We demonstrate that OCT images quantify subdiffractional tissue structure. Optical coherence tomography (OCT) measures stratified tissue morphology with spatial resolution limited by the temporal coherence length. Spectroscopic OCT processing, on the other hand, has enabled nanoscale sensitive analysis, presenting an unexplored question: how does subdiffractional information get folded into the OCT image and how does one best analyze to allow for unambiguous quantification of ultrastructure? We first develop an FDTD simulation to model spectral domain OCT with nanometer resolution. Using this, we validate an analytical relationship between the sample statistics through the power spectral density (PSD) of refractive index fluctuations and three measurable quantities (image mean, image variance, and spectral slope), and have found that each probes different aspects of the PSD (amplitude, integral and slope, respectively). Finally, we found that only the spectral slope, quantifying mass scaling, is monotonic with the sample autocorrelation shape.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8221934 | PMC |
http://dx.doi.org/10.1364/BOE.416572 | DOI Listing |
Background: To evaluate the associations between anatomical changes and visual outcomes after membrane peeling in eyes with different stages of idiopathic epiretinal membrane (iERM) using optical coherence tomography angiography (OCTA).
Methods: All iERM eyes were graded into four stages based on the presence of ectopic inner foveal layers (EIFL) and underwent 23-gauge vitrectomy combined with ERM and internal limiting membrane (ILM) peeling, while their fellow eyes were treated as the control group. OCTA was used to measure retinal thickness(RT), foveal avascular zone (FAZ)-related parameters and superficial and deep capillary plexus (SCP and DCP) layers using 6 × 6 mm scans before, 1 month and 3 months after surgery.
BMC Ophthalmol
January 2025
St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK.
Background: The post-operative evaluation of trabeculectomy blebs has traditionally relied on subjective clinical grading systems performed at the slit-lamp. This study explores the use of swept source anterior-segment optical coherence tomography (AS-OCT) to objectively measure bleb internal reflectivity and morphology, and to distinguish blebs with surgical success vs. failure.
View Article and Find Full Text PDFGraefes Arch Clin Exp Ophthalmol
January 2025
Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
Purpose: To investigate the role of corneal epithelium- and Bowman's layer-thickness (ET and BLT) changes as possible early biomarkers of keratoconus (KC) development.
Methods: In this cross-sectional study patients with unilateral KC (UKC) and a group of healthy controls underwent polarization sensitive optical coherence tomography (PS-OCT) for the evaluation of corneal ET and BLT. These values were compared among three subgroups of eyes, i.
J Glob Health
January 2025
Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Background: Recreational screen time (RST) has been found to be associated with cognitive decline and neurodegenerative diseases. However, the association between RST and age-related macular degeneration (AMD), an ocular neurodegenerative disease, is still unclear. We aimed to elucidate the association between RST and AMD.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Purpose: To investigate the heritability of genetic influence on macular choroidal vascularity index (CVI).
Methods: Total choroidal area (TCA), luminal area (LA), and CVI was measured using horizontal scan of spectral-domain optical coherence tomography with enhanced depth imaging in the 373 healthy twin participants. Characteristics of the participants were investigated, including age, sex, axial length, hypertension, diabetes, drinking habits, and smoking status.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!