Optical distortion correction in Optical
Coherence Tomography for quantitative ocular
anterior segment by three-dimensional imaging
Sergio Ortiz1,2,*, Damian Siedlecki1,3, Ireneusz Grulkowski4,Laura Remon,1 Daniel
Pascual,1 Maciej Wojtkowski,4 and Susana Marcos1
1Instituto de Óptica “Daza de Valdés”, Consejo Superior de Investigaciones Científicas,
C/Serrano 121, 28006 Madrid, Spain
2Laboratorio de Ensayos. Centro de Investigación y Desarrollo de la Armada (CIDA).
C/Arturo Soria 289, 28033 Madrid, Spain
3Institute of Physics, Wroclaw University of Technology,
Wybrzeze Wyspianskiego 27, 50370 Wroclaw, Poland
4Institute of Physics, Nicolaus Copernicus University,
ul. Grudziądzka 5/7, 87100 Toruń, Poland
*sortiz@io.cfmac.csic.es
Abstract: A method for three-dimensional 3-D optical distortion
(refraction) correction on anterior segment Optical Coherence Tomography
(OCT) images has been developed. The method consists of 3-D ray tracing
through the different surfaces, following denoising, segmentation of the
surfaces, Delaunay representation of the surfaces, and application of fan
distortion correction. The correction has been applied theoretically to
realistic computer eye models, and experimentally to OCT images of: an
artificial eye with a Polymethyl Methacrylate (PMMA) cornea and an
intraocular lens (IOL), an enucleated porcine eye, and a human eye in vivo
obtained from two OCT laboratory set-ups (time domain and spectral). Data
are analyzed in terms of surface radii of curvature and asphericity.
Comparisons are established between the reference values for the surfaces
(nominal values in the computer model; non-contact profilometric
measurements for the artificial eye; Scheimpflug imaging for the real eyes
in vivo and vitro). The results from the OCT data were analyzed following
the conventional approach of dividing the optical path by the refractive
index, after application of 2-D optical correction, and 3-D optical correction
(in all cases after fan distortion correction). The application of 3-D optical
distortion correction increased significantly both the accuracy of the radius
of curvature estimates and particularly asphericity of the surfaces, with
respect to conventional methods of OCT image analysis. We found that the
discrepancies of the radii of curvature estimates from 3-D optical distortion
corrected OCT images are less than 1% with respect to nominal values.
Optical distortion correction in 3-D is critical for quantitative analysis of
OCT anterior segment imaging, and allows accurate topography of the
internal surfaces of the eye.
©2010 Optical Society of America
OCIS codes: (110.4500) Optical coherence tomography; (120.6650) Surface measurements,
figure; (120.4640) Optical instruments; (120.4800) Optical standards and testing; (110.6880)
Three-dimensional image acquisition; (330.7327) Visual optics, ophthalmic instrumentation;
References and links
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2204–2218 (2007), http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-15-5-2204.
2. P. Rosales, M. Dubbelman, S. Marcos, and G.L. van der Heijde, “Crystalline lens radii of curvature from Purkinje
and Scheimpflug imaging,” J. Vis. 6(10), 1057–1067 (2006).
3. M. Dubbelman, G. L. Van der Heijde, and H. A. Weeber, “Change in shape of the aging human crystalline lens
with accommodation,” Vision Res. 45(1), 117–132 (2005).
#119890 - $15.00 USD Received 13 Nov 2009; revised 30 Dec 2009; accepted 5 Jan 2010; published 26 Jan 2010
(C) 2010 OSA 1 February 2010 / Vol. 18, No. 3 / OPTICS EXPRESS 2782