmn;20.14） mu;m (P＜0.01). Conclusion Combining treatment with PDT and intravitreal injection of Bevacizumab is safe and effective for CNV which caused by AMD. It has significant improvement in BCVA, leakage of CNV and retinal edema. (Chin J Ocul Fundus Dis,2008,24:164-167)
The introduction of anti-vascular endothelial growth factor (VEGF) therapy represents a landmark in the management of wet age-related macular degeneration (AMD). However, as a new therapy, several problems such as durability of the therapeutic effects, medication side effects, and medication selection have emerged. We should make appoint of improving the therapeutic effect and safety by realizing the limitation of the therapy, monitoring the clinical potential adverse reactions of anti-VEGF agents, and recommending individualized treatment.
Objective To investigate the effects of celecoxib-poly lactide-co-glycolide microparticles (CEL-PLGA-MS) on rat retina after intravitreal injection. Methods A total of 32 male Brown Norway rats were randomly divided into CEL-PLGA-MS group and celecoxib group, 16 rats in each group. The rats in CEL-PLGA-MS group were divided into four dosage group, four rats in each group, which received intravitreal injection of PLGA with celecoxib at the concentration of 40, 80, 160, 320 mu;mol/L, respectively. The rats in celecoxib group were divided into four dosage group, four rats in each group, which received intravitreal injection of celecoxib at the concentration of 40, 80, 160, 320 mu;mol/L, respectively. Phosphate buffer solution (PBS) was injected in two rats as PBS control group. Two rats as normal control group received no treatment. The difference of retinal thickness among groups was measured by optical coherence tomography (OCT). The morphological and histological change of retina was evaluated under light microscope and transmission electron microscope. Results There was no difference of retinal thickness between normal control group and PBS control group (F=0.12,P＞0.05). At the first week after injection, the retinal thickness of CEL-PLGA-MS group and celecoxib group were thicker than that in normal control group and PBS control group (F=9.62, 46.13;P＜0.01). The retinal thickness of celecoxib group was thicker than that in CEL-PLGA-MS group (F=165.15,P＜0.01). The retinal thickness was estimated equal among 40, 80, 320 mu;mol/L dosage groups in CEL-PLGA-MS group (F=4.79,P＜0.01). The retinal thickness of 160, 320 mu;mol/L dosage group were thicker than that in 40, 80 mu;mol/L dosage group in celecoxib group (F=28.10,P＜0.01). At the second week after injection, there was no difference of retinal thickness between CEL-PLGA-MS and celecoxib group (F=3.79,P＞0.05); the retinal thickness of CEL-PLGA-MS and celecoxib group became thinner gradually compare to the first week after injection (F=7.28, 103.99; P＜0.01). At the fourth week after injection, the retinal thickness of celecoxib group was thicker than that in CEL-PLGA-MS group (F=19.11,P＜0.01). The retinal thickness of CEL-PLGA-MS group was approximately the same to normal control group and PBS control group (F=2.02,P＞0.05). The retinal thickness of celecoxib group was thicker than that in normal control group and PBS control group. No considerable abnormality of the retina was seen by light microscope and the retinal thickness corresponded with the values measured by OCT at the first week after injection. The abnormal structures of the retina were seen in 160, 320 mu;mol/L dosage group of celecoxib group and inner changed evidently by the transmission electron microscope. Disordered arrangement of microfilaments, dilated microtubule and some mitochondria vacuolation were observed in 320mu;mol/L dosage group of celecoxib group. Others changed slightly. Conclusions CEL-PLGA-MS has less toxicity on the retina than free-celecoxib after intravitreal injection. The safety of intravitreal injection with CEL-PLGA-MS is better than celecoxib.