The hallmark lesions of age-related macular degeneration (AMD) are drusen and basal linear deposit which are lipid substances deposited in Bruch membrane or the compartment on the Bruch membrane. There is a prevailing hypothesis that lipid and its oxidized derivant deposited in retina may have important roles in the pathogenesis of AMD. Lipid oxidation products are toxic, may affect the adjacent cells, induce inflammation, and trigger neovascularization.7-ketocholestoral (7KCh), a naturally occurring oxidized form of cholesterol, had been found to be toxic to retinal cells and able to induce chronic inflammation, which may play a critical role in the development of AMD. However the precise mechanism remains to be elucidated. Thus we will make a brief review of 7KCh and its association with AMD.
Objective
To analyse the indocyanine green angiographic findings in contralateral eyes of patients with unilateral exudative age-related macular degeneration(AMD).
Methods
Fundus photograph,fundus fluorescein angiography(FFA) and indocyanine green angiography(ICGA) were performed in a series of 70 patients with unilateral AMD and drusens and pigmentary changes in the macular region in contralateral eyes.The findings of fluoroangiograms were observed and analysed.
Results
ICGA revealed the characteristics of the contralateral eyes as follows:(1)Drusen could be hypofluorescent,hyperfluorescent or normal fluorescent;(2)14 eyes revealed plaque-like late hyperfluorescent;(3)13 eyes revealed choroidal filling defect;(4)18 eyes revealed pindot-like clusters of late hyperfluorescence.
Conclusion
ICGA is useful in evaluating the lesions and circulation disturbance of the contralateral eye,and may help to find the risk factors of developing future exudative changes.
(Chin J Ocul Fundus Dis, 1999, 15: 216-218)
Objective To observe the optical coherence tomography (OCT) features of Best vitelliform macular dystrophy (BVMD) at different stages.Methods Twenty-eight BVMD patients (56 eyes) were enrolled in this study. All the patients were examined for visual acuity, slit-lamp microscopy, direct ophthalmoscope, fundus photography, electrooculogram, fundus fluorescein angiography (FFA) and OCT. Fifty-six eyes were classified into stage 0 (eight eyes)、Ⅰ (two eyes)、Ⅱ(10 eyes)、Ⅱa （12 eyes）、Ⅲ (six eyes) 、Ⅳa (six eyes)、Ⅳb (five eyes) and Ⅳc (seven eyes) accordingly. The OCT features of BVMD at different stages were observed.Results The OCT results showed that the macular area was normal in eyes of stage 0; disturbance of retinal pigment epithelium (RPE) and subretinal hyporeflective area were found in eyes of stage I; the location of the yellowish material between RPE and the inner segment and outer segment (IS/OS) with normal appearance in RPE and IS/OS interface were found in eyes of stage Ⅱ. In all the other progressing stages from Ⅱa、Ⅲ and Ⅳ, the vitelliform material appeared as a thicker highly reflective lesion located between the outer nuclear layer and RPE layer, usually accompanied by optical hyporeflective lesion. Images of stage Ⅳc were in similar appearance besides edema of retina. OCT images of Ⅳb stage were demonstrated atrophy of retinal layer and IS/OS loss with fibrosis. Conclusions OCT demonstrated the location of the yellowish material between RPE and IS/OS. Optical hyporeflective lesion between the outer nuclear layer and RPE layer accompanied thicker highly reflected lesion might be the characteristic image in stages II a to IV of BVMD.
Objective To investigate the clinical characte ristic of vernier acuity in age-related macular degeneration (AMD) patients. Methods The vernier acuity test soft wear system was developed to detect the 23 cases (39 eyes) of AMD patients. Tweenty-one eyes were atrophic type and 17 eyes were exudative type. Two fixed targets and a movable target are shown on the computer screen. The examinee was asked to adjust the position of the central target and the relationship between it and align them by using a track ball. The computer automatically recorded the deviations of distances between the movable target and the specific one, and then computed and analysed the results of average threshold and variance.Results Both the atrophic and exudative AMD had higher vernier acuity threshold and its variance than normal subjects, and the differences were significant (P＜0.01). The correlation coefficient between visual acuity and vernier acuity threshold was -0.78, and that between visual acuity and threshold variance was -0.80. The results suggest that vernier acuity thre shold and its variance were reliable parameters that reflect the visual acuity in AMD patients.Conclusions The results suggest that vernier acuity threshold and its variance were reliable parameters that reflect the visual acuity in AMD patients.(Chin J Ocul Fundus Dis，2003，19：201-268)
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.
Age-related macular degeneration is one of the major causes of blindness in the elderly. As an important pathway of cell metabolism, autophagy maintains intracellular homeostasis through the degradation and recycle of damaged organelles and macromolecules. Understanding its mechanism may promote discoveries to delay aging process, reduce the incidence of age-related diseases. In mammals, silent information regulator protein 6 (SIRT6) plays its deacetylase and ribonucleotransferase activity in multiple signaling pathways, including inhibition of cellular senescence, tumorigenesis, metabolic diseases, regulating cellular lifespan. It has a significant impact on the structure and function of tissues and organs. SIRT6 regulates intracellular autophagy mainly through the insulin-like growth factor-protein kinase B-mammalian target of rapamycin, reducing the accumulation of toxic metabolites and cellular senescence. The function of SIRT6 in age-related macular degeneration need to be combined with the genetic background, pathogenesis, clinical manifestations and other aspects of the disease, and it is expected to be further studied in subsequent studies.
ObjectiveTo establish an artificial intelligence robot-assisted diagnosis system for fundus diseases based on deep learning optical coherence tomography (OCT) and evaluate its application value. MethodsDiagnostic test studies. From 2016 to 2019, 25 000 OCT images of 25 000 patients treated at the Eye Center of the Second Affiliated Hospital of Zhejiang University School of Medicine were used as training sets and validation sets for the fundus intelligent assisted diagnosis system. Among them, macular epiretinal membrane (MERM), macular edema, macular hole, choroidal neovascularization (CNV), and age-related macular degeneration (AMD) were 5 000 sheets each. The training set and the verification set are 18 124 and 6 876 sheets, respectively. Through the transfer learning Attention ResNet structure algorithm, the OCT image was characterized by lesion identification, the disease feature was extracted by a specific procedure, and the given image was distinguished from other types of disease according to the statistical characteristics of the target lesion. The model algorithms of MERM, macular edema, macular hole, CNV and AMD were initially formed, and the fundus intelligent auxiliary diagnosis system of five models was established. The performance of each model-assisted diagnosis in the fundus intelligent auxiliary diagnostic system was evaluated by applying the subject working characteristic curve, area under the curve (AUC), sensitivity, and specificity. ResultsWith the intelligent auxiliary diagnosis system, the diagnostic sensitivity of the MERM was 93.5%, the specificity was 99.23%, and AUC was 0.983 7; the diagnostic sensitivity of macular edema was 99.02%, the specificity was 98.17%, and AUC was 0.994 6; the diagnostic sensitivity of macular hole was 98.91%, the specificity was 99.91%, AUC was 0.996 2; the diagnostic sensitivity of CNV was 97.54%, the specificity was 94.71%, AUC was 0.987 5; the diagnostic sensitivity of AMD was 95.12%, the specificity was 97.09%, AUC was 0.985 3. ConclusionsThe artificial intelligence robot-assisted diagnosis system for fundus diseases based on deep learning for OCT images has accurate and efficient diagnostic performance for assisting the diagnosis of MERM, macular edema, macular hole, CNV, and AMD.
Objective To observe the clinical features of polypoidal choroidal vasculopathy (PCV) in Chinese patients.Methods Nine cases (9 eyes ) were examined with fundus examination, fundus fluorescein angiography (FFA) and indocyanine green angiography angiography (ICGA).Results FFA and ICGA showed the branching vascular networks (7 cases) and polyplike dilation at terminals of branches (9 cases), which mainly located in macular area (8 cases) and in peripapillary area (1 case), and which accompanied hemorrhagic or serous pigment epithelial detachment in 7 cases,and 4 of 7 cases had a significant horizontal black-white damarcation line. It definitely differed from fine choroidal neovascularization (CNV).Conclusion PCV in Chinese patients has the cardinal clinical features, i.e., polyplike lesions located mainly in macular area and most cases accompanied by hemorrhagic or serous pigment epithelium detachment. (Chin J Ocul Fundus Dis，2003，19：269-332)
Objective
To investigate the method and the effects of the surgical treatment of massive subretinal hemorrhage and vitreous hemorrhage associated with age-related macular degeneration.
Methods
A retrospective study of 14 consecutive patients underwent a complete pars plana vitrectomy. Retinotomy was carried out for removing subretinal hemorrhage by using balanced salt solution. Complete air-fluid exchange and gas or silicone oil tamponade were performed in all patients. The follow-up period was within 3～7 months.
Results
Atrophy of eyeball in 2 eyes (14.3%) postoperatively. Improvement of corrected final visual acuity and anatomical retinal reattachment were achieved in 12 (85.7%) of the 14 eyes postoperatively. Seven days after operation, muddy-sand-hemorrhage in anterior chamber occurred in 4(28.6%)of the eyes and paracenteses of anterior chamber were performed for these eyes.
Conclusion
Surgical intervention should be applied in the eyes with the massive subretinal hemorrhage associated with age-related macular degeneration in order to avoid the affected eyes becoming atrophic due to the subsequent complication of vitreous hemorrhage, anterior chamber muddy sand hemorrhage,ghost cell-glaucoma or retinal detachment.
(Chin J Ocul Fundus Dis,2000,16:217-219)
