A Review of Methods for Measuring Corneal Topography

Mejía, Yobani; Malacara-Hernández, Daniel

doi:10.1097/00006324-200104000-00013

Cited by 73 publications

(55 citation statements)

References 23 publications

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“…Los principios ópticos de algunos métodos que son implementados para medir la topografía de la córnea se pueden clasificar de acuerdo a los principios físicos usados en la medición [3], entre éstos se encuentran la reflexión especular, la reflexión difusa y luz dispersada. La técnica de reflexión especular considera la superficie anterior de la córnea como un espejo convexo, como en los sistemas basados en los discos de Plácido [4].…”

Section: Introductionunclassified

Three-dimensional scanning of the cornea by using a structured light module

Barrios¹,

Morón²,

Contreras³

et al. 2017

Opt. Pura Apl.

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ABSTRACT:Corneal topography is a computerized diagnostic tool that creates a three-dimensional map of the surface of the cornea. Corneal topography provides tools needed to know the morphology, optics, power distribution and radii of the anterior surface of the cornea. This is of great help for multiple fields of optometry and ophthalmology: contact lens fitting, keratoconus detection and tracking and corneal ecstasies, detection of suspicious corneas in refractive surgery, etc. Although there are basically two types of corneal surveyors: specular reflection and elevation, many authors agree that the accuracy of these devices is affected by multiple factors, which obey both the mathematical process used and certain physiological variables. Three-dimensional (3D) scanning systems, consisting of devices based on a structured light module, are widely used to perform high-precision measurements in primarily industrial and medical applications. The present work is proposed to show the application of fringe projection technique in three-dimensional scanning of corneal surface.Key words: Three-dimensional scanning, corneal surface, optometry RESUMEN:La topografía corneal es una herramienta diagnóstica computarizada que crea un mapa tridimensional de la superficie de la córnea. La topografía corneal proporciona herramientas necesarias para conocer la morfología, la óptica, la distribución de la potencia y de los radios, de la superficie anterior de la córnea. Esto es de gran ayuda para múltiples campos de la optometría y la oftalmología: adaptación de lentes de contacto, detección y seguimiento de queratocono y ectasias corneales, detección de córneas sospechosas en cirugía refractiva, etc. Aunque existen básicamente dos tipos de topógrafos corneales: de reflexión especular y de elevación, muchos autores coinciden que la precisión de estos dispositivos es afectada por múltiples factores, que obedecen tanto al proceso matemático empleado como a ciertas variables fisiológicas. Los sistemas de digitalización tridimensional (3D), formados por dispositivos que se basan en un módulo de luz estructurada, son usados ampliamente para realizar mediciones de alta precisión en aplicaciones industriales y médicas principalmente. El presente trabajo se plantea con el objetivo de mostrar la aplicación de la técnica de proyección de franjas en la digitalización tridimensional de la superficie de la córnea.Palabras clave: Digitalización tridimensional, superficie de la córnea, optometría

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Section: Introductionunclassified

Three-dimensional scanning of the cornea by using a structured light module

Barrios¹,

Morón²,

Contreras³

et al. 2017

Opt. Pura Apl.

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“…PDCT was the pioneer method in videokeratoscopes (4) , whereby a patient's cornea is illuminated by concentric rings, which create an image that is reflected by the anterior surface of the cornea. The reflected image is computer analyzed, and a curvature color map of the corneal surface is generated (4) .…”

mentioning

confidence: 99%

“…The reflected image is computer analyzed, and a curvature color map of the corneal surface is generated (4) . PDCT is established as a valid and reliable method of corneal evaluation, and its use has become part of routine clinical practice (1)(2)5) .…”

mentioning

confidence: 99%

“…As new technologies have been developed, new instruments have become available, claiming performance similar to that of systems based solely on PDCT (3)(4)(6)(7)(8) . For example, the Orbscan II (Bausch & Lomb, Inc., San Dimas, CA, USA) uses a slitscanning system associated with a Placido disk to obtain curvature and elevation measurements (6,(9)(10) .…”

mentioning

confidence: 99%

“…These new instruments aggregate different views of the anterior segment that are referred to as anterior segment tomographs. It is not known if PDCT is interchangeable with Scheimpflug-based corneal elevation (SBCE), which can be mathematically-derived to produce a model of corneal curvature (4) . Quantitative information of corneal topography color maps generated by the EyeSys and the Pentacam was analyzed.…”

mentioning

confidence: 99%

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