Objective To observe the pathological changes of branch retinal artery occlusion (BRAO) by optical coherence tomography (OCT). Methods Twenty-six eyes of 26 patients with BRAO diagnosed in our Center from December 2002 to June 2005 were examined by OCT. The intervals of disease onsets and OCT examinations in all patients were within 2 weeks. The OCT scan modes were horizontal or vertical lines, and the locations of OCT scanning were macular area and the posterior pole of retina. The retinal thicknesses of macular foveola were measured and the macular thicknesses in different obstructive locations were compared using ANOVA analysis. The correlations of visual acuity and retinal thickness were analyzed by Pearson correlation analysis. Results Among the 26 eyes with BRAO, 9 eyes with temporosuperior artery occlusion, 8 eyes with temporoinferior artery occlusion, 7 eyes with arteriole occlusion and 2 eyes with retinal ciliary artery occlusion were observed. The pathological characteristics of OCT images of BRAO were increased retinal thickness and reflectivity in the obstructive locations, and widened dark area of photoreceptors (edema), while there was no obvious foveal edema were observed. The retinal images in other locations were normal. The average macular foveal thickness in the groups of temporosuperior artery occlusion, temporoinferior artery occlusion and retina arteriole occlusion were (161.11plusmn;17.66) mu;m, (148.38plusmn;18.48) mu;m and (136.29plusmn;14.94) mu;m, respectively (F=4.137,P=0.031,Pgt;0.01). There was no correlation of visual acuity with retinal thickness in 24 eyes (r＝0.285，P＝0.176，Pgt;0.01). Conclusion OCT could display the pathological changes of retinal tissue of BRAO in vivo. The increases of macular foveal thicknesses in BRAO eyes are not so obvious, and no correlations could be seen between visual acuity and macular foveal thickness. OCT is indicated on the old patients and the patients with systemic diseases for whom FFA is contraindicated. The unique characteristics of pathological changes of BRAO indicated by OCT images supply the objective signs for the instant clinical diagnosis. (Chin J Ocul Fundus Dis, 2007, 23: 173-176)
Objective To investigate the characteristics of optical coherence tomography (OCT) images in idiopathic macular hole. Methods OCT、color photography and fundus fluorescein angiography were performed in 65 cases(70 eyes) of macular holes and which were then graded by connecting to their clinical characteristics. Results Among the 70 eyes the number of 1～4 stages of macular holes were 11,12,36 and 11 eyes respectively.In eyes of stage 1 OCT images showed flattening or disappearing of fovea and minimally reflective space within or beneath the neurosensory retina;stage 2 showed a fullthickness hole with an attached operculum and surrounding edema;stage 3 displayed a full-thickness hole with surrounding edema and stage 4 showed a full-thickness hole and a complete separation of the poterior hyaloid membrane from the retina.The dimeter of the macular holes in stage 2,3 and 4 were (241.75plusmn;107.08),(699.78plusmn;160.99), (631.36plusmn;243.46)mu;m,respectively. Conclusions OCT can display the characteristics of idiopathic macular holes and measure the diameters of holes quantitatively. (Chin J Ocul Fundus Dis, 1999, 15: 205-208)
Objective To study the characteristics of optic al coherence tomography (OCT) in idiopathic macular epiretinal membranes (IMEM) and the relationship between the thickness of fovea and the vision of affected eyes. Methods Total of 67 cases (73 eyes) with clinica l diagnosis of IMEM by direct, indirect ophthalmoscopy, three mirror contact len s, fundus color photography or fundus fluorescein angiography(FFA）were examined with OCT. Results Epiretinal membranes(ERMs) with macular edema were found in 32 eyes, proliferative ERMs in 20 eyes, ERMs with macular pseudoholes in 14 eyes and ERMs with laminar macular holes in 7 eyes. Based on OCT, the ERMs were clearly and partially seperated from the retina (27 eyes, 38.36%), the retinal thickness of the fovea was the thickest in proliferative ERMs and the thinnest in ERMs with laminar macular holes. The statistical an alysis showed there was a negative correlation between the thickness of fovea an d visual acuity (r=－0.454, P= 0.000 ). Conclusion There were four types of image of OCT in IMEM: ERMs with macularedema, proliferative ERMs, ERMs with macular pseudohole and ERMs with laminar macular hole；and the thicker the fovea under the OCT, the poorer th e visual acnity in the affected eyes with ERMs. (Chin J Ocul Fundus Dis, 2001,17:115-118)
In recent years, optical coherence tomography (OCT) has developed into a popular coronary imaging technology at home and abroad. The segmentation of plaque regions in coronary OCT images has great significance for vulnerable plaque recognition and research. In this paper, a new algorithm based on K-means clustering and improved random walk is proposed and Semi-automated segmentation of calcified plaque, fibrotic plaque and lipid pool was achieved. And the weight function of random walk is improved. The distance between the edges of pixels in the image and the seed points is added to the definition of the weight function. It increases the weak edge weights and prevent over-segmentation. Based on the above methods, the OCT images of 9 coronary atherosclerotic patients were selected for plaque segmentation. By contrasting the doctor’s manual segmentation results with this method, it was proved that this method had good robustness and accuracy. It is hoped that this method can be helpful for the clinical diagnosis of coronary heart disease.
Objective To analyze the pathogenesis of cystoid macular edema (CME) secondary to exudative age-related macular degeneration (AMD). Methods From October 2000 to December 2003, OCT images of 171 eyes of 140 patients with exudative AMD were evaluated. The CNV types were classified according to its location (above or below the RPE), and the correlation between the types of CNV and the development of CME were analyzed. Results Of the 171 eyes with AMD, 89 eyes (52.0%) had CME, and 82 eyes (48.0%) had no CME. Among the 89 eyes with CME, 76 eyes (85.4% ) had an active CNV lesion, and 13 eyes (14.6%) had a disciform scar. Among the 82 eyes without CME, 69 eyes (84.1%) had an active CNV lesion, and 13 eyes (15.9 %) had a disciform scar. In the 76 eyes with both CME and active CNV, 75 eyes (9 8.7%) had a subretinal CNV, which included 61 eyes (80.3%)with a combined CNV complex and 14 eyes (18.4%) with a Gass 2 type CNV, only 1 eye (1.3%) had a Gass 1 type CNV. Whereas, in the 69 eyes with active CNV but without CME, 57 eyes (82.6%) had a Gass 1 type CNV, only 12 eyes (17.4%) had a subretinal CNV. There was a significant difference in the incidence of subretinal CNV between eyes with or without CME (χ2=99.5838, P=0.0000). Conclusions CME formation was highly corre lated with the invasion of CNV into the subretinal space. Subretinal CNV might be the direct cause of CME secondary to exudative AMD.(Chin J Ocul Fundus Dis，2004，20：299-302)
Objective To investigate the characteristics of congenital retinoschisis of optical coherence tomography(OCT) and its clinical application. Methods Eight cases(15 eyes) which were diagnosed as or suspected to retinoschisis in clinic were examined by OCT,direct ophthalmoscopy and color fundus photograph.Three cases(6 eyes) were examined by electroretinogram(ERG) and fundus fluorescein angiography(FFA). Results The typical characteristic OCT images of congenital retinoschisis were cystic maculopathy with tilted and vertical connective filaments,typical split in innner retinal layers in posterior retina and thickening of neurosensory retina with the split of outer retinal layers in membranous remnants. Conclusions OCT can display the characteristics of congenital retinoschisis．It is potentially useful as a new technique for the diagnosis of congenital retinoschisis. (Chin J Ocul Fundus Dis, 1999, 15: 209-211)
Objective To observe the morphologic characters of macular lesions in patients with central retinal vein occlusion(CRVO) in optical coherence tomography(OCT). Methods Thirty-eight patients with the clinical diagnosis of CRVO were examined by OCT.Four scan lines traversing the fovea with the same length and the same angle gap were performed as the basic scan in every eye.Additional scan were selected according to individuals including changing the length or angle of the scan lines and selecting different diameter circle pattern scan. Results Cystoid macular edema (CME) was found in 15 eyes,detachment of the neurosensory retina in 6 eyes，thickened neurosesory retina in 11 eyes,slight intraretinal fluid in 4 eyes,and markedly thichened neurosensory retina in 2 eyes with secondary premacular membrane and intraretinal fluid. Conclusions The major OCT morphologic characters of macular lesions in patinets with CRVO may include:cystoid macular edema,detachment of neurosensory retina,and secondary premacular membrane and pigmentary epithelial changes.These would be helpful for diagnosing and evaluating macular lesion in CRVO. (Chin J Ocul Fundus Dis, 1999, 15: 201-204)
【摘要】 目的 探讨机械法准分子激光角膜上皮瓣下磨镶术（Epi-LASIK）对大视杯高度近视患者的视网膜神经纤维层 （RNFL）的影响。 方法 对2007年1月-2009年1月拟行Epi-LASIK手术的眼底杯盘比gt;0.5的44例44只眼行光相干断层扫描（OCT）检查，测量以视盘为中心、直径为3.4 mm的RNFL厚度， 以象限图分4个区域（上方、下方、颞侧、鼻侧）显示。并分别于手术前及手术后第10 天，1、3 个月，1、2年进行随访。对所测数据进行方差分析。 结果 RNFL厚度测量结果显示， 手术前上方、下方、鼻侧、颞侧RNFL厚度与手术后比较， 差异均无统计学意义（Pgt;0.05）。 结论 Epi-LASIK手术对大视杯近视的RNFL厚度无明显影响。【Abstract】 Objective To investigate the effects of Epi-LASIK on retinal nerve fiber layer (RNFL) thickness in patients with large cup. Methods Forty-four patients (44 eyes) with high myopia from January 2007 to January 2009, whose C /D area ratios were above 0.5, underwent optical coherence tomography(OCT)examination. To measure the RNFL thickness taking optic disk as the center, diameter as 3.4 mm, for quadrant graph as above, below, temporal, lateral. After the operation in the first 10 days, and one, three months, and one, two years after surgery were followed. The data were analyzed by analysis of variance. Results The RNFL thickness at every quadrant had no statistical significant difference between preoperative period and postoperative time(Pgt;0.05). Conclusion Epi-LASIK surgery has no effect on RNFL thickness in high myopic patients with large cup.