Optical coherence tomography angiography (OCTA) is a novel and clinically promising imaging modality to image retinal and sub-retinal vasculature. Based on repeated optical coherence tomography (OCT) scans, intensity changes are observed over time and used to compute OCTA image data. OCTA data are prone to noise and artifacts caused by variations in flow speed and patient movement. We propose a novel iterative maximum a posteriori signal recovery algorithm in order to generate OCTA volumes with reduced noise and increased image quality. This algorithm is based on previous work on probabilistic OCTA signal models and maximum likelihood estimates. Reconstruction results using total variation minimization and wavelet shrinkage for regularization were compared against an OCTA ground truth volume, merged from six co-registered single OCTA volumes. The results show a significant improvement in peak signal-to-noise ratio and structural similarity. The presented algorithm brings together OCTA image generation and Bayesian statistics and can be developed into new OCTA image generation and denoising algorithms.
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http://dx.doi.org/10.1364/BOE.408903 | DOI Listing |
J Ophthalmic Inflamm Infect
January 2025
School of Medicine, National Taiwan University, Taipei, Taiwan.
Purpose: To identify the macular retinal layer thickness changes in polyarteritis nodosa (PAN) patients without pathological findings appearing in color fundus photography (CFP), and to investigate the correlations with disease durations.
Methods: A total of 24 PAN patients who had been for 3 years or more and underwent SD-OCT were recruited from the UK Biobank, with exclusions for diabetes, eye disease, or abnormal CFP findings. Only the right eyes were included, with each PAN patient paired one-to-one with a control matched for age, sex, and ethnicity.
Transl Vis Sci Technol
January 2025
Department of Biomedical Engineering, Duke University, Durham, NC, USA.
The introduction of optical coherence tomography (OCT) in the 1990s revolutionized diagnostic ophthalmic imaging. Initially, OCT's role was primarily in the adult ambulatory ophthalmic clinics. Subsequent advances in handheld form factors, integration into surgical microscopes, and robotic assistance have expanded OCT's utility and impact outside of its initial environment in the adult outpatient ophthalmic clinic.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom.
Purpose: To investigate the effect of average intraocular pressure (IOP) on the true rate of glaucoma progression (RoP) in the United Kingdom Glaucoma Treatment Study (UKGTS).
Methods: UKGTS participants were randomized to placebo or Latanoprost drops and monitored for up to two years with visual field tests (VF, 24-2 SITA standard), IOP measurements, and optic nerve imaging. We included eyes with at least three structural or functional assessments (VF with <15% false-positive errors).
Cornea
January 2025
Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA.
Purpose: To report on optical coherence tomography angiography (OCTA) in patients with a type 1 Boston keratoprosthesis (KPro) and determine its feasibility through assessment of imaging artifacts.
Methods: KPro and non-KPro subjects were matched for age, gender, and glaucoma diagnosis. OCTA images of the peripapillary optic nerve were obtained, reviewed by 2 readers masked to the diagnosis for artifacts and usability, and used for microvascular measurements.
Retin Cases Brief Rep
June 2024
Department of Ophthalmology, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905.
Purpose: To report the rare clinical, optical coherence tomography (OCT), and OCT-angiography findings of a visually significant choroidal neovascular membrane (CNV) in the setting of focal choroidal excavation (FCE) in a child.
Methods: Case report and literature review.
Results: A 9-year-old girl with FCE-related central CNV based on clinical findings and multimodal imaging.
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