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1.
Curr Opin Ophthalmol ; 33(3): 202-210, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35102096

RESUMO

PURPOSE OF REVIEW: This article reviews the latest proteomic research on uveal melanoma. RECENT FINDINGS: Proteomic analysis of uveal melanoma cell lines and tissue specimens has improved our understanding of the pathophysiology of uveal melanoma and helped identify potential prognostic biomarkers. Circulating proteins in patient serum may aid in the surveillance of metastatic disease. The proteomes of aqueous and vitreous biopsy specimens may provide safer biomarkers for metastatic risk and candidate therapeutic targets in uveal melanoma. Proteomic analysis has the potential to benefit patient outcomes by improving diagnosis, prognostication, surveillance, and treatment of uveal melanoma. SUMMARY: These recent findings demonstrate that proteomic analysis is an important area of research to better understand the pathophysiology of uveal melanoma and improve the personalized management of our patients.


Assuntos
Melanoma , Neoplasias Uveais , Biópsia , Humanos , Melanoma/diagnóstico , Melanoma/patologia , Proteômica , Neoplasias Uveais/diagnóstico , Neoplasias Uveais/patologia
2.
Retina ; 37(11): 2084-2094, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28151840

RESUMO

PURPOSE: To investigate choroidal involvement in acute posterior multifocal placoid pigment epitheliopathy (APMPPE). METHODS: A retrospective observational case series using multimodal imaging including optical coherence tomography (OCT) angiography. RESULTS: Five patients with APMPPE were included. In most acute lesions, OCT angiography revealed outer retinal and retinal pigment epithelium (RPE) hyperreflective lesions with attenuated OCT signal in the underlying choroid, but careful examination allowed us to identify a single lesion with decreased choriocapillaris flow outside the signal attenuation. Optical coherence tomography angiography obtained after healing of lesions revealed areas of hypointense circular flow voids clustered in groups surrounded by either isointense or hyperintense signal background. Point-by-point evaluation revealed these flow voids did not correspond to areas of RPE thickening or focal pigmentary changes. Larger hypointense lesions were observed and did correlate with pigmentary changes. CONCLUSION: Our case series demonstrates choriocapillaris flow abnormalities in acute APMPPE extending beyond the OCT lesions, and distinct residual vascular abnormalities in healed APMPPE lesions on OCT angiography. Our findings support a primary ischemic insult to the photoreceptors and RPE, but choriocapillaris flow abnormalities could be secondary to (OCT invisible) retinal and RPE involvement. The lack of understanding of the etiology along with the inability to visualize most of the choroid in acute lesions precludes definite conclusions about the true pathogenesis of APMPPE.


Assuntos
Corioidite/diagnóstico , Angiofluoresceinografia/métodos , Epitélio Pigmentado Ocular/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Doença Aguda , Adulto , Corioide/irrigação sanguínea , Corioidite/fisiopatologia , Feminino , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Coroidite Multifocal , Adulto Jovem
3.
Retina ; 36 Suppl 1: S137-S146, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28005672

RESUMO

PURPOSE: To identify the origin and significance of discordance between blue-light autofluorescence (BL-AF; 488 nm) and near-infrared autofluorescence (NI-AF; 787 nm) in patients with age-related macular degeneration (AMD). METHODS: A total of 86 eyes of 59 patients with a diagnosis of AMD were included in this cross-sectional study conducted between March 9, 2015 and May 1, 2015. A masked observer examined the BL-AF, NI-AF, and spectral-domain optical coherence tomography images. Areas with discordance of autofluorescence patterns between NI-AF and BL-AF images were correlated with structural findings at the corresponding location in optical coherence tomography scans. RESULTS: Seventy-nine eyes had discordance between BL-AF and NI-AF. The most common optical coherence tomography finding accounting for these discrepancies was pigment migration accounting for 35 lesions in 21 eyes. The most clinically relevant finding was geographic atrophy missed on BL-AF in 7 eyes. CONCLUSION: Our findings indicate that variations in the distribution of lipofuscin, melanin and melanolipofuscin account for the majority of discordance between BL-AF and NI-AF. Given our finding of missed geographic atrophy lesions on BL-AF in 24% of eyes with geographic atrophy (7/29 eyes), clinicians should consider multimodal imaging, including NI-AF and optical coherence tomography, especially in clinical trials of geographic atrophy.


Assuntos
Degeneração Macular/diagnóstico por imagem , Estudos Transversais , Diagnóstico Tardio , Atrofia Geográfica/diagnóstico por imagem , Humanos , Luz , Imagem Óptica/métodos , Células Fotorreceptoras , Drusas Retinianas/diagnóstico por imagem , Estudos Retrospectivos
4.
Cancer Immunol Immunother ; 64(9): 1185-91, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26047578

RESUMO

OBJECTIVES: Lung cancer is the leading cause of cancer-related death in the USA. Regulatory T cells (Tregs) normally function to temper immune responses and decrease inflammation. Previous research has demonstrated different subsets of Tregs with contrasting anti- or pro-inflammatory properties. This study aimed to determine Treg subset distributions and characteristics present in non-small cell lung cancer (NSCLC) patients. METHODS: Peripheral blood was collected from healthy controls (HC) and NSCLC patients preceding surgical resection, and mononuclear cells were isolated, stained, and analyzed by flow cytometry. Tregs were defined by expression of CD4 and CD25 and classified into CD45RA(+)Foxp3(int) (naïve, Fr. I) or CD45RA(-)Foxp3(hi) (activated Fr. II). Activated conventional T cells were CD4(+)CD45RA(-)Foxp3(int) (Fr. III). RESULTS: Samples from 23 HC and 26 NSCLC patients were collected. Tregs isolated from patients with NSCLC were found to have enhanced suppressive function on naive T cells. Cancer patients had significantly increased frequencies of activated Tregs (fraction II: FrII), 17.5 versus 3.2% (P < 0.001). FrII Tregs demonstrated increased RORγt and IL17 expression and decreased IL10 expression compared to Tregs from HC, indicating pro-inflammatory characteristics. CONCLUSIONS: This study demonstrates that a novel subset of Tregs with pro-inflammatory characteristics preferentially expand in NSCLC patients. This Treg subset appears identical to previously reported pro-inflammatory Tregs in human colon cancer patients and in mouse models of polyposis. We expect the pro-inflammatory Tregs in lung cancer to contribute to the immune pathogenesis of disease and propose that targeting this Treg subset may have protective benefits in NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/imunologia , Neoplasias Pulmonares/imunologia , Linfócitos T Reguladores/imunologia , Idoso , Feminino , Humanos , Ativação Linfocitária , Masculino
5.
Retina ; 35(12): 2593-603, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26131588

RESUMO

PURPOSE: To evaluate the quantitative and topographic relationship between reticular pseudodrusen (RPD) on infrared reflectance (IR) and subretinal drusenoid deposits (SDD) on en face volumetric spectral domain optical coherence tomography. METHODS: Reticular pseudodrusen were marked on IR images by a masked observer. Subretinal drusenoid deposits were visualized on en face sections of spectral domain optical coherence tomography below the external limiting membrane and identified by a semiautomated technique. Control RPD lesions were generated in a random distribution for each IR image. Binary maps of control and experimental RPD and SDD were merged and analyzed in terms of topographic localization and quantitative drusen load comparison. RESULTS: A total of 54 eyes of 41 patients diagnosed with RPD were included in this study. The average number of RPD lesions on IR images was 320 ± 44.62 compared with 127 ± 26.02 SDD lesions on en face (P < 0.001). The majority of RPD lesions did not overlap with SDD lesions and were located >30 µm away (92%). The percentage of total SDD lesions overlapping RPD was 2.91 ± 0.87% compared with 1.73 ± 0.68% overlapping control RPD lesions (P < 0.05). The percentage of total SDD lesions between 1 and 3 pixels of the nearest RPD lesion was 5.08 ± 1.40% compared with 3.33 ± 1.07% between 1 and 3 pixels of the nearest control RPD lesion (P < 0.05). CONCLUSION: This study identified significantly more RPD lesions on IR compared with SDD lesions on en face spectral domain optical coherence tomography and found that a large majority of SDD (>90% of lesions) were >30 µm away from the nearest RPD. Together, our findings indicate that RPD and SDD are two entities that are only occasionally topographically associated, suggesting that at some stage in their development, they may be pathologically related.


Assuntos
Técnicas de Diagnóstico Oftalmológico , Drusas Retinianas/diagnóstico , Tomografia de Coerência Óptica/métodos , Adulto , Idoso , Corioide/patologia , Feminino , Humanos , Masculino , Estudos Retrospectivos
7.
Can J Ophthalmol ; 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38768649

RESUMO

OBJECTIVE: Uveal melanoma is the most common intraocular malignancy in adults. Current screening and triaging methods for melanocytic choroidal tumours face inherent limitations, particularly in regions with limited access to specialized ocular oncologists. This study explores the potential of machine learning to automate tumour segmentation. We develop and evaluate a machine-learning model for lesion segmentation using ultra-wide-field fundus photography. METHOD: A retrospective chart review was conducted of patients diagnosed with uveal melanoma, choroidal nevi, or congenital hypertrophy of the retinal pigmented epithelium at a tertiary academic medical centre. Included patients had a single ultra-wide-field fundus photograph (Optos PLC, Dunfermline, Fife, Scotland) of adequate quality to visualize the lesion of interest, as confirmed by a single ocular oncologist. These images were used to develop and test a machine-learning algorithm for lesion segmentation. RESULTS: A total of 396 images were used to develop a machine-learning algorithm for lesion segmentation. Ninety additional images were used in the testing data set along with images of 30 healthy control individuals. Of the images with successfully detected lesions, the machine-learning segmentation yielded Dice coefficients of 0.86, 0.81, and 0.85 for uveal melanoma, choroidal nevi, and congenital hypertrophy of the retinal pigmented epithelium, respectively. Sensitivities for any lesion detection per image were 1.00, 0.90, and 0.87, respectively. For images without lesions, specificity was 0.93. CONCLUSION: Our study demonstrates a novel machine-learning algorithm's performance, suggesting its potential clinical utility as a widely accessible method of screening choroidal tumours. Additional evaluation methods are necessary to further enhance the model's lesion classification and diagnostic accuracy.

8.
Anticancer Res ; 44(8): 3375-3380, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39060061

RESUMO

BACKGROUND/AIM: Allostatic load (AL) is a measure of chronic stress that is associated with worse cancer outcomes. The purpose of this retrospective cohort study was to investigate the relationship between AL and uveal melanoma (UM) clinical features. PATIENTS AND METHODS: AL score was calculated as a composite of ten biomarkers in 111 patients with UM from the University of Illinois Hospital. One point was assigned to an AL score for each biomarker based on predetermined cutoff values. Linear and logistic regression analyses evaluated the relationship between AL score and several tumor clinical characteristics. RESULTS: High AL score had a significant relationship with extraocular extension (p=0.015). There was also a significant difference in mean blood glucose levels between the different tumor size groups (p=0.029). Higher AL scores also had a trend of being associated with a smaller tumor size (p=0.069). CONCLUSION: AL score was significantly associated with the presence of extraocular extension for uveal melanoma, while the smallest tumor size group was associated with the highest blood glucose level. No other significant correlations were found between AL and other clinical features of UM. The relationship between AL score and extraocular extension warrants further investigation. Additional research is needed to evaluate socioeconomic factors and their effect on the relationship between chronic stress and the clinical features of UM.


Assuntos
Alostase , Melanoma , Neoplasias Uveais , Humanos , Neoplasias Uveais/patologia , Melanoma/patologia , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Idoso , Alostase/fisiologia , Adulto , Glicemia/metabolismo , Biomarcadores Tumorais/metabolismo , Biomarcadores Tumorais/sangue , Idoso de 80 Anos ou mais
9.
Biomed Opt Express ; 15(6): 3889-3899, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38867785

RESUMO

This study investigates the impact of differential artery-vein (AV) analysis in optical coherence tomography angiography (OCTA) on machine learning classification of diabetic retinopathy (DR). Leveraging deep learning for arterial-venous area (AVA) segmentation, six quantitative features, including perfusion intensity density (PID), blood vessel density (BVD), vessel area flux (VAF), blood vessel caliber (BVC), blood vessel tortuosity (BVT), and vessel perimeter index (VPI) features, were derived from OCTA images before and after AV differentiation. A support vector machine (SVM) classifier was utilized to assess both binary and multiclass classifications of control, diabetic patients without DR (NoDR), mild DR, moderate DR, and severe DR groups. Initially, one-region features, i.e., quantitative features extracted from the entire OCTA, were evaluated for DR classification. Differential AV analysis improved classification accuracies from 78.86% to 87.63% and from 79.62% to 85.66% for binary and multiclass classifications, respectively. Additionally, three-region features derived from the entire image, parafovea, and perifovea, were incorporated for DR classification. Differential AV analysis further enhanced classification accuracies from 84.43% to 93.33% and from 83.40% to 89.25% for binary and multiclass classifications, respectively. These findings highlight the potential of differential AV analysis in augmenting disease diagnosis and treatment assessment using OCTA.

10.
medRxiv ; 2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38260269

RESUMO

Purpose: To investigate the spectral characteristics of choroidal nevi and assess the feasibility of quantifying the basal diameter of choroidal nevi using multispectral fundus images captured with trans-palpebral illumination. Methods: The study employed a widefield fundus camera with multispectral (625 nm, 780 nm, 850 nm, and 970 nm) trans-palpebral illumination. Geometric features of choroidal nevi, including border clarity, overlying drusen, and lesion basal diameter, were characterized. Clinical imagers, including scanning laser ophthalmoscopy (SLO), autofluorescence (AF), and optical coherence tomography (OCT), were utilized for comparative assessment. Results: Fundus images captured with trans-palpebral illumination depicted nevi as dark regions with high contrast against the background. Near-infrared (NIR) fundus images provided enhanced visibility of lesion borders compared to visible light fundus images and SLO images. Lesion-background contrast measurements revealed 635 nm SLO at 11% and 625 nm fundus at 42%. Significantly enhanced contrasts were observed in NIR fundus images at 780 nm (73%), 850 nm (63%), and 970 nm (67%). For quantifying the basal diameter of nevi, NIR fundus images at 780 nm and 850 nm yielded a deviation of less than 10% when compared to OCT B-scan measurements. Conclusion: NIR fundus photography with trans-palpebral illumination enhances nevi visibility and boundary definition compared to SLO. Agreement in basal diameter measurements with OCT validates the accuracy and reliability of this method for choroidal nevi assessment.

11.
Transl Vis Sci Technol ; 13(3): 25, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38546980

RESUMO

Purpose: The purpose of this study was to investigate the spectral characteristics of choroidal nevi and assess the feasibility of quantifying the basal diameter of choroidal nevi using multispectral fundus images captured with trans-palpebral illumination. Methods: The study used a widefield fundus camera with multispectral (625 nm, 780 nm, 850 nm, and 970 nm) trans-palpebral illumination to examine eight subjects diagnosed with choroidal nevi. Geometric features of nevi, including border clarity, overlying drusen, and lesion basal diameter, were characterized. Clinical imagers, including scanning laser ophthalmoscopy (SLO), autofluorescence (AF), and optical coherence tomography (OCT), were utilized for comparative assessment. Results: Fundus images depicted nevi as dark regions with high contrast against the background. Near-infrared (NIR) fundus images provided enhanced visibility of lesion borders compared to visible fundus images and SLO images. Lesion-background contrast measurements revealed 635 nm SLO at 11% and 625 nm fundus at 42%. Significantly enhanced contrasts were observed in NIR fundus images at 780 nm (73%), 850 nm (63%), and 970 nm (67%). For quantifying the diameter of nevi, NIR fundus images at 780 nm and 850 nm yielded a deviation of less than 10% when compared to OCT measurements. Conclusions: NIR fundus photography with trans-palpebral illumination enhances nevi visibility and boundary definition compared to SLO. Agreement in diameter measurements with OCT validates the accuracy and reliability of this method for choroidal nevi assessment. Translational Relevance: Multispectral fundus imaging with trans-palpebral illumination improves choroidal nevi visibility and accurately measures basal diameter, promising to enhance clinical practices in screening, diagnosis, and monitoring of choroidal nevi.


Assuntos
Neoplasias da Coroide , Nevo Pigmentado , Nevo , Neoplasias Cutâneas , Humanos , Iluminação , Reprodutibilidade dos Testes , Nevo Pigmentado/diagnóstico por imagem , Nevo Pigmentado/patologia , Neoplasias da Coroide/diagnóstico por imagem , Neoplasias da Coroide/patologia , Nevo/diagnóstico por imagem , Fotografação
12.
Eye (Lond) ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773261

RESUMO

BACKGROUND: Reliable differentiation of uveal melanoma and choroidal nevi is crucial to guide appropriate treatment, preventing unnecessary procedures for benign lesions and ensuring timely treatment for potentially malignant cases. The purpose of this study is to validate deep learning classification of uveal melanoma and choroidal nevi, and to evaluate the effect of colour fusion options on the classification performance. METHODS: A total of 798 ultra-widefield retinal images of 438 patients were included in this retrospective study, comprising 157 patients diagnosed with UM and 281 patients diagnosed with choroidal naevus. Colour fusion options, including early fusion, intermediate fusion and late fusion, were tested for deep learning image classification with a convolutional neural network (CNN). F1-score, accuracy and the area under the curve (AUC) of a receiver operating characteristic (ROC) were used to evaluate the classification performance. RESULTS: Colour fusion options were observed to affect the deep learning performance significantly. For single-colour learning, the red colour image was observed to have superior performance compared to green and blue channels. For multi-colour learning, the intermediate fusion is better than early and late fusion options. CONCLUSION: Deep learning is a promising approach for automated classification of uveal melanoma and choroidal nevi. Colour fusion options can significantly affect the classification performance.

13.
Biosensors (Basel) ; 14(3)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38534234

RESUMO

Ultrasound A-scan is an important tool for quantitative assessment of ocular lesions. However, its usability is limited by the difficulty of accurately localizing the ultrasound probe to a lesion of interest. In this study, a transparent LiNbO3 single crystal ultrasound transducer was fabricated, and integrated with a widefield fundus camera to guide the ultrasound local position. The electrical impedance, phase spectrum, pulse-echo performance, and optical transmission spectrum of the ultrasound transducer were validated. The novel fundus camera-guided ultrasound probe was tested for in vivo measurement of rat eyes. Anterior and posterior segments of the rat eye could be unambiguously differentiated with the fundus photography-guided ultrasound measurement. A model eye was also used to verify the imaging performance of the prototype device in the human eye. The prototype shows the potential of being used in the clinic to accurately measure the thickness and echogenicity of ocular lesions in vivo.


Assuntos
Angiofluoresceinografia , Ratos , Animais , Humanos , Angiofluoresceinografia/métodos , Ultrassonografia
15.
Gut ; 61(10): 1454-64, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22234980

RESUMO

BACKGROUND AND AIMS: Pigment epithelium-derived factor (PEDF), a non-inhibitory SERPIN with potent antiangiogenic activity, has been recently implicated in metabolism and adipogenesis, both of which are known to influence pancreatic cancer progression. Increased pancreatic fat in human pancreatic tumour correlates with greater tumour dissemination while PEDF deficiency in mice promotes pancreatic hyperplasia and visceral obesity. Oncogenic Ras, the most common mutation in pancreatic ductal adenocarcinoma (PDAC), has similarly been shown to promote adipogenesis and premalignant lesions. METHODS: In order to determine whether concurrent loss of PEDF is sufficient to promote adipogenesis and tumorigenesis in the pancreas, the authors ablated PEDF in an EL-Kras(G12D) mouse model of non-invasive cystic papillary neoplasms. RESULTS: EL-Kras(G12D)/PEDF deficient mice developed invasive PDAC associated with enhanced matrix metalloproteinase (MMP)-2 and MMP-9 expression and increased peripancreatic fat with adipocyte hypertrophy and intrapancreatic adipocyte infiltration (pancreatic steatosis). In support of increased adipogenesis, the stroma of the pancreas of EL-Kras(G12D)/PEDF deficient mice demonstrated higher tissue levels of two lipid droplet associated proteins, tail-interacting protein 47 (TIP47, perilipin 3) and adipose differentiation-related protein (ADRP, Pperilipin 2), while adipose triglyceride lipase, a key factor in lipolysis, was decreased. In patients with PDAC, both tissue and serum levels of PEDF were decreased, stromal TIP47 expression was higher and the tissue VEGF to PEDF ratio was increased (p<0.05). CONCLUSIONS: These data highlight the importance of lipid metabolism in the tumour microenvironment and identify PEDF as a critical negative regulator of both adiposity and tumour invasion in the pancreas.


Assuntos
Adipócitos Brancos/patologia , Biomarcadores Tumorais/deficiência , Carcinoma Ductal Pancreático/metabolismo , Fatores de Crescimento Neural/deficiência , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Serpinas/deficiência , Adipócitos Brancos/metabolismo , Adiposidade , Animais , Biomarcadores Tumorais/metabolismo , Western Blotting , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proteínas do Olho , Marcadores Genéticos , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Knockout , Mutação , Invasividade Neoplásica , Pâncreas/metabolismo , Pâncreas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Reação em Cadeia da Polimerase em Tempo Real , Células Estromais/metabolismo , Células Estromais/patologia
16.
Exp Biol Med (Maywood) ; 248(5): 371-379, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37212384

RESUMO

Due to its accessibility and ability for real-time image acquisition of ocular structures, ultrasound has high utility in the visualization of the eye, especially in ocular oncology. In this minireview, we summarize the technical rationale and applications of ultrasound modalities, A-scan, B-scan, high-frequency ultrasound biomicroscopy (UBM), and Doppler measurement. A-scan ultrasound uses a transducer of 7-11 MHz, making it useful for determining the echogenicity of ocular tumors (7-8 MHz) and measuring the axial length of the eye (10-11 MHz). B-scan ultrasound operates at 10-20 MHz, which can be used for measuring posterior ocular tumors while UBM operates at 40-100 MHz to evaluate anterior ocular structures. Doppler ultrasonography allows for the detection of tumor vascularization. While ultrasonography has numerous clinical applications due to its favorable penetration compared with optical coherence tomography, it is still limited by its relatively lower resolution. Ultrasound also requires an experienced sonographer due to the need for accurate probe localization to areas of interest.


Assuntos
Oftalmopatias , Neoplasias , Humanos , Olho/diagnóstico por imagem , Ultrassonografia , Oftalmopatias/diagnóstico por imagem , Tomografia de Coerência Óptica
17.
Biomed Opt Express ; 14(11): 5932-5945, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38021139

RESUMO

The purpose of this study is to demonstrate the feasibility of using polarization maintaining photons for enhanced contrast imaging of the retina. Orthogonal-polarization control has been frequently used in conventional fundus imaging systems to minimize reflection artifacts. However, the orthogonal-polarization configuration also rejects the directly reflected photons, which preserve the polarization condition of incident light, from the superficial layer of the fundus, i.e., the retina, and thus reduce the contrast of retinal imaging. We report here a portable fundus camera which can simultaneously perform orthogonal-polarization control to reject back-reflected light from the ophthalmic lens and parallel-polarization control to preserve the backscattered light from the retina which partially maintains the polarization state of the incoming light. This portable device utilizes miniaturized indirect ophthalmoscopy illumination to achieve non-mydriatic imaging, with a snapshot field of view of 101° eye-angle (67° visual-angle). Comparative analysis of retinal images acquired with a traditional orthogonal-polarization fundus camera from both normal and diseased eyes was conducted to validate the usefulness of the proposed design. The parallel-polarization control for enhanced contrast in high dynamic range imaging has also been validated.

18.
Biomed Opt Express ; 14(2): 906-917, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36874492

RESUMO

Fundus photography is indispensable for the clinical detection and management of eye diseases. Low image contrast and small field of view (FOV) are common limitations of conventional fundus photography, making it difficult to detect subtle abnormalities at the early stages of eye diseases. Further improvements in image contrast and FOV coverage are important for early disease detection and reliable treatment assessment. We report here a portable, wide FOV fundus camera with high dynamic range (HDR) imaging capability. Miniaturized indirect ophthalmoscopy illumination was employed to achieve the portable design for nonmydriatic, widefield fundus photography. Orthogonal polarization control was used to eliminate illumination reflectance artifacts. With independent power controls, three fundus images were sequentially acquired and fused to achieve HDR function for local image contrast enhancement. A 101° eye-angle (67° visual-angle) snapshot FOV was achieved for nonmydriatic fundus photography. The effective FOV was readily expanded up to 190° eye-angle (134° visual-angle) with the aid of a fixation target without the need for pharmacologic pupillary dilation. The effectiveness of HDR imaging was validated with both normal healthy and pathologic eyes, compared to a conventional fundus camera.

19.
Biomed Opt Express ; 14(11): 5629-5641, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38021114

RESUMO

Multi-spectral widefield fundus photography is valuable for the clinical diagnosis and management of ocular conditions that may impact both central and peripheral regions of the retina and choroid. Trans-palpebral illumination has been demonstrated as an alternative to transpupillary illumination for widefield fundus photography without requiring pupil dilation. However, spectral efficiency can be complicated due to the spatial variance of the light property through the palpebra and sclera. This study aims to investigate the effect of light delivery location on spectral efficiency in trans-palpebral illumination. Four narrow-band light sources, covering both visible and near infrared (NIR) wavelengths, were used to evaluate spatial dependency of spectral illumination efficiency. Comparative analysis indicated a significant dependence of visible light efficiency on spatial location, while NIR light efficiency is only slightly affected by the illumination location. This study confirmed the pars plana as the optimal location for delivering visible light to achieve color imaging of the retina. Conversely, spatial location is not critical for NIR light imaging of the choroid.

20.
Res Sq ; 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38196619

RESUMO

Objective: This study aims to assess a machine learning (ML) algorithm using multimodal imaging to accurately identify risk factors for uveal melanoma (UM) and aid in the diagnosis of melanocytic choroidal tumors. Subjects and Methods: This study included 223 eyes from 221 patients with melanocytic choroidal lesions seen at the eye clinic of the University of Illinois at Chicago between 01/2010 and 07/2022. An ML algorithm was developed and trained on ultra-widefield fundus imaging and B-scan ultrasonography to detect risk factors of malignant transformation of choroidal lesions into UM. The risk factors were verified using all multimodal imaging available from the time of diagnosis. We also explore classification of lesions into UM and choroidal nevi using the ML algorithm. Results: The ML algorithm assessed features of ultra-widefield fundus imaging and B-scan ultrasonography to determine the presence of the following risk factors for malignant transformation: lesion thickness, subretinal fluid, orange pigment, proximity to optic nerve, ultrasound hollowness, and drusen. The algorithm also provided classification of lesions into UM and choroidal nevi. A total of 115 patients with choroidal nevi and 108 patients with UM were included. The mean lesion thickness for choroidal nevi was 1.6 mm and for UM was 5.9 mm. Eleven ML models were implemented and achieved high accuracy, with an area under the curve of 0.982 for thickness prediction and 0.964 for subretinal fluid prediction. Sensitivity/specificity values ranged from 0.900/0.818 to 1.000/0.727 for different features. The ML algorithm demonstrated high accuracy in identifying risk factors and differentiating lesions based on the analyzed imaging data. Conclusions: This study provides proof of concept that ML can accurately identify risk factors for malignant transformation in melanocytic choroidal tumors based on a single ultra-widefield fundus image or B-scan ultrasound at the time of initial presentation. By leveraging the efficiency and availability of ML, this study has the potential to provide a non-invasive tool that helps to prevent unnecessary treatment, improve our ability to predict malignant transformation, reduce the risk of metastasis, and potentially save patient lives.

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