Sofia Otin

Background: This study explored the diagnostic potential of image-processing analysis in optical coherence tomography (OCT) images to detect systemic vascular changes in individuals with systemic diseases. Methods: Ocular OCT images from two cohorts diabetic patients and healthy control subjects were analyzed. A novel Superpixel Segmentation (SpS) algorithm was used to process these images and extract optical image density information from ocular vascular tissue. The algorithm was applied to isolate the choroid layer for analysis of its optical properties. The procedure was performed by separate examiners, and both inter- and intra-observer repeatability were assessed. Choroidal area (CA) and choroidal optical image density (COID) metrics were used to assess structural changes in the vascular tissue and predict alterations in the choroidal parameters. Results: A total of 110 diabetic patient eye images and 92 healthy control images were processed. The results showed significant differences in CA and COID between diabetic and healthy eyes, indicating that these parameters could serve as valuable biomarkers for early vascular damage. Conclusions: The use of the SpS algorithm on OCT B-scan images allows for the identification of new parameters linked to ocular vascular damage. These findings suggest that digital image-processing techniques can reveal differences in vascular tissue, offering potential new indicators of pathology.

Purpose: This study explores the diagnostic potential of applying image-processing analysis to optical coherence tomography (OCT) images to detect systemic vascular changes in individuals with systemic diseases. Methods: The study enrolled analyzed ocular OCT images obtained from two cohorts: diabetic patients and healthy control subjects. The novel Superpixel Segmentation (SpS) algorithm developed for this paper was used to process these images and extract optical image density information from ocular vascular tissue. This procedure was employed in the image segmentation phase to isolate the choroid layer for subsequent analysis of the images’ optical properties. Separate examiners performed the image treatment and processing procedure and both inter- and intra-observer method repeatability were assessed. Choroidal area (CA) and choroidal optical image density (COID) metrics were used to assess structural alterations in the vascular tissue and predict changes to analytical choroidal parameters. Results: A total of 110 diabetic patient eye images and 92 healthy subjects eye images were processed. The results revealed significant differences in CA and COID between diabetic and healthy eyes. In short, detected image density remained unaffected by the extent of the choroidal tissue analyzed, indicating that these parameters could serve as valuable biomarkers of early vascular damage in OCT images. Conclusions: Use of the SpS algorithm on OCT B-scan images allows for the determination of a new parameter linked to ocular vascular damage. Translational relevance: The application of digital image processing techniques reveals differences in vascular tissue in OCT images, offering potential new indicators of pathology.

An efficient mode of evaluation for eye movements is the use of objective eye tracking systems combined with subjective tests (NSUCO or DEM), which are easily applicable across all age groups and in eye care clinical settings. The objective of this study was to characterize fixations during reading in two groups: a group of children with neurodevelopmental disorders (NDDG, 24 children, age: 6–12 years) and a group of children with oculomotor anomalies but without NDD (OAG, 24 children, age: 6–12 years). The results obtained were compared with those from a control group (CG, 20 children, age: 6–12 years). Specifically, the outcomes obtained with two subjective score systems, the Northeastern State University College of Optometry’s Oculomotor (NSUCO) test and the Developmental Eye Movement (DEM) test, were compared with the objective analysis obtained through a commercially available eye tracker (Tobii Eye X, Tobii, Stockholm, Sweden). Specialized analysis software, namely Clinical Eye Tracker 2020 (Thomson Software Solutions, Welham Green, UK), was used. It was found that children with NDD had impaired oculomotor skills. A higher number of regressions, more fixations, and longer durations of fixations appear to be characteristic signs of this population group. Additionally, children with NDD took longer to complete the DEM test, as well as exhibiting more errors. The use of objective videoculographic systems for eye tracking and subjective tests like the NSUCO or DEM are good tools to assess saccadic movements, allowing the detection of oculomotor abnormalities in children with NDD.

Spatial aspects of visual performance are usually evaluated through visual acuity charts and contrast sensitivity (CS) tests. CS tests are generated by vanishing the contrast level of the visual charts. However, the quality of retinal images can be affected by both ocular aberrations and scattering effects and none of those factors are incorporated as parameters in visual tests in clinical practice. We propose a new computational methodology to generate visual acuity charts affected by ocular scattering effects. The generation of glare effects on the visual tests is reached by combining an ocular straylight meter methodology with the Commission Internationale de l’Eclairage’s (CIE) general disability glare formula. A new function for retinal contrast assessment is proposed, the subjective straylight function (SSF), which provides the maximum tolerance to the perception of straylight in an observed visual acuity test. Once the SSF is obtained, the subjective straylight index (SSI) is defined as the area under the SSF curve. Results report the normal values of the SSI in a population of 30 young healthy subjects (19 ± 1 years old), a peak centered at SSI = 0.46 of a normal distribution was found. SSI was also evaluated as a function of both spatial and temporal aspects of vision. Ocular wavefront measures revealed a statistical correlation of the SSI with defocus and trefoil terms. In addition, the time recovery (TR) after induced total disability glare and the SSI were related; in particular, the higher the RT, the greater the SSI value for high- and mid-contrast levels of the visual test. No relationships were found for low contrast visual targets. To conclude, a new computational method for retinal contrast assessment as a function of ocular straylight was proposed as a complementary subjective test for visual function performance.

Relevance: A tool for decision-making in the optometry clinic.Summary: This work establishes evidence-based clinical recommendations for treatment selection in myopia progression control. An exhaustive literature review was conducted in biomedical databases following the Grading of Recommendations Assessment, Development, and Evaluations (GRADE) method. This methodology, accepted by international organizations (such as Cochrane, the Ministry of Health, Food and Drug Administration, etc.), defines how to conduct a search for scientific information and how it should be classified based on the quality of studies according to specific standards. From this organized information, clinical recommendations of varying strength are developed, taking into account a balance of benefit/risk of the intervention. After filtering more than 1000 publications, a series of clinical recommendations for various interventions aimed at controlling myopia progression have been developed. The use of standardized methodologies for developing clinical recommendations facilitates the interpretation and applicability of scientific research results.

Purpose: To evaluate alterations of the choroid in patients with a neurodegenerative disease versus healthy controls, a custom algorithm based on superpixel segmentation was used. Design: A cross-sectional study was conducted on data obtained in a previous cohort study. Subjects: Swept-source optical coherence tomography (OCT) B-scan images obtained using a Triton (Topcon, Japan) device were compiled according to current OSCAR IB and APOSTEL OCT image quality criteria. Images were included from three cohorts: multiple sclerosis (MS) patients, Parkinson disease (PD) patients, and healthy subjects. Only patients with early-stage MS and PD were included. Methods: In total, 104 OCT B-scan images were processed using a custom superpixel segmentation (SpS) algorithm to detect boundary limits in the choroidal layer and the optical properties of the image. The algorithm groups pixels with similar structural properties to generate clusters with similar meaningful properties. Main outcomes: SpS selects and groups the superpixels in a segmented choroidal area, computing the choroidal optical image density (COID), measured as the standard mean gray level, and the total choroidal area (CA), measured as px². Results: The CA and choroidal density (CD) were significantly reduced in the two neurodegenerative disease groups (higher in PD than in MS) versus the healthy subjects (p < 0.001); choroidal area was also significantly reduced in the MS group versus the healthy subjects. The COID increased significantly in the PD patients versus the MS patients and in the MS patients versus the healthy controls (p < 0.001). Conclusions: The SpS algorithm detected choroidal tissue boundary limits and differences optical density in MS and PD patients versus healthy controls. The application of the SpS algorithm to OCT images potentially acts as a non-invasive biomarker for the early diagnosis of MS and PD.

Background To evaluate alterations of the choroid in neurodegenerative disease patients versus healthy controls using a custom supervised algorithm based on superpixel segmentation. Methods The prospective study protocol and procedures were approved by the Aragon Research Ethics Committee (CEICA) according to Declaration of Helsinki. Informed consent was obtained from all participants included in the study. Swept-source optical coherence tomography (OCT) B-scan images obtained using a Triton (Topcon, Japan) device were compiled. Images were included from three cohorts: multiple sclerosis (MS) patients and Parkinson disease (PD) patients diagnosed by a neurologist, and healthy subjects. 104 OCT B-scan images were processed using a custom supervised superpixel segmentation (SpS) algorithm to detect boundary limits in the choroidal layer. The algorithm groups pixels with similar structural image properties to generate clusters with similar meaningful properties. SpS automatically selects and groups the superpixels in a segmented choroidal area, computing the choroidal optical image density (COID), the total choroidal area (CA), and choroid density (CD). Results CA and CD were significantly reduced in the two neurodegenerative diseases (higher in PD than in MS) versus healthy subjects (p < 0.001). COID increased significantly in PD patients versus MS patients and in MS patients versus healthy controls (p < 0.001). Conclusions The SpS algorithm detects choroidal tissue and significant changes in choroidal images proprieties in MS and PD patients versus healthy controls. Application of the SpS algorithm to OCT images potentially acts as a non-invasive biomarker for early diagnosis of MS and PD.