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Optical Engineering • Open Access

Intraocular lens alignment from an en face optical coherence tomography image Purkinje-like method
Author(s): Mengchan Sun; Alberto de Castro; Sergio Ortiz; Pablo Perez-Merino; Judith Birkenfeld; Susana Marcos

Paper Abstract

Measurement of intraocular lens (IOL) alignment implanted in patients in cataract surgery is important to understand their optical performance. We present a method to estimate tilt and decentration of IOLs based on optical coherence tomography (OCT) images. En face OCT images show Purkinje-like images that correspond to the specular reflections from the corneal and IOL surfaces. Unlike in standard Purkinje-imaging, the tomographic nature of OCT allows unequivocal association of the reflection with the corresponding surface. The locations of the Purkinje-like images are linear combinations of IOL tilt, IOL decentration, and eye rotation. The weighting coefficients depend on the individual anterior segment geometry, obtained from the same OCT datasets. The methodology was demonstrated on an artificial model eye with set amounts of lens tilt and decentration and five pseudophakic eyes. Measured tilt and decentration in the artificial eye differed by 3.7% and 0.9%, respectively, from nominal values. In patients, average IOL tilt and decentration from Purkinje were 3.30±4.68  deg and 0.16±0.16  mm, respectively, and differed on average by 0.5 deg and 0.09 mm, respectively, from direct measurements on distortion-corrected OCT images. Purkinje-based methodology from anterior segment en face OCT imaging provided, therefore, reliable measurements of IOL tilt and decentration.

Paper Details

Date Published: 10 January 2014
PDF: 9 pages
Opt. Eng. 53(6) 061704 doi: 10.1117/1.OE.53.6.061704
Published in: Optical Engineering Volume 53, Issue 6
Show Author Affiliations
Mengchan Sun, Consejo Superior de Investigaciones Científicas (Spain)
Alberto de Castro, Consejo Superior de Investigaciones Científicas (Spain)
Sergio Ortiz, Consejo Superior de Investigaciones Científicas (Spain)
Pablo Perez-Merino, Consejo Superior de Investigaciones Científicas (Spain)
Judith Birkenfeld, Consejo Superior de Investigaciones Científicas (Spain)
Susana Marcos, Consejo Superior de Investigaciones Científicas (Spain)


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