A review of feature-based retinal image analysis

Retinal imaging is a fundamental tool in ophthalmic diagnostics. The potential use of retinal imaging within screening programs, with consequent need to analyze large numbers of images with high throughput, is pushing the digital image analysis field to find new solutions for the extraction of specific information from the retinal image. The aim of this review is to explore the latest progress in image processing techniques able to recognize specific retinal image features. and potential features of disease. In particular, this review aims to describe publically available retinal image databases, highlight different performance evaluators commonly used within the field, outline current approaches in feature-based retinal image analysis, and to map related trends. This review found two key areas to be addressed for the future development of automatic retinal image analysis: fundus image quality and the affect image processing may impose on relevant clinical information within the images. Performance evaluators of the algorithms reviewed are very promising, however absolute values are difficult to interpret when validating system suitability for use within clinical practice

Asymmetry of retinal physiological measurements in young adults measured with optical coherence tomography

Introduction: Optical coherence tomography (OCT) is a useful technique to assess the retina. In this study, we explored the physiological inter-ocular asymmetry of several retinal parameters in a sample of young Caucasian adults. Methods: A transversal study was designed in which the macular exploration protocol of the 3D-OCT-2000 was employed to evaluate several retinal parameters in a sample of 37 young adults aged between 12 and 23 years (spherical equivalent from -3.00 to +4.00 D). Normal inter-ocular asymmetry values were determined and compared with previous published tolerance values. Results: Statically significant differences were found between males and females in mean thickness of the retinal nerve fibre layer (RNFL) in the right eye. In addition, Inter-ocular statistically significant differences were uncovered in mean and superior RNFL thickness, as well as in central macular thickness (all p<0.05). Mean RNFL thickness for the left eye was higher than for the right eye by 1.70 μm. Conclusions: The exploration of the normal asymmetries of the retina may be an effective approach for an early detection of pathologies of the retina such as glaucoma. Differences in instrumentation and sample characteristics do not allow for a direct comparison between the present findings and previous research

Structural and functional macular inter-ocular asymmetry in patients with high myopia

BACKGROUND: Retinal evaluation performed in the optometry clinic allows optometrists to track the prognosis of retinal disease and to assess anatomical and functional changes related to age and pathological and non-pathological conditions. OBJECTIVES: The purpose of this research was to investigate the normal range of inter-ocular asymmetry in retinal and choroidal thickness and in retinal sensitivity high myopia without ocular fundus manifestations and to determine the relationship between inter-ocular asymmetry and refractive error. METHODS: Forty-three patients (35 07 ± 13.31 years) with high myopia, and 45 healthy participants (39.9 ± 14.1 years) were administered an ocular coherence tomography and a microperimetry examination to determine retinal and choroidal thickness and retinal sensitivity at the foveal region and at 1, 2 and 3 mm, nasally, temporally, superiorly and inferiorly. Absolute inter-ocular differences were calculated to determine the normal range of asymmetry, in 95% confidence intervals. RESULTS: The choroid was thinner in the myopic group at all explored locations (all p < 0.05), with larger absolute inter­ ocular differences in most of the choroidal locations under evaluation (all p < 0.05). Similarly, retinal sensitivity was reduced in the myopic group, although statistically significant differences were only encountered at the subfoveal location (p = 0.001). Retinar sensitivity asymmetry was found to increase with refractive error. CONCLUSION: The expanded range of retinal and choroidal thickness, as well as retinal sensitivity asymmetry found in high myopia in the absence of disease is of relevance when exploring these patients for early signs of ocular pathology.Fundamento y objetivos: La evaluación de la retina que se realiza en la clínica optométrica permite a los optometristas evaluar el estado de la retina y explorar los cambios funcionales y anatómicos asociados a la edad y a condiciones patológicas y no patológicas. El objetivo de la presente tesis era investigar el rango normal de asimetría inter-ocular en espesor retiniano y coroideo y en sensibilidad retiniana en pacientes con miopía alta sin manifestaciones oculares y determinar la posible asociación entre asimetría y error refractivo. Métodos: Cuarenta y tres pacientes (35.07 ± 13.31 años) con miopía alta y 45 participantes sanos (39.9 ± 14.1 años) siguieron un examen con tomografía de coherencia óptica y microperimetría para determinar el espesor de la retina y la coroides y la sensibilidad en retina en la zona foveal y a 1, 2 y 3 mm, en los cuadrantes nasal, temporal, superior e inferior. Se calcularon las diferencias inter-oculares absolutas para determinar el rango normal de asimetría, y los intervalos de confianza al 95%. Resultados: La coroides presento mayor delgadez en el grupo de miopes en todas las zonas sometidas a examen (todas las p < 0.05), con mayores diferencias absolutas en términos de asimetría en la mayoría de las zonas exploradas (p < 0.05). Igualmente, la sensibilidad retiniana se encontró reducida en el grupo miope, si bien sólo se hallaron diferencias estadísticas en la zona subfoveal (p = 0.001). La asimetría en sensibilidad retiniana aumentaba con el error refractivo. Conclusiones: El rango extendido en asimetría en espesor de retina y coroides y en sensibilidad retiniana hallado en miopía alta sin afectación ocular es muy relevante en el momento de explorar estos pacientes para la detección de los primeros signos de patología ocular.Postprint (published version

XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016)

En la presente edición, más de 150 trabajos de alto nivel científico van a ser presentados en 18 sesiones paralelas y 3 sesiones de póster, que se centrarán en áreas relevantes de la Ingeniería Biomédica. Entre las sesiones paralelas se pueden destacar la sesión plenaria Premio José María Ferrero Corral y la sesión de Competición de alumnos de Grado en Ingeniería Biomédica, con la participación de 16 alumnos de los Grados en Ingeniería Biomédica a nivel nacional. El programa científico se complementa con dos ponencias invitadas de científicos reconocidos internacionalmente, dos mesas redondas con una importante participación de sociedades científicas médicas y de profesionales de la industria de tecnología médica, y dos actos sociales que permitirán a los participantes acercarse a la historia y cultura valenciana. Por primera vez, en colaboración con FENIN, seJane Campos, R. (2017). XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016). Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/79277EDITORIA