Optical Coherence Tomography Sections Research Articles

Peripapillary intrachoroidal cavitation at the crossroads of peripapillary myopic changes.

To analyze the prevalence of peripapillary intra-choroidal cavitation (PICC) in eyes with gamma peripapillary atrophy (γPPA), in eyes with peripapillary staphyloma (PPS) and in those combining γPPA and PPS and to analyze border tissue discontinuity in PICC. This prospective cross-sectional non interventional study included highly myopic eyes. Non-highly myopic eyes were used as control. Radial and linear scans centered on the optic nerve head were performed using spectral-domain optical coherence tomography. Variables were analyzed along the twelve hourly optical coherence tomography sections in both eyes of each subject. A total of 667 eyes of 334 subjects were included: 229 (34.3%) highly myopic eyes and 438 (65.7%) non highly myopic eyes. The mean age of the highly myopic group was 48.99±17.81y. PICC was found in a total of 40 eyes and in 13.2% (29/220) of highly myopic eyes. PICC was found in 10.4% (40/386) of eyes with γPPA, in 20.5% (40/195) of eyes with PPS and in 22.7% (40/176) of those combining γPPA and PPS. All the eyes with PICC showed the co-existence of γPPA and PPS whereas none of the eyes presenting only one of these entities exhibited PICC. A border tissue discontinuity in the γPPA area was found in all eyes with PICC. We confirm the presence of a border tissue discontinuity in the γPPA area of all eyes with PICC. These findings suggest the involvement of mechanical factors in the pathogenesis of PICC which may contribute to PICC-related visual field defects.

“En Face” Spectral-Domain Optical Coherence Tomography versus Multifocal Electroretinogram in Hydroxychloroquine Retinopathy Screening

Introduction: The performance of “en face” optical coherence tomography (OCT) in screening for chloroquine (CQ) or hydroxychloroquine (HCQ) retinopathy has not been largely explored. The aim of this study was to determine the concordance of “en face” OCT with multifocal electroretinography (mfERG) in screening for CQ/HCQ retinopathy. Methods: This is a prospective cohort study conducted at the Rothschild Foundation Hospital, Paris, between August 2016 and February 2021. Patients taking HCQ were followed up over 2 consecutive years and received an “en face” OCT and a mfERG on each visit. Results: A total of 91 patients (182 eyes) were analyzed. mfERG and “en face” OCT were concordant in 147 eyes (86.3%). Cohen’s kappa coefficient for concordance between mfERG and “en face” OCT was considered weak with a value 0.61 (95% CI: 0.50–0.72). The sensitivity and specificity of “en face” OCT were 70% (95% CI: 59–79%) and 91% (95% CI: 83–96%), respectively, relatively to mfERG. Proportion of abnormal R2/R5 and R3/R5 ratios did not differ between patients with normal and abnormal “en face” OCT (p = 0.2). Discussion: “En face” OCT and mfERG have low concordance and cannot be used interchangeably as each investigation evaluates a different facet of CQ/HCQ retinopathy. “En face” OCT could be used as a complement in screening for CQ/HCQ retinal toxicity if the anomalies detected on “en face” OCT are confirmed by B-scan OCT sections.

Analysis of Peripapillary Intrachoroidal Cavitation and Myopic Peripapillary Distortions in Polar Regions by Optical Coherence Tomography.

PurposeTo compare the peripapillary polar characteristics in eyes combining peripapillary staphyloma and gamma peripapillary atrophy according to whether peripapillary intrachoroidal cavitation (PICC) was present or absent (combination-group).Patients and methodsThis prospective non-interventional cross-sectional study included 667 eyes of 334 subjects. From the polar peripapillary regions to the opening of Bruch’s membrane, the following elements and their topographic relationships were analyzed using optical coherence tomography sections: configuration of the posterior curvature of the choroid, visibility of the subarachnoid space (SAS), and suprachoroidal detachment (SCD). Chi-squared and Fisher exact tests were used for statistical analysis.ResultsThe protrusion of the posterior choroidal wall, with anterior elevation on either side, observed in both groups progressed and transformed into a wedge-shaped deformity on the side of gamma peripapillary atrophy. This wedge configuration was significantly more frequent in PICC-group than in combination-group (p = 0.004 and p < 0.001) for the upper and lower poles, respectively. SAS was more frequently observed in PICC-group than in combination-group (p = 0.002 and p < 0.001) for the upper and lower poles, respectively. SCD was detected exclusively in PICC-group (p < 0.001, both poles). The wedge-shaped configuration and the SCD were aligned antero-posteriorly with the SAS.ConclusionWe confirmed that PICC is an SCD. We observed its constant alignment with the SAS. We suggest that the tensile forces of the optic nerve sheaths during adduction promote the collapse of the scleral flange onto the SAS, leading to PICC. Further studies are warranted to confirm this hypothesis.

Peripapillary Choroidal Vasculature in Pediatric Eyes with Type 1 Diabetes Mellitus.

Choroidal vasculature change in children with diabetes mellitus is not investigated enough although it could reflect clinical outcome. Pediatric Type 1 diabetes mellitus (T1DM) patients and healthy controls were retrospectively evaluated. Peripapillary retinal nerve fiber layer optical coherence tomography (OCT) images of the right eyes were analyzed. Choroidal parameters including total choroidal area, luminal area, stromal area, and choroidal vascularity index were measured through image binarization. Twenty eyes of 20 patients were compared with 46 eyes of 46 healthy controls. Mean total choroidal area, luminal area, and stromal area were 1.59±0.35, 1.10±0.24, and 0.50±0.13 mm2 in patients' eyes and 1.52±0.49, 1.05±0.34, and 0.47±0.17 mm2 in healthy eyes. No difference was found in choroidal vascularity indices between patients and healthy eyes (68.8±3.9% vs. 69.4±4.4%, p=0.521). Temporal choroidal vascularity index was significantly higher than its nasal counterpart in healthy eyes (71.8±5.0% vs. 68.6±4.9%, p<0.001) which was not significant in patients' eyes (70.7±4.0% vs. 68.9±5.1%, p=0.067). Temporal quadrant had the highest choroidal vascularity index score among all quadrants in healthy controls (all p<0.05), whereas no choroidal vascularity index difference between quadrants was detected in patients (p=0.75). Peripapillary choroidal vasculature has shown subtle sectoral changes which did not reflect the overall peripapillary OCT section in pediatric T1DM patients when compared with healthy controls.

Analysis of the Peripapillary Choroidal Vascular Characteristics in Papilledema Associated with Pseudotumor Cerebri

Choroidal vascularity index measured by image binarization method from peripapillary optical coherence tomography sections has been found significantly lower in papilledema patients than healthy controls. The purpose of this study was to compare peripapillary choroidal parameters in papilledema patients with control subjects. Peripapillary spectral domain optical coherence tomography scans of 34 patients with papilledema and 34 healthy controls are acquired for the study. Images are binarized with the ImageJ software (National Institutes of Health, Bethesda, MD) to calculate total choroidal area, stromal area, luminal area, and choroidal vascularity index. Total choroidal area, luminal area, and choroidal vascularity were significantly lower in papilledema patients compared with healthy controls on right (1.343 ± 0.286 vs. 1.694 ± 0.344, P < .001; 0.880 ± 0.209 vs. 1.167 ± 0.255, P < .001; 65.28 ± 2.99% vs. 68.68 ± 2.81%, P < .001, respectively) and left eyes (1.376 ± 0.308 vs. 1.647 ± 0.339, P < .001; 0.899 ± 0.231 vs. 1.134 ± 0.237, P < .001; 64.92 ± 3.44 vs. 68.84 ± 3.23, P < .001, respectively). No difference was found between active and remitted stages of papilledema in terms of choroidal parameters. Peripapillary total choroidal area, luminal area, and choroidal vascularity index are significantly reduced in patients with papilledema. These parameters might be beneficial tools for evaluating choroidal vascularity in papilledema quantitatively and differential diagnosis for optic disc edema.

Integrated System for Combined Optical Coherence Tomography-Raman Spectroscopy of Neocaridina denticulate sinensis

Optical coherence tomography (OCT) and Raman spectroscopy (RS) can be complementary biological tissue optical analysis methods. To study the internal structure and tissue compositions of biological samples, an OCT-RS system was built to carry out OCT section imaging and RS analysis in common. Neocaridina denticulate sinensis were collected regularly for morphological observation by OCT imaging and biochemical investigation based on the Raman spectra. The internal structure of the N. denticulate sinensis was imaged by OCT, and the morphology of the tissues and the position in the body were distinguished according to the gray scale changes. The imaging depth along the vertical direction of Z-axis in N. denticulate sinensis is about 1.60 mm. RS detection was selectively performed based on the OCT images. The main Raman peaks of the rostrum, the cephalothorax, the abdominal segment, and the telson section are at 1006, 1156, 1447, 1491 and 1515 cm−1, which are identified as proteins and amino acids. The presence of 1497 cm−1 at the cephalothorax is different from other parts, probably due to the presence of organs such as ovary, whose compositions are different from those of other tissues. The combination of optical coherence tomography and Raman spectroscopy can provide information about morphological and biochemical features of tissues, and has potential applications in biomedical detection and imaging.

Green tea catechins alleviate autoimmune symptoms and visual impairment in a murine model for human chronic intraocular inflammation by inhibiting Th17-associated pro-inflammatory gene expression

Autoimmune uveitis is a sight-threatening disease mainly caused by dysregulation of immunity. We investigated the therapeutic effects of green tea extract (GTE) and its major component, epigallocatechin-3-gallate (EGCG), on a murine model of experimental autoimmune uveoretinitis (EAU). Oral administration of GTE, EGCG, dexamethasone, or water, which started 5 days before the induction, was fed every two days to each group. On day 21 post induction, the eyes were examined by confocal scanning laser ophthalmoscopy, optical coherence tomography (OCT), fundus fluorescein angiography (FFA) and electroretinography (ERG) prior to sacrificing the animals for histological assessments and gene expression studies. Retinal-choroidal thicknesses (RCT) and major retinal vessel diameter were measured on OCT sections and FFA images, respectively. Comparing to water-treated EAU animals, GTE attenuated uveitis clinical manifestations, RCT increase (1.100 ± 0.013 times vs 1.005 ± 0.012 times, P < 0.001), retinal vessel dilation (308.9 ± 6.189 units vs 240.8 units, P < 0.001), ERG amplitudes attenuation, histopathological ocular damages, and splenomegaly in EAU mice. The therapeutic effects of GTE were dose dependent and were comparable to dexamethasone. EGCG, a major active constituent of GTE, partially alleviated uveitic phenotypes including recovering visual function. Th-17 associated pro-inflammatory gene [interleukin 1 beta (IL-1β), IL-6, IL-17A, and tumor necrosis factor alpha (TNF-α)] expressions were down regulated by GTE and EGCG treatments, which showed no detectable morphological defects in liver and kidney in non-induced and EAU mice. Our findings suggest that GTE consumption can serve as a potent therapeutic agent as well as a food supplement for developing alternative treatments against autoimmune uveitis.

Dome-shaped macula: a potential protective factor for visual acuity after cataract surgery in patients with high myopia

PurposeTo evaluate whether the presence of dome-shaped macula (DSM) is a protective factor for visual acuity after cataract surgery in patients with high myopia.MethodsIncluded were 891 highly myopic cataract eyes...

Intraoperative Optical Coherence Tomography-Guided Femtosecond Laser-Assisted Deep Anterior Lamellar Keratoplasty.

To describe the feasibility and outcomes of intraoperative optical coherence tomography (OCT)-guided, femtosecond laser-assisted deep anterior lamellar keratoplasty in which the lamellar and tunnel cuts were completed by laser. The Ziemer Z8 system was used to scan the corneas intraoperatively and guide the stromal lamellar and tunnel cuts created by the laser. Thirty porcine eyes and 3 human cadaver globes were used to evaluate the accuracy of laser-created intrastromal tunnels and the feasibility of achieving big-bubble pneumatic dissection. The tunnel distance above the Descemet membrane (Dt-dm) was set at 100 and 130 μm, and the accuracy of laser cut was assessed by anterior segment OCT and histological sections. Fourteen patients with keratoconus or corneal scars were then included to evaluate the clinical outcomes. The deviation from the targeted Dt-dm was 5.5% to 8.6% and 0.7% to 9.8% for the 100 and 130 μm groups, respectively. The achieved thickness had a significantly and positively strong correlation with the targeted thickness (r = 0.86; P < 0.001). In all cases, the anterior stromal lamella was removed without difficulty, except in the patients with corneal scars in whom some remaining stromal fiber attachments were observed. A type 1 big bubble was successfully achieved in all patients. We present the accuracy and clinical outcomes of femtosecond laser-assisted, intraoperative OCT-guided deep anterior lamellar keratoplasty, in which controlled lamellar and tunnel cuts at desired depths were performed by laser in one step, and a successful big bubble was achieved.

Coronary calcification as a mechanism of plaque/media shrinkage in vessels treated with bioresorbable vascular scaffold: A multimodality intracoronary imaging study

Background and aimsWhether coronary calcification is correlated with plaque/media shrinkage (PS) remains unclear. The aim of this study was to assess the relationship between the calcification process and PS, combining serial optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in vessels treated with bioresorbable vascular scaffolds (BVS). MethodsIn 15 patients (16 vessels), OCT and IVUS images were matched using anatomic landmarks at post-procedure and five years. PS was defined as relative decrease in plaque/media area >5%. The association between the calcification process and PS was investigated. Mixed effect models were used to assess correlations and changes over time. ResultsSeventy-two OCT and IVUS paired cross sections in- and out-scaffolded segments were matched at baseline and follow-up (432 images). In total, 35 out of the 72 cross sections showed PS, and 37 cross sections showed no PS (non-PS) at 5-year follow-up. Delta (Δ) plaque/media area showed negative correlation with Δ OCT calcium area (r = −0.29, p = 0.004), Δ OCT calcium arc (r = −0.42, p < 0.001), Δ OCT calcium length (r = −0.5, p < 0.001), and Δ IVUS calcium arc (r = −0.31, p = 0.024), respectively. On echogenicity analysis, Δ plaque/media area was positively associated with Δ hypoechogenic area (r = 0.47, p = 0.002). An increase in calcium area was negatively correlated to Δ hypoechogenicity (r = −0.29, p < 0.016). The increase in calcium area was positively correlated with Δ lumen area (r = 0.24, p = 0.044). ConclusionsIn segments treated with BVS, the calcification process was associated with PS, decrease in the hypoechogenic tissue and late luminal enlargement. Combining IVUS and OCT provides a unique method to assess the correlation between the calcification process and plaque/media shrinkage.

Paravascular inner retinal abnormalities in healthy eyes.

To investigate the prevalence and characteristics of paravascular inner retinal abnormalities in healthy eyes. In this prospective observational case series, we included 178 healthy eyes (178 patients) with no ocular diseases. Eyes with co-existing ocular diseases, e.g., epiretinal membrane, glaucoma, or high myopia, were excluded from the current study. The posterior pole and paravascular areas of the temporal arcade vessels were comprehensively examined by dense radial scanning of optical coherence tomography (OCT) with the extended field imaging technique. On fundus photography, no inner retinal abnormalities were detected along the temporal arcade vessels. On OCT sections, paravascular inner retinal abnormalities were seen in 77 (43.3%) eyes. In 71 (39.9%) eyes, inner retinal cystoid or fissure-like spaces that had no connection to the vitreous cavity were seen adjacent to the temporal arcade vessels. Most of these lesions were detected only on several consecutive OCT sections. In four (2.2%) eyes, inner retinal cleavages with openings to the vitreous cavity were seen adjacent to the temporal arcade vessels. These lesions were more frequently detected in the inferior hemisphere and along the major retinal veins. No eyes showed typical broad defects of the inner retinal tissue. There were no significant differences in age, gender, visual acuity, refractive error, or axial length between eyes with or without paravascular inner retinal abnormalities. Paravascular cystoid or fissure-like spaces were frequently seen in the inner retina of healthy eyes. However, we detected no typical paravascular inner retinal defects in healthy eyes.

Comparisons of the diagnostic accuracies of optical coherence tomography, micro-computed tomography, and histology in periodontal disease: anex vivostudy

PurposeOptical coherence tomography (OCT) is a noninvasive diagnostic technique that may be useful for both qualitative and quantitative analyses of the periodontium. Micro-computed tomography (micro-CT) is another noninvasive imaging technique capable of providing submicron spatial resolution. The purpose of this study was to present periodontal images obtained using ex vivo dental OCT and to compare OCT images with micro-CT images and histologic sections.MethodsImages of ex vivo canine periodontal structures were obtained using OCT. Biologic depth measurements made using OCT were compared to measurements made on histologic sections prepared from the same sites. Visual comparisons were made among OCT, micro-CT, and histologic sections to evaluate whether anatomical details were accurately revealed by OCT.ResultsThe periodontal tissue contour, gingival sulcus, and the presence of supragingival and subgingival calculus could be visualized using OCT. OCT was able to depict the surface topography of the dentogingival complex with higher resolution than micro-CT, but the imaging depth was typically limited to 1.2–1.5 mm. Biologic depth measurements made using OCT were a mean of 0.51 mm shallower than the histologic measurements.ConclusionsDental OCT as used in this study was able to generate high-resolution, cross-sectional images of the superficial portions of periodontal structures. Improvements in imaging depth and the development of an intraoral sensor are likely to make OCT a useful technique for periodontal applications.

WIDE-FIELD SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

To describe wide-field spectral domain optical coherence tomography morphologic relationships of the vitreous, retina, and choroid in healthy and pathologic eyes. Standardized horizontal, vertical, and two oblique (supertemporal to inferonasal and supranasal to inferotemporal) spectral domain optical coherence tomography sections were collected for each patient. For extramacular imaging, images were obtained from 8 locations: (1) nasal to the optic disk, (2) extreme nasal periphery, (3) superior to the superotemporal vascular arcade, (4) extreme superior periphery, (5) inferior to the inferotemporal vascular arcade, (6) extreme inferior periphery, (7) temporal to the macula, and (8) extreme temporal periphery. Wide-angle montage images of optical coherence tomography from equator-to-equator were composed with a montaging software. Wide-field spectral domain optical coherence tomography scans were obtained in 10 healthy subjects, in 7 patients with central serous chorioretinopathy, in 5 patients with wet age-related macular degenerations, in 5 patients with dry age-related macular degenerations, in 4 patients with retinitis pigmentosa, and in 1 patient with acute exudative polymorphous vitelliform maculopathy. The novel approach of montaging spectral domain optical coherence tomography images to examine relationships between the choroid, retina, and associated structures adjacent to and outside of the macula may have a number of relevant applications in the study of vitreoretinal interface, paramacular and macular pathologic features.

Comparison of Clinical Features in Highly Myopic Eyes with and without a Dome-Shaped Macula

To compare the clinical features of highly myopic eyes with a dome-shaped macula (DSM) with those without a DSM and to identify the funduscopic clues to suspect the presence of DSM. Retrospective case series. A total of 586 patients (1118 eyes) with high myopia (refractive error <-8 diopters [D] or axial length ≥26.5 mm) who had optical coherence tomography (OCT) examinations through the central fovea at our High Myopia Clinic between February 2012 and November2013. Vertical and horizontal OCT scans across the central fovea were retrospectively analyzed. A DSM was defined by the presence of an inward bulge of >50 μm in the vertical OCT image. Fundus photographs also were analyzed to identify the funduscopic clues to suspect the presence of DSM. The rate of DSM in 1118 highly myopic eyes. The rate of DSM in highly myopic eyes with macular complications. Funduscopic features to suggest the presence of DSM. Among the 1118 eyes, 225 (20.1%) had a DSM. A DSM was present in both vertical and horizontal OCT sections in 20% of eyes, along only the vertical section in 77% of eyes, and in only the horizontal section in 2% of eyes. The results of multiple regression analyses showed that serous retinal detachment and foveal and extrafoveal retinoschisis were significantly associated with the presence of DSM and that choroidal neovascularization was not. Ophthalmoscopically, 91.4% of the eyes with the appearance of a horizontal ridge connecting the optic disc and the fovea had a DSM. A DSM is found in as many as 20% of highly myopic individuals. Horizontal ridges connecting the optic disc and the fovea might be an important clue to suspect the presence of a DSM on the basis of fundus photographs.

Paravascular inner retinal defect associated with high myopia or epiretinal membrane.

Paravascular retinal abnormalities are common in highly myopic eyes. However, affected areas may be underestimated, and the pathogenesis and effects on retinal function remain unclear. To prospectively investigate the characteristics and pathogenesis of paravascular inner retinal defects (PIRDs). Prospective and observational case series (between April 2013 and April 2014) at a referral retinal practice among 28 patients (41 eyes) with PIRDs. The entire affected retinal area was examined in 4 quadrants in sequential thin sections using optical coherence tomography. The effect of PIRDs on retinal function was examined using Goldmann perimetry. Morphological changes on optical coherence tomography sections and visual field test by Goldmann perimetry. On fundus photography, PIRDs appeared as spindle-shaped or caterpillar-shaped dark areas along the major retinal vessels disconnected from the optic disc. On optical coherence tomography cross-sections of retinal vessels, PIRDs often appeared as cystoid or fissure-like spaces; however, longitudinal optical coherence tomography sections along retinal vessels revealed that most PIRDs were actually wide defects in the inner retina or located beneath the major retinal vessels, often deviating into the vitreous cavity. Of 41 eyes with PIRDs, 37 (90%) were myopic; 21 eyes (51%) had high myopia. The mean refractive error of the eyes with PIRDs was -7.94 (95% CI, -9.48 to -6.40) diopters. The mean axial length of the eyes with PIRDs was 26.96 (95% CI, 25.42-28.49) mm. Twenty-one eyes (51%) showed epiretinal membrane in the macular area. In these eyes, PIRDs had formed along the temporal arcade vessels, which increasingly deviated toward the fovea by epiretinal membrane traction. Of 41 eyes with PIRDs, 35 showed visual field defects corresponding to the PIRD locations. The most common visual field defects were relative Bjerrum scotoma (in 75% [60 of 80]; 95% CI, 66%-85%) and nasal steps (in 59% [47 of 80]; 95% CI, 48%-70%) corresponding to the PIRD predilection locations. Paravascular inner retinal defects primarily occur in eyes with high myopia or epiretinal membrane. Deviated retinal vessels due to axial elongation or epiretinal membrane traction may be involved in the pathogenesis. Paravascular inner retinal defects often cause retinal dysfunction corresponding to the location. A PIRD may partially overlap with retinal lesions previously reported as cleavage of the retinal nerve fiber layer, inner retinal cleavage, paravascular retinal cysts, or lamellar holes. However, the term PIRD more precisely describes the characteristic features of the lesion.

Peri-strut low-intensity areas in optical coherence tomography correlate with peri-strut inflammation and neointimal proliferation

Peri-strut low-intensity area (PLI) is a common imaging finding during the evaluation of in-stent neointima using optical coherence tomography (OCT). We aimed to determine the biological significance of PLI by comparing in-vivo OCT images with the corresponding histological sections obtained from the familial hypercholesterolemic swine model of coronary stenosis. A total of 26 coronary vessels of nine familial hypercholesterolemic swine were injured with 30% balloon overstretch and then immediately followed by everolimus eluting or bare metal stent placement at 20% overstretch. At 30 days, all stented vessels were subjected to in-vivo OCT analysis and were harvested for histological evaluation. For OCT analysis, stent cross-sections (three per stent) were categorized into presence (PLI+) or absence (PLI-) of PLI. In histology, inflammation and fibrin deposition were scored semiquantitatively from 0 (none) to 3 (severe). PLI was found in 64.9% of stent sections. Peri-strut inflammation was more frequently observed in OCT sections PLI (+) compared with PLI (-) (56.0 vs. 7.4%, P=0.01). In contrast, peri-strut fibrin deposits was similar in both groups (PLI+=58.0% vs. PLI-=59.3%, P=0.94). Histological neointimal thickness was significantly higher in PLI (+) sections (mean±SE: 0.68±0.06 vs. 0.34±0.02 mm; P<0.01), yielding a higher percent area stenosis compared with PLI (-) (mean±SE: 59.0±4.4 vs. 34.1±2.2%, P<0.01). The PLI diagnostic sensitivity and specificity for inflammation were 80 and 76.1%, respectively (>56% PLI, area under the curve=0.86, P<0.01), whereas for fibrin deposition, the sensitivity and specificity were 42.2 and 76.1%, respectively (area under the curve=0.56, P=NS). Area under the receiver operating characteristic curve was significantly higher for identifying inflammation than fibrin (0.86 vs. 0.56, P<0.01). The severity of PLI correlated with the neointimal thickness when assessed by OCT (R=0.79, P<0.001). The presence of PLI in OCT correlates with neointimal thickness and appears to have a diagnostic value in the recognition of peri-strut inflammation, therefore possibly serving as a surrogate for in-vivo assessment of stent efficacy.

In-vivo segmentation and quantification of coronary lesions by optical coherence tomography images for a lesion type definition and stenosis grading.

Optical coherence tomography (OCT) is a catheter-based medical imaging technique that produces cross-sectional images of blood vessels. This technique is particularly useful for studying coronary atherosclerosis. In this paper, we present a new framework that allows a segmentation and quantification of OCT images of coronary arteries to define the plaque type and stenosis grading. These analyses are usually carried out on-line on the OCT-workstation where measuring is mainly operator-dependent and mouse-based. The aim of this program is to simplify and improve the processing of OCT images for morphometric investigations and to present a fast procedure to obtain 3D geometrical models that can also be used for external purposes such as for finite element simulations. The main phases of our toolbox are the lumen segmentation and the identification of the main tissues in the artery wall. We validated the proposed method with identification and segmentation manually performed by expert OCT readers. The method was evaluated on ten datasets from clinical routine and the validation was performed on 210 images randomly extracted from the pullbacks. Our results show that automated segmentation of the vessel and of the tissue components are possible off-line with a precision that is comparable to manual segmentation for the tissue component and to the proprietary-OCT-console for the lumen segmentation. Several OCT sections have been processed to provide clinical outcome.

Characteristics of intrachoroidal cavitation located temporal to optic disc in highly myopic eyes

To investigate the anatomic characteristics of eyes with pathological myopia and peripapillary intrachoroidal cavitation (ICC) located temporal to the optic disc. A total of 125 with pathologic myopia were scanned with swept-source optical coherence tomography (OCT). Temporal ICC was defined as ICC located temporal to the optic disc seen in horizontal OCT section through the optic disc center. Definition of pathologic myopia was refractive error >8.00 diopters (D) or an axial length >26.5 mm. In all, 17 eyes of 16 patients had temporal ICC. All of the eyes had temporal or temporally wider annular conus. The ICC was observed temporal to the optic disc in 15 of 17 eyes, and 2 of the remaining eyes also had inferior ICC. Even in the two eyes with both temporal and inferior ICC, the temporal ICC was much wider than the inferior ICC. Inner retinal defect at the border of conus and temporal ICC was detected in two eyes. The temporal ICC was extensive in the posterior fundus with the average width of 1467.8 ± 1328.1 μm (range; 442-6200 μm) in a horizontal section. In two eyes, the temporal ICC extended beyond the central fovea. Peripapillary ICC can develop temporal to the optic disc without involving the area inferior to optic disc in highly myopic eyes. Temporal ICC appeared much wider than inferior ICC, which is usually restricted to the area around the optic disc. The possible reasons why ICC develops in temporal to the optic disc are presented.

Three-Dimensional Tomographic Features of Dome-Shaped Macula by Swept-Source Optical Coherence Tomography

To study the tomographic and pathomorphologic features of dome-shaped maculas with swept-source optical coherence tomography (OCT). Prospective, cross-sectional study. The macular area of 51 highly myopic eyes (35 patients) with dome-shaped maculas was studied with swept-source OCT at 1050nm. Three-dimensional (3-D) data sets were obtained with raster scanning covering a 12× 8-mm(2) area; 3-D images of the posterior pole were constructed by autosegmentation of the retinal pigment epithelium (RPE). In all reconstructed 3-D images of the RPE, 2 outward concavities were seen within the posterior staphyloma and a horizontal ridge was formed between these 2 concavities. In 42 of these eyes, this horizontal ridge was band shaped. The vertical OCT section through the fovea showed a convex configuration of RPE, but the horizontal section showed an almost flat RPE line. In 9eyes, 3-D images showed a typical dome-shaped convexity within the staphyloma. OCT scans showed no outward protrusions in the external scleral surface, but marked scleral thinning was seen consistent with the 2 outward concavities of the RPE. The sclera of the fovea (518.6 ± 97.6μm) was significantly thicker than that in all 4 quadrants of the parafoveal area (range, 277.2 to 360.3μm; P< .001). In highly myopic eyes with a dome-shaped macula, a horizontal ridge is formed within the posterior staphyloma by uneven thinning of the sclera.

RETINAL SURFACE EN FACE OPTICAL COHERENCE TOMOGRAPHY

To describe the clinical effectiveness of a new imaging approach: en face spectral domain optical coherence tomography of the retinal surface before and after epiretinal membrane (ERM) and internal limiting membrane peeling. Retrospective analysis of preoperative and postoperative en face spectral domain optical coherence tomography images of the inner face of the macula obtained from 20 eyes of 20 patients undergoing vitrectomy with internal limiting membrane peeling for ERM. Preoperatively, en face spectral domain optical coherence tomography imaging of the retinal surface clearly showed plaques surrounded by radiating folds because of ERM. It could also disclose areas possibly devoid of internal limiting membrane secondary to ERM contraction. A rough retinal surface was visible in the peeled area during the first postoperative month. At 3 months, various amounts of dimples were progressively observed in 13 of 15 eyes (87%). In all these cases, they lasted or increased in size and number at the last follow-up examination. Some residual epiretinal tissue was also detected by this technique. En face spectral domain optical coherence tomography of the retinal surface is an interesting complement to standard retinal optical coherence tomography section that provides an easy-to-understand global overview of the retinal surface. It can detect and classify tiny progressive morphologic changes in the texture of the retinal surface occurring after internal limiting membrane peeling.