Probing bio-tissue films by optical internal reflectivity: modeling and measurements

2021 ◽  
Vol 60 (27) ◽  
pp. 8588
Author(s):  
Anays Acevedo-Barrera ◽  
Augusto García-Valenzuela
Keyword(s):  
Internal Reflectivity

scholarly journals Diagnostic A-Scan of Choroidal Tumors: Comparison of Quantified Parameters

2019 ◽  
Vol 5 (5) ◽  
pp. 358-368 ◽  
Author(s):  
Nakul Singh ◽  
Yombe Fonkeu ◽  
Brandy H. Lorek ◽  
Arun D. Singh
Keyword(s):  
Clinical Diagnosis ◽  
Choroidal Melanoma ◽  
Choroidal Metastasis ◽  
Choroidal Hemangioma ◽  
Custom Made ◽  
Tissue Sensitivity ◽  
Choroidal Nevus ◽  
The Mean ◽  
Standard Techniques ◽  
Internal Reflectivity

Aim: To compare quantified ultrasonographic A-scan parameters of common choroidal tumors. Methods: Consecutive patients with a clinical diagnosis of choroidal melanoma (n = 100), choroidal nevus (n = 30), choroidal metastasis (n = 10), and circumscribed choroidal hemangioma (n = 10) were included in this study. Ultrasonographic A-scans (8 MHz, 1,550 m/s, tissue sensitivity = 67 dB) were performed by standard techniques. Using a custom made MATLAB® script, four quantifiable A-scan parameters: tumor height (mm), number of internal reflectivity peaks (numerical value), median internal reflectivity (%), and angle κ (°) were obtained for all (n = 150) tumors. Results: The mean number of internal reflectivity peaks for choroidal nevus, choroidal metastasis, and circumscribed choroidal hemangioma was 3.1, 5.1, and 4.0, respectively. The median internal reflectivity for choroidal melanoma varied from 21.5 to 99.5% (mean = 76.4%). The median internal reflectivity was ≥65% in all choroidal nevus (100%), choroidal metastasis (100%), and circumscribed choroidal hemangioma (100%), and majority of the choroidal melanoma (78%). Conclusions: The quantified A-scan patterns of common choroidal tumors were significantly influenced by the tumor height. Other than median internal reflectivity of < 65%, which seems to distinguish choroidal melanoma from other tumors (choroidal nevus, choroidal metastasis, and circumscribed choroidal hemangioma), there were no specific diagnostic patterns.

Photon Diffusion and Internal Reflectivity

1993 ◽  
pp. 171-179 ◽  
Author(s):  
A. A. Lisyansky ◽  
J. H. Li ◽  
D. Livdan ◽  
N. Garcia ◽  
T. D. Cheung ◽  
...  
Keyword(s):  
Photon Diffusion ◽  
Internal Reflectivity

scholarly journals Pigmented Free-Floating Posterior Vitreous Cyst

2012 ◽  
Vol 2012 ◽  
pp. 1-3
Author(s):  
Claudia Bruè ◽  
Cesare Mariotti ◽  
Edoardo De Franco ◽  
Nicola De Franco ◽  
Alfonso Giovannini
Keyword(s):  
Unusual Case ◽  
Color Doppler ◽  
Color Doppler Ultrasound ◽  
Fundus Examination ◽  
Pigmented Lesion ◽  
Ocular Disorders ◽  
Vitreous Cyst ◽  
The Right ◽  
Internal Reflectivity

Vitreous cysts are very rare ocular malformations. In this observational case study, we report on an unusual case of a pigmented free-floating vitreous cyst and discuss its differential diagnosis. A 14-year-old male was referred to ophthalmology for a pigmented lesion in his left eye. He complained of an intermittent floater in the left eye. Visual acuity was 20/20 in the right eye and 20/40 in the left eye. Fundus examination was unremarkable bilaterally, except for a piece of brownish oval material floating in the vitreous in the left eye. He had received a knock on the left side of his head a few days before the visual discomfort of the left eye. Real-time ultrasound of the left eye detected a piece of hyperechogenic spherical material with no internal reflectivity, floating in the middle of the vitreous. The first use of color Doppler ultrasound in this context indicated no arterial flow, ruling out the presence of a persistent hyaloid artery. Intraocular cysts are rare ocular disorders, which have been divided into clear and pigmented cysts, and into those that occupy the anterior chamber, the retrolental space, and the vitreous cavity. This last is extremely rare. We describe such a case.

scholarly journals An atypically distributed fleck case with multiple retinal pigment epithelial detachments

2021 ◽  
Vol 11 (1) ◽  
pp. 1-3
Author(s):  
Sercan Cate ◽  
Caglar Bektas ◽  
Burak Turgut
Keyword(s):  
Optical Coherence Tomography ◽  
Retinal Pigment Epithelial ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Peripheral Retina ◽  
Fundus Examination ◽  
Blurred Vision ◽  
Pigment Epithelial ◽  
The Right ◽  
Internal Reflectivity

A 45-year-old female patient presented with complaints of blurred vision and metamorphopsia with a duration of two months. Visual acuities were 0.1 in the right eye and 1.0 in the left eye. Fundus examination revealed bilateral, subretinal, round and yellow-white flecks with scattered localization in the fovea, macula and peripheral retina. Flecks were mostly concentrated in the macula and midperipheral fundus however were rare in the peripheral fundus. In fluorescein angiography, flecks were stained as well-demarcated hyperfluorescent lesions. In optical coherence tomography, there were hump-shaped lesions which have medium degree internal reflectivity at the level of retinal pigment epithelium along with hyporeflective dome-shaped pigment epithelial detachments. No genetic predisposition was found. As a consequence of these findings, the patient was diagnosed with an atypically distributed fleck case with multiple retinal pigment epithelial detachments

scholarly journals Diagnostic A-Scan of Choroidal Melanoma: Automated Quantification of Parameters

2019 ◽  
Vol 5 (5) ◽  
pp. 350-357
Author(s):  
Yombe Fonkeu ◽  
Nakul Singh ◽  
Brandy Hayden-Loreck ◽  
Arun D. Singh
Keyword(s):  
Clinical Diagnosis ◽  
Choroidal Melanoma ◽  
Automated Algorithm ◽  
Automated Quantification ◽  
Tissue Sensitivity ◽  
The Mean ◽  
Positive Angle ◽  
Standard Techniques ◽  
Internal Reflectivity

Aim: To develop an automated algorithm to quantify ultrasonographic A-scan parameters of choroidal melanoma. Methods: The study included 100 consecutive patients with a clinical diagnosis of choroidal melanoma. Ultrasonographic A-scans (8 MHz, 1,550 m/s, tissue sensitivity = 67 dB) were performed by standard techniques. We created and then utilized a MATLAB® script to generate four quantifiable A-scan parameters: (1) tumor height (mm), (2) the number of internal reflectivity peaks (numerical value), (3) median internal reflectivity (%), and (4) angle κ (°). Results: There were small (≤2.5 mm, n = 32), medium (2.6–10.0 mm, n = 53), and large (> 10.0 mm, n = 14) tumors. The mean number of internal reflectivity peaks counted between the two tumor boundary spikes (surface and base) was 10.0 (σ = 8.7, range 1–37). The median value of the internal reflectivity peaks for all cases varied from 19.8 to 99.5 (mean = 68.3, σ = 20.5). A statistically significant correlation was observed between the tumor height categories and each of the three A-scan parameters: the number of internal reflectivity peaks (ρ = 0.90, p < 0.01), median internal reflectivity (ρ = –0.63, p < 0.01), and a positive angle κ (ρ = –0.32, p = 0.03). Conclusions: An automated algorithm can provide quantifiable A-scan parameters for choroidal melanoma.

scholarly journals Metastatic Choroidal Melanoma Presenting as Neovascular Glaucoma

2021 ◽  
pp. 791-796
Author(s):  
Gregory Fliney ◽  
Osama Ahmed ◽  
Benjamin Young ◽  
Christopher Teng ◽  
Renelle Pointdujour-Lim
Keyword(s):  
Uveal Melanoma ◽  
Hepatic Metastases ◽  
Choroidal Melanoma ◽  
Neovascular Glaucoma ◽  
Rare Presentation ◽  
Intraocular Tumor ◽  
Ultrasonographic Examination ◽  
Life Threatening ◽  
Unclear Etiology ◽  
Internal Reflectivity

Uveal melanoma is the most common primary intraocular tumor in adults and can have varying presentations, although it is frequently asymptomatic. One rare presentation of uveal melanoma is neovascular glaucoma (NVG). We present a case of a 20-year-old male who presented with 2 weeks of left eye redness and decreased vision who was found to have NVG. He was referred for evaluation of glaucoma. Fundoscopic and ultrasonographic examination revealed a mushroom-shaped choroidal mass with low internal reflectivity consistent with choroidal melanoma. The patient underwent enucleation, and metastatic workup revealed hepatic metastases. The patient died 18 months after initial diagnosis. This case emphasizes the importance of a complete ophthalmic evaluation in cases presenting with NVG of unclear etiology to exclude the presence of a potentially life-threatening intraocular tumor.

Morphometric analysis of fibrovascular pigment epithelial detachments treated with ranibizumab and aflibercept

2021 ◽  
pp. 112067212110057
Author(s):  
Michael Karampelas ◽  
Maria Syriga ◽  
Petros Petrou ◽  
Ilias Georgalas ◽  
Dimitrios Papaconstantinou ◽  
...  
Keyword(s):  
Morphometric Analysis ◽  
Maximum Height ◽  
Strongly Correlated ◽  
Base Area ◽  
Pigment Epithelial ◽  
Anti Vegf ◽  
Custom Made ◽  
Significant Difference ◽  
Treatment Naïve ◽  
Internal Reflectivity

Purpose: To assess fibrovascular pigment epithelial detachments (PED) and their response to two different anti-VEGF agents using optical coherence tomography (OCT) morphometric analysis. Methods: Seventy-three consecutive, treatment-naïve eyes with fibrovascular PED (>125 μm) treated with ranibizumab or aflibercept were retrospectively included. A custom-made software was used to manually segment and calculate PED maximum height, base area, volume and internal reflectivity at baseline, after three injections and 1 year. Results: Visual acuity (VA) change was 2 ETDRS letters ± 7.6 after three injections and 3.2 ETDRS letters ± 10.3 at 1 year. There was no significant difference between VA changes amongst the two drugs. At 1 year, anti-VEGF treatment resulted in a mean reduction of 125 μm in maximum PED height, of 2.26 mm2 in base area and of 0.54 mm3 in volume with a corresponding increase in reflectivity. These changes were more prominent in the aflilbercept group. The observed PED and VA changes at year 1 were strongly correlated with their values at baseline and after three injections. Conclusions: Anti-VEGF treatment resulted in a reduction of all PED dimensions and a corresponding increase in optical reflectivity. Higher, larger and more hypo-reflective PEDs demonstrated a better anatomical response, especially with aflibercept, but this was not correlated with VA.

Sign in / Sign up

Export Citation Format

Share Document