Principles of operation, accuracy and precision of an Eye Surface Profiler

Iskander, D. Robert; Wachel, Paweł; Simpson, Patrick N. D.; Consejo, Alejandra; Jesus, Danilo Andrade De

doi:10.1111/opo.12292

Cited by 64 publications

(108 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In particular, it has been proved that the Eye Surface Profiler (ESP) provides excellent levels of accuracy for the central area of 8 mm diameter. This error increases with the radial distance . Our preliminary experience with ESP showed changes in the scleral shape within measurements from a particular subject but not in the corneal shape.…”

Section: Introductionmentioning

confidence: 78%

Scleral changes with accommodation

Consejo

Radhakrishnan

Iskander

2017

Ophthalmic Physiologic Optic

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 78%

Scleral changes with accommodation

Consejo

Radhakrishnan

Iskander

2017

Ophthalmic Physiologic Optic

Self Cite

View full text Add to dashboard Cite

show abstract

“…This device provides a complete characterization of the corneal profile as well as of the geometry of the anterior sclera and limbus. 8 To our knowledge, this is the first report of a scleral CL fitting guided or optimized by using the measurements provided by an eye surface profilometer.…”

Section: Discussionmentioning

confidence: 99%

Anterior Eye Profilometry-guided Scleral Contact Lens Fitting in Keratoconus

Soto-Negro¹

2017

International Journal of Keratoconus and Ectatic Corneal Diseases

View full text Add to dashboard Cite

We report the case of a 35-year-old woman diagnosed with keratoconus since she was 18 years old and wearer of corneal rigid contact lenses (CLs). We refitted the case with the fully scleral CL ICD16.5 (Paragon Vision Sciences) for obtaining not only a successful visual restoration, but also a comfortable wear. We initiated the fitting with the spherical model of the CL, but it failed due to instability of the lens. We confirmed the presence of a clear asymmetry in the anterior scleral geometry in both eyes by using the profilometer eye surface profiler (ESP, Eaglet Eye), with a difference between nasal and temporal sagittal heights of 470 and 170 µm in right and left eyes respectively. Although this profile suggested the need for the fitting of a CL with significant peripheral toricity, we followed the manufacturer's guidelines and performed a trial with a CL of moderate peripheral toricity (125 µm of difference between steep and flat meridian). The stability of the CL failed again and finally a CL with a peripheral toricity close to that measured with the profilometer was fitted. With this lens, good visual performance, lens stability, and comfort was obtained and maintained during a 1-year follow-up. This case suggests that fully scleral CLs fitting might be optimized with the use of corneo-scleral profilometers, minimizing potentially the number of trials. This potential benefit should be investigated further in future studies.

show abstract

“…En la actualidad existen diferentes técnicas que permiten realizar mediciones sobre la superficie de la córnea [1]. Asumiendo que la superficie de la córnea esté dada por ( , ) z f x y  en un sistema cartesiano, con primeras y segundas derivadas continuas en cualquier punto, hay al menos tres formas diferentes en las que la topografía de la córnea se puede especificar:…”

Section: Introductionunclassified

“…Estas curvaturas se obtienen matemáticamente calculando las primeras y segundas derivadas parciales de ( , ). f x y Asumiendo que el índice de refracción de la córnea es constante, 1,3375 n  una representación equivalente frecuentemente utilizada por los optómetras es el poder refractivo en dioptrías dado por ( 1) , D n R  donde R es el radio de curvatura de la superficie.…”

Section: Introductionunclassified

“…La técnica de reflexión difusa modifica la reflexión especular de la superficie anterior de la córnea convirtiéndola en un reflector difuso, lo cual se logra aplicando fluoresceína a la película lagrimal. Con esta modificación se pueden aplicar los métodos usuales de análisis de superficies difusas, como el método de proyección de franjas [1]. La técnica de luz dispersada usa el fenómeno de dispersión de la luz cuando se propaga en un medio óptico.…”

Section: Introductionunclassified

See 1 more Smart Citation

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

Barrios¹,

Morón²,

Contreras³

et al. 2017

Opt. Pura Apl.

View full text Add to dashboard Cite

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

show abstract

Principles of operation, accuracy and precision of an Eye Surface Profiler

Cited by 64 publications

References 32 publications

Scleral changes with accommodation

Scleral changes with accommodation

Anterior Eye Profilometry-guided Scleral Contact Lens Fitting in Keratoconus

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

Contact Info

Product

Resources

About