Publications (8)24.11 Total impact
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Article: Vitreoschisis in macular diseases.
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ABSTRACT: Vitreoschisis is a possible pathogenic mechanism in macular diseases. Thus, the vitreoretinal interface was evaluated in monkey eyes and patients with various macular diseases in search of vitreoschisis. It is hypothesised that vitreoschisis is present in macular holes (MH) and macular pucker (MP), but not in other maculopathies. Histopathology was studied in 14 monkey eyes and a vitrectomy specimen of a patient with macular pucker. Optical coherence tomography/scanning laser ophthalmoscopy (OCT/SLO) was performed in 239 eyes: 45 MH, 45 MP, 51 dry age-related macular degeneration (AMD), 53 non-proliferative diabetic retinopathy (NPDR) and 45 controls. Immunohistochemistry demonstrated lamellae in the posterior vitreous cortex of 12/14 (86%) monkey eyes. With OCT/SLO, vitreoschisis was detected in 24/45 (53%) MH and 19/45 (42%) MP eyes, but in only 7/53 (13%) NPDR, 3/51 (6%) AMD and 3/45 (7%) control eyes (p<0.001 for all comparisons). Rejoining of the inner and outer walls of the split posterior vitreous cortex was visible in 16/45 (36%) MH eyes and 15/45 (33%) MP eyes. Histopathology of the MP specimen confirmed a split with rejoining in the posterior vitreous cortex. Vitreoschisis was detected in half of eyes with MH and MP, but much less frequently in controls, AMD and NPDR patients. These findings suggest that anomalous PVD with vitreoschisis may be pathogenic in MH and MP.The British journal of ophthalmology 03/2011; 95(3):376-80. · 2.92 Impact Factor -
Article: Correlation between fluorescein angiography and spectral-domain optical coherence tomography in the diagnosis of cystoid macular edema.
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ABSTRACT: To compare the ability to detect cystoid macular edema (CME) and its late complications between spectral-domain optical coherence tomography (SD-OCT) and fluorescein angiography (FA). Retrospective, observational, case series. 85 Eyes who had FA and SD-OCT performed on the same day at first visit and/or at follow-up visits were included. FA and SD-OCT images were evaluated for the evidences associated with CME and other structural changes of macula. FA and SD-OCT images were then superimposed to determine the relationships of diagnostic features between the two images. Main outcome measure was the correlation between FA and SD-OCT findings of macula in patients with CME. The common causes of CME in our study were retinal vein occlusion (RVO, 63%), diabetic retinopathy (DR, 21.18%) and posterior uveitis (3.53%). CME associated with RVO, age-related macular degeneration and DR were missed by FA in 18.52%, 33.33% and 33.33% of cases, respectively. Subretinal fluid was undetectable by FA in 54.55%, which mainly were in the RVO group. SD-OCT gave earlier CME diagnosis than FA in three (3.53%) eyes. Residual CME at follow-up visits were missed by FA in one (1.18%) eye. Late complications of long-standing CME (secondary macular hole (two eyes), secondary subretinal fluid (five eyes), retinal pigment epithelium detachment (one eye) and photoreceptor atrophy (one eye)) were detectable only by SD-OCT. SD-OCT demonstrated greater sensitivity than FA in detecting CME, particularly those associated with RVO, DR and age-related macular degeneration. SD-OCT was also more sensitive than FA for detecting subretinal fluid and late complications of long-standing CME.The British journal of ophthalmology 12/2009; 94(9):1197-200. · 2.92 Impact Factor -
Article: Multidimensional en-face OCT imaging of the retina.
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ABSTRACT: Fast T-scanning (transverse scanning, en-face) was used to build B-scan or C-scan optical coherence tomography (OCT) images of the retina. Several unique signature patterns of en-face (coronal) are reviewed in conjunction with associated confocal images of the fundus and B-scan OCT images. Benefits in combining T-scan OCT with confocal imaging to generate pairs of OCT and confocal images similar to those generated by scanning laser ophthalmoscopy (SLO) are discussed in comparison with the spectral OCT systems. The multichannel potential of the OCT/SLO system is demonstrated with the addition of a third hardware channel which acquires and generates indocyanine green (ICG) fluorescence images. The OCT, confocal SLO and ICG fluorescence images are simultaneously presented in a two or a three screen format. A fourth channel which displays a live mix of frames of the ICG sequence superimposed on the corresponding coronal OCT slices for immediate multidimensional comparison, is also included. OSA ISP software is employed to illustrate the synergy between the simultaneously provided perspectives. This synergy promotes interpretation of information by enhancing diagnostic comparisons and facilitates internal correction of movement artifacts within C-scan and B-scan OCT images using information provided by the SLO channel.Optics Express 04/2009; 17(5):4112-33. · 3.59 Impact Factor -
Article: Correlation between spectral domain optical coherence tomography findings and fluorescein angiography patterns in diabetic macular edema.
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ABSTRACT: To study the relationship between spectral domain optical coherence tomography (SD-OCT) findings and fluorescein angiography (FA) patterns in patients with diabetic macular edema (DME). Retrospective, observational, cross-sectional study. We included 59 eyes from 59 patients with DME that had SD-OCT/scanning laser ophthalmoscope (SLO) and FA performed on the same day. Eyes with macular edema owing to other ocular diseases were excluded. The relationship between SD-OCT and FA findings was evaluated by superimposing and aligning the SLO images onto the FA photos. The SLO image of the OPKO/OTI Spectral OCT/SLO (OPKO-OTI, Miami, FL) corresponds with the exact origin and orientation of the SD-OCT scan, which was then correlated with the FA image. Foveal and extrafoveal regions were studied separately. Leakage on FA and pathologic changes on OCT were graded by using standard photographs. Pathologic changes studied in the OCT images included edema and cystic spaces in the inner and outer retina, loss of retinal layers, and foveal cysts. Correlation between SD-OCT changes and corresponding FA patterns. The outer retina was the predominant location of fluid in DME. The severity of the outer retinal edema on OCT was positively correlated with the severity of leakage on FA (r = 0.735; P<0.001). Cystic changes in the inner and outer retina were also correlated with the severity of fluorescein leakage (r = 0.507 and P<0.001; r = 0.561 and P<0.001, respectively). Loss of inner retinal layers on OCT was highly correlated with capillary nonperfusion on FA (r = 0.953; P<0.001). Large foveal cysts on SD-OCT corresponded to cystoid leakage patterns on FA. Pathologic changes on SD-OCT correlated well with FA findings. Loss of inner retinal layers was specifically correlated with capillary nonperfusion and severe ischemia. Judgment of whether management of DME based on fine retinal structural changes influences clinical outcomes must be reserved pending further investigation with prospective trials. Proprietary or commercial disclosure may be found after the references.Ophthalmology 04/2009; 116(6):1158-67. · 5.45 Impact Factor -
Article: Imaging vitreomacular interface abnormalities in the coronal plane by simultaneous combined scanning laser and optical coherence tomography.
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ABSTRACT: To describe vitreoretinal imaging of eyes with vitreomacular abnormalities using high-resolution coronal-plane optical coherence tomography (OCT) scanning combined with simultaneous scanning laser ophthalmoscope (SLO) imaging. A SLO-OCT (OTI, Canada) was used to scan 835 eyes in 736 patients with vitreomacular interface abnormalities including epiretinal membranes, macular hole, incomplete posterior vitreous detachment, vitreomacular traction syndromes and diabetic and cystoid macular oedema in a retrospective study. The longitudinal-B scan images and the transverse -C scan images in the coronal plane were used to describe vitreomacular interface abnormalities. The SLO-OCT simultaneously produces a confocal image of the retina. The longitudinal "B" scan and en-face "C" scan images allowed identification of tractive forces of epiretinal membrane, contour of the hyaloid membrane and changes in inner retinal surface. A simultaneously obtained OCT scan and SLO image of the fundus offered exact co-localisation of retinal structures and vitreomacular interface abnormalities. Scanning the vitreomacular interface by using combined OCT and SLO enables the visualisation and better understanding of various vitreomacular interface abnormalities, due to the ability to colocalise pathology on OCT with retinal vascular landmarks and the ability to visualise pathology from a new perspective, coronal plane parallel to retinal surface.The British journal of ophthalmology 12/2008; 93(3):366-72. · 2.92 Impact Factor -
Article: Macular holes and macular pucker: the role of vitreoschisis as imaged by optical coherence tomography/scanning laser ophthalmoscopy.
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ABSTRACT: The pathogenesis of macular pucker and macular holes is poorly understood. Anomalous posterior vitreous detachment (PVD) and vitreoschisis have been proposed as possible mechanisms. This study used clinical imaging to seek vitreoschisis and study the topographic features of macular pucker and macular holes. Combined optical coherence tomography and scanning laser ophthalmoscopy (OCT/SLO) was performed in 45 eyes with macular hole and 44 eyes with macular pucker. Longitudinal imaging was used to identify vitreoschisis and measure retinal thickness. The topographic features of eyes with macular hole with eccentric macular contraction were compared to 24 eyes with unifocal macular pucker using coronal plane imaging. Vitreoschisis was detected in 24 of 45 eyes (53.3%) with macular hole and 19 of 44 (43.2%) with macular pucker. Retinal contraction was detected eccentrically in the macula of 18 of 45 eyes (40%) with macular hole. In eyes with macular hole with unifocal retinal contraction, the average surface area of contraction (23.12 +/- 18.79 mm(2)) was significantly smaller than in eyes with macular pucker (63.20 +/- 23.68 mm(2); P = .006). The distance from the center of retinal contraction to the center of the macula was significantly greater in eyes with macular hole (8.64 +/- 2.33 mm) than eyes with macular pucker (4.45 +/- 1.90 mm; P = .0001). Vitreoschisis was detected in about half of all eyes with macular hole and macular pucker. The topographic and structural features in eyes with macular hole with retinal contraction differed in comparison to eyes with macular pucker alone, suggesting that although each condition may begin with anomalous PVD, differences in subsequent cell migration and proliferation probably result in the different clinical appearances detected in this study.Transactions of the American Ophthalmological Society 02/2007; 105:121-9; discusion 129-31. -
Article: Investigations of the eye fundus using a simultaneous optical coherence tomography/indocyanine green fluorescence imaging system.
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ABSTRACT: We develop a dual-channel optical coherence tomography/indocyanine green (OCT/ICG) fluorescence system based on our previously reported ophthalmic OCT/confocal imaging system. The confocal channel is tuned to the fluorescence wavelength range of the ICG dye and light from the same optical source is used to generate the OCT image and to excite the ICG fluorescence. The system enables the clinician to visualize simultaneously en face OCT slices and corresponding ICG angiograms of the ocular fundus, displayed side by side. C-scan (constant depth) and B-scan (cross section) images are collected by fast en face scanning (T-scan). The pixel-to-pixel correspondence between the OCT and angiography images enables the user to precisely capture OCT B-scans at selected points on the ICG confocal images.Journal of Biomedical Optics 12(1):014019. · 3.16 Impact Factor -
Article: Combined multiplanar optical coherence tomography and confocal scanning ophthalmoscopy.
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ABSTRACT: We demonstrate the clinical application of a multiplanar imaging system that simultaneously acquires en face (C-scan) optical coherence tomography (OCT) and the corresponding confocal ophthalmoscopic images, along with cross-sectional (B-scan) OCT at specifiable locations on the confocal image. The advantages of the simultaneous OCT and confocal acquisition as well as the challenges of interpreting the C-scan OCT images are discussed. Variations in tissue inclination with respect to the coherence wave surface alter the sampling of structures within the depth of the retina, producing novel slice orientations that are often challenging to interpret. We have evaluated for the first time the utility of C-scan OCT for a variety of pathologies, including melanocytoma, diabetic retinopathy, choroidal neovascular membrane, and macular pucker. Several remarkable new aspects of clinical anatomy were revealed using this new technique. The versatility of selective capture of C-scan OCT images and B-scan OCT images at precise points on the confocal image affords the clinician a more complete and interactive tool for 3-D imaging of retinal pathology.Journal of Biomedical Optics 9(1):86-93. · 3.16 Impact Factor
