Microparticles are small vesicles that are released by budding of the plasma membrane during cellular activation and apoptotic cell breakdown. A spectrum of cell types can release microparticles including endothelial cells, platelets, macrophages, lymphocytes and tumor cells. Biological effects of microparticles mainly include procoagulant activity, inhibition of inflammation and cancer progression. The present study shows that vitreous microparticles isolated from proliferative diabetic retinopathy (PDR) stimulated endothelial cell proliferation and increased new vessel formation, promoting the pathological neovascularization in PDR patients. Oxidative stress induces the formation of retina pigment epithelium-derived microparticles carrying membrane complement regulatory proteins, which is associated with drusen formation and age related macular degeneration. Microparticles from lymphocyte (LMP) play an important role in anti-angiogenesis by altering the gene expression pattern of angiogenesis-related factors in macrophages. Besides, LMP are important proapoptotic regulators for retinoblastoma cells through reduction of spleen tyrosine kinase expression and upregulation of the p53-p21 pathway which ultimately activates caspase-3. However, how to apply the microparticles in the prevention and treatment of retinal diseases is a major challenge, because the study of the microparticles in the fundus diseases is still limited. Further studies conducted would certainly enhance the application of microparticles in the fundus diseases.
Objective To evaluate the visual function before and after photodynamic therapy(PDT) in patients with subfoveal choroidal neovascularization ( CNV) caused by age-related macular degeneration (AMD). Methods Twenty-five consecutive patients (34 eyes) treated with PDT (verteporfin) for subfoveal CNV in age-related macular degeneration diagnosed by fluorescein angiography (FFA), indocyanine green angiography (ICGA) and optical coherence tomography (OCT). Visual function including best corrected visual acuity, contrast sensitivity frequency, binocular function, confusion, stereo-vision, color vision, metamorphopsis and central scotoma were examed before photodynamic therapy and 1 week, 1 month, 3 month after photodynamic therapy. The follow-up time varied from 3 months to 2 years (mean 7.6 months). Results The changes of visual function at the 3rd month after photodynamic therapy revealed improving in 13 eyes (38.24%), without any change in 17 eyes (50.00%), and decreasing in 6 eyes (17.65%). Visual acuity with logMRA improved after photodynamic therapy, but without statistic difference. All spatial contrast sensitivity improved. Contrast sensitivity for spatial frequencies 5 cycles per degree (cpd) was better after photodynamic therapy with significant difference (P=0.045).Binocular function, fusion function, stereo function and color vision were slightly improved without statistic difference. Conclusion Damage of visual function in macular degeneration is many-sided. The treatment of PDT for exudative AMD can improve part visual function. (Chin J Ocul Fundus Dis，2004，20：289-291)
For the past few years, artificial intelligence (AI) technology has developed rapidly and has become frontier and hot topics in medical research. While the deep learning algorithm based on artificial neural networks is one of the most representative tool in this field. The advancement of ophthalmology is inseparable from a variety of imaging methods, and the pronounced convenience and high efficiency endow AI technology with promising applications in screening, diagnosis and follow-up of ophthalmic diseases. At present, related research on ophthalmologic AI technology has been carried out in terms of multiple diseases and multimodality. Many valuable results have been reported aiming at several common diseases of ophthalmology. It should be emphasized that ophthalmic AI products are still faced with some problems towards practical application. The regulatory mechanism and evaluation criteria have not yet integrated as a standardized system. There are still a number of aspects to be optimized before large-scale distribution in clinical utility. Briefly, the innovation of ophthalmologic AI technology is attributed to multidisciplinary cooperation, which is of great significance to China's public health undertakings, and will be bound to benefit patients in future clinical practice.
Objective To study the significance of detection the short-term fluctuation (SF) of macular light threshold detected by Octopus-123 automatic perimeter in suspected early age-related macular dege-neration (AMD). Methods SF of macular light sensitivity, Amsler chart and central visual acuity were examined in 51 patients(66 eyes) with suspected early AMD group and in 32 patients (40 eyes) in the control group. Results SF were significantly different in suspected early AMD group and control group. SF was more sensitive than the examination of central visual acuity and Amsler chart. SF was related to the quantity, location and quality of drusen. Conclusion Visual function of some suspected early AMD patients with drusen may be damaged, though the central visual acuity appears normal. (Chin J Ocul Fundus Dis, 2002, 18: 119-120)
Flicker and photopic eletroretinogram(ERG)were recorded for 45 eyes of dry type of age-related macular degeneration(AMD)and 24 eyes of wet type of AMD respectively,the amplitud and phase of fundamental response compomeng(30Hz)by discrete Fourier tranform(DFT)were analysed.The abnormality ratios of phases and amplitudes in fundamental responses,amplitudes of photopic white or red b-waves were 48.89%,8.89%,10.11% and 8.89% respectively.The visual acuities of 24 eyes were 1.0 or better,the abnormality ratios of phases were up to 37.50%.These suggest that the change of phases is a sensitive method for detecting the early abnormality of visual function in AMD.The abnormality ratios of phases and amplitudes in fundamental responses were 62.5% and 45.84% in wet type of AMD.The differences between dry type and wet type in amplitudes of fundamental responses and photopic b-waves were statistically significant(P＜0.01).This shows that the change of amplitudes is associated with the degree of pathological change of AMD. （Chin J Ocul Fundus Dis,1996,12: 41-43）
ObjectiveTo assess the efficacy and safety of intravitreal aflibercept injection (IAI) compared with photodynamic therapy (PDT) in the treatment of Chinese patients with predominantly classic subfoveal choroidal neovascularization (CNV) lesions secondary to neovascular age-related macular degeneration (nAMD).MethodsA randomized, double-blind, multi-center phase-3 clinical trial lasting for 52 weeks (from December 2011 to August 2014). Subjects were randomized in a 3:1 ratio to either IAI group or PDT-to-IAI group. Subjects in the IAI group received 2 mg IAI at baseline and at week 4, 8, 16, 24, 32, 40, 48, with sham injection at week 28, 36. Subjects in the PDT-to-IAI group were forced to receive PDT once at baseline and more time at week 12, 24 if PDT retreatment conditions were met. Sham injections were given in PDT-to-IAI group at baseline and at week 4, 8, 16 and 24, followed by 2 mg IAI at week 28, 32, 36, 40, 48. The primary outcome of efficacy were the change in mean Best Corrected Visual Acuity (BCVA) from baseline to week 28, and that of week 52. Safety evaluation included the percentage of subjects who suffered treatment emergent adverse events (TEAEs).ResultsAmong the 304 subjects enrolled, there were 228 and 76 cases in IAI group and PDT-to-IAI group respectively. At week 28, the changes of mean BCVA in IAI group, PDT-to-IAI group compared to baseline were +14.0, +3.9 letters, respectively. At week 52, the changes of mean BCVA in two groups were +15.2, +8.9 letters respectively with the difference of +6.2 letters (95%CI 2.6−9.9, P=0.000 9). At week 52, the mean foveal retinal thickness in the two groups decreased by −189.6, −170.0 μm, respectively. Subjects with the most BCVA increase in IAI group were those aged ＜65, and those with active CNV lesion area ＜50% of total lesion area. The most common TEAEs in IAI group and PDT-to-IAI group are macular fibrosis [11.8% (27/228), 6.6% (5/76)] and BCVA decline [6.6% (15/228), 21.1% (16/76)]. There were 3 cases of arterial thromboembolic events defined in the antiplatelet experimental collaboration group, but all were considered unrelated to interventions.ConclusionsThe efficacy of aflibercept is superior to that of PDT in nAMD patients in China. The therapeutic effect of aflibercept persisted to week 52 in all subjects. The rate of adverse events was consistent with the safety data of aflibercept known before.
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.
Purpose To evaluate shortterm visual acuity effects of a single photodynamic therapy(PDT) treatment with Visudyne (CIBA Vision Corp, Duluth, Ga) for choroidal neovascularization (CNV) in age-related macular degeneration (AMD). Methods Definitely diagnostic AMD patients with classic CNV were treated with PDT (5 cases, 7 eyes). The data of visual acuity testing, ophthalmic examination, color photographs, optic coherence tomography, fluorescein angiograms and indocyanine green angiogram before photodynamic therapy and 1 week ,1 month after it were used to evaluate the effects of a single treatment of PDT with Visudyne. Results The visual acuity of all the treated eyes at the follow-up examination at 1 month after PDT were not reduced. Distinct reduction of fluorescein leakage from CNV was noted in all patients by 1 week after PDT. Fluorescein leakage from a portion of the CNV reappeared by 1 month after treatment in 2 eyes. Conclusion PDT with Visudyne achieved short-term cessation of fluorescein leakage from CNV without loss of vision or growth of classic CNV in some patwo ients with AMD. (Chin J Ocul Fundus Dis,2000,16:213-216)