Combined Rotating Ultra-High-Resolution Spectral Domain OCT and Scheimpflug Imaging for In Vivo Corneal Optical Biopsy.

PURPOSE: This article introduces the Pentacam® Cornea OCT (optical coherence tomography). This advanced corneal imaging system combines rotating ultra-high-resolution spectral domain OCT with sub- 2-micron axial resolution and Scheimpflug photography. The purpose of this study is to present the first experience with the instrument and its potential for corneal diagnostics, including optical biopsy. METHODS: In this prospective study, the Pentacam® Cornea OCT was used to image the corneas of seven patients. The novel wide-angle pericentric scan system enables optimal OCT imaging performance for the corneal layer structure over the entire width of the cornea, including the limbal regions. A detailed analysis of the resulting images assessed the synergism between the OCT and Scheimpflug photography. RESULTS: The Pentacam® Cornea OCT demonstrated significantly improved image resolution and ability to individualize corneal layers with high quality. There is a synergism between the OCT high-definition signal to individualize details on the cornea and Scheimpflug photography to detect and quantify corneal scattering. The noncontact exam was proven safe, user-friendly, and effective for enabling optical biopsy. CONCLUSIONS: Pentacam® Cornea OCT is an advancement in corneal imaging technology. The ultra-high-resolution spectral domain OCT and Scheimpflug photography provide unprecedented detail and resolution, enabling optical biopsy and improving the understanding of corneal pathology. Further studies are necessary to compare and analyze the tomographic reconstructions of the cornea with the different wavelengths, which may provide helpful information for diagnosing and managing corneal diseases.

LINC00662 Promotes Aggressive Traits by Modulating OCT4 Expression through miR-335-5p in Gallbladder Cancer Cells.

Long non-coding RNAs (lncRNAs) are nucleotide sequences that participate in different biological processes and are associated with different pathologies, including cancer. Long intergenic non-protein-coding RNA 662 (LINC00662) has been reported to be involved in different cancers, including colorectal, prostate, and breast cancer. However, its role in gallbladder cancer has not yet been described. In this article, we hypothesize that LINC00662 has an important role in the acquisition of aggressiveness traits such as a stem-like phenotype, invasion, and chemoresistance in gallbladder cancer. Here, we show that LINC00662 is associated with larger tumor size and lymph node metastasis in patients with gallbladder cancer. Furthermore, we show that the overexpression of LINC00662 promotes an increase in CD133+/CD44+ cell populations and the expression of stemness-associated genes. LINC00662 promotes greater invasive capacity and the expression of genes associated with epithelial-mesenchymal transition. In addition, the expression of LINC00662 promotes resistance to cisplatin and 5-fluorouracil, associated with increased expression of chemoresistance-related ATP-binding cassette (ABC) transporters in gallbladder cancer (GBC) cell lines. Finally, we show that the mechanism by which LINC00662 exerts its function is through a decrease in microRNA 335-5p (miR-335-5p) and an increase in octamer-binding transcription factor 4 (OCT4) in GBC cells. Thus, our data allow us to propose LINC00662 as a biomarker of poor prognosis and a potential therapeutic target for patients with GBC.

Optical coherence tomography and gray scale digital analysis as noninvasive techniques for evaluating molar-incisor hypomineralization severity: A comparative study with microcomputed tomography.

Molar-incisor hypomineralization (MIH) is a qualitative defect of dental enamel characterized by demarcated opacities present in permanent first molars and other teeth. It is considered a major clinical challenge in dentistry because it makes affected teeth more susceptible to fractures and dental caries. Its diagnosis is mainly clinical and there are few technological resources that allow for a more accurate diagnosis, especially with respect to the depth of the defect in the dental enamel. In this context, optical coherence tomography (OCT), which is routinely used in ophthalmology, can produce images of the depth of the dental enamel, making it a promising method. In this study, 33 teeth with different MIH severities were evaluated using OCT and microcomputed tomography (microCT). Semi-quantitative methods of grayscale pattern analysis were used to compare images obtained from different severities of MIH with the mineral density obtained through microCT. MicroCT evaluation revealed that hypomineralized enamel had a significantly lower mineral density than intact enamel. However, this difference was not observed between the mild and severe MIH lesions. In the OCT evaluation, significant differences were observed between the intact and hypomineralized enamel, and the gray value comparison provided a method for quantitative differentiation between the two. This study suggests that OCT could be a useful adjunct to traditional diagnostic methods for MIH, offering a noninvasive approach to evaluate enamel defects. RESEARCH HIGHLIGHTS: Combining optical coherence tomography with grayscale digital analysis shows potential as a promising method for diagnosing molar-incisor hypomineralization and assessing its level of severity.

Optical coherence tomography detection of retinal neural loss in patients with tuberous sclerosis.

PURPOSE: Tuberous Sclerosis (TS) is a rare, multisystem genetic disease caused by mutations in the TSC1 and TSC2 genes, leading to abnormalities in cell differentiation and proliferation. This study aimed to evaluate the neural integrity of individuals with TS by using Optical Coherence Tomography (OCT) to examine the peripapillary retinal nerve fiber layer (RNFL) thickness and the macular thickness in patients with TS and to compare with healthy controls. METHODS: Peripapillary and macular OCT scans (Optopol Revo NX SD OCT) were performed on 41 eyes from 22 TS patients, divided into two groups based on the presence of retinal hamartomas, and compared to 20 eyes from a control group. The average peripapillary RNFL thickness was measured for each quadrant. The macular total thickness and ganglion cell layer (GCL) + inner plexiform layer (IPL) thickness were measured based on the Early Treatment Diabetic Retinopathy Study (ETDRS) map. All measurements were then compared between the groups and controls. RESULTS: The TS group showed significantly reduced RNFL thickness and macular thickness when compared to the control group. Specifically, patients with retinal hamartomas exhibited an even more pronounced thinning of both RNFL and macular thickness. CONCLUSIONS: These findings suggest that TS patients undergo significant changes in retinal neurodevelopment and experience axonal loss. This finding may have significant prognostic utility regarding central nervous system degeneration in TS, particularly among patients with retinal hamartomas. OCT may serve as a valuable tool for assessing axonal structural abnormalities in TS patients. TRIAL REGISTRATION NUMBER: Not applicable.

Early gonadogenesis in Columba livia (birds: Columbiformes): Migration, colonization, and differentiation of germ cells.

In birds, primordial germ cells (PGCs) use the bloodstream to travel to a specific region, where the cells undergo extravasation followed by intrastromal migration to the gonadal crest for further colonization. Currently, DDX4, SSEA1, and Oct4 are used to identify germ cells. Other germline cell-associated molecules are N-cadherin, GnRHR, and 3ß hydroxysteroid dehydrogenase (3ßHSD), which have been used in mice and birds during gonadal development; however, its role in early gonadogenesis in birds is poorly described. This study aimed to evaluate the differential immunodetection of N-cadherin binding molecule, Oct4 pluripotency protein, GnRHR receptor, and 3ßHSD enzyme in Columba livia embryos during migration colonization of PGCs in the gonadal crest and early gonadogenesis. These markers were revealed by immunohistochemistry in histological preparations of C. livia corresponding to stages (S)15 to S40. Immunodetection of N-cadherin, Oct4, GnRHR, and 3ßHSD in the germ line of C. livia allowed the identification of PGCs in the yolk sac membrane at the level of the splanchnic mesoderm during migration to the genital crest and its colonization. In the same way, it was possible to characterize and localize PGCs during early gonadogenesis. This study in C. livia demonstrates that Oct4, N-cadherin, GNRHR, and 3ßHSD are immunodetected in PGCs and could be used as potential germline cell markers during cell migration out of blood vessels, colonization in the genital crest, and early gonadogenesis. Furthermore, this study could be used as a novel general model to understand the early gonadogenesis in altricial species.

Retinal shadows produced by myopia control spectacles.

PURPOSE: To analyse ocular coherence tomography (OCT) images of the retinal shadows caused by defocus and diffusion optics spectacles. METHODS: One eye was fitted successively with the Hoya Defocus Incorporated Multiple Segments (DIMS) spectacle lens, two variations of the +3.50 D peripheral add spectacle (DEFOCUS) and the low-contrast dot lens (Diffusion Optics Multiple Segments, DOMS); each at a vertex distance of 12 mm. Simultaneously, a retinal image of the macular region with central fixation was obtained using infrared OCT. The corneal power and intraocular distances were determined using an optical biometer. RESULTS: The retinal images for the DIMS and DOMS lenses showed patterns of obvious retinal shadows in the periphery, while the central 10-11° remained clear. The DEFOCUS lens produced a darkened peripheral area. Dividing the size of the retinal pattern, measured with the calliper of the OCT software, by the actual size on the spectacle lens gave a magnification of -0.57 times. This is consistent with the incoming OCT beam being imaged to a position approximately 31 mm beyond the front of the eye. [Correction added on 26 October 2023 after first online publication: The preceding paragraph was corrected.] CONCLUSION: With device-specific correction, retinal OCT images can help visualise the regions affected by the defocus or lowered contrast induced by myopia control spectacles. This is of potential value for improving myopia therapies.

Caracterización de marcadores de células madre tumorales en cáncer escamocelular de cavidad oral

Introducción: El cáncer escamocelular de cavidad oral es una patología con bajas tasas de sobrevivencia. Cuando no es tratado adecuadamente es un tumor de alta recurrencia y resistente al tratamiento. Nuevas hipótesis plantean que las células tumorales progenitoras por sus propiedades de auto renovación, iniciación tumoral, migración y metástasis pueden ser responsables de la manutención y renovación de este tumor. Sin embargo, aún no existe un consenso sobre la verdadera participación de ellas, debido a que su identificación y caracterización es aún un reto experimental. Objetivo: En este trabajo se busca detectar células con expresión de marcadores de células tumorales Progenitoras en muestras cáncer escamocelular de cavidad oral y relacionarlo con los estadios de diferenciación del tumor. Metodología: En esta investigación se tomaron 32 muestras de pacientes con carcinoma escamocelular de cavidad oral. Se logró detectar in situ, mediante la técnica de inmunofluorescencia, cuatro reconocidos marcadores de células tumorales progenitoras. Resultados: Se identificaron los marcadores OCT4, SSEA4, NANOG y TRA-1-60 en los diferentes estadios de diferenciación tumoral, lo que sugiere la participación de las células progenitoras tumorales en la evolución de esta patología. Conclusiones: El establecimiento y correcta identificación de las células tumorales progenitoras abre nuevas vías terapéuticas para el abordaje de este tumor, en busca de mejorar el pronóstico, tasa de sobrevivencia y calidad de vida del paciente.

Introduction: Squamous cell carcinoma of the oral cavity is a pathology with poor survival rates. When it is not adequately treated, it is a tumor with high recurrence and resistance to treatment. According to new hypotheses, progenitor tumor cells, due to their properties of self-renewal, tumor initiation, migration, and metastasis, could be responsible for the maintenance and renewal of this tumor. However, there is still no consensus on their true participation, subsequent to difficult in their identification and characterization. Materials and methods: In this research, 32 samples provided from patients diagnosis with squamous cell carcinoma of the oral cavity were used. To detect specific markers progenitor tumor cells were used immunofluorescence microscopy. Results: The cells markers OCT4, SSEA4, NANOG and TRA-1-60 were identified in the different stages of the tumor samples, all these findings suggest the role of tumor progenitor cells in the evolution of this pathology. Conclusions: The establishment and correct identification of the progenitor tumor cells provide new therapeutic options for the approach of this tumor seeking to improve the prognosis, survival rate and quality of life of the patient.

Maculopatía paracentral aguda media y neurorretinopatía macular aguda / Paracentral Acute Middle Maculopathy and Acute Macular Neuroretinopathy

La neurorretinopatía macular aguda es una condición rara con patogenia microvascular. Se presenta con un inicio agudo con escotomas paracentrales correspondientes a lesiones paramaculares evidentes. Los avances en las imágenes multimodales permitieron caracterizar este trastorno de retina y crear nuevos conceptos. Serraf, en el 2013, identificó dos formas por medio de la tomografía de coherencia óptica dominio espectral: el tipo 1 conocido como maculopatía paracentral aguda media en la cual se observa una banda hiperreflectiva en la capa nuclear interna, y el tipo 2 en el cual la banda hiperreflectiva se ubica en la capa nuclear externa, que involucra la zona elipsoide y la zona de interdigitación con el epitelio pigmentario de la retina. Hasta el momento no existe cura; pero se puede actuar sobre los factores de riesgo. Por ser una condición rara y por no existir reportes hasta el momento en Cuba es que se presentan a continuación dos pacientes con cuadros clínicos similares de estas dos variantes; concluyendo la importancia que presentan las imágenes multimodales como medio auxiliar diagnóstico(AU)

Acute macular neuroretinopathy is a rare condition with complex pathogenesis and microvascular cause. It appears with acute onset, with paracentral scotomas corresponding to obvious paramacular lesions. Advances in multimodal imaging made it possible to characterize this retinal disorder and to create new concepts. Serraf, in 2013, identified two forms by spectral domain optical coherence tomography: type 1, known as paracentral acute middle maculopathy, in which a hyperreflective band is observed in the inner nuclear layer; and type 2, in which the hyperreflective band is located in the outer nuclear layer, involving the ellipsoid zone and the zone of interdigitation with the retinal pigment epithelium. Up to this moment, there is no cure; but it is possible to act on the risk factors. Because it is a rare condition and because there are no reports so far in Cuba, two patients with similar clinical pictures of these two variants are presented; concluding the importance of multimodal images as an auxiliary diagnostic tool(AU)

Correlations between subfoveal choroidal thickness, macular thickness, and visual outcome in neovascular age-related macular degeneration using swept source OCT: insights from intravitreal aflibercept treatment.

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of visual impairment among individuals aged 50 and above, often resulting in irreversible vision loss (1). Currently, antiangiogenic therapy is the primary treatment approach for neovascular AMD (2). The choroid has gained significant attention in recent years due to its involvement in various ocular pathologies (7). The objective of this study was to evaluate visual acuity and correlate pre-treatment variables, such as foveal thickness and choroidal thickness, with post-treatment outcomes. MATERIALS AND METHODS: This study was designed as a prospective interventional study to investigate the changes in choroidal and macular thickness in patients with neovascular AMD who received intravitreal aflibercept injections. The study utilized medical records and employed Swept Source Optical Coherence Tomography (OCT-SS) for evaluation. The data was collected from patients treated in Presidente Prudente, Brazil, during a three-month load dose period. RESULTS: The best-corrected mean visual acuity significantly improved from 1.0 logarithm of the minimum resolution angle (logMAR) units to 0.55 logMAR after treatment with aflibercept (p < 0.001). Patients undergoing treatment exhibited a significant decrease in average macular thickness from 323 µm to 232 µm (p = 0.001), as well as a reduction in choroidal thickness from 206 µm to 172 µm (p = 0.031), while maintaining intraocular pressure within the normal range (p = 0.719) without significant variation. Statistically significant associations were found between the difference in pre- and post-treatment choroidal thickness and the pretreatment values of macular thickness (p = 0.005) and choroidal thickness (p = 0.013). There was also a statistically significant correlation between the difference in pre- and post-treatment macular thickness and the pretreatment macular thickness value (p < 0.001). CONCLUSION: In this study, aflibercept exhibited remarkable effectiveness in reducing macular and choroidal thickness, as evaluated using OCT-SS, and significantly improved visual acuity in patients with neovascular AMD. The assessment of both choroidal and macular changes, as well as their correlations, can provide valuable insights for clinicians, enabling them to make well-informed therapeutic decisions and effectively monitor treatment outcomes. Notably, this study contributes to the existing body of literature as the first to establish a correlation between pretreatment foveal thickness, variation in choroidal thickness, and post-treatment choroidal thickness.

Agreement and Reproducibility of Anterior Chamber Angle Measurements between CASIA2 Built-In Software and Human Graders.

PURPOSE: This study evaluated the agreement and reproducibility of ACA measurements obtained using the built-in software of the CASIA2 (Version 3G.1) and the measurements derived from expert clinicians. METHODS: Healthy volunteers underwent ophthalmological evaluation and AS-OCT examination. ACA measurements derived from automated and manual SS location were obtained using the CASIA2 automated software and clinician identification, respectively. The intraobserver, interobserver reproducibility, CASIA2-human grader reproducibility and CASIA2 repeatability were assessed using intraclass correlation coefficients (ICCs). RESULTS: The study examined 58 eyes of 30 participants. The CASIA2 software showed excellent repeatability for all ACA parameters (ICC > 0.84). Intraobserver, interobserver, and CASIA2-human grader reproducibility were also excellent (ICC > 0.87). Interobserver agreement was high, except for nasal TISA500, differing between observers 1 and 2 (p < 0.05). The agreement between CASIA2 measurements and human graders was high, except for nasal TISA500, where observer 1 values were smaller (p < 0.05). CONCLUSION: The CASIA2 built-in software reliably measures ACA parameters in healthy individuals, demonstrating high consistency. Although a small difference was observed in nasal TISA500 measurements, interobserver and CASIA2-human grader reproducibility remained excellent. Automated SS detection has the potential to facilitate evaluation and monitoring of primary angle closure disease.

Exogenous OCT4 and SOX2 Contribution to In Vitro Reprogramming in Cattle.

Mechanisms of cell reprogramming by pluripotency-related transcription factors or nuclear transfer seem to be mediated by similar pathways, and the study of the contribution of OCT4 and SOX2 in both processes may help elucidate the mechanisms responsible for pluripotency. Bovine fibroblasts expressing exogenous OCT4 or SOX2, or both, were analyzed regarding the expression of pluripotency factors and imprinted genes H19 and IGF2R, and used for in vitro reprogramming. The expression of the H19 gene was increased in the control sorted group, and putative iPSC-like cells were obtained when cells were not submitted to cell sorting. When sorted cells expressing OCT4, SOX2, or none (control) were used as donor cells for somatic cell nuclear transfer, fusion rates were 60.0% vs. 64.95% and 70.53% vs. 67.24% for SOX2 vs. control and OCT4 vs. control groups, respectively; cleavage rates were 66.66% vs. 81.68% and 86.47% vs. 85.18%, respectively; blastocyst rates were 33.05% vs. 44.15% and 52.06% vs. 44.78%, respectively. These results show that the production of embryos by NT resulted in similar rates of in vitro developmental competence compared to control cells regardless of different profiles of pluripotency-related gene expression presented by donor cells; however, induced reprogramming was compromised after cell sorting.

Application of the Yamanaka Transcription Factors Oct4, Sox2, Klf4, and c-Myc from the Laboratory to the Clinic.

The transcription factors Oct4, Sox2, Klf4, and c-Myc enable the reprogramming of somatic cells into induced pluripotent cells. Reprogramming generates newly differentiated cells for potential therapies in cancer, neurodegenerative diseases, and rejuvenation processes. In cancer therapies, these transcription factors lead to a reduction in the size and aggressiveness of certain tumors, such as sarcomas, and in neurodegenerative diseases, they enable the production of dopaminergic cells in Parkinson's disease, the replacement of affected neuronal cells in olivopontocerebellar atrophy, and the regeneration of the optic nerve. However, there are limitations, such as an increased risk of cancer development when using Klf4 and c-Myc and the occurrence of abnormal dyskinesias in the medium term, possibly generated by the uncontrolled growth of differentiated dopaminergic cells and the impairment of the survival of the new cells. Therefore, the Yamanaka transcription factors have shown therapeutic potential through cell reprogramming for some carcinomas, neurodegenerative diseases, and rejuvenation. However, the limitations found in the studies require further investigation before the use of these transcription factors in humans.

High OCT4 Expression Might Be Associated with an Aggressive Phenotype in Rectal Cancer.

Rectal cancer (RC) is one of the most common malignant neoplasms, and cancer stem cells (CSCs) of the intestinal tract have been implicated in its origin. The oncofetal protein OCT4 has been linked to neoplastic processes, but its role and clinical significance in RC are unknown. This study investigates the expression of the stem cell marker OCT4 related to clinical-pathological characteristics and its clinical significance in RC patients. The expression level of stem cell marker OCT4 was analyzed in 22 primary rectal tumors by western blot. The association between OCT4 protein expression and the clinical-pathological features of tumors was evaluated by χ2 test and Fisher's exact test. We demonstrated that the expression of the stem cell marker OCT4 was observed in tumor tissue but not adjacent non-tumor tissue. High expression of the stem cell marker OCT4 was significantly associated with histological differentiation grade (p = 0.039), tumor invasion level (p = 0.004), lymph node involvement (p = 0.044), tumor-node-metastasis (TNM) stage (p = 0.002), and clinical stage (p = 0.021). These findings suggest that high OCT4 expression is associated with a more aggressive RC phenotype, with a greater likelihood of progression and metastasis. These results shed light on the importance of targeting this CSC marker to attenuate RC progression.

Correlation of RETINAL Artery Diameter with Coronary Artery Disease: The RETINA CAD Pilot Study-Are the Eyes the Windows to the Heart?

INTRODUCTION: This study aimed to determine whether there was any correlation between coronary artery disease (CAD) and retinal artery diameter at an academic tertiary medical center in Trinidad and Tobago. METHODS: This prospective study evaluated patients (n = 77) with recent invasive coronary angiography (CAG) and the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score who subsequently underwent optical coherence tomography-angiography (OCT-A) at the Eric Williams Medical Sciences Complex (EWMSC) from January 2021 to March 2021. Routine medical history and cardiovascular medications were also recorded. Spearman's rank correlation coefficient and Mann-Whitney U-tests were used to compare correlations and medians between groups. RESULTS: The average patient age was 57.8 years old, with the majority being male [n = 55 (71.4%)] and of South Asian ethnicity [n = 53 (68.8%)]. Retinal artery diameter was negatively correlated with the SYNTAX score (-0.332 for the right eye, p = 0.003 and -0.237 for the left eye, p = 0.038). A statistically significant relationship was also demonstrated in females and diabetic patients. There were no serious adverse events (SAEs). CONCLUSION: A significantly negative correlation was observed between retinal artery diameter and SYNTAX score. This study alludes to the practical use of optical coherence tomography-angiography (OCT-A) as a noninvasive diagnostic modality for patients with cardiovascular disease (CVD). Further large-scale, multicentric studies are required to confirm these exploratory findings. TRIAL REGISTRATION NUMBER: NCT04233619.

Desprendimiento de la capa bacilar de la retina asociado a enfermedad inflamatoria ocular / Detachment of the Bacillary Layer of the Retina Associated with Ocular Inflammatory Disease

El desprendimiento de la capa bacilar de la retina es la separación de los segmentos internos de los fotorreceptores del resto de la retina neurosensorial, o separación entre la zona miode y elipsoide de la retina, que en un hallazgo reciente se puede identificar mediante la tomografía de coherencia óptica de dominio espectral. El objetivo es actualizar los conocimientos sobre el desprendimiento de la capa bacilar de la retina y el uso de la tomografía de coherencia óptica de dominio espectral en las enfermedades oculares que están asociadas con este signo. Se consultaron las fuentes bibliográficas como Google académico, SciELO LAC, Medline y MEDICARIBE. Se limitaron los resultados al idioma español e inglés y a los últimos cinco años. Se recuperaron 54 documentos, de ellos 18 resultaron relevantes a esta investigación. Los autores más mencionados fueron Ramtohul, Metha y Cicinelli. Ellos trabajaron el signo clínico en cuestión y reportaron la experiencia en la atención a los pacientes aquejados con esta enfermedad ocular. El desprendimiento de la capa bacilar de la retina es un signo presente en varias enfermedades asociadas a inflamación del segmento posterior ocular. La tomografía de coherencia óptica de dominio espectral es una técnica efectiva para determinarlo, aunque estos planteamientos aún son escasos en la literatura, lo cual reafirma la importancia científica de continuar los estudios a partir de hipótesis iniciales desde el punto de vista histológico y tomográfico(AU)

Retinal bacillary layer detachment is the separation of the inner segments of the photoreceptors from the rest of the neurosensory retina, or separation between the myode and ellipsoid zone of the retina, which in a recent finding can be identified by spectral-domain optical coherence tomography. The objective is to update the knowledge about the detachment of the bacillary layer of the retina and the use of spectral-domain optical coherence tomography in ocular diseases that are associated with this sign. Bibliographic sources such as academic Google, SciELO LAC, MEDLINE and MEDICARIBE were consulted. Fifty-four documents were retrieved, of which 18 were relevant to this research. The results were limited to the Spanish and English language and to the last five years. The most mentioned authors were Ramtohul, Metha and Cicinelli. They worked on the clinical sign in question and reported the experience in caring for patients afflicted with this ocular disease. Detachment of the bacillary layer of the retina is a sign present in several diseases associated with ocular posterior segment inflammation. Spectral-domain optical coherence tomography is an effective technique to determine it, although it is still scarce in the literature, which reaffirms the scientific validity of continuing studies from initial hypotheses from the histological and tomographic point of view(AU)

Detección de glaucoma mediante tomografía de coherencia óptica / Detection of Glaucoma Using Optical Coherence Tomography

La tomografía de coherencia óptica se ha convertido en el sistema de imagen más común para detectar de manera precoz el daño glaucomatoso; de ahí que resulte imprescindible para las decisiones clínicas y como criterio de inclusión en investigaciones y ensayos clínicos. El objetivo es exponer los avances en la aplicación de la tomografía de coherencia óptica en la detección del glaucoma a través de la revisión de las publicaciones de los últimos cinco años. La búsqueda se realizó en Google Académico para lo cual se emplearon palabras clave. Las mejoras en la tecnología de dominio espectral y de fuente de barrido han permitido la segmentación de células ganglionares, el reconocimiento de la apertura de la membrana de Bruch como punto de referencia para el análisis de los parámetros del disco óptico y el desarrollo de la angiografía sin contraste. Para el diagnóstico de glaucoma se analizó la estructura en tres localizaciones (células ganglionares maculares, capa de fibras neuroretiniana peripapilar, anillo neuroretiniano y copa en el disco óptico) y el plexo vascular superficial en dos (parafoveal y peripapilar). Se recomienda chequear calidad y presencia de artefactos previo al análisis de los resultados; así como complementar estos resultados con el interrogatorio y hallazgos al examen oftalmológico, fundamentalmente mediante biomicroscopia de polo posterior, para minimizar posibilidad de errores diagnósticos. Es útil tener esto en cuenta, a pesar de que sea numerosa la cantidad de pacientes que acuden cada día a la clínica del glaucoma. Se señalan ventajas y limitaciones de los parámetros estructurales y vasculares en el diagnóstico de glaucoma(AU)

Optical coherence tomography has become the most common imaging system for early detection of glaucomatous damage; hence, it is essential for clinical decisions and as a criterion for inclusion in research and clinical trials. The objective is to present the advances in the application of optical coherence tomography in the detection of glaucoma by reviewing the publications of the last five years. The search was performed in Google Scholar using keywords. Improvements in spectral domain and scanning source technology have allowed the segmentation of ganglion cells, the recognition of Bruch's membrane aperture as a reference point for the analysis of optic disc parameters and the development of non-contrast angiography. For the diagnosis of glaucoma, the structure was analyzed in three locations (macular ganglion cells, peripapillary neuroretinal fiber layer, neuroretinal ring and optic disc cup) and the superficial vascular plexus in two (parafoveal and peripapillary). It is recommended to check quality and presence of artifacts prior to the analysis of the results; as well as to complement these results with the interrogation and findings on ophthalmologic examination, mainly by posterior pole biomicroscopy, to minimize the possibility of diagnostic errors. It is useful to keep this in mind, despite the large number of patients that come to the glaucoma clinic every day. Advantages and limitations of structural and vascular parameters in the diagnosis of glaucoma are pointed out(AU)

Preliminary characterization of a novel form of progressive retinal atrophy in the German Spitz dog associated with a frameshift mutation in GUCY2D.

OBJECTIVE: To describe the clinical, preliminary electroretinographic and optical coherence tomography features of a newly identified form of progressive retinal atrophy (PRA) in German Spitzes, and identify the causal gene mutation. ANIMALS: Thirty-three client-owned German Spitz dogs were included. PROCEDURES: All animals underwent a full ophthalmic examination, including vision testing. In addition, fundus photography, ERG, and OCT were performed. A DNA-marker-based association analysis was performed to screen potential candidate genes and the whole genomes of four animals were sequenced. RESULTS: Initial fundus changes were pale papilla and mild vascular attenuation. Oscillatory nystagmus was noted in 14 of 16 clinically affected puppies. Vision was impaired under both scotopic and photopic conditions. Rod-mediated ERGs were unrecordable in all affected dogs tested, reduced cone-mediated responses were present in one animal at 3 months of age and unrecordable in the other affected animals tested. Multiple small retinal bullae were observed in three clinically affected animals (two with confirmed genetic diagnosis). OCT showed that despite loss of function, retinal structure was initially well-preserved, although a slight retinal thinning developed in older animals with the ventral retina being more severely affected. Pedigree analysis supported an autosomal recessive inheritance. A mutation was identified in GUCY2D, which segregated with the disease (NM_001003207.1:c.1598_1599insT; p.(Ser534GlufsTer20)). Human subjects with GUCY2D mutations typically show an initial disconnect between loss of function and loss of structure, a feature recapitulated in the affected dogs in this study. CONCLUSION: We identified early-onset PRA in the German Spitz associated with a frameshift mutation in GUCY2D.

Microvascular lung vessels obstructive thromboinflammatory syndrome in patients with COVID-19: Insights from lung intravascular optical coherence tomography.

Background: Microvascular lung vessels obstructive thromboinflammatory syndrome has been proposed as a possible mechanism of respiratory failure in COVID-19 patients. However, it has only been observed in post-mortem studies and has never been documented in vivo, probably because of a lack of CT scan sensitivity in small pulmonary arteries. The aim of the present study was to assess the safety, tolerability, and diagnostic value of optical coherence tomography (OCT) for the assessment of patients with COVID-19 pneumonia for pulmonary microvascular thromboinflammatory syndrome. Methods: The COVID-OCT trial was a multicenter, open-label, prospective, interventional clinical study. Two cohorts of patients were included in the study and underwent pulmonary OCT evaluation. Cohort A consisted of patients with COVID-19 with a negative CT scan for pulmonary thrombosis and elevated thromboinflammatory markers (D-dimer > 10,000 ng/mL or 5,000 < D-dimer < 10,000 ng/mL and one of: C-reactive Protein > 100 mg/dL, IL-6 > 6 pg/mL, or ferritin > 900 ng/L). Cohort B consisted of patients with COVID-19 and a CT scan positive for pulmonary thrombosis. The primary endpoints of the study were: (i) to evaluate the overall safety of OCT investigation in patients with COVID-19 pneumonia, and (ii) to report on the potential value of OCT as a novel diagnostic tool for the diagnosis of microvascular pulmonary thrombosis in COVID-19 patients. Results: A total of 13 patients were enrolled. The mean number of OCT runs performed in each patient was 6.1 ± 2.0, both in ground glass and healthy lung areas, achieving a good evaluation of the distal pulmonary arteries. Overall, OCT runs identified microvascular thrombosis in 8 patients (61.5%): 5 cases of red thrombus, 1 case of white thrombus, and 2 cases of mixed thrombus. In Cohort A, the minimal lumen area was 3.5 ± 4.6 mm2, with stenosis of 60.9 ± 35.9% of the area, and the mean length of thrombus-containing lesions was 5.4 ± 3.0 mm. In Cohort B, the percentage area obstruction was 92.6 ± 2.6, and the mean thrombus-containing lesion length was 14.1 ± 13.9 mm. No peri-procedural complications occurred in any of the 13 patients. Conclusion: OCT appears to be a safe and accurate method of evaluating the distal pulmonary arteries in hospitalized COVID-19 patients. Here, it enabled the first in vivo documentation of distal pulmonary arterial thrombosis in patients with elevated thromboinflammatory markers, even when their CT angiogram was negative for pulmonary thrombosis. Clinical trial registration: ClinicalTrial.gov, identifier NCT04410549.

MATE1 expression in the cochlea and its potential involvement in cisplatin cellular uptake and ototoxicity.

BACKGROUND: Cisplatin appears to enter the cochlear cells through the organic cation transporter 2 (OCT2). There is recent evidence that multidrug and toxin extrusion protein 1 (MATE1) is involved in cisplatin-induced nephrotoxicity. Its presence and role in the ear are unknown. AIMS/OBJECTIVES: Evaluate the presence and localization of MATE1, and determine the localization of OCT2, in the cochlea. Evaluate cisplatin uptake with regard to MATE1 and OCT2 expression. MATERIAL AND METHODS: Murine cochlear explants and paraffin-embedded cochleae were evaluated with immunohistochemistry for OCT2 and MATE1. Explant cultures were also treated with Texas Red cisplatin to determine their cellular uptake. RESULTS: MATE1 is present in the cochlea. Most intense labeling of MATE1 and OCT2 was seen in the outer hair cells (OHCs) and pillar cells, respectively. Both transporters were observed in the spiral ganglion neurons and stria vascularis. Expression levels of OCT2 and MATE1 decreased following cisplatin exposure. Texas Red cisplatin staining was strong in OHCs and pillar cells. CONCLUSIONS AND SIGNIFICANCE: To the best of our knowledge, this is the first study demonstrating the presence and localization of MATE1 in the cochlea. OCT2 labeling was seen in pillar cells. Consistently, OHCs and pillar cells uptake Texas Red cisplatin.