14 results on '"Heiduschka P"'
Search Results
2. Prospective PED-study of intravitreal aflibercept for refractory vascularized pigment epithelium detachment due to age-related macular degeneration: morphologic characteristics of non-responders in optical coherence tomography.
- Author
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Clemens, C. R., Alten, F., Termühlen, J., Mihailovic, N., Rosenberger, F., Heiduschka, P., and Eter, N.
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OPTICAL coherence tomography ,RETINAL degeneration ,POLYPOIDAL choroidal vasculopathy ,PATHOLOGIC neovascularization ,FLUORESCENCE angiography ,EPITHELIUM ,DIFFUSION barriers - Abstract
Purpose: The aim of this study was to investigate the outcomes of a fixed intravitreal aflibercept regimen in patients with vascular pigment epithelium detachment (vPED) secondary to age-related macular degeneration with refractory subretinal fluid. Methods: A prospective, interventional case series involved 20 eyes of 20 patients with refractory subretinal fluid and vPED treated with at least three injections of intravitreal anti-VEGF prior to study inclusion. After study inclusion, patients were treated with three injections of intravitreal aflibercept 2 mg/0.05 mL monthly followed by injections every 8 weeks. Best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) were evaluated at all visits. Fluorescein angiography and indocyanine green angiography were performed at baseline and quarterly. Primary outcomes were effectivity of a fixed treatment as measured in change in BCVA, PED greatest linear diameter (GLD), and PED height from baseline to month 12. In an additional post hoc analysis, vPED patients were differentiated into two groups: (1) vPED lesions that showed persistence of subretinal fluid throughout 1 year of treatment and (2) vPED lesions that showed complete resolution of subretinal fluid at least at one of the monthly performed OCT volume scans. Reflectivity values were determined in the subretinal pigment epithelium (RPE) compartment in OCT scans at baseline, month 6 and 12. Results: A total of 18 patients completed the study protocol. The mean age was 74.8 ± 10.6 years, and six patients were female. The median BCVA of all patients was 72.0 ± 8.0 EDTRS letters at baseline and 72.5 ± 9.5 EDTRS letters at 12-month follow-up (p = 0.7420). The median PED height in all patients as measured in the OCT images significantly decreased from 372.0 ± 140.0 μm to 149.0 ± 142.0 μm after 12 months of treatment (p = 0.0020). Persistent subretinal fluid was present at every OCT control in six patients (group 1). Twelve patients showed resolution of subretinal fluid at least at one OCT control (group 2). Reflectivity values in the sub-RPE compartment in OCT scans were 41.48 ± 4.48 (group 1) and 42.62 ± 12.34 (group 2) at baseline (p = 0.854) and 65.88 ± 6.74 and 50.87 ± 14.11 at month 12 (p = 0.038). Conclusions: Intravitreal aflibercept in refractory vPED leads to a significant reduction in PED height and disease activity as well as preservation of BCVA over 1 year. Persistent subretinal fluid was present in PED lesions with high values of reflectivity under the RPE, suggesting both a diffusion barrier and an increasing fibrovascular maturization of the choroidal neovascularization. Trial registration: ClinicalTrials.gov Identifier: NCT03370380 [ABSTRACT FROM AUTHOR]
- Published
- 2020
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3. Impact of integrated multiple image averaging on OCT angiography image quality and quantitative parameters.
- Author
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Lauermann, Jost L., Xu, Y., Heiduschka, P., Treder, M., Alten, F., Eter, N., and Alnawaiseh, M.
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RETINAL imaging ,SIGNAL-to-noise ratio ,OPTICAL coherence tomography - Abstract
Purpose: Multiple image averaging (MIA) is a new approach to improve OCT angiography (OCTA) imaging. The aim of this work was to analyze the impact of MIA on image quality and quantitative OCTA parameters. Methods: Twenty eyes from 20 healthy volunteers (55.65 ± 14.8 years) were prospectively enrolled. Imaging was performed using two commercially available OCTA devices (Canon OCT HS-100, Optovue AngioVue) using a uniform imaging protocol. Each participant had two single scans of the macula (3 × 3mm, Canon and Optovue) as well as five continuous single scan imaging procedures (3 × 3mm each) using the Canon device. Three out of five of these images with highest quality were manually chosen and then automatically processed by the Canon device using MIA. The superficial retinal plexus of the single scans and of MIA images was analyzed with regard to the device' own image quality scores (IQS), peak signal-to-noise ratio (PSNR), the size of the foveolar avascular zone (FAZ), and vessel density (VD). Image acquisition times were recorded. Parameters were compared between the devices and the different imaging protocols. Results: Average acquisition time was significantly higher for the MIA compared with the single measurements (29.09 ± 10.19 seconds (s) (MIA) vs. 5.56 ± 2.17 s (Canon single scan) vs. 20.28 ± 6.81 s (Optovue) (p < 0.001)). IQS showed no significant differences between the devices and between the recording protocols. PSNR was 12.38 ± 0.20 (Canon single scan), 13.01 ± 0.36 (Canon MIA), and 14.34 ± 0.60 (Optovue) (p < 0.001 between the groups). Mean FAZ area in Canon single scans was 0.29 ± 0.06 mm
2 , 0.27 ± 0.07 mm2 using MIA, and 0.27 ± 0.08 mm2 using the Optovue device. There was no significant difference between mean FAZ measurements before and after averaging (Canon single scan vs. MIA, p = 0.168). VD of the parafoveal area using MIA was significantly lower compared with both single scans (p < 0.001). Conclusions: MIA can improve PSNR, but it also reduces imaging speed and significantly affects VD measurements. Therefore, when comparing OCTA data, the use of uniform imaging protocols is required. [ABSTRACT FROM AUTHOR]- Published
- 2019
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4. Volumetrische Analyse der vaskularisierten Pigmentepithelabhebung bei AMD: Post-hoc-Analyse der RECOVER-Studie.
- Author
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Clemens, C. R., Alten, F., Heiduschka, P., Gamulescu, M. A., Wolf, A., and Eter, N.
- Abstract
Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
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5. Signal reduction in choriocapillaris and segmentation errors in spectral domain OCT angiography caused by soft drusen.
- Author
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Alten, F., Lauermann, J., Clemens, C., Heiduschka, P., and Eter, N.
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CAPILLARIES ,RETINAL imaging ,OPTICAL coherence tomography ,ANGIOGRAPHY ,SPECTRUM analysis - Abstract
Purpose: To analyze signal reduction in choriocapillaris (CC) and segmentation errors in spectral domain optical coherence tomography angiography (OCT-A) caused by soft drusen due to age-related macular degeneration (AMD). Methods: Twenty-four eyes of 24 patients underwent multimodal retinal imaging including central 3 × 3mm OCT-A (AngioVue, Optovue). Three drusen per study eye were randomly chosen and evaluated regarding drusen height, diameter, and accuracy of OCT-A layer segmentation in lesion proximity. Structural en-face OCT CC images were graded qualitatively and quantitatively regarding signal loss underneath the individual drusen area. Those drusen that showed no distinct signal loss in structural en-face OCT CC images were further evaluated in OCT-A. CC decorrelation signal index was measured within a 30-μm OCT-A CC slab in the exact area of drusen affection. Data were compared to healthy age-matched control subjects. Accuracy of layer segmentation, OCT CC data, and OCT-A CC data were correlated to morphological drusen parameters. Results: Mean drusen height and diameter were 91.57 ± 19.5μm and 315.17 ± 116.7μm. OCT-A layer segmentation of the inner plexiform layer (IPL) was disturbed by more than 50 μm in proximity to 26 drusen (36.1%). In these patients, drusen height was significantly higher compared to those with accurate IPL segmentation ( p = 0.0126). Sixty-six out of 72 drusen (91.7%) caused a distinct signal loss in the structural en-face OCT CC image. Drusen height and drusen diameter were significantly higher in this group compared to the six drusen with a sufficient signal ( p = 0.0276, p = 0.0025). CC decorrelation signal index measured in the area of these six drusen without OCT signal loss (8.3%) was reduced compared to age-matched healthy controls (73.6 vs. 100.1; p = 0.001). Conclusions: Signal attenuation in CC slabs and segmentation errors of the IPL depend on drusen morphology. Both are frequent artifacts in OCT-A imaging in patients with soft drusen and must be considered during image analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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6. Impact of eye-tracking technology on OCT-angiography imaging quality in age-related macular degeneration.
- Author
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Lauermann, J., Treder, M., Heiduschka, P., Clemens, C., Eter, N., and Alten, F.
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RETINAL degeneration ,RETINAL imaging ,OPTICAL coherence tomography ,ANGIOGRAPHY ,EYE movements ,DIAGNOSIS - Abstract
Objective: To evaluate the impact of eye-tracking (ET) technology on optical coherence tomography angiography (OCT-A) image quality and manifestation of motion artifacts in patients with age-related macular degeneration (AMD). Methods: In a prospective trial, multimodal retinal imaging including OCT-A was performed in 30 patients (78.97 ± 9.7 years) affected by different stages of AMD. Central 3 × 3 mm OCT-A imaging was performed four times consecutively in each patient, twice with active, and twice with inactive ET. Parameters for image evaluation were signal strength index (SSI), variability of foveal vessel density (VD), acquisition time, presence of motion artifacts caused by eye movement (blink lines, displacement) and by software correction of eye movement (quilting, stretch artifacts, vessel doubling). Images were evaluated by two independent readers with subsequent senior reader arbitration for presence of artifacts, and an OCT-A motion artifact score (MAS) was calculated. Results: Eight patients had early and eight patients had intermediate stages of AMD. Four patients had an atrophic late stage and ten patients an exudative stage of the disease. SSI was 53.55 with inactive and 57.18 with active ET ( p = 0.0005). Coefficients of variability of VD between the first and second measurement were 8.9% with inactive and 5.7% with active ET. Mean image acquisition time was 15.97 s (active ET: 22.88 s, p < 0.001). Presence of motion artifacts was significantly higher with inactive ET (mean MAS 3.27 vs. 1.93; p < 0.0001). MAS correlated with AMD disease stage [ p = 0.0031 (inactive ET) and p < 0.0001 (active ET)] and with SSI ( p = 0.0072 and p = 0.0006). Conclusions: In patients with AMD, active ET technology offers an improved image quality in OCT-A imaging regarding presence of motion artifacts at the expense of higher acquisition time. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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7. Quantification of changes in foveal capillary architecture caused by idiopathic epiretinal membrane using OCT angiography.
- Author
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Nelis, P., Alten, F., Clemens, C., Heiduschka, P., and Eter, N.
- Subjects
OPTICAL coherence tomography ,RETINAL blood vessels ,RETINAL degeneration ,RETINAL surgery ,VASOCONSTRICTION - Abstract
Purpose: To quantify the extent and depth of distortion of the foveal capillary architecture due to traction of an idiopathic epiretinal membrane (ERM) using optical coherence tomography angiography (OCT-A). Methods: Multimodal imaging including OCT-A (Angiovue, Optovue) was performed in 42 eyes with idiopathic ERM (72.4 years ±6.8). Best corrected visual acuity (BCVA), OCT-A vessel density of the foveal (VDfo) and parafoveal (VDp) region were assessed. Based on 6 × 6-mm OCT-A images, a macular vessel density ratio (MVR = VDfo/VDp) was calculated for the superficial (s), deep (d) and full-thickness (f) slabs to assess a depth-resolved, non-invasive evaluation of foveal distortion. The acquired data were subdivided in a patient group with mild and significant BCVA reduction due to ERM. Data was compared to age-matched healthy controls. Results: In all three slabs, MVR was significantly smaller in the control group in comparison with the ERM group: MVRs: 0.63 ± 0.1 vs 0.83 ± 0.1 ( p > 0.001); MVRd: 0.60 ± 0.1 vs 0.73 ± 0.1 ( p < 0.001); MVRf: 0.68 ± 0.1 vs 0.82 ± 0.1 ( p < 0.001). Group 1 (BCVA <0.4 LogMar) showed a significantly higher MVR in comparison with the control group in the superficial plexus only: MVRs: 0.64 ± 0.1 vs 0.78 ± 0.1 ( p < 0.001); MVRd: 0.60 ± 0.1 vs 0.65 ± 0.2 ( p = 0.3); MVRf: 0.68 ± 0.1 vs 0.77 ± 0.1 ( p = 0.01). However, group 2 (BCVA > = 0.4 LogMar) showed a significantly higher MVR in all three slabs: MVRs: 0.64 ± 0.1 vs 0.86 ± 0.1 ( p < 0.001); MVRd: 0.60 ± 0.1 vs 0.77 ± 0.2 ( p < 0.001); MVRf: 0.68 ± 0.1 vs 0.85 ± 0.1 ( p < 0.001). Conclusion: Assessing MVR using OCT-A may serve as a tool to quantify the extent and depth of distortion of the foveal capillary architecture due to traction of ERM. BCVA reduction appears to be associated with extent and depth of distortion. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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8. Implantable visual prostheses.
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Steiger, H. -J., Sakas, Damianos E., Simpson, Brian A., Thanos, Solon, Heiduschka, P., and Stupp, T.
- Abstract
Visual impairment and blindness is primarily caused by optic neuropathies like injuries and glaucomas, as well as retinopathies like agerelated macular degeneration (MD), systemic diseases like diabetes, hypertonia and hereditary retinitis pigmentosa (RP). These pathological conditions may affect retinal photoreceptors, or retinal pigment epithelium, or particular subsets of retinal neurons, and in particular retinal ganglion cells (RGCs). The RGCs which connect the retina with the brain are unique cells with extremely long axons bridging the distance from the retina to visual relays within the thalamus and midbrain, being therefore vulnerable to heterogeneous pathological conditions along this pathway. When becoming mature, RGCs loose the ability to divide and to regenerate their accidentally or experimentally injured axons. Consequently, any loss of RGCs is irreversible and results to loss of visual function. The advent of micro- and nanotechnology, and the construction of artificial implants prompted to create visual prostheses which aimed at compensating for the loss of visual function in particular cases. The purpose of the present contribution is to review the considerable engineering expertise that is essential to fabricate current visual prostheses in connection with their functional features and applicability to the animal and human eye. In this chapter, 1) Retinal and cortical implants are introduced, with particular emphasis given to the requirements they have to fulfil in order to replace very complex functions like vision. 2) Advanced work on material research is presented both from the technological and from the biocompatibility aspect as prerequisites of any perspectives for implantation. 3) Ultimately, experimental studies are presented showing the shaping of implants, the procedures of testing their biocompatibility and essential modifications to improve the interfaces between technical devices and the biological environment. The review ends by pointing to future perspectives in the rapidly accelerating process of visual prosthetics and in the increasing hope that restoration of the visual system becomes reality. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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9. Characterisation of reticular pseudodrusen and their central target aspect in multi-spectral, confocal scanning laser ophthalmoscopy.
- Author
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Alten, F., Clemens, C., Heiduschka, P., and Eter, N.
- Subjects
RETICULAR formation ,SCANNING laser ophthalmoscopy ,RETINAL degeneration ,AGE factors in disease ,IMAGE analysis - Abstract
Background: To analyse reticular pseudodrusen (RPD) in patients with age-related macular degeneration (AMD) using multi-spectral (MS), confocal scanning laser ophthalmoscopy (cSLO). Methods: cSLO images (blue fundus autofluorescence [FAF; exc., λ = 488; em., λ = 500-700 nm], near-infrared reflectance [IR; λ = 820 nm], MS [blue reflectance (BR) λ = 488 nm, green reflectance (GR) λ = 515 nm, IR λ = 820 nm], as well as colour fundus photographs (CFP) were taken of 200 eyes from 100 AMD patients suspected to show RPD on the basis of funduscopy or previous fundus imaging. FAF and IR images were graded by two independent readers. If both readers concordantly confirmed the presence of RPD in both modalities, eyes were subsequently also graded for RPD in MS, BR, GR, green-blue enhanced mode (GBE), and CFP. Besides, FAF, IR, and MS images were evaluated for the presence of a target aspect, which represents a common feature of RPD lesions. Results: The presence of RPD was confirmed using FAF and IR images by both readers in 130 eyes of 76 patients. In those eyes, both readers concordantly diagnosed RPD in MS images in 124 (95.4 %) eyes (BR: 52 [40.0 %], GR: 63 [48.5 %], GBE: 101 [77.7 %], CF: 27 [20.8 %]). Cohen kappa statistics revealed excellent inter-observer agreement for MS (0.95) and GBE (0.85), substantial agreement for BR (0.75), GR (0.78), and moderate agreement for CFP (0.59). A target aspect within RPD lesions was detected in 45 of 130 (35.0 %) included eyes using FAF and IR. The presence of a target aspect improved the recognition of RPD lesions in all modalities. If a target aspect was present, RPD were diagnosed in 45 eyes (100 %) using MS (GBE: 42 eyes [93.3 %], BR: 30 eyes [66.7 %], GR: 37 eyes [82.2 %], CFP: 17 eyes [37.8 %]). Using MS cSLO, a target aspect could be identified in 75 of 130 (57.7 %) included eyes. Conclusions: MS cSLO imaging is equivalent to FAF and IR in identifying RPD in AMD patients. Higher identification rates in BR and GR of those RPD lesions featuring a target aspect confirm the current hypothesis of RPD localisation and its progression further into the photoreceptor layers. MS seems to be more sensitive in identifying a central target aspect in RPD lesions compared to blue FAF and IR. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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10. Non-viral gene therapy for GDNF production in RCS rat: the crucial role of the plasmid dose.
- Author
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Touchard, E, Heiduschka, P, Berdugo, M, Kowalczuk, L, Bigey, P, Chahory, S, Gandolphe, C, Jeanny, J-C, and Behar-Cohen, F
- Subjects
- *
VIRAL genetics , *GENE therapy , *GLIAL cell line-derived neurotrophic factor , *PLASMIDS , *DRUG dosage , *NEUROTROPHINS , *LABORATORY rats - Abstract
Glial cell line-derived neurotrophic factor (GDNF) is one of the candidate molecules among neurotrophic factors proposed for a potential treatment of retinitis pigmentosa (RP). It must be administered repeatedly or through sustained releasing systems to exert prolonged neuroprotective effects. In the dystrophic Royal College of Surgeon's (RCS) rat model of RP, we found that endogenous GDNF levels dropped during retinal degeneration time course, opening a therapeutic window for GDNF supplementation. We showed that after a single electrotransfer of 30 μg of GDNF-encoding plasmid in the rat ciliary muscle, GDNF was produced for at least 7 months. Morphometric, electroretinographic and optokinetic analyses highlighted that this continuous release of GDNF delayed photoreceptors (PRs) as well as retinal functions loss until at least 70 days of age in RCS rats. Unexpectedly, increasing the GDNF secretion level accelerated PR degeneration and the loss of electrophysiological responses. This is the first report: (i) demonstrating the efficacy of GDNF delivery through non-viral gene therapy in RP; (ii) establishing the efficacy of intravitreal administration of GDNF in RP associated with a mutation in the retinal pigment epithelium; and (iii) warning against potential toxic effects of GDNF within the eye/retina. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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11. Einsatz von Nanopartikeln in der Augenheilkunde.
- Author
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Hahn, I., Heiduschka, P., Endl, E., and Eter, N.
- Abstract
Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
- Full Text
- View/download PDF
12. Lokalisation von Bevacizumab in der Netzhaut von Affen nach einer intravitrealen Bevacizumab-Injektion.
- Author
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Schraermeyer, U., Heiduschka, P., and Bartz-Schmidt, K.U.
- Abstract
Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2009
- Full Text
- View/download PDF
13. Poppers maculopathy or retinopathy?
- Author
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Clemens, C R, Alten, F, Loos, D, Uhlig, C E, Heiduschka, P, and Eter, N
- Subjects
RETROLENTAL fibroplasia ,RETINAL diseases - Abstract
A letter to the editor is presented in which poppers maculopathy is being discussed.
- Published
- 2015
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14. Shot-noise limited, supercontinuum-based optical coherence tomography.
- Author
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Rao D S S, Jensen M, Grüner-Nielsen L, Olsen JT, Heiduschka P, Kemper B, Schnekenburger J, Glud M, Mogensen M, Israelsen NM, and Bang O
- Abstract
We present the first demonstration of shot-noise limited supercontinuum-based spectral domain optical coherence tomography (SD-OCT) with an axial resolution of 5.9 μm at a center wavelength of 1370 nm. Current supercontinuum-based SD-OCT systems cannot be operated in the shot-noise limited detection regime because of severe pulse-to-pulse relative intensity noise of the supercontinuum source. To overcome this disadvantage, we have developed a low-noise supercontinuum source based on an all-normal dispersion (ANDi) fiber, pumped by a femtosecond laser. The noise performance of our 90 MHz ANDi fiber-based supercontinuum source is compared to that of two commercial sources operating at 80 and 320 MHz repetition rate. We show that the low-noise of the ANDi fiber-based supercontinuum source improves the OCT images significantly in terms of both higher contrast, better sensitivity, and improved penetration. From SD-OCT imaging of skin, retina, and multilayer stacks we conclude that supercontinuum-based SD-OCT can enter the domain of shot-noise limited detection.
- Published
- 2021
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