The performance of optically coherent imaging systems can be limited by measurement and speckle noise. In this paper, we develop an image formation framework for computing the maximum a posteriori estimate of an object's reflectivity when imaged using coherent illumination and detection. The proposed approach allows for the use of Gaussian denoising algorithms (GDAs), without modification, to mitigate the exponentially distributed and signal-dependent noise that occurs in coherent imaging. Several GDAs are compared using both simulated and experimental data. The proposed framework is shown to be robust to noise and significantly reduce reconstruction error compared to the standard inversion technique.
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http://dx.doi.org/10.1364/AO.56.004735 | DOI Listing |
Int Ophthalmol
January 2025
Department of Ophthalmology, Staedtisches Klinikum Dessau, Brandenburg Medical School Theodor Fontane, Dessau, Germany.
Purpose: Uveal melanoma (UM) is the most common primary ocular malignancy. The size and location of the tumor are decisive for brachytherapy with the β-emitting ruthenium-106 (Ru-106) plaque. The treatment of juxtapapillary and juxtafoveolar UM may be challenging because of the proximity or involvement of the macula and optic nerve and high recurrence rates.
View Article and Find Full Text PDFJ Clin Med
January 2025
Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples "Federico II", 80131 Napoli, Italy.
: This study aimed to assess the role of macular pigment optical density (MPOD) in patients with a full-thickness macular hole (FTMH) compared to healthy controls, evaluating postoperative changes in MPOD and exploring potential correlations with visual outcomes. : This prospective, cross-sectional, comparative study included 16 eyes from FTMH patients who achieved anatomical hole closure following pars plana vitrectomy with the inverted ILM flap technique. Each eye underwent a comprehensive ophthalmologic examination, including BCVA and intraocular pressure measurements, anterior segment evaluation, fundus examination, and macular assessment with Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT, Spectralis, Heidelberg Engineering Inc.
View Article and Find Full Text PDFJ Clin Med
January 2025
Department of Ophthalmology, St. Barbara Hospital, Trauma Centre, 41-200 Sosnowiec, Poland.
The aim of this retrospective study was to compare corneal parameters and compliance using a Pentacam HR-Scheimpflug (Pentacam HR) and a swept-source OCT Casia (Casia) in keratoconus (KC) patients post penetrating keratoplasty (PKP) and KC patients without PKP, as well as a control group. Pachymetry measurements were also analyzed using a spectral domain OCT Solix (OCT Solix), Pentacam HR, and Casia. The study included 71 patients (136 keratoconic eyes; group A), 86 eyes with KC post-PKP (group B), 50 eyes with KC without PKP (group C), and 52 control participants (104 eyes).
View Article and Find Full Text PDFJ Clin Med
December 2024
Lions Eye Institute, Perth, WA 6009, Australia.
Diabetic macular edema (DME) is a significant cause of vision loss. The development of peripheral non-perfusion (PNP) might be associated with the natural course, severity, and treatment of DME. The present study seeks to understand the predictive power of central macular changes and clinico-demographic features for PNP in patients with clinically significant DME.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Research and Educational Center for Physics of Solid State Nanostructures of Lobachevsky State University of Nizhniy Novgorod, 603950 Nizhniy Novgorod, Russia.
This paper proposes and implements a novel scheme for recording signals from fibre optic sensors based on tandem low-coherence interferometry with an integrated optical reference interferometer. The circuit allows precision control of the phase shift. Additionally, the paper illustrates the potential for detecting vibration and object deformation using fibre optic Fabry-Perot sensors connected to the registration system.
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