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Iris Morphological Features in Patients with 360° Angle-Closure Neovascular Glaucoma: An Anterior Segment Optical Coherence Tomography Study
摘要： Purpose: To investigate iris morphological features in 360° angle-closure neovascular glaucoma (NVG) by swept-source anterior segment optical coherence tomography (ASOCT). Patients and Methods: In this retrospective, clinic-based, comparative study, 14 patients with 360° angle-closure NVG and 14 healthy age-matched control subjects were enrolled. All patients enrolled had no prior glaucoma surgery but underwent cataract surgery with intraocular lens implantation. Horizontal scanning images of swept-source ASOCT were analyzed using software calipers in temporal and nasal angle areas. The iris thickness at 1 and 2 mm from the pupil edge, iris length, trabecular meshwork length, peripheral anterior synechia (PAS) length, PAS height ratio (PAS length/trabecular meshwork length), and pupil diameter were measured. Results: Between the groups, there were no statistically significant differences in iris length, trabecular meshwork length, and pupil diameter (p > 0.05). However, the iris thickness was significantly reduced in the NVG group compared with the control group in the temporal and nasal areas (0.306 vs. 0.563 mm/0.326 vs. 0.645 mm at 1 mm, 0.278 vs. 0.523 mm/0.282 vs. 0.546 mm at 2 mm, respectively) (mean, all p < 0.001). In the NVG group, PAS height ratios were 1.55 ± 0.45 (mean ± standard deviation) (range, 0.58–2.30) and 1.55 ± 0.78 (range, 0.68–3.68) at the temporal and nasal angles, respectively. Conclusions: In patients with 360° angle-closure NVG, the iris thickness decreased to about 50% of that in healthy subjects, and the PAS length exceeded the trabecular meshwork length by about 1.5 times.
关键词： Neovascular glaucoma,Angle closure,Peripheral anterior synechia,Anterior segment optical coherence tomography
更新于2025-09-10 09:29:36
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“Baumkuchen” Structure Assessed by Optical Coherence Tomography After 15?Years of Bare-Metal Stent Implantation
摘要： A 64-year old man who had hypertension, diabetes, and dyslipidemia was admitted to our hospital with worsening chest pain. He has undergone percutaneous coronary intervention (PCI) for placement of a bare-metal stent in the proximal left anterior descending coronary artery (LAD) 15 years ago. Urgent coronary angiography revealed in-stent restenosis at the proximal LAD, then ad hoc PCI was performed. Optical coherence tomography (OCT) pre-procedure revealed a “Baumkuchen-like” structure with triple layers according to the neointimal OCT signal pattern at the narrowed segment. Because a scoring balloon failed to dilate the lesion properly, rotational atherectomy was applied for lesion modification. After atherectomy, the lesion was fully expanded by noncompliant balloon followed by successful drug-eluting stent implantation. Follow-up angiography and OCT at 6 months revealed no angiographic restenosis and minimal neointimal hyperplasia. Here, we report for the first time to our knowledge a case with multiple layers of intima and neo-atherosclerosis, assessed by OCT, 15 years after PCI. Further investigation is warranted to verify whether this unique OCT finding will help us to elucidate the mechanism of neoatherosclerosis in metallic stents and to consider the appropriate strategy of revascularization, particularly in very late in-stent restenosis cases.
关键词： in-stent restenosis,optical coherence tomography,multiple signal layer,bare-metal stent(s)
更新于2025-09-10 09:29:36
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Functional Loss of the Inner Retina in Childhood Optic Gliomas Detected by Photopic Negative Response
摘要： To determine whether the Ganzfeld ERG photopic negative response (PhNR), an assay of inner retinal activity, is altered in childhood optic glioma (OPG). Seventeen pediatric patients with a diagnosis of OPG, established on neuro-ophthalmologic and brain/orbit magnetic resonance imaging (MRI) criteria, were enrolled. The examination protocol included determination of visual acuity (VA), fundus examination, retinal nerve fiber layer (RNFL) measurement with spectral-domain optical coherence tomography (SD-OCT) and photopic ERG. Fifteen normal children served as control group. Ten of the 17 OPG patients were retested 1 to 3 months after the first examination. Photopic ERGs were recorded after 10 minutes of light adaptation in response to a Ganzfeld flash presented on a steady light–adapting background. Amplitude and peak-time of b-wave and PhNR were measured. Compared with normal values, PhNR amplitude was significantly reduced (P < 0.0001) in the OPG group. Peak-time of PhNR as well as b-wave amplitude and peak-time were similar in both patients and controls. Losses of PhNR were found in patients with involvement of either anterior or retro-chiasmatic optic pathways. Linear regression analysis showed significant positive correlation between RNFL thickness and PhNR amplitude (r2 ? 0.34, P ? 0.008). Mean percentage test–retest difference for PhNR amplitude and peak-time was 12% and 6%, respectively. These findings indicate that flash ERG PhNR can detect a loss of inner retinal function in childhood OPGs supporting the use of this technique, as an adjunct to standard psychophysical and electrophysiological tests, to monitor visual function in OPG.
关键词： photopic negative response,optical coherence tomography,ganglion cells,optic pathways glioma,neurofibromatosis
更新于2025-09-10 09:29:36
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Mapping of Corneal Layer Thicknesses With Polarization-Sensitive Optical Coherence Tomography Using a Conical Scan Pattern
摘要： PURPOSE. We demonstrate segmentation and mapping of corneal layers (epithelium, Bowman’s layer, and stroma) across the entire cornea (limbus to limbus), using additional contrast provided by polarization-sensitive optical coherence tomography (PS-OCT) and analyze the reproducibility of the procedure. METHODS. A custom built PS-OCT system operating at 1045 nm central wavelength with conical scanning was used for image acquisition. Conical scanning allows for almost perpendicular beam incidence on the corneal surface and provides good signal quality over the entire ?eld of view. Epithelium, Bowman’s layer, and stroma were segmented using the additional contrast provided by PS-OCT. Thickness maps were computed and analyzed in sectors. Both eyes of 20 healthy volunteers were imaged at least three times to test this method and to quantify reproducibility. RESULTS. Thickness maps of the epithelium show signi?cant (P < 0.001) superior thinning and an inferior thickening. Bowman’s layer appears homogeneous within the central 7 to 8 mm diameter of the cornea and gets thinner toward the periphery until this layer disappears between 4 and 5.5 mm eccentricity from the center. Intersubject variations of the measured thicknesses of epithelium (coef?cient of variation [CV] ~8%), Bowman’s layer (CV~25%), and stroma (CV~10%) were observed. Very good reproducibility of thickness measurements of epithelium (CV < 3%), Bowman’s layer (CV < 5%), and stroma (CV < 2%) was found. Furthermore, a signi?cant correlation (P < 0.001) between layer thicknesses of the right and left eyes of the same subject was found. CONCLUSIONS. PS-OCT with conical scanning is a feasible approach for determining thickness maps of corneal layers on a large ?eld of view with high reproducibility.
关键词： cornea,optical coherence tomography,polarization-sensitive imaging,corneal epithelium,Bowman’s layer
更新于2025-09-10 09:29:36
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Functional optical coherence tomography of retinal photoreceptors
摘要： Age-related macular degeneration (AMD) is the leading cause of severe vision loss and legal blindness. It is known that retinal photoreceptors are the primary target of AMD. Therefore, a reliable method for objective assessment of photoreceptor function is needed for early detection and reliable treatment evaluation of AMD and other eye diseases such as retinitis pigmentosa that are known to cause photoreceptor dysfunctions. Stimulus-evoked intrinsic optical signal (IOS) changes promise a unique opportunity for objective assessment of physiological function of retinal photoreceptor and inner neurons. Instead of a comprehensive review, this mini-review is to provide a brief summary of our recent in vitro and in vivo optical coherence tomography (OCT) studies of stimulus-evoked IOS changes in animal retinas. By providing excellent axial resolution to differentiate individual retinal layers, depth-resolved OCT revealed rapid IOS response at the photoreceptor outer segment. The fast photoreceptor-IOS occurred almost right away ((cid:1) 2 ms) after the onset of retinal stimulation, differentiating itself from slow IOS changes correlated with inner neural and hemodynamic changes. Further development of the functional IOS instruments and retinal stimulation protocols may provide a feasible solution to pursue clinical application of functional IOS imaging for objective assessment of human photoreceptors.
关键词： intrinsic optical signal,photoreceptors,Optical coherence tomography,age-related macular degeneration
更新于2025-09-10 09:29:36
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Comparison of Reliability in Diabetic Macular Edema Estimates between Two Image Analysis Algorithms
摘要： Purpose: To evaluate segmentation reliability in diabetic macular edema (DME) estimates between a CirrusTM HD-OCT image analysis algorithm and an Iowa reference algorithm, which are an automatic segmentation software. Methods: Thirty eyes from 23 patients diagnosed with DME were included and underwent spectral-domain optical coherence scans (CirrusTM HD-OCT). Central foveal thickness (CFT) and ganglion cell layer-inner plexiform layer segmentation data were compared with those produced by the CirrusTM HD-OCT segmentation algorithm and Iowa reference algorithm. Measurement agreement was assessed using intraclass correlation (ICC) and segmentation errors were confirmed by 2 ophthalmologists. Results: The mean CFT in the 1-mm central area determined by the manufacturer-supplied Cirrus software and Iowa reference algorithm was 512.07 ± 182.35 μm and 476.53 ± 32.36 μm, respectively (p < 0.05). The mean paired difference was 35.53 ± 92.46 μm (ICC, 0.929). Segmentation errors were demonstrated in eyes with a CFT less than 400 μm, specifically for 45% of scans obtained by the Cirrus algorithm and 9% from the Iowa algorithm; in eyes with a CFT equal to or higher than 400 μm, the error rates were 95% and 42%, respectively. Conclusions: CFT measurement in eyes with diabetic macular edema using the Cirrus algorithm and Iowa algorithm showed relatively high degrees of agreement and significant correlation. In eyes with a CFT equal to or higher than 400 μm, the Iowa algorithm showed higher reliability in retinal segmentation than the Cirrus algorithm.
关键词： Reliability,Segmentation algorithm,Diabetic macular edema,Optical coherence tomography,Central foveal thickness
更新于2025-09-10 09:29:36
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The Repeatability of Retinal Layer Thickness Measurements with Spectral-Domain Optical Coherence Tomography in Normal Eyes
摘要： Purpose: To evaluate the repeatability of retinal layer thickness measurements in normal eyes imaged using spectral domain optical coherence tomography (SD-OCT). Methods: Sixty-eight eyes of 34 healthy subjects were enrolled in this study. Imaging was performed 4 times using 9 × 9 mm macular scans with SD-OCT (RS 3000 Advance HD OCT, NIDEK, Gamagori, Japan) at the same visit by an experienced examiner. After automatic retinal segmentation (layering) in 5 layers, the thickness of each layer was calculated. Macular thickness of 9 Early Treatment of Diabetic Retinopathy Study (ETDRS)–like regions was obtained. Repeatability for each of the 9 subfield areas was calculated by their repeatability coefficients and intraclass correlation coefficients (ICCs). Results: There was no significant difference in average retinal thickness and each retinal layer thickness between all measurements acquired by the experienced examiner. The ICCs of retinal layer thickness ranged from 0.826 to 0.847 for the ganglion cell layer + inner plexiform layer, inner nuclear layer + outer plexiform layer and outer nuclear layer + external limiting membrane in the fovea. The ICCs were greater than 0.909 for the other intra-retinal layers in all 9 ETDRS subfield thickness between all measurement pairs. Conclusions: Excellent repeatability was observed for SD-OCT retinal segmented layer thickness measurements in healthy subjects.
关键词： Repeatability,Spectral domain optical coherence tomography,Retinal layer thickness,Automated segmentation,Intraclass correlation coefficients
更新于2025-09-10 09:29:36
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Retinal Nerve Fiber Layer Volume Measurements in Normal Children Using Spectral Domain Optical Coherence Tomography
摘要： Purpose: To measure retinal nerve fiber layer (RNFL) volume in normal children using spectral domain optical coherence tomography (SD-OCT). Methods: This study included 79 eyes of 54 normal children between 4 and 15 years of age evaluated from February 2012 to November 2012. All participants underwent ocular examination and 3D-disc scanning using SD-OCT. RNFL volume was calculated between 2.5 and 5 mm diameter circles using the length, width, and height of each pixel derived from the RNFL thickness map with Matlab software. The relationship between RNFL volume and thickness was analyzed. Results: The RNFL volumes of the mean total, superior, nasal, inferior, and temporal areas were 1.48 ± 0.09 mm3, 0.45 ± 0.04 mm3, 0.29 ± 0.04 mm3, 0.46 ± 0.03 mm3, and 0.29 ± 0.04 mm3, respectively. Comparing RNFL volume and conventional circumpapillary RNFL thickness measured using built-in software, a strong correlation between mean total, superior, and inferior areas (R = 0.980, 0.953 and 0.932, respectively) and a moderate correlation between the nasal and temporal areas were observed (R = 0.545 and 0.514, respectively). The negative correlations between RNFL thickness and RNFL volumes of the mean total, superior, nasal, inferior, and temporal areas and age were not significant (p > 0.05). Conclusions: This study reports RNFL volume measured from RNFL thickness map analysis in normal children. These data regarding RNFL volume of normal children may provide useful information for diagnosis and monitoring of pediatric glaucoma.
关键词： Normal children,Retinal nerve fiber layer,Spectral domain optical coherence tomography,Volume
更新于2025-09-10 09:29:36
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Macular microvasculature features before and after vitrectomy in idiopathic macular epiretinal membrane: an OCT angiography analysis
摘要： Purpose To evaluate pre-operative and post-operative morphologic characteristics in idiopathic macular epiretinal membrane (ERM) by optical coherence tomography angiography (OCTA). Methods Thirty-three subjects with unilateral idiopathic ERM were enrolled and the contralateral eyes served as controls. Vascular parameters including super?cial capillary plexus (SCP), deep capillary plexus (DCP), outer capillary plexus (OCP), and choroidal capillary plexus (CCP) were evaluated by OCTA. Results The super?cial foveal avascular zone (FAZ) was signi?cantly smaller in eyes with ERM (P < 0.0001). The vessel densities (VDs) were signi?cantly increased in the fovea but dramatically decreased in the parafovea in SCP and DCP of ERM eyes (all P < 0.0001), in contrast to those in OCP and CCP. The blood ?ow was augmented in OCP but declined in choroid compared with the controls. In CCP, the mean foveal VD in ERM was signi?cantly smaller (P = 0.023), whereas parafoveal VD did not signi?cantly change (P = 0.66). At 6 months after surgery, ?ow area was decreased in OCP (P = 0.0007), and foveal and parafoveal VDs were signi?cantly altered in all layers except the foveal VD in OCP and the choroid (all P < 0.05). The total and inner retinal thickness of the fovea and parafovea were correlated with pre-operative and post-operative visual outcomes, respectively. Smaller FAZ and greater interocular differences between post-operative and fellow eyes in FAZ were associated with worse post-operative visual outcomes. Conclusions OCTA provides a better display of the vascular network of the retina and choroid to evaluate the severity and surgical prognosis of ERM patients.
关键词： Microvasculature,Vitrectomy,Epiretinal membrane,Optical coherence tomography angiography
更新于2025-09-10 09:29:36
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Changes in retinal flow density measured by optical coherence tomography angiography in patients with carotid artery stenosis after carotid endarterectomy
摘要： The aim of the study presented here was to evaluate retinal and optic nerve head (ONH) perfusion in patients with severe asymptomatic carotid artery stenosis (CAS) compared with healthy controls and to analyze the impact of carotid endarterectomy using optical coherence tomography angiography (OCT-A). 25 eyes of 25 patients with CAS (study group) and 25 eyes of 25 healthy controls (control group) were prospectively included in this study. OCT-A was performed using RTVue XR Avanti (Optovue, Inc, Fremont, California, USA). The flow density data in the superficial and deep retinal OCT-angiogram of the macula and in the radial peripapillary capillary network (RPC) of the ONH were extracted and analyzed. The flow density in the superficial retinal OCT angiogram of the macula and in the ONH were significantly lower in the study group compared with the control group (macula: p = 0.003) (ONH: p = 0.013). The flow density in the ONH improved significantly after carotid endarterectomy (p = 0.004). A reduced flow density was observed in patients with CAS when compared with healthy controls. The flow density also improved after carotid endarterectomy. Quantitative changes in the microvascular density, as measured using OCT-A, could well be useful in the diagnosis of CAS and the evaluation of therapy success.
关键词： carotid endarterectomy,optical coherence tomography angiography,carotid artery stenosis,retinal flow density
更新于2025-09-10 09:29:36