1. Articles from Marco Ruggeri

    1-22 of 22
    1. Off-axis optical coherence tomography imaging of the crystalline lens to reconstruct the gradient refractive index using optical methods

      Off-axis optical coherence tomography imaging of the crystalline lens to reconstruct the gradient refractive index using optical methods

      Earlier studies have shown that the gradient index of refraction (GRIN) of the crystalline lens can be reconstructed in vitro using Optical Coherence Tomography (OCT) images. However, the methodology cannot be extended in vivo because it requires accurate measurements of the external geometry of the lens. Specifically, the posterior surface is measured by flipping the lens so that the posterior lens surface faces the OCT beam, a method that cannot be implemented in vivo . When the posterior surface is imaged through the lens in its natural position, it appears distorted by the unknown GRIN. In this study, we demonstrate a ...

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    2. Use of High-Resolution Optical Coherence Tomography in the Surgical Management of Ocular Surface Squamous Neoplasia: A Pilot Study

      Use of High-Resolution Optical Coherence Tomography in the Surgical Management of Ocular Surface Squamous Neoplasia: A Pilot Study

      Purpose To evaluate whether high-resolution optical coherence tomography (HR-OCT) can detect histologic tumor margins of ocular surface squamous neoplasia (OSSN). Methods Eight eyes of 8 patients with OSSN undergoing excision were studied prospectively. Immediately before surgery, the tumor was imaged using a commercially available HR-OCT (Bioptigen/Leica Microsystems, Buffalo Grove, IL) to identify the conjunctival margins of the neoplastic lesion. The tumor borders of the lesion determined by HR-OCT were mapped in relation to an anatomical reference point and transferred intraoperatively. The tumor was excised with 4 mm margins from the visible edge of the lesion with a “no-touch” technique ...

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    3. Evaluation of endothelial/Descemet membrane complex of eye bank donor corneas using enhanced depth imaging optical coherence tomography

      Evaluation of endothelial/Descemet membrane complex of eye bank donor corneas using enhanced depth imaging optical coherence tomography

      Objective: We present a novel method for screening eye bank donor corneas using high definition optical coherence tomography (HD-OCT). This technology allows for the quantification of endothelial/Descemet membrane (En/DM) complex thickness ex vivo. Design: Prospective interventional study. Participants: Fifty-two corneal grafts from 27 donors were included in this study. Twenty additional control eyes and 11 eyes with Fuchs’ endothelial corneal dystrophy were also evaluated for comparison. Methods: A custom built, high speed HD-OCT device (Envisu R2210, Bioptigen, Buffalo Grove, IL, USA) was used to obtain images, and custom-made graph-based segmentation software was used to automatically deconstruct corneal images ...

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    4. Variability of manual ciliary muscle segmentation in optical coherence tomography images

      Variability of manual ciliary muscle segmentation in optical coherence tomography images

      Optical coherence tomography (OCT) offers new options for imaging the ciliary muscle allowing direct in vivo visualization. However, variation in image quality along the length of the muscle prevents accurate delineation and quantification of the muscle. Quantitative analyses of the muscle are accompanied by variability in segmentation between examiners and between sessions for the same examiner. In processes such as accommodation where changes in muscle thickness may be tens of microns- the equivalent of a small number of image pixels, differences in segmentation can influence the magnitude and potentially the direction of thickness change. A detailed analysis of variability in ...

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    5. Extended-depth spectral-domain optical coherence tomography imaging of the crystalline lens in Weill-Marchesani-like syndrome

      Extended-depth spectral-domain optical coherence tomography imaging of the crystalline lens in Weill-Marchesani-like syndrome

      A 26-year-old woman presented with signs and symptoms of acute angle-closure glaucoma (ACG) in her left eye. Extended-depth spectral-domain optical coherence tomography (SD-OCT) was performed to biometrically assess the anterior chamber depth and crystalline lens conformation. Extended-depth SD-OCT imaging of the crystalline lens showed bilateral spherophakia without dislocation. Neither eye manifested a highly myopic refractive error despite spherophakia. Unanticipated conformation of the anterior and posterior lenticular curvatures, increased thickness of the crystalline lenses, and short axial lengths explained the lack of a highly myopic refractive error. These findings demonstrated a lens-related cause of the ACG. The use of extended-depth SD-OCT ...

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    6. Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography

      Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography

      Purpose To study the accommodation process in normal eyes using a commercially available clinical system based on swept-source anterior segment optical coherence tomography (AS-OCT). Setting Ophthalmology Department, University of Parma, Italy. Design Evaluation of diagnostic technology. Methods Right eyes were analyzed using swept-source AS-OCT (Casia SS-1000). The optical vergence of the internal coaxial fixation target was adjusted during imaging to obtain monocular accommodation stimuli with different amplitudes (0, 3.0, 6.0, and 9.0 diopters [D]). Overlapping of real and conjugate OCT images enabled imaging of all the anterior segment optical surfaces in a single frame. Central corneal thickness ...

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    7. Biometry of the ciliary muscle during dynamic accommodation assessed with OCT

      Biometry of the ciliary muscle during dynamic accommodation assessed with OCT

      Little is known about the structural changes of the ciliary muscle with age and how it may contribute to presbyopia. Optical coherence tomography (OCT) has been used to perform ciliary muscle biometry at different age and accommodative states with low resolution and speed. Dynamic imaging and accurate biometry of the ciliary muscle requires high-speed, high-resolution and correction of the OCT image distortions. We integrate an existing custom-made Spectral Domain OCT (SD-OCT) platform working at 840nm for biometry of the human eye with a SD-OCT system working at 1325nm that enables high-speed and high-resolution transscleral imaging of the ciliary muscle dynamically ...

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    8. Optical coherence contrast imaging using gold nanorods in living mice eyes

      Optical coherence contrast imaging using gold nanorods in living mice eyes

      Background Optical Coherence Tomography (OCT) is a powerful imaging modality to visualize tissue structures, with axial image pixel resolution as high as 1.6 um in tissue. However, OCT is intrinsically limited to providing structural information as the OCT contrast is produced by optically scattering tissues. Methods Here we demonstrate gold nanorods (GNRs) injected into the anterior chamber (AC) and cornea of mice eyes can create a significant OCT signal and hence can be used as a contrast agent for in vivo OCT imaging. Results We show that a low dose of 30 nM of GNRs (13 nm in diameter ...

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    9. High-Resolution Optical Coherence Tomography-Guided Donor Tissue Preparation for Descemet Membrane Endothelial Keratoplasty Using the Reverse Big Bubble Technique

      High-Resolution Optical Coherence Tomography-Guided Donor Tissue Preparation for Descemet Membrane Endothelial Keratoplasty Using the Reverse Big Bubble Technique

      Purpose: The aim of this study was to assess the feasibility of high-resolution spectral domain optical coherence tomography (HR-SDOCT) to guide donor tissue preparation in Descemet membrane endothelial keratoplasty using the reverse big bubble technique. Methods: Three corneoscleral discs were included in this ex vivo experimental study. A 27-G cannula was introduced into each cornea at the periphery by 3 different surgeons. Each surgeon attempted to achieve the ideal depth (pre-Descemetic plane) of the tip of the cannula for air injection to produce the reverse big bubble to separate the Descemet membrane (DM) from the posterior stroma. A supine optical ...

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    10. In vivo measurement of the average refractive index of the human crystalline lens using optical coherence tomography

      In vivo measurement of the average refractive index of the human crystalline lens using optical coherence tomography

      We present a method for measuring the average group refractive index of the human crystalline lens in vivo using an optical coherence tomography (OCT) system which, allows full-length biometry of the eye. A series of OCT images of the eye including the anterior segment and retina were recorded during accommodation. Optical lengths of the anterior chamber, lens, and vitreous were measured dynamically along the central axis on the OCT images. The group refractive index of the crystalline lens along the central axis was determined using linear regression analysis of the intraocular optical length measurements. Measurements were acquired on three subjects ...

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    11. Intraoperative OCT of Bilateral Macular Coloboma in a Child With Down Syndrome

      Intraoperative OCT of Bilateral Macular Coloboma in a Child With Down Syndrome
      A 3-year-old girl with Down syndrome presented with a macular lesion in both eyes. With intraoperative optical coherence tomography confirmation, the patient was diagnosed as having bilateral macular coloboma. These findings were previously reported in two patients with Down syndrome. The documentation of similar findings in three separate patients suggests that macular coloboma may be a rare ophthalmic pathology associated with Down syndrome. Moreover, optical coherence tomography imaging may be a useful adjunct in diagnosing macular coloboma in the pediatric population.
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    12. Structural Correlation Between the Nerve Fiber Layer and Retinal Ganglion Cell Loss in Mice with Targeted Disruption of the Brn3b Gene

      Structural Correlation Between the Nerve Fiber Layer and Retinal Ganglion Cell Loss in Mice with Targeted Disruption of the Brn3b Gene
      Purpose. Mice with a targeted disruption of Brn3b (knockout Brn3b-/-) undergo the loss of a majority of retinal ganglion cells (RGCs) before birth. Spectral domain optical coherence tomography (SD-OCT) allows for the noninvasive examination of Brn3b-/- cellular loss in vivo. Methods. The central retinas of Brn3b-/- and phenotypically wild-type (Brn3b+/+ and Brn3b±) mice were imaged by SD-OCT. The combined nerve fiber layer (NFL) and inner plexiform layer (IPL) were manually segmented and thickness maps were generated. The results were confirmed by histologic and immunofluorescence cell counts of the RGC layer (RGCL) of the same retinas. Results. The combined NFL and ...
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    13. Postnatal Elongation of Eye Size in DBA/2J Mice Compared with C57BL/6J Mice: In vivo Analysis with Whole-eye OCT

      Postnatal Elongation of Eye Size in DBA/2J Mice Compared with C57BL/6J Mice: In vivo Analysis with Whole-eye OCT
      Purpose. To characterize postnatal changes in eye size in glaucomatous DBA/2J (D2) mice and in non glaucomatous C57BL/6J mice (B6) in vivo by means of whole-eye optical coherence tomography (OCT). Methods. D2 mice (n=32) and B6 mice (n=36) were tested between 2 and 20 months of age in 8 age bins. A custom time-domain OCT system with a center wavelength of 825 nm and an axial scan length of 7.1 mm produced axial a-scan interferograms at a rate of 20 A-lines/s with a resolution 8 μm. Axial length (AL), corneal thickness (CT) anterior chamber ...
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    14. Retinal Structure of Birds of Prey Revealed by Ultra-High Resolution Spectral-Domain Optical Coherence Tomography

      Retinal Structure of Birds of Prey Revealed by Ultra-High Resolution Spectral-Domain Optical Coherence Tomography
      PURPOSE. To reveal three-dimensional (3D) information about the retinal structures of birds of prey in vivo METHODS. An ultra-high resolution spectral-domain optical coherence tomography (SDOCT) system was built for in vivo imaging of bird of prey retina. The calibrated imaging depth and axial resolution of the system were 3.1 mm and 2.8 µm (in tissue), respectively. 3D segmentation was performed for calculation of the retinal nerve fiber layer (RNFL) map. RESULTS. High resolution OCT images of the retinas of four species of birds of prey: two diurnal hawks (Buteo platypterus and Buteo brachyurus) and two nocturnal owls (Bubo ...
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    15. Small animal ocular biometry using optical coherence tomography

      Small animal ocular biometry using optical coherence tomography

      A custom-built OCT system was used to obtain images of the whole mouse eye. We developed a semi-automated segmentation method to detect the boundaries of the anterior and posterior corneal, lens and retinal surfaces as well as the anterior surface of the iris. The radii of curvature of the surfaces were calculated using a conic section fit of each boundary. Image distortions due to refraction of the OCT beam at the successive boundaries were corrected using a ray-tracing algorithm. Corrected ocular distances, radii of curvature of the cornea and lens surfaces, and anterior chamber angle were obtained on 3 C57BL ...

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    16. Intraoperative OCT of a Full-Thickness Macular Hole Before and After Internal Limiting Membrane Peeling

      A child with a traumatic full-thickness macular hole was imaged perioperatively using spectral-domain optical coherence tomography (SD-OCT). Intraoperative imaging using a portable SD-OCT device equipped with a handheld probe demonstrated the full-thickness macular hole to be nearly completely closed following vitrectomy and internal limiting membrane peeling. Air was used as a tamponade agent and prone positioning was used postoperatively for 2 days. SD-OCT imaging confirmed closure of the full-thickness macular hole 5 days and 1 month postoperatively.

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    17. Spectral Domain Optical Coherence Tomography in a Murine Retinal Detachment Model

      Spectral Domain Optical Coherence Tomography in a Murine Retinal Detachment Model

      Spectral domain optical coherence tomography (SD-OCT) was used to image retinal detachments in vivo, in a murine model of retinal detachment. Subretinal injections of hyaluronic acid (Healon) were delivered to the right eye of seventeen 10-20 week-old C57Bl6 mice. Evaluation of the fundus with an operating microscope and fundus photography were performed. In vivo, non-contact, ultra high resolution SD-OCT imaging was performed on day 0, day 1-2, day 5-6 and day 15-16. The retinal morphology at the edge and in the area of maximal RD was evaluated. Eyes were enucleated for histologic analysis. The retinal detachment was confirmed by microscopy ...

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    18. Retinal tumor imaging and volume quantification in mouse model using spectral-domain optical coherence tomography

      Retinal tumor imaging and volume quantification in mouse model using spectral-domain optical coherence tomography

      We have successfully imaged the retinal tumor in a mouse model using an ultra-high resolution spectral-domain optical coherence tomography (SD-OCT) designed for small animal retinal imaging. For segmentation of the tumor boundaries and calculation of the tumor volume, we developed a novel segmentation algorithm. The algorithm is based on parametric deformable models (active contours) and is driven by machine learning-based region classification, namely a Conditional Random Field. With this algorithm we are able to obtain the tumor boundaries automatically, while the user can specify additional constraints (points on the boundary) to correct the segmentation result, if needed. The system and ...

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    19. Polarization effect on the depth resolution of optical coherence tomography

      Shuliang Jiao and Marco Ruggeri We find for the first time that polarization mismatch of the sample and reference arms in optical-fiber-based optical coherence tomography (OCT) has critical effect on its depth resolution when the light source is partially polarized. When the polarization states of the two arms are matched, the mea ... [J. Biomed. Opt. 13, 060503 (2008)] published Thu Dec 11, 2008.
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    20. Direct visualization of tear film on soft contact lens using ultra-high resolution spectral domain optical coherence tomography

      Jianhua Wang, Shuliang Jiao, Marco Ruggeri et al. The integrity of the tear film on the surface of contact lenses is essential to maintaining visual clarity and the overall health of the superficial structures of the eye (cornea and conjunctiva) for contact lens wearers. It is very critical to evaluate pre- and post-lens tear films in contact lens ... [Proc. SPIE Int. Soc. Opt. Eng. 6844, 68441E (2008)] published Mon Feb 11, 2008.
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    21. In vivo imaging of raptor retina with ultra high resolution spectral domain optical coherence tomography

      Among birds, raptors are well known for their exceptional eyesight, which is partly due to the unique structure of their retina. Because the raptor retina is the most advanced of any animal species, in vivo examination of its structure would be remarkable. Furthermore, a noticeable percentage of traumatic ocular injuries are identified in birds of prey presented to rehabilitation facilities. Injuries affecting the posterior segment have been considered as a major impact on raptor vision. Hence, in vivo examination of the structure of the posterior segment of the raptors would be helpful for the diagnosis of traumatized birds. The purpose ...

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    22. Automatic retinal blood flow calculation using spectral domain optical coherence tomography

      Keywords (OCIS): (110.4500) Imaging systems : Optical coherence tomography (120.3890) Instrumentation, measurement, and metrology : Medical optics instrumentation (170.4580) Medical optics and biotechnology : Optical diagnostics for medicine Abstract Optical Doppler tomography (ODT) is a branch of optical coherence tomography (OCT) that can measure the speed of a blood flow by measuring the Doppler shift impinged on the probing sample light by the moving blood cells. However, the measured speed
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    1-22 of 22
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  2. Topics in the News

    1. (22 articles) Marco B. Ruggeri
    2. (20 articles) University of Miami
    3. (6 articles) Shuliang Jiao
    4. (6 articles) Jean-Marie Parel
    5. (6 articles) Fabrice Manns
    6. (4 articles) University of Southern California
    7. (4 articles) Carmen A. Puliafito
    8. (3 articles) Hassan M. Wehbe
    9. (2 articles) Sonia H. Yoo
    10. (2 articles) Arthur Ho
    11. (1 articles) University of Sydney
    12. (1 articles) University of Zurich
    13. (1 articles) UCSD
    14. (1 articles) University of Pittsburgh
    15. (1 articles) L V Prasad Eye Institute
    16. (1 articles) Giuseppe Querques
    17. (1 articles) Carl Zeiss Meditec
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    Retinal tumor imaging and volume quantification in mouse model using spectral-domain optical coherence tomography Small animal ocular biometry using optical coherence tomography Retinal Structure of Birds of Prey Revealed by Ultra-High Resolution Spectral-Domain Optical Coherence Tomography Postnatal Elongation of Eye Size in DBA/2J Mice Compared with C57BL/6J Mice: In vivo Analysis with Whole-eye OCT Intraoperative OCT of Bilateral Macular Coloboma in a Child With Down Syndrome Optical coherence tomography features of neovascularization in proliferative diabetic retinopathy: a systematic review Retinal microvascular metrics in untreated essential hypertensives using optical coherence tomography angiography Optical coherence tomography angiography findings of fellow eye of proliferative macular telangiectasia type 2: Long term study Reorganization of the perifoveal microvasculature after macular hole closure assessed via optical coherence tomography angiography Optical coherence tomography angiography (OCTA) findings in Serpiginous Choroiditis Changes in retinal layer thickness with maturation in the dog: an in vivo spectral domain - optical coherence tomography imaging study Optical coherence tomography angiography analysis of fabry disease