Abstract

A reliable and objective method to measure aberration changes due to the tear film is essential in improving clinical assessment of the tear film and in vivo retinal imaging. The tear film of 11 subjects are studied by acquiring continuous wavefront measurements in real-time with a customized Shack-Hartmann wavefront sensor. The device has a high resolution lenslet array (190 µm) and a topographer unit with an infrared pupil illuminator (940 nm). A Fourier transform reconstructor algorithm [1] was used to estimate the eyes’ wavefront aberrations from slope measurements. Increasing irregularities in the tear film produced observable wavefront variations. The temporal behavior of tear induced aberrations and retinal image quality was evaluated by the root mean squared (RMS) error of the residual wavefront and the volume modulation transfer function (MTF). Similar trends were observed from both metrics. Our analysis demonstrates the applicability of the SH wavefront sensor to assessing the dynamics of the human tear film.

© 2006 Optical Society of America

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References

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    [CrossRef] [PubMed]
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    [CrossRef]
  3. R. Montes-Mico, J. L. Alio, and W. N. Charman, "Dynamic changes in the tear film in dry eyes," Invest. Ophthalmol. Visual Sci. 46, 1615-1619 (2005).
    [CrossRef] [PubMed]
  4. J. Craig, "Structure and function of the preocular tear film," in The Tear Film: Structure, Function and Clinical Examination, R. Edwards, and C. Hutchins, eds. (Butterworth-Heinemann, 2002), pp. 18-50.
  5. R. Montes-Mico, J. L. Alio, G. Munoz, J. J. Perez-Santonja, and W. N. Charman, "Postblink changes in total and corneal ocular aberrations," Ophthalmology 111, 758-767 (2004).
    [CrossRef] [PubMed]
  6. R. Tutt, A. Bradley, C. Begley, and L. N. Thibos, "Optical and visual impact of tear break-up in human eyes," Invest. Ophthalmol. Visual Sci. 41, 4117-4123 (2000).
    [PubMed]
  7. A. Dubra, C. Paterson, and C. Dainty, "Study of the tear topography dynamics using a lateral shearing interferometer," Opt. Express 12, 6278-6288 (2004).
    [CrossRef]
  8. S. Gruppetta, F. Lacombe, and P. Puget, "Study of the dynamic aberrations of the human tear film," Opt. Express 13, 7631-7636 (2005).
    [CrossRef] [PubMed]
  9. D. R. Iskander, M. J. Collins, and B. Davis, "Evaluating tear film stability in the human eye with high-speed videokeratoscopy," IEEE Trans. Biomed. Eng. 52, 1939-1949 (2005).
    [CrossRef] [PubMed]
  10. J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
    [PubMed]
  11. L. A. Carvalho, "Accuracy of Zernike polynomials in characterizing optical aberrations and the corneal surface of the eye," Invest. Ophthalmol. Visual Sci. 46, 1915-1926 (2005).
    [CrossRef] [PubMed]
  12. M. K. Smolek, and S. D. Klyce, "Zernike polynomial fitting fails to represent all visually significant corneal aberrations," Invest. Ophthalmol. Visual Sci. 44, 4676-4681 (2003).
    [CrossRef] [PubMed]
  13. J. C. Wyant, and K. Creath, "Basic wavefront aberration theory for optical metrology," in Applied Optics and Optical Engineering, J. C. Wyant, and R. R. Shannon, eds. (Academic Press, 1992), pp. 2-53.
  14. W. H. Southwell, "Wave-front estimation from wave-front slope measurements," J. Opt. Soc. Am. 70, 998-1009 (1980).
    [CrossRef]

2005

R. Montes-Mico, J. L. Alio, and W. N. Charman, "Dynamic changes in the tear film in dry eyes," Invest. Ophthalmol. Visual Sci. 46, 1615-1619 (2005).
[CrossRef] [PubMed]

S. Gruppetta, F. Lacombe, and P. Puget, "Study of the dynamic aberrations of the human tear film," Opt. Express 13, 7631-7636 (2005).
[CrossRef] [PubMed]

D. R. Iskander, M. J. Collins, and B. Davis, "Evaluating tear film stability in the human eye with high-speed videokeratoscopy," IEEE Trans. Biomed. Eng. 52, 1939-1949 (2005).
[CrossRef] [PubMed]

L. A. Carvalho, "Accuracy of Zernike polynomials in characterizing optical aberrations and the corneal surface of the eye," Invest. Ophthalmol. Visual Sci. 46, 1915-1926 (2005).
[CrossRef] [PubMed]

2004

R. Montes-Mico, J. L. Alio, G. Munoz, J. J. Perez-Santonja, and W. N. Charman, "Postblink changes in total and corneal ocular aberrations," Ophthalmology 111, 758-767 (2004).
[CrossRef] [PubMed]

2003

M. K. Smolek, and S. D. Klyce, "Zernike polynomial fitting fails to represent all visually significant corneal aberrations," Invest. Ophthalmol. Visual Sci. 44, 4676-4681 (2003).
[CrossRef] [PubMed]

2002

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

2001

2000

R. Tutt, A. Bradley, C. Begley, and L. N. Thibos, "Optical and visual impact of tear break-up in human eyes," Invest. Ophthalmol. Visual Sci. 41, 4117-4123 (2000).
[PubMed]

1991

1980

Alio, J. L.

R. Montes-Mico, J. L. Alio, and W. N. Charman, "Dynamic changes in the tear film in dry eyes," Invest. Ophthalmol. Visual Sci. 46, 1615-1619 (2005).
[CrossRef] [PubMed]

R. Montes-Mico, J. L. Alio, G. Munoz, J. J. Perez-Santonja, and W. N. Charman, "Postblink changes in total and corneal ocular aberrations," Ophthalmology 111, 758-767 (2004).
[CrossRef] [PubMed]

Aragon, J. L.

Artal, P.

Begley, C.

R. Tutt, A. Bradley, C. Begley, and L. N. Thibos, "Optical and visual impact of tear break-up in human eyes," Invest. Ophthalmol. Visual Sci. 41, 4117-4123 (2000).
[PubMed]

Bradley, A.

R. Tutt, A. Bradley, C. Begley, and L. N. Thibos, "Optical and visual impact of tear break-up in human eyes," Invest. Ophthalmol. Visual Sci. 41, 4117-4123 (2000).
[PubMed]

Carvalho, L. A.

L. A. Carvalho, "Accuracy of Zernike polynomials in characterizing optical aberrations and the corneal surface of the eye," Invest. Ophthalmol. Visual Sci. 46, 1915-1926 (2005).
[CrossRef] [PubMed]

Charman, W. N.

R. Montes-Mico, J. L. Alio, and W. N. Charman, "Dynamic changes in the tear film in dry eyes," Invest. Ophthalmol. Visual Sci. 46, 1615-1619 (2005).
[CrossRef] [PubMed]

R. Montes-Mico, J. L. Alio, G. Munoz, J. J. Perez-Santonja, and W. N. Charman, "Postblink changes in total and corneal ocular aberrations," Ophthalmology 111, 758-767 (2004).
[CrossRef] [PubMed]

Collins, M. J.

D. R. Iskander, M. J. Collins, and B. Davis, "Evaluating tear film stability in the human eye with high-speed videokeratoscopy," IEEE Trans. Biomed. Eng. 52, 1939-1949 (2005).
[CrossRef] [PubMed]

Csakany, B.

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

Davis, B.

D. R. Iskander, M. J. Collins, and B. Davis, "Evaluating tear film stability in the human eye with high-speed videokeratoscopy," IEEE Trans. Biomed. Eng. 52, 1939-1949 (2005).
[CrossRef] [PubMed]

Erdelyi, B.

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

Gaspar, M.

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

Gruppetta, S.

Hofer, H.

Iskander, D. R.

D. R. Iskander, M. J. Collins, and B. Davis, "Evaluating tear film stability in the human eye with high-speed videokeratoscopy," IEEE Trans. Biomed. Eng. 52, 1939-1949 (2005).
[CrossRef] [PubMed]

Kablesz, F.

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

Klyce, S. D.

M. K. Smolek, and S. D. Klyce, "Zernike polynomial fitting fails to represent all visually significant corneal aberrations," Invest. Ophthalmol. Visual Sci. 44, 4676-4681 (2003).
[CrossRef] [PubMed]

Lacombe, F.

Lang, Z.

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

Montes-Mico, R.

R. Montes-Mico, J. L. Alio, and W. N. Charman, "Dynamic changes in the tear film in dry eyes," Invest. Ophthalmol. Visual Sci. 46, 1615-1619 (2005).
[CrossRef] [PubMed]

R. Montes-Mico, J. L. Alio, G. Munoz, J. J. Perez-Santonja, and W. N. Charman, "Postblink changes in total and corneal ocular aberrations," Ophthalmology 111, 758-767 (2004).
[CrossRef] [PubMed]

Munoz, G.

R. Montes-Mico, J. L. Alio, G. Munoz, J. J. Perez-Santonja, and W. N. Charman, "Postblink changes in total and corneal ocular aberrations," Ophthalmology 111, 758-767 (2004).
[CrossRef] [PubMed]

Nemeth, J.

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

Perez-Santonja, J. J.

R. Montes-Mico, J. L. Alio, G. Munoz, J. J. Perez-Santonja, and W. N. Charman, "Postblink changes in total and corneal ocular aberrations," Ophthalmology 111, 758-767 (2004).
[CrossRef] [PubMed]

Puget, P.

Roddier, C.

Roddier, F.

Singer, B.

Smolek, M. K.

M. K. Smolek, and S. D. Klyce, "Zernike polynomial fitting fails to represent all visually significant corneal aberrations," Invest. Ophthalmol. Visual Sci. 44, 4676-4681 (2003).
[CrossRef] [PubMed]

Soumelidis, A.

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

Southwell, W. H.

Thibos, L. N.

R. Tutt, A. Bradley, C. Begley, and L. N. Thibos, "Optical and visual impact of tear break-up in human eyes," Invest. Ophthalmol. Visual Sci. 41, 4117-4123 (2000).
[PubMed]

Tutt, R.

R. Tutt, A. Bradley, C. Begley, and L. N. Thibos, "Optical and visual impact of tear break-up in human eyes," Invest. Ophthalmol. Visual Sci. 41, 4117-4123 (2000).
[PubMed]

Williams, D. R.

Appl. Opt.

IEEE Trans. Biomed. Eng.

D. R. Iskander, M. J. Collins, and B. Davis, "Evaluating tear film stability in the human eye with high-speed videokeratoscopy," IEEE Trans. Biomed. Eng. 52, 1939-1949 (2005).
[CrossRef] [PubMed]

Invest. Ophthalmol. Visual Sci.

J. Nemeth, B. Erdelyi, B. Csakany, M. Gaspar, A. Soumelidis, F. Kablesz, and Z. Lang, "High-speed videotopographic measurement of tear film build-up time," Invest. Ophthalmol. Visual Sci. 43, 1783-1790 (2002).
[PubMed]

L. A. Carvalho, "Accuracy of Zernike polynomials in characterizing optical aberrations and the corneal surface of the eye," Invest. Ophthalmol. Visual Sci. 46, 1915-1926 (2005).
[CrossRef] [PubMed]

M. K. Smolek, and S. D. Klyce, "Zernike polynomial fitting fails to represent all visually significant corneal aberrations," Invest. Ophthalmol. Visual Sci. 44, 4676-4681 (2003).
[CrossRef] [PubMed]

R. Montes-Mico, J. L. Alio, and W. N. Charman, "Dynamic changes in the tear film in dry eyes," Invest. Ophthalmol. Visual Sci. 46, 1615-1619 (2005).
[CrossRef] [PubMed]

R. Tutt, A. Bradley, C. Begley, and L. N. Thibos, "Optical and visual impact of tear break-up in human eyes," Invest. Ophthalmol. Visual Sci. 41, 4117-4123 (2000).
[PubMed]

J. Opt. Soc. Am.

J. Opt. Soc. Am. A

Ophthalmology

R. Montes-Mico, J. L. Alio, G. Munoz, J. J. Perez-Santonja, and W. N. Charman, "Postblink changes in total and corneal ocular aberrations," Ophthalmology 111, 758-767 (2004).
[CrossRef] [PubMed]

Opt. Express

Other

A. Dubra, C. Paterson, and C. Dainty, "Study of the tear topography dynamics using a lateral shearing interferometer," Opt. Express 12, 6278-6288 (2004).
[CrossRef]

J. Craig, "Structure and function of the preocular tear film," in The Tear Film: Structure, Function and Clinical Examination, R. Edwards, and C. Hutchins, eds. (Butterworth-Heinemann, 2002), pp. 18-50.

J. C. Wyant, and K. Creath, "Basic wavefront aberration theory for optical metrology," in Applied Optics and Optical Engineering, J. C. Wyant, and R. R. Shannon, eds. (Academic Press, 1992), pp. 2-53.

Supplementary Material (5)

» Media 1: AVI (2963 KB)     
» Media 2: AVI (2609 KB)     
» Media 3: AVI (3196 KB)     
» Media 4: AVI (3511 KB)     
» Media 5: AVI (4278 KB)     

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Figures (8)

Fig. 1.
Fig. 1.

Schematic diagram of the Shack-Hartmann wavefront sensor. The PBS places the beam from the SLD into the imaging path, and a dichroic mirror is used to separate the 940 nm light used to image the pupil and the aberrated wavefront at 830 nm.

Fig. 2.
Fig. 2.

Tear film breakup in a healthy eye due to a lengthy non-blink interval. Irregularities of the tear film surface are seen in both the reflection of the topography mires from the pupil cameral (a) and SH wavefront sensor image (b).

Fig. 3.
Fig. 3.

Residual wavefront maps from the same SH data (shown in Fig. 2 above) using Zernike modes (a) and the Fourier transform reconstructor (b). Color bar is in microns.

Fig 4.
Fig 4.

Movies illustrating the progression of the residual wavefront for a typical healthy eye with a highly stable tear film (a) (2.89 MB), the healthy eye corresponding to the raw data in Fig. 2 that has a less stable tear film (b) (2.54 MB) and a rather prominent dry eye (c) (3.12 MB). Color bar is in microns

Fig. 5.
Fig. 5.

Movies capturing the reflection of the topography mire on the pupil show the differences in tear film dynamics of a healthy eye (a) (3.42 MB) and a dry eye (b) (4.18 MB).

Fig. 6.
Fig. 6.

Evolution of the residual RMS wavefront error (a) and volume MTF (b) for measurements corresponding to the movies in Fig. 5. Both evaluation metrics illustrates how the tear film of the healthy eye remained relatively stable in comparison with the dry eye

Fig. 7.
Fig. 7.

Evolution of the residual RMS wavefront error (a) and volume MTF (b) from one healthy eye and one dry eye. Error bars represent standard deviations resulting from four separate measurements of the healthy eye and three of the dry eye. Data corresponds to the same pair of eyes represented in Figs. 5 and 6.

Fig. 8.
Fig. 8.

A highly non-uniform optical surface due to the tear film produces more blurring and irregular spot displacements in the SH image. The corresponding aberrations induced by the tear film are clearly visible in the residual wavefront maps

Tables (1)

Tables Icon

Table 1. Temporal variability of residual RMS and volume MTF

Equations (2)

Equations on this page are rendered with MathJax. Learn more.

W Tear ( x , y , t ) = W ( x , y , t ) W static ( x , y )
Volume ( M T F , t ) = ω 60 c p d M T F ( ω , t )

Metrics