Robust estimation of tear film surface quality in lateral shearing interferometry

Dorota Helena Szczesna; D. Robert Iskander

doi:10.1117/1.3275474

1 November 2009 Robust estimation of tear film surface quality in lateral shearing interferometry

Dorota Helena Szczesna, D. Robert Iskander

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Journal of Biomedical Optics, Vol. 14, Issue 6, 064039 (November 2009). https://doi.org/10.1117/1.3275474

Abstract

Interferometry is a sensitive technique for recording tear film surface irregularities in a noninvasive manner. At the same time, the technique is hindered by natural eye movements resulting in measurement noise. Estimating tear film surface quality from interferograms can be reduced to a spatial-average-localized weighted estimate of the first harmonic of the interference fringes. However, previously reported estimation techniques proved to perform poorly in cases where the pattern fringes were significantly disturbed. This can occur in cases of measuring tear film surface quality on a contact lens on the eye or in a dry eye. We present a new estimation technique for extracting the first harmonic from the interference fringes that combines the traditional spectral estimation techniques with morphological image processing techniques. The proposed technique proves to be more robust to changes in interference fringes caused by natural eye movements and the degree of dryness of the contact lens and corneal surfaces than its predecessors, resulting in tear film surface quality estimates that are less noisy.

©(2009) Society of Photo-Optical Instrumentation Engineers (SPIE)

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Dorota Helena Szczesna and D. Robert Iskander "Robust estimation of tear film surface quality in lateral shearing interferometry," Journal of Biomedical Optics 14(6), 064039 (1 November 2009). https://doi.org/10.1117/1.3275474

Published: 1 November 2009

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