OCT is usually employed for the measurement of retinal thickness. However, coherent reflected light carries more information characterizing the optical properties of tissue. Therefore, optical property changes may pro...OCT is usually employed for the measurement of retinal thickness. However, coherent reflected light carries more information characterizing the optical properties of tissue. Therefore, optical property changes may provide further information regarding cellular layers and early damage in ocular diseases. We investigated the possibility of OCT in detecting changes in the optical backscattered signal from layered retinal structures. OCT images were obtained from diabetic patients without retinopathy (DM, n = 38 eyes) or mild diabetic retinopathy (MDR, n = 43 eyes) and normal healthy subjects (n = 74 eyes). The thickness and reflectivity of various layered structures were assessed using a custom-built algorithm. In addition, we evaluated the usefulness of quantifying the reflectivity of layered structures in the detection of retinal damage. Generalized estimating equations considering within-subject inter-eye relations were used to test for differences between the groups. A modified p value of <0.001 was considered statistically significant. Receiver operating characteristic (ROC) curves were constructed to describe the ability of each parameter to discriminate between the eyes of DM, MDR and healthy eyes. Thickness values of the GCL + IPL and OPL showed a significant decrease in the MDR eyes compared to controls. Significant decreases of total reflectance average values were observed in all layers in the MDR eyes compared with controls. The highest AUROC values estimated for the total reflectance were observed for the GCL+IPL, OPL and OS when comparing MDR eyes with controls. Total reflectance showed a better discriminating power between the MDR eyes and healthy eyes compared to thickness values. Our results suggest that the optical properties of the intraretinal layers may provide useful information to differentiate pathological from healthy eyes. Further research is warranted to determine how this approach may be used to improve diagnosis of early retinal neurodegeneration.展开更多
AIM:To compare thickness and reflectivity spectral domain optical coherence tomography(SD-OCT)findings in patients with idiopathic epiretinal membranes(ERMs),before and after ERM peeling surgery,with normal contr...AIM:To compare thickness and reflectivity spectral domain optical coherence tomography(SD-OCT)findings in patients with idiopathic epiretinal membranes(ERMs),before and after ERM peeling surgery,with normal controls.·METHODS:A retrospective study analyzing SD-OCTs of eyes with ERMs undergoing ERM peeling surgery by one surgeon from 2008 to 2010 and normal control eyes.SD-OCTs were analyzed using a customized algorithm to measure reflectivity and thickness.The relationship between the SD-OCT findings and best corrected visual acuity(BCVA)outcomes was also studied.·RESULTS:Thirty-four ERM eyes and 12 normal eyes were identified.Preoperative eyes had high reflectivity and thickness of the group of layers from the internal limiting membrane(ILM)to the retinal pigment epithelium(RPE)and the group of layers from the ILM to the external limiting membrane(ELM).The values of reflectivity of these two groups of layers decreased postoperatively,but were still higher than normal eyes.In contrast,preoperative eyes had lower reflectivity of two10×15 pixel regions of interest(ROIs)incorporating:1)ELM+outer nuclear layer(ONL)and 2)photoreceptor layer(PRL)+RPE,compared to controls.The values of reflectivity of these ROIs increased postoperatively,but were still lower than normal controls.A larger improvement in BCVA postoperatively was correlated with a greater degree of abnormal preoperative reflectivity and thickness findings.·C ONCLUSION:Quantitative differences in reflectivity and thickness between preoperative,postoperative,and normal SD-OCTs allow assessment of changes in the retina secondary to ERM.Our study identified hyperreflective inner retina changes and hyporeflective outer retina changes in patients with ERMs.SD-OCT quantitative measures of reflectivity and/or thickness of specific groups of retinal layers and/or ROIs correlate with improvement in BCVA.展开更多
AIM:To evaluate a high-resolution functional imaging device that yields quantitative data regarding macular blood flow and capillary network features in eyes with diabetic retinopathy(DR).METHODS:Prospective,cross-sec...AIM:To evaluate a high-resolution functional imaging device that yields quantitative data regarding macular blood flow and capillary network features in eyes with diabetic retinopathy(DR).METHODS:Prospective,cross-sectional comparative case-series in which blood flow velocities(BFVs)and noninvasive capillary perfusion maps(nCPMs)in macular vessels were measured in patients with DR and in healthy controls using the Retinal Functional Imager(RFI)device.RESULTS:A total of 27 eyes of 21 subjects were studied[9 eyes nonproliferative diabetic retinopathy(NPDR),9 eyes proliferative diabetic retinopathy(PDR)and 9 controls].All diabetic patients were type 2.All patients with NPDR and 5 eyes with PDR also had diabetic macular edema(DME).The NPDR group included eyes with severe(n=3)and moderate NPDR(n=6),and were symptomatic.A significant decrease in venular BFVs was observed in the macular region of PDR eyes when compared to controls(2.61±0.6 mm/s and 2.92±0.72 mm/s in PDR and controls,respectively,P=0.019)as well as PDR eyes with DME compared to NPDR eyes(2.36±0.51 mm/s and 2.94±1.09 mm/s in PDR with DME and NPDR,respectively,P=0.01).CONCLUSION:The RFI,a non-invasive imaging tool,provides high-resolution functional imaging of the retinal microvasculature and quantitative measurement of BFVs in visually impaired DR patients.The isolated diminish venular BFVs in PDR eyes compared to healthy eyes and PDR eyes with DME in comparison to NPDR eyes may indicate the possibility of more retinal vein compromise than suspected in advanced DR.展开更多
基金supported in part by a Juvenile Diabetes Research Foundation grant(JDRF 2007-727)a NIH center grant P30-EY014801Department of Defense(DOD-Grant#W81XWH-09-1-0675)and by an unrestricted grant to the University of Miami from Research to Prevent Blindness,Inc.
文摘OCT is usually employed for the measurement of retinal thickness. However, coherent reflected light carries more information characterizing the optical properties of tissue. Therefore, optical property changes may provide further information regarding cellular layers and early damage in ocular diseases. We investigated the possibility of OCT in detecting changes in the optical backscattered signal from layered retinal structures. OCT images were obtained from diabetic patients without retinopathy (DM, n = 38 eyes) or mild diabetic retinopathy (MDR, n = 43 eyes) and normal healthy subjects (n = 74 eyes). The thickness and reflectivity of various layered structures were assessed using a custom-built algorithm. In addition, we evaluated the usefulness of quantifying the reflectivity of layered structures in the detection of retinal damage. Generalized estimating equations considering within-subject inter-eye relations were used to test for differences between the groups. A modified p value of <0.001 was considered statistically significant. Receiver operating characteristic (ROC) curves were constructed to describe the ability of each parameter to discriminate between the eyes of DM, MDR and healthy eyes. Thickness values of the GCL + IPL and OPL showed a significant decrease in the MDR eyes compared to controls. Significant decreases of total reflectance average values were observed in all layers in the MDR eyes compared with controls. The highest AUROC values estimated for the total reflectance were observed for the GCL+IPL, OPL and OS when comparing MDR eyes with controls. Total reflectance showed a better discriminating power between the MDR eyes and healthy eyes compared to thickness values. Our results suggest that the optical properties of the intraretinal layers may provide useful information to differentiate pathological from healthy eyes. Further research is warranted to determine how this approach may be used to improve diagnosis of early retinal neurodegeneration.
基金Supported in part by NIH R01EY008684-10S1(Bethesda,Maryland)Stanley J.Glaser Foundation Biomedical Research Support Grant(Miami,Florida)+2 种基金NIH Center Core Grant P30EY014801(Bethesda,Maryland)Research to Prevent Blindness Unrestricted Grant(New York,New York)the Department of Defense(DOD Grant#W81XWH-09-1-0675)(Washington,DC)
文摘AIM:To compare thickness and reflectivity spectral domain optical coherence tomography(SD-OCT)findings in patients with idiopathic epiretinal membranes(ERMs),before and after ERM peeling surgery,with normal controls.·METHODS:A retrospective study analyzing SD-OCTs of eyes with ERMs undergoing ERM peeling surgery by one surgeon from 2008 to 2010 and normal control eyes.SD-OCTs were analyzed using a customized algorithm to measure reflectivity and thickness.The relationship between the SD-OCT findings and best corrected visual acuity(BCVA)outcomes was also studied.·RESULTS:Thirty-four ERM eyes and 12 normal eyes were identified.Preoperative eyes had high reflectivity and thickness of the group of layers from the internal limiting membrane(ILM)to the retinal pigment epithelium(RPE)and the group of layers from the ILM to the external limiting membrane(ELM).The values of reflectivity of these two groups of layers decreased postoperatively,but were still higher than normal eyes.In contrast,preoperative eyes had lower reflectivity of two10×15 pixel regions of interest(ROIs)incorporating:1)ELM+outer nuclear layer(ONL)and 2)photoreceptor layer(PRL)+RPE,compared to controls.The values of reflectivity of these ROIs increased postoperatively,but were still lower than normal controls.A larger improvement in BCVA postoperatively was correlated with a greater degree of abnormal preoperative reflectivity and thickness findings.·C ONCLUSION:Quantitative differences in reflectivity and thickness between preoperative,postoperative,and normal SD-OCTs allow assessment of changes in the retina secondary to ERM.Our study identified hyperreflective inner retina changes and hyporeflective outer retina changes in patients with ERMs.SD-OCT quantitative measures of reflectivity and/or thickness of specific groups of retinal layers and/or ROIs correlate with improvement in BCVA.
文摘AIM:To evaluate a high-resolution functional imaging device that yields quantitative data regarding macular blood flow and capillary network features in eyes with diabetic retinopathy(DR).METHODS:Prospective,cross-sectional comparative case-series in which blood flow velocities(BFVs)and noninvasive capillary perfusion maps(nCPMs)in macular vessels were measured in patients with DR and in healthy controls using the Retinal Functional Imager(RFI)device.RESULTS:A total of 27 eyes of 21 subjects were studied[9 eyes nonproliferative diabetic retinopathy(NPDR),9 eyes proliferative diabetic retinopathy(PDR)and 9 controls].All diabetic patients were type 2.All patients with NPDR and 5 eyes with PDR also had diabetic macular edema(DME).The NPDR group included eyes with severe(n=3)and moderate NPDR(n=6),and were symptomatic.A significant decrease in venular BFVs was observed in the macular region of PDR eyes when compared to controls(2.61±0.6 mm/s and 2.92±0.72 mm/s in PDR and controls,respectively,P=0.019)as well as PDR eyes with DME compared to NPDR eyes(2.36±0.51 mm/s and 2.94±1.09 mm/s in PDR with DME and NPDR,respectively,P=0.01).CONCLUSION:The RFI,a non-invasive imaging tool,provides high-resolution functional imaging of the retinal microvasculature and quantitative measurement of BFVs in visually impaired DR patients.The isolated diminish venular BFVs in PDR eyes compared to healthy eyes and PDR eyes with DME in comparison to NPDR eyes may indicate the possibility of more retinal vein compromise than suspected in advanced DR.