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 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.
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)
Purpose To measure and compare the difference of multifocal electroretinogram in normal subjects and patients with age-related macular degeneration. Methods Seventeen cases(20 eyes)of normal subjects,7 cases(10 eyes)of dry form AMD(age-related macular degeneration),8 cases(8 eyes)of wet-form AMD and 11 cases(11 eyes)of idiopathic macular hole(IMH)were tested with VERIS SciencesTM 4.0 made by EDI company of America.The latencies and average response densities of 6 ring retinal regions in normal subjects were compared with those in various types of age-related maculopathies. Results The N1 and P1 wave latencies of all 6 rings in wet-form AMD and the N1 wave latencies of 3～6 rings in dry-form AMD were delayed statistically.The N1 and P1 wave average response densities of 1～4 rings in and the P1 wave average response densities of 1-6 rings wet-form AMD and the N 1 wave average response densities of 1～5 and the P1 wave average response densties of 1-6 rings in dry-form AMD were decreased statistically.The N1 and P1 wave average response densities of 1～2 and the P1 wave average esponse densities of 1～3 rings were decrease statistically in IMH. Conclusion Multifocal electroretinogram can be used to quantitate the visual function of the affected location in age-related macular degeneration. (Chin J Ocul Fundus Dis,2000,16:224-226)
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 compare the characteristics of the ocular fundus of exudative age-related macular degeneration (AMD) with polypoidal choroidal vasculopathy (PCV). Methods The photographs of ocular fundus of 123 patients (137 eyes) with exudative AMD and 42 patients (48 eyes) with PCV diagnosed by fundus photography, fundus fluorescein angiography (FFA), and indocyanine green angiography (ICGA) were retrospectively analyzed. Results In 137 eyes with exudative AMD, 16 eyes (11.7%) had classic neovascularization (CNV), 121 (88.3%) had occult CNV. In the eyes with occult CNV, 42 eyes (34.7%) had hot spots, 74 eyes (61.2%) showed plaque hyperfluorescences and 2 eyes (1.7%) had hot spots with PCV in ICGA. In 48 eyes with PCV, 7 eyes (14.6%) had subretinal reddish-orange lesions, 2 eyes (4.2%) of the polypoidal dilations with branching vascular network were detected with FFA, 36 eyes (75.0%) demonstrated polypoidal dilations with branching vascular network, and 12 eyes (25.0%) showed scattered polypoidal dilations without identifiable continuous branching vascular network, 16 eyes (33.3%) had the polypoidal dilations resembling a cluster of grapes, and 32 eyes (66.3%) showed the polypoidal dilations as several solitary round aneurismal dilations. The polypoidal dilations showed either a washout of the dye from the polyp with staining of its walls or staining of the dye in the late phase of ICGA. Conclusions The different features of exudative AMD and PCV in the ICGA, and the PCV with subretinal reddish-orange lesions are useful in the differentiate diagnosis of the both diseases. (Chin J Ocul Fundus Dis，2004，20：307-309)
Objective To verifying the characteristics of optical coherence tomography(OCT) in exudative age-related macular degeneration (AMD). Methods The patients being investigated in this series included 16 cases (19 eyes) of exudative age-related macular degeneration diagnosed by FFA and OCT examinations, among them 4 cases (6 eyes) were examined with ICGA. The color photographs of ocular fundi, FFA, ICGA and OCT were investigated by contrasting each other. Results As compared with the FFA and ICGA examinations, the characteristic findings found in OCT in patients with exudative AMD in this series were as the following:①serous detachment of neurosensory epithelium in 11 eyes,②retinal hemorrhage in 2 eyes,③serous detachment of retinal pigment epithelium in 5 eyes,④hemorrhagic detachment of retinal pigment epithelium in 10 eyes,⑤disciform scar in 4 eyes,⑥fibrovascular pigment epithelial detachment and occult CNV in 12 eyes. Conclusion OCT can supply a comprehensive survey of exudative AMD, in making the diagnosis as an important complementary examination of FFA and ICGA. (Chin J Ocul Fundus Dis,2000,16:220-223)
Objective To investigate the manifestations of indocyanine green an giography (ICGA) of the choroidal neovascular membrane (CNV) and the relationship with histopathological changes in patients with age-related macular degeneration (AMD). Methods Twenty-one eyes of 21 patients with AMD diagnosed by ICGA were classified into three types based on ICGA findings: developing type in 9 eyes , degenerating type in 9, and stabilizing type in 3. CNV was extracted by vitrectomy and the histopathological characteristics of CNV was observed under the light and electron microscope. Results The histopathological characteristics of the specimens of developing type revealed abundant CNV partly enwrapped with non-pigmental cells and fibrous tissue or a few pigmental cells; degenerating type revealed reduced activation duration of CNV, many pigmental cells and a little fibrous tissue; stabilizing type revealed a mass of fibrous tissue，few CNV and nonexistence of pigmental cells. Conclusion The histopathological characteristics of exudative AMD may be related to the manifestations of ICGA. (Chin J Ocul Fundus Dis，2004，20：71-74)
Objective To investigate the relationship between lipid deposition in the Bruch's membrane and the retinal pigment epithelium(RPE)cells and age,and characteristics of lipid deposition in the age-related macular degeneration(AMD). Methods Thirty-two normal eyes from dead people aged 20 days to 84 years and 2 AMD eyes from corpses were examined by using histochemistry stains to identify characteristics of lipid depositi on in the Bruch's membrane and the retinal pigment epithelium(RPE)cells. Results In the normal eyes,lipid deposition in the Bruch's membrane increased with aging,especially in the macular region.The main composition of the lipid deposition was neutral lipid.AMD eyes were more intensively stained than normal aged eyes,especially in the macular region. Conclusion Lipid deposition distributed in the same regions both in normal and AMD eyes in the elderly,which may play an important role in the aging process and the development of AMD.Stain of RPE increasing with aging may reflect the deposition of lipofuscin in the cells. (Chin J Ocul Fundus Dis,1999,15:84-87)