Abstract

We have developed and validated in vivo magnetic resonance imaging (MRI) protocols to extract parameters (T2 and geometry) of the human lens that, combined with biometric measures of the eye and optical modelling, enable us to investigate the relative contributions made by the gradient of refractive index (GRIN) and the shape of the lens to the refractive properties of each subject tested. Seven young and healthy participants (mean age: 25.6 ± 3.6 years) underwent an ophthalmic examination, and two sessions of MRI scans using a 3 T clinical magnet. Our MRI protocols for studying lens physiological optics and geometrical measurements were repeatable and reliable, using both 1D (95% confidence interval (CI) for mean differences for exponents = [-2.1, 2.6]) and 2D analysis (anterior T2 CI for differences [-6.4, 8.1] ms; posterior T2 CI for differences [-6.4, 8.3] ms). The lens thickness measured from MRI showed good correlation with that measured with clinical ‘gold standard’ LenStar (mean differences = [-0.18, 0.2] mm). The predicted refractive errors from ZEMAX had reasonable agreements with participants’ clinic records (mean differences = [-1.7, 1.2] D). Quantitative measurements of lens geometry and GRIN with our MRI technique showed high inter-day repeatability. Our clinical MRI technique also provides reliable measures of lens geometry that are comparable to optical biometry. Finally, our ZEMAX optical models produced accurate refractive error and lens power estimations.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Full Article  |  PDF Article
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References

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    [Crossref]
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    [Crossref]
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    [Crossref]
  4. P. J. Donaldson, K.-S. N. Chee, J. C. Lim, and K. F. Webb, “Regulation of lens volume: implications for lens transparency,” Exp. Eye Res. 88(2), 144–150 (2009).
    [Crossref]
  5. R. T. Mathias, J. K. Kistler, and P. J. Donaldson, “The lens circulation,” J. Membr. Biol. 216(1), 1–16 (2007).
    [Crossref]
  6. E. Vaghefi, A. Kim, and P. J. Donaldson, “Active maintenance of the gradient of refractive index is required to sustain the optical properties of the lens,” Invest. Ophthalmol. Visual Sci. 56(12), 7195–7208 (2015).
    [Crossref]
  7. J. C. Lim, E. Vaghefi, B. Li, M. G. Nye-Wood, and P. J. Donaldson, “Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine LensEffects of HBO on the Bovine Lens,” Invest. Ophthalmol. Visual Sci. 57(4), 1961–1973 (2016).
    [Crossref]
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  9. P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
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  10. E. Vaghefi, K. Walker, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion,” Am J Physiol Regul Integr Comp Physiol 302(11), R1250–R1259 (2012).
    [Crossref]
  11. E. Vaghefi, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Visualizing ocular lens fluid dynamics using MRI: manipulation of steady-state water content and water fluxes,” Am J Physiol Regul Integr Comp Physiol 301(2), R335–R342 (2011).
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  12. B. A. Moffat, D. A. Atchison, and J. M. Pope, “Age-related changes in refractive index distribution and power of the human lens as measured by magnetic resonance micro-imaging in vitro,” Vision Res. 42(13), 1683–1693 (2002).
    [Crossref]
  13. P. Rácz, C. Hargitai, B. Alföldy, P. Banki, and K. Tompa, “1 H Spin-Spin Relaxation in Normal and Cataractous Human, Normal Fish and Birds Eye Lenses,” Exp. Eye Res. 70(4), 529–536 (2000).
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    [Crossref]
  24. L. Thaler, A. C. Schütz, M. A. Goodale, and K. R. Gegenfurtner, “What is the best fixation target? The effect of target shape on the stability of fixational eye movements,” Vision Res. 76, 31–42 (2013).
    [Crossref]
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    [Crossref]
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    [Crossref]
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    [Crossref]
  31. M. Dubbelman and G. Van der Heijde, “The shape of the aging human lens: curvature, equivalent refractive index and the lens paradox,” Vision Res. 41(14), 1867–1877 (2001).
    [Crossref]
  32. X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
    [Crossref]
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  37. F. A. Bettelheim, M. J. Lizak, and J. S. Zigler, “Relaxographic studies of aging normal human lenses,” Exp. Eye Res. 75(6), 695–702 (2002).
    [Crossref]
  38. S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “In vivo study of changes in refractive index distribution in the human crystalline lens with age and accommodation,” Invest. Ophthalmol. Visual Sci. 49(6), 2531–2540 (2008).
    [Crossref]
  39. B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
    [Crossref]
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    [Crossref]
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  44. R. Navarro, F. Palos, and L. M. González, “Adaptive model of the gradient index of the human lens. II. Optics of the accommodating aging lens,” J. Opt. Soc. Am. A 24(9), 2911–2920 (2007).
    [Crossref]

2018 (1)

2017 (2)

P. J. Donaldson, A. C. Grey, B. M. Heilman, J. C. Lim, and E. Vaghefi, “The physiological optics of the lens,” Prog. Retinal Eye Res. 56, e1–e24 (2017).
[Crossref]

B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
[Crossref]

2016 (2)

J. C. Lim, E. Vaghefi, B. Li, M. G. Nye-Wood, and P. J. Donaldson, “Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine LensEffects of HBO on the Bovine Lens,” Invest. Ophthalmol. Visual Sci. 57(4), 1961–1973 (2016).
[Crossref]

C. J. Sheil and A. V. Goncharov, “Accommodating volume-constant age-dependent optical (AVOCADO) model of the crystalline GRIN lens,” Biomed. Opt. Express 7(5), 1985–1999 (2016).
[Crossref]

2015 (4)

E. Vaghefi, A. Kim, and P. J. Donaldson, “Active maintenance of the gradient of refractive index is required to sustain the optical properties of the lens,” Invest. Ophthalmol. Visual Sci. 56(12), 7195–7208 (2015).
[Crossref]

B. K. Pierscionek, M. Bahrami, M. Hoshino, K. Uesugi, J. Regini, and N. Yagi, “The eye lens: age-related trends and individual variations in refractive index and shape parameters,” OncoTargets Ther. 6(31), 30532–30544 (2015).
[Crossref]

J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
[Crossref]

X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

2013 (2)

A. C. Kingston and I. G. Cox, “Predicting through-focus visual acuity with the eye’s natural aberrations,” Optometry and Vision Science 90(10), 1111–1118 (2013).
[Crossref]

L. Thaler, A. C. Schütz, M. A. Goodale, and K. R. Gegenfurtner, “What is the best fixation target? The effect of target shape on the stability of fixational eye movements,” Vision Res. 76, 31–42 (2013).
[Crossref]

2012 (2)

E. Vaghefi, K. Walker, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion,” Am J Physiol Regul Integr Comp Physiol 302(11), R1250–R1259 (2012).
[Crossref]

B. K. Pierscionek and J. W. Regini, “The gradient index lens of the eye: opto-biological synchrony,” Prog. Retinal Eye Res. 31(4), 332–349 (2012).
[Crossref]

2011 (4)

E. Vaghefi, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Visualizing ocular lens fluid dynamics using MRI: manipulation of steady-state water content and water fluxes,” Am J Physiol Regul Integr Comp Physiol 301(2), R335–R342 (2011).
[Crossref]

J. J. Rozema, D. A. Atchison, and M.-J. Tassignon, “Comparing methods to estimate the human lens power,” Invest. Ophthalmol. Visual Sci. 52(11), 7937–7942 (2011).
[Crossref]

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “MRI study of the changes in crystalline lens shape with accommodation and aging in humans,” Journal of vision 11(3), 19 (2011).
[Crossref]

S. Jasvinder, T. Khang, K. Sarinder, V. Loo, and V. Subrayan, “Agreement analysis of LENSTAR with other techniques of biometry,” Eye 25(6), 717–724 (2011).
[Crossref]

2010 (1)

2009 (3)

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
[Crossref]

E. Vaghefi, B. P. Pontre, P. J. Donaldson, P. J. Hunter, and M. D. Jacobs, “Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI,” Physiological measurement 30(10), 1061–1073 (2009).
[Crossref]

P. J. Donaldson, K.-S. N. Chee, J. C. Lim, and K. F. Webb, “Regulation of lens volume: implications for lens transparency,” Exp. Eye Res. 88(2), 144–150 (2009).
[Crossref]

2008 (1)

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “In vivo study of changes in refractive index distribution in the human crystalline lens with age and accommodation,” Invest. Ophthalmol. Visual Sci. 49(6), 2531–2540 (2008).
[Crossref]

2007 (6)

A. V. Goncharov and C. Dainty, “Wide-field schematic eye models with gradient-index lens,” J. Opt. Soc. Am. A 24(8), 2157–2174 (2007).
[Crossref]

R. Navarro, F. Palos, and L. González, “Adaptive model of the gradient index of the human lens. I. Formulation and model of aging ex vivo lenses,” J. Opt. Soc. Am. A 24(8), 2175–2185 (2007).
[Crossref]

R. Navarro, F. Palos, and L. M. González, “Adaptive model of the gradient index of the human lens. II. Optics of the accommodating aging lens,” J. Opt. Soc. Am. A 24(9), 2911–2920 (2007).
[Crossref]

R. T. Mathias, J. K. Kistler, and P. J. Donaldson, “The lens circulation,” J. Membr. Biol. 216(1), 1–16 (2007).
[Crossref]

S. Patz, R. J. Bert, E. Frederick, and T. F. Freddo, “T1 and T2 measurements of the fine structures of the in vivo and enucleated human eye,” Cigongzhen Chengxiang 26(3), 510–518 (2007).
[Crossref]

O. Dietrich, J. G. Raya, S. B. Reeder, M. F. Reiser, and S. O. Schoenberg, “Measurement of signal-to-noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters,” Cigongzhen Chengxiang 26(2), 375–385 (2007).
[Crossref]

2006 (1)

R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
[Crossref]

2005 (2)

P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
[Crossref]

C. E. Jones, D. A. Atchison, R. Meder, and J. M. Pope, “Refractive index distribution and optical properties of the isolated human lens measured using magnetic resonance imaging (MRI),” Vision Res. 45(18), 2352–2366 (2005).
[Crossref]

2002 (2)

B. A. Moffat, D. A. Atchison, and J. M. Pope, “Age-related changes in refractive index distribution and power of the human lens as measured by magnetic resonance micro-imaging in vitro,” Vision Res. 42(13), 1683–1693 (2002).
[Crossref]

F. A. Bettelheim, M. J. Lizak, and J. S. Zigler, “Relaxographic studies of aging normal human lenses,” Exp. Eye Res. 75(6), 695–702 (2002).
[Crossref]

2001 (2)

G. Smith, M. J. Cox, R. Calver, and L. F. Garner, “The spherical aberration of the crystalline lens of the human eye,” Vision Res. 41(2), 235–243 (2001).
[Crossref]

M. Dubbelman and G. Van der Heijde, “The shape of the aging human lens: curvature, equivalent refractive index and the lens paradox,” Vision Res. 41(14), 1867–1877 (2001).
[Crossref]

2000 (1)

P. Rácz, C. Hargitai, B. Alföldy, P. Banki, and K. Tompa, “1 H Spin-Spin Relaxation in Normal and Cataractous Human, Normal Fish and Birds Eye Lenses,” Exp. Eye Res. 70(4), 529–536 (2000).
[Crossref]

1999 (1)

A. Glasser and P. L. Kaufman, “The mechanism of accommodation in primates1,” Ophthalmology 106(5), 863–872 (1999).
[Crossref]

1997 (1)

B. K. Pierscionek, “Refractive index contours in the human lens,” Exp. Eye Res. 64(6), 887–893 (1997).
[Crossref]

1994 (2)

H. Tabandeh, G. M. Thompson, P. Heyworth, S. Dorey, A. J. Woods, and D. Lynch, “Water content, lens hardness and cataract appearance,” Eye 8(1), 125–129 (1994).
[Crossref]

J. C. Russ, J. R. Matey, A. J. Mallinckrodt, and S. McKay, “The image processing handbook,” Comput. Phys. 8(2), 177–178 (1994).
[Crossref]

1987 (1)

B. K. Pierscionek, G. Smith, and R. C. Augusteyn, “The refractive increments of bovine α-, β-and γ-crystallins,” Vision Res. 27(9), 1539–1541 (1987).
[Crossref]

Abduljalil, A.

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
[Crossref]

Adnan, X.

X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

Ahmad, M.

P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
[Crossref]

Alföldy, B.

P. Rácz, C. Hargitai, B. Alföldy, P. Banki, and K. Tompa, “1 H Spin-Spin Relaxation in Normal and Cataractous Human, Normal Fish and Birds Eye Lenses,” Exp. Eye Res. 70(4), 529–536 (2000).
[Crossref]

Arrieta, E.

Asbell, P. A.

P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
[Crossref]

Atchison, D. A.

A. Khan, J. M. Pope, P. K. Verkicharla, M. Suheimat, and D. A. Atchison, “Change in human lens dimensions, lens refractive index distribution and ciliary body ring diameter with accommodation,” Biomed. Opt. Express 9(3), 1272–1282 (2018).
[Crossref]

X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “MRI study of the changes in crystalline lens shape with accommodation and aging in humans,” Journal of vision 11(3), 19 (2011).
[Crossref]

J. J. Rozema, D. A. Atchison, and M.-J. Tassignon, “Comparing methods to estimate the human lens power,” Invest. Ophthalmol. Visual Sci. 52(11), 7937–7942 (2011).
[Crossref]

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “In vivo study of changes in refractive index distribution in the human crystalline lens with age and accommodation,” Invest. Ophthalmol. Visual Sci. 49(6), 2531–2540 (2008).
[Crossref]

C. E. Jones, D. A. Atchison, R. Meder, and J. M. Pope, “Refractive index distribution and optical properties of the isolated human lens measured using magnetic resonance imaging (MRI),” Vision Res. 45(18), 2352–2366 (2005).
[Crossref]

B. A. Moffat, D. A. Atchison, and J. M. Pope, “Age-related changes in refractive index distribution and power of the human lens as measured by magnetic resonance micro-imaging in vitro,” Vision Res. 42(13), 1683–1693 (2002).
[Crossref]

D. A. Atchison and G. Smith, “Optics of the Human Eye” (Butterworth-Heinemann,2000).

Augusteyn, R. C.

B. K. Pierscionek, G. Smith, and R. C. Augusteyn, “The refractive increments of bovine α-, β-and γ-crystallins,” Vision Res. 27(9), 1539–1541 (1987).
[Crossref]

Bahrami, M.

B. K. Pierscionek, M. Bahrami, M. Hoshino, K. Uesugi, J. Regini, and N. Yagi, “The eye lens: age-related trends and individual variations in refractive index and shape parameters,” OncoTargets Ther. 6(31), 30532–30544 (2015).
[Crossref]

Banki, P.

P. Rácz, C. Hargitai, B. Alföldy, P. Banki, and K. Tompa, “1 H Spin-Spin Relaxation in Normal and Cataractous Human, Normal Fish and Birds Eye Lenses,” Exp. Eye Res. 70(4), 529–536 (2000).
[Crossref]

Bert, R. J.

S. Patz, R. J. Bert, E. Frederick, and T. F. Freddo, “T1 and T2 measurements of the fine structures of the in vivo and enucleated human eye,” Cigongzhen Chengxiang 26(3), 510–518 (2007).
[Crossref]

R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
[Crossref]

Bettelheim, F. A.

F. A. Bettelheim, M. J. Lizak, and J. S. Zigler, “Relaxographic studies of aging normal human lenses,” Exp. Eye Res. 75(6), 695–702 (2002).
[Crossref]

Borja, D.

Brocks, D.

P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
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G. Smith, M. J. Cox, R. Calver, and L. F. Garner, “The spherical aberration of the crystalline lens of the human eye,” Vision Res. 41(2), 235–243 (2001).
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R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
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Chee, K.-S. N.

P. J. Donaldson, K.-S. N. Chee, J. C. Lim, and K. F. Webb, “Regulation of lens volume: implications for lens transparency,” Exp. Eye Res. 88(2), 144–150 (2009).
[Crossref]

Christoforidis, J. A.

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
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A. C. Kingston and I. G. Cox, “Predicting through-focus visual acuity with the eye’s natural aberrations,” Optometry and Vision Science 90(10), 1111–1118 (2013).
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Cox, M. J.

G. Smith, M. J. Cox, R. Calver, and L. F. Garner, “The spherical aberration of the crystalline lens of the human eye,” Vision Res. 41(2), 235–243 (2001).
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O. Dietrich, J. G. Raya, S. B. Reeder, M. F. Reiser, and S. O. Schoenberg, “Measurement of signal-to-noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters,” Cigongzhen Chengxiang 26(2), 375–385 (2007).
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P. J. Donaldson, A. C. Grey, B. M. Heilman, J. C. Lim, and E. Vaghefi, “The physiological optics of the lens,” Prog. Retinal Eye Res. 56, e1–e24 (2017).
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J. C. Lim, E. Vaghefi, B. Li, M. G. Nye-Wood, and P. J. Donaldson, “Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine LensEffects of HBO on the Bovine Lens,” Invest. Ophthalmol. Visual Sci. 57(4), 1961–1973 (2016).
[Crossref]

E. Vaghefi, A. Kim, and P. J. Donaldson, “Active maintenance of the gradient of refractive index is required to sustain the optical properties of the lens,” Invest. Ophthalmol. Visual Sci. 56(12), 7195–7208 (2015).
[Crossref]

E. Vaghefi, K. Walker, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion,” Am J Physiol Regul Integr Comp Physiol 302(11), R1250–R1259 (2012).
[Crossref]

E. Vaghefi, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Visualizing ocular lens fluid dynamics using MRI: manipulation of steady-state water content and water fluxes,” Am J Physiol Regul Integr Comp Physiol 301(2), R335–R342 (2011).
[Crossref]

P. J. Donaldson, K.-S. N. Chee, J. C. Lim, and K. F. Webb, “Regulation of lens volume: implications for lens transparency,” Exp. Eye Res. 88(2), 144–150 (2009).
[Crossref]

E. Vaghefi, B. P. Pontre, P. J. Donaldson, P. J. Hunter, and M. D. Jacobs, “Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI,” Physiological measurement 30(10), 1061–1073 (2009).
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R. T. Mathias, J. K. Kistler, and P. J. Donaldson, “The lens circulation,” J. Membr. Biol. 216(1), 1–16 (2007).
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H. Tabandeh, G. M. Thompson, P. Heyworth, S. Dorey, A. J. Woods, and D. Lynch, “Water content, lens hardness and cataract appearance,” Eye 8(1), 125–129 (1994).
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P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
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M. Dubbelman and G. Van der Heijde, “The shape of the aging human lens: curvature, equivalent refractive index and the lens paradox,” Vision Res. 41(14), 1867–1877 (2001).
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P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
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R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
[Crossref]

Freddo, T. F.

S. Patz, R. J. Bert, E. Frederick, and T. F. Freddo, “T1 and T2 measurements of the fine structures of the in vivo and enucleated human eye,” Cigongzhen Chengxiang 26(3), 510–518 (2007).
[Crossref]

Frederick, E.

S. Patz, R. J. Bert, E. Frederick, and T. F. Freddo, “T1 and T2 measurements of the fine structures of the in vivo and enucleated human eye,” Cigongzhen Chengxiang 26(3), 510–518 (2007).
[Crossref]

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G. Smith, M. J. Cox, R. Calver, and L. F. Garner, “The spherical aberration of the crystalline lens of the human eye,” Vision Res. 41(2), 235–243 (2001).
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L. Thaler, A. C. Schütz, M. A. Goodale, and K. R. Gegenfurtner, “What is the best fixation target? The effect of target shape on the stability of fixational eye movements,” Vision Res. 76, 31–42 (2013).
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A. Glasser and P. L. Kaufman, “The mechanism of accommodation in primates1,” Ophthalmology 106(5), 863–872 (1999).
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González, L.

González, L. M.

Goodale, M. A.

L. Thaler, A. C. Schütz, M. A. Goodale, and K. R. Gegenfurtner, “What is the best fixation target? The effect of target shape on the stability of fixational eye movements,” Vision Res. 76, 31–42 (2013).
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P. J. Donaldson, A. C. Grey, B. M. Heilman, J. C. Lim, and E. Vaghefi, “The physiological optics of the lens,” Prog. Retinal Eye Res. 56, e1–e24 (2017).
[Crossref]

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P. Rácz, C. Hargitai, B. Alföldy, P. Banki, and K. Tompa, “1 H Spin-Spin Relaxation in Normal and Cataractous Human, Normal Fish and Birds Eye Lenses,” Exp. Eye Res. 70(4), 529–536 (2000).
[Crossref]

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B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
[Crossref]

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P. J. Donaldson, A. C. Grey, B. M. Heilman, J. C. Lim, and E. Vaghefi, “The physiological optics of the lens,” Prog. Retinal Eye Res. 56, e1–e24 (2017).
[Crossref]

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H. Tabandeh, G. M. Thompson, P. Heyworth, S. Dorey, A. J. Woods, and D. Lynch, “Water content, lens hardness and cataract appearance,” Eye 8(1), 125–129 (1994).
[Crossref]

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B. K. Pierscionek, M. Bahrami, M. Hoshino, K. Uesugi, J. Regini, and N. Yagi, “The eye lens: age-related trends and individual variations in refractive index and shape parameters,” OncoTargets Ther. 6(31), 30532–30544 (2015).
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E. Vaghefi, B. P. Pontre, P. J. Donaldson, P. J. Hunter, and M. D. Jacobs, “Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI,” Physiological measurement 30(10), 1061–1073 (2009).
[Crossref]

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J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
[Crossref]

Jacobs, M. D.

E. Vaghefi, K. Walker, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion,” Am J Physiol Regul Integr Comp Physiol 302(11), R1250–R1259 (2012).
[Crossref]

E. Vaghefi, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Visualizing ocular lens fluid dynamics using MRI: manipulation of steady-state water content and water fluxes,” Am J Physiol Regul Integr Comp Physiol 301(2), R335–R342 (2011).
[Crossref]

E. Vaghefi, B. P. Pontre, P. J. Donaldson, P. J. Hunter, and M. D. Jacobs, “Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI,” Physiological measurement 30(10), 1061–1073 (2009).
[Crossref]

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R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
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S. Jasvinder, T. Khang, K. Sarinder, V. Loo, and V. Subrayan, “Agreement analysis of LENSTAR with other techniques of biometry,” Eye 25(6), 717–724 (2011).
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B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
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J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
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Jones, C. E.

C. E. Jones, D. A. Atchison, R. Meder, and J. M. Pope, “Refractive index distribution and optical properties of the isolated human lens measured using magnetic resonance imaging (MRI),” Vision Res. 45(18), 2352–2366 (2005).
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Kasthurirangan, S.

X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “MRI study of the changes in crystalline lens shape with accommodation and aging in humans,” Journal of vision 11(3), 19 (2011).
[Crossref]

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “In vivo study of changes in refractive index distribution in the human crystalline lens with age and accommodation,” Invest. Ophthalmol. Visual Sci. 49(6), 2531–2540 (2008).
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Kaufman, P. L.

A. Glasser and P. L. Kaufman, “The mechanism of accommodation in primates1,” Ophthalmology 106(5), 863–872 (1999).
[Crossref]

Ke, B.

B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
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Khang, T.

S. Jasvinder, T. Khang, K. Sarinder, V. Loo, and V. Subrayan, “Agreement analysis of LENSTAR with other techniques of biometry,” Eye 25(6), 717–724 (2011).
[Crossref]

Kim, A.

E. Vaghefi, A. Kim, and P. J. Donaldson, “Active maintenance of the gradient of refractive index is required to sustain the optical properties of the lens,” Invest. Ophthalmol. Visual Sci. 56(12), 7195–7208 (2015).
[Crossref]

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A. C. Kingston and I. G. Cox, “Predicting through-focus visual acuity with the eye’s natural aberrations,” Optometry and Vision Science 90(10), 1111–1118 (2013).
[Crossref]

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R. T. Mathias, J. K. Kistler, and P. J. Donaldson, “The lens circulation,” J. Membr. Biol. 216(1), 1–16 (2007).
[Crossref]

Knopp, M. V.

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
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R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
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Lanz, T.

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
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Li, B.

J. C. Lim, E. Vaghefi, B. Li, M. G. Nye-Wood, and P. J. Donaldson, “Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine LensEffects of HBO on the Bovine Lens,” Invest. Ophthalmol. Visual Sci. 57(4), 1961–1973 (2016).
[Crossref]

Li, M.

B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
[Crossref]

Lim, J. C.

P. J. Donaldson, A. C. Grey, B. M. Heilman, J. C. Lim, and E. Vaghefi, “The physiological optics of the lens,” Prog. Retinal Eye Res. 56, e1–e24 (2017).
[Crossref]

J. C. Lim, E. Vaghefi, B. Li, M. G. Nye-Wood, and P. J. Donaldson, “Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine LensEffects of HBO on the Bovine Lens,” Invest. Ophthalmol. Visual Sci. 57(4), 1961–1973 (2016).
[Crossref]

P. J. Donaldson, K.-S. N. Chee, J. C. Lim, and K. F. Webb, “Regulation of lens volume: implications for lens transparency,” Exp. Eye Res. 88(2), 144–150 (2009).
[Crossref]

Liu, C.

B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
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F. A. Bettelheim, M. J. Lizak, and J. S. Zigler, “Relaxographic studies of aging normal human lenses,” Exp. Eye Res. 75(6), 695–702 (2002).
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S. Jasvinder, T. Khang, K. Sarinder, V. Loo, and V. Subrayan, “Agreement analysis of LENSTAR with other techniques of biometry,” Eye 25(6), 717–724 (2011).
[Crossref]

Lynch, D.

H. Tabandeh, G. M. Thompson, P. Heyworth, S. Dorey, A. J. Woods, and D. Lynch, “Water content, lens hardness and cataract appearance,” Eye 8(1), 125–129 (1994).
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J. C. Russ, J. R. Matey, A. J. Mallinckrodt, and S. McKay, “The image processing handbook,” Comput. Phys. 8(2), 177–178 (1994).
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Mao, X.

B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
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Marcos, S.

Markwell, E. L.

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “MRI study of the changes in crystalline lens shape with accommodation and aging in humans,” Journal of vision 11(3), 19 (2011).
[Crossref]

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “In vivo study of changes in refractive index distribution in the human crystalline lens with age and accommodation,” Invest. Ophthalmol. Visual Sci. 49(6), 2531–2540 (2008).
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J. C. Russ, J. R. Matey, A. J. Mallinckrodt, and S. McKay, “The image processing handbook,” Comput. Phys. 8(2), 177–178 (1994).
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Mathias, R. T.

R. T. Mathias, J. K. Kistler, and P. J. Donaldson, “The lens circulation,” J. Membr. Biol. 216(1), 1–16 (2007).
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J. C. Russ, J. R. Matey, A. J. Mallinckrodt, and S. McKay, “The image processing handbook,” Comput. Phys. 8(2), 177–178 (1994).
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Meder, R.

C. E. Jones, D. A. Atchison, R. Meder, and J. M. Pope, “Refractive index distribution and optical properties of the isolated human lens measured using magnetic resonance imaging (MRI),” Vision Res. 45(18), 2352–2366 (2005).
[Crossref]

Mindel, J.

P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
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Moffat, B. A.

B. A. Moffat, D. A. Atchison, and J. M. Pope, “Age-related changes in refractive index distribution and power of the human lens as measured by magnetic resonance micro-imaging in vitro,” Vision Res. 42(13), 1683–1693 (2002).
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Nangia, V.

J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
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Navarro, R.

Nye-Wood, M. G.

J. C. Lim, E. Vaghefi, B. Li, M. G. Nye-Wood, and P. J. Donaldson, “Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine LensEffects of HBO on the Bovine Lens,” Invest. Ophthalmol. Visual Sci. 57(4), 1961–1973 (2016).
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Ossiani, M.

R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
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Panda-Jonas, S.

J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
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Pardhi, P.

J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
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Patz, S.

S. Patz, R. J. Bert, E. Frederick, and T. F. Freddo, “T1 and T2 measurements of the fine structures of the in vivo and enucleated human eye,” Cigongzhen Chengxiang 26(3), 510–518 (2007).
[Crossref]

R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
[Crossref]

Pierscionek, B. K.

B. K. Pierscionek, M. Bahrami, M. Hoshino, K. Uesugi, J. Regini, and N. Yagi, “The eye lens: age-related trends and individual variations in refractive index and shape parameters,” OncoTargets Ther. 6(31), 30532–30544 (2015).
[Crossref]

B. K. Pierscionek and J. W. Regini, “The gradient index lens of the eye: opto-biological synchrony,” Prog. Retinal Eye Res. 31(4), 332–349 (2012).
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B. K. Pierscionek, “Refractive index contours in the human lens,” Exp. Eye Res. 64(6), 887–893 (1997).
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Pontre, B. P.

E. Vaghefi, K. Walker, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion,” Am J Physiol Regul Integr Comp Physiol 302(11), R1250–R1259 (2012).
[Crossref]

E. Vaghefi, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Visualizing ocular lens fluid dynamics using MRI: manipulation of steady-state water content and water fluxes,” Am J Physiol Regul Integr Comp Physiol 301(2), R335–R342 (2011).
[Crossref]

E. Vaghefi, B. P. Pontre, P. J. Donaldson, P. J. Hunter, and M. D. Jacobs, “Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI,” Physiological measurement 30(10), 1061–1073 (2009).
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A. Khan, J. M. Pope, P. K. Verkicharla, M. Suheimat, and D. A. Atchison, “Change in human lens dimensions, lens refractive index distribution and ciliary body ring diameter with accommodation,” Biomed. Opt. Express 9(3), 1272–1282 (2018).
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X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “MRI study of the changes in crystalline lens shape with accommodation and aging in humans,” Journal of vision 11(3), 19 (2011).
[Crossref]

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “In vivo study of changes in refractive index distribution in the human crystalline lens with age and accommodation,” Invest. Ophthalmol. Visual Sci. 49(6), 2531–2540 (2008).
[Crossref]

C. E. Jones, D. A. Atchison, R. Meder, and J. M. Pope, “Refractive index distribution and optical properties of the isolated human lens measured using magnetic resonance imaging (MRI),” Vision Res. 45(18), 2352–2366 (2005).
[Crossref]

B. A. Moffat, D. A. Atchison, and J. M. Pope, “Age-related changes in refractive index distribution and power of the human lens as measured by magnetic resonance micro-imaging in vitro,” Vision Res. 42(13), 1683–1693 (2002).
[Crossref]

Rácz, P.

P. Rácz, C. Hargitai, B. Alföldy, P. Banki, and K. Tompa, “1 H Spin-Spin Relaxation in Normal and Cataractous Human, Normal Fish and Birds Eye Lenses,” Exp. Eye Res. 70(4), 529–536 (2000).
[Crossref]

Raya, J. G.

O. Dietrich, J. G. Raya, S. B. Reeder, M. F. Reiser, and S. O. Schoenberg, “Measurement of signal-to-noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters,” Cigongzhen Chengxiang 26(2), 375–385 (2007).
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O. Dietrich, J. G. Raya, S. B. Reeder, M. F. Reiser, and S. O. Schoenberg, “Measurement of signal-to-noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters,” Cigongzhen Chengxiang 26(2), 375–385 (2007).
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Regini, J.

B. K. Pierscionek, M. Bahrami, M. Hoshino, K. Uesugi, J. Regini, and N. Yagi, “The eye lens: age-related trends and individual variations in refractive index and shape parameters,” OncoTargets Ther. 6(31), 30532–30544 (2015).
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Regini, J. W.

B. K. Pierscionek and J. W. Regini, “The gradient index lens of the eye: opto-biological synchrony,” Prog. Retinal Eye Res. 31(4), 332–349 (2012).
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O. Dietrich, J. G. Raya, S. B. Reeder, M. F. Reiser, and S. O. Schoenberg, “Measurement of signal-to-noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters,” Cigongzhen Chengxiang 26(2), 375–385 (2007).
[Crossref]

Richdale, K.

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
[Crossref]

Rozema, J. J.

J. J. Rozema, D. A. Atchison, and M.-J. Tassignon, “Comparing methods to estimate the human lens power,” Invest. Ophthalmol. Visual Sci. 52(11), 7937–7942 (2011).
[Crossref]

Russ, J. C.

J. C. Russ, J. R. Matey, A. J. Mallinckrodt, and S. McKay, “The image processing handbook,” Comput. Phys. 8(2), 177–178 (1994).
[Crossref]

Sarinder, K.

S. Jasvinder, T. Khang, K. Sarinder, V. Loo, and V. Subrayan, “Agreement analysis of LENSTAR with other techniques of biometry,” Eye 25(6), 717–724 (2011).
[Crossref]

Schmalbrock, P.

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
[Crossref]

Schoenberg, S. O.

O. Dietrich, J. G. Raya, S. B. Reeder, M. F. Reiser, and S. O. Schoenberg, “Measurement of signal-to-noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters,” Cigongzhen Chengxiang 26(2), 375–385 (2007).
[Crossref]

Schütz, A. C.

L. Thaler, A. C. Schütz, M. A. Goodale, and K. R. Gegenfurtner, “What is the best fixation target? The effect of target shape on the stability of fixational eye movements,” Vision Res. 76, 31–42 (2013).
[Crossref]

Sepehrband, F.

X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

Sheil, C. J.

Shukla, R.

J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
[Crossref]

Siedlecki, D.

Sinha, A.

J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
[Crossref]

Smith, G.

G. Smith, M. J. Cox, R. Calver, and L. F. Garner, “The spherical aberration of the crystalline lens of the human eye,” Vision Res. 41(2), 235–243 (2001).
[Crossref]

B. K. Pierscionek, G. Smith, and R. C. Augusteyn, “The refractive increments of bovine α-, β-and γ-crystallins,” Vision Res. 27(9), 1539–1541 (1987).
[Crossref]

D. A. Atchison and G. Smith, “Optics of the Human Eye” (Butterworth-Heinemann,2000).

Subrayan, V.

S. Jasvinder, T. Khang, K. Sarinder, V. Loo, and V. Subrayan, “Agreement analysis of LENSTAR with other techniques of biometry,” Eye 25(6), 717–724 (2011).
[Crossref]

Suheimat, M.

A. Khan, J. M. Pope, P. K. Verkicharla, M. Suheimat, and D. A. Atchison, “Change in human lens dimensions, lens refractive index distribution and ciliary body ring diameter with accommodation,” Biomed. Opt. Express 9(3), 1272–1282 (2018).
[Crossref]

X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

Tabandeh, H.

H. Tabandeh, G. M. Thompson, P. Heyworth, S. Dorey, A. J. Woods, and D. Lynch, “Water content, lens hardness and cataract appearance,” Eye 8(1), 125–129 (1994).
[Crossref]

Tassignon, M.-J.

J. J. Rozema, D. A. Atchison, and M.-J. Tassignon, “Comparing methods to estimate the human lens power,” Invest. Ophthalmol. Visual Sci. 52(11), 7937–7942 (2011).
[Crossref]

Teal Bluestein, K.

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
[Crossref]

Thaler, L.

L. Thaler, A. C. Schütz, M. A. Goodale, and K. R. Gegenfurtner, “What is the best fixation target? The effect of target shape on the stability of fixational eye movements,” Vision Res. 76, 31–42 (2013).
[Crossref]

Thompson, G. M.

H. Tabandeh, G. M. Thompson, P. Heyworth, S. Dorey, A. J. Woods, and D. Lynch, “Water content, lens hardness and cataract appearance,” Eye 8(1), 125–129 (1994).
[Crossref]

Tocci, M.

M. Tocci, “How to model the human eye in ZEMAX,” Opt. Design Eng.23 (2007).

Tompa, K.

P. Rácz, C. Hargitai, B. Alföldy, P. Banki, and K. Tompa, “1 H Spin-Spin Relaxation in Normal and Cataractous Human, Normal Fish and Birds Eye Lenses,” Exp. Eye Res. 70(4), 529–536 (2000).
[Crossref]

Uesugi, K.

B. K. Pierscionek, M. Bahrami, M. Hoshino, K. Uesugi, J. Regini, and N. Yagi, “The eye lens: age-related trends and individual variations in refractive index and shape parameters,” OncoTargets Ther. 6(31), 30532–30544 (2015).
[Crossref]

Uhlhorn, S.

Vaghefi, E.

P. J. Donaldson, A. C. Grey, B. M. Heilman, J. C. Lim, and E. Vaghefi, “The physiological optics of the lens,” Prog. Retinal Eye Res. 56, e1–e24 (2017).
[Crossref]

J. C. Lim, E. Vaghefi, B. Li, M. G. Nye-Wood, and P. J. Donaldson, “Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine LensEffects of HBO on the Bovine Lens,” Invest. Ophthalmol. Visual Sci. 57(4), 1961–1973 (2016).
[Crossref]

E. Vaghefi, A. Kim, and P. J. Donaldson, “Active maintenance of the gradient of refractive index is required to sustain the optical properties of the lens,” Invest. Ophthalmol. Visual Sci. 56(12), 7195–7208 (2015).
[Crossref]

E. Vaghefi, K. Walker, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion,” Am J Physiol Regul Integr Comp Physiol 302(11), R1250–R1259 (2012).
[Crossref]

E. Vaghefi, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Visualizing ocular lens fluid dynamics using MRI: manipulation of steady-state water content and water fluxes,” Am J Physiol Regul Integr Comp Physiol 301(2), R335–R342 (2011).
[Crossref]

E. Vaghefi, B. P. Pontre, P. J. Donaldson, P. J. Hunter, and M. D. Jacobs, “Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI,” Physiological measurement 30(10), 1061–1073 (2009).
[Crossref]

Van der Heijde, G.

M. Dubbelman and G. Van der Heijde, “The shape of the aging human lens: curvature, equivalent refractive index and the lens paradox,” Vision Res. 41(14), 1867–1877 (2001).
[Crossref]

Verkicharla, P. K.

A. Khan, J. M. Pope, P. K. Verkicharla, M. Suheimat, and D. A. Atchison, “Change in human lens dimensions, lens refractive index distribution and ciliary body ring diameter with accommodation,” Biomed. Opt. Express 9(3), 1272–1282 (2018).
[Crossref]

X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

Vezhnevets, V.

V. Vezhnevets and V. Konouchine, “GrowCut: Interactive multi-label ND image segmentation by cellular automata,” in proc. of Graphicon, 2005), 150–156.

Walker, K.

E. Vaghefi, K. Walker, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion,” Am J Physiol Regul Integr Comp Physiol 302(11), R1250–R1259 (2012).
[Crossref]

Wang, J.

B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
[Crossref]

Wassenaar, P.

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
[Crossref]

Webb, K. F.

P. J. Donaldson, K.-S. N. Chee, J. C. Lim, and K. F. Webb, “Regulation of lens volume: implications for lens transparency,” Exp. Eye Res. 88(2), 144–150 (2009).
[Crossref]

Woods, A. J.

H. Tabandeh, G. M. Thompson, P. Heyworth, S. Dorey, A. J. Woods, and D. Lynch, “Water content, lens hardness and cataract appearance,” Eye 8(1), 125–129 (1994).
[Crossref]

Yagi, N.

B. K. Pierscionek, M. Bahrami, M. Hoshino, K. Uesugi, J. Regini, and N. Yagi, “The eye lens: age-related trends and individual variations in refractive index and shape parameters,” OncoTargets Ther. 6(31), 30532–30544 (2015).
[Crossref]

Yuan, Y.

B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
[Crossref]

Zigler, J. S.

F. A. Bettelheim, M. J. Lizak, and J. S. Zigler, “Relaxographic studies of aging normal human lenses,” Exp. Eye Res. 75(6), 695–702 (2002).
[Crossref]

Academic radiology (1)

R. J. Bert, S. Patz, M. Ossiani, S. D. Caruthers, H. Jara, J. Krejza, and T. Freddo, “High-resolution MR imaging of the human eye 2005,” Academic radiology 13(3), 368–378 (2006).
[Crossref]

Am J Physiol Regul Integr Comp Physiol (2)

E. Vaghefi, K. Walker, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Magnetic resonance and confocal imaging of solute penetration into the lens reveals a zone of restricted extracellular space diffusion,” Am J Physiol Regul Integr Comp Physiol 302(11), R1250–R1259 (2012).
[Crossref]

E. Vaghefi, B. P. Pontre, M. D. Jacobs, and P. J. Donaldson, “Visualizing ocular lens fluid dynamics using MRI: manipulation of steady-state water content and water fluxes,” Am J Physiol Regul Integr Comp Physiol 301(2), R335–R342 (2011).
[Crossref]

Biomed. Opt. Express (3)

Cigongzhen Chengxiang (3)

S. Patz, R. J. Bert, E. Frederick, and T. F. Freddo, “T1 and T2 measurements of the fine structures of the in vivo and enucleated human eye,” Cigongzhen Chengxiang 26(3), 510–518 (2007).
[Crossref]

K. Richdale, P. Wassenaar, K. Teal Bluestein, A. Abduljalil, J. A. Christoforidis, T. Lanz, M. V. Knopp, and P. Schmalbrock, “7 Tesla MR imaging of the human eye in vivo,” Cigongzhen Chengxiang 30(5), 924–932 (2009).
[Crossref]

O. Dietrich, J. G. Raya, S. B. Reeder, M. F. Reiser, and S. O. Schoenberg, “Measurement of signal-to-noise ratios in MR images: Influence of multichannel coils, parallel imaging, and reconstruction filters,” Cigongzhen Chengxiang 26(2), 375–385 (2007).
[Crossref]

Comput. Phys. (1)

J. C. Russ, J. R. Matey, A. J. Mallinckrodt, and S. McKay, “The image processing handbook,” Comput. Phys. 8(2), 177–178 (1994).
[Crossref]

Exp. Eye Res. (4)

P. Rácz, C. Hargitai, B. Alföldy, P. Banki, and K. Tompa, “1 H Spin-Spin Relaxation in Normal and Cataractous Human, Normal Fish and Birds Eye Lenses,” Exp. Eye Res. 70(4), 529–536 (2000).
[Crossref]

F. A. Bettelheim, M. J. Lizak, and J. S. Zigler, “Relaxographic studies of aging normal human lenses,” Exp. Eye Res. 75(6), 695–702 (2002).
[Crossref]

B. K. Pierscionek, “Refractive index contours in the human lens,” Exp. Eye Res. 64(6), 887–893 (1997).
[Crossref]

P. J. Donaldson, K.-S. N. Chee, J. C. Lim, and K. F. Webb, “Regulation of lens volume: implications for lens transparency,” Exp. Eye Res. 88(2), 144–150 (2009).
[Crossref]

Eye (2)

S. Jasvinder, T. Khang, K. Sarinder, V. Loo, and V. Subrayan, “Agreement analysis of LENSTAR with other techniques of biometry,” Eye 25(6), 717–724 (2011).
[Crossref]

H. Tabandeh, G. M. Thompson, P. Heyworth, S. Dorey, A. J. Woods, and D. Lynch, “Water content, lens hardness and cataract appearance,” Eye 8(1), 125–129 (1994).
[Crossref]

Invest. Ophthalmol. Visual Sci. (7)

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “In vivo study of changes in refractive index distribution in the human crystalline lens with age and accommodation,” Invest. Ophthalmol. Visual Sci. 49(6), 2531–2540 (2008).
[Crossref]

B. Ke, X. Mao, H. Jiang, J. He, C. Liu, M. Li, Y. Yuan, and J. Wang, “The relationship between high-order aberration and anterior ocular biometry during accommodation in young healthy adults,” Invest. Ophthalmol. Visual Sci. 58(13), 5628–5635 (2017).
[Crossref]

J. B. Jonas, R. Iribarren, V. Nangia, A. Sinha, P. Pardhi, R. Shukla, and S. Panda-Jonas, “Lens position and age: the Central India eye and medical study,” Invest. Ophthalmol. Visual Sci. 56(9), 5309–5314 (2015).
[Crossref]

X. Adnan, J. M. Pope, F. Sepehrband, M. Suheimat, P. K. Verkicharla, D. A. Atchison, and S. Kasthurirangan, “Lens shape and refractive index distribution in type 1 diabetes,” Invest. Ophthalmol. Visual Sci. 56(8), 4759–4766 (2015).
[Crossref]

E. Vaghefi, A. Kim, and P. J. Donaldson, “Active maintenance of the gradient of refractive index is required to sustain the optical properties of the lens,” Invest. Ophthalmol. Visual Sci. 56(12), 7195–7208 (2015).
[Crossref]

J. C. Lim, E. Vaghefi, B. Li, M. G. Nye-Wood, and P. J. Donaldson, “Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine LensEffects of HBO on the Bovine Lens,” Invest. Ophthalmol. Visual Sci. 57(4), 1961–1973 (2016).
[Crossref]

J. J. Rozema, D. A. Atchison, and M.-J. Tassignon, “Comparing methods to estimate the human lens power,” Invest. Ophthalmol. Visual Sci. 52(11), 7937–7942 (2011).
[Crossref]

J. Membr. Biol. (1)

R. T. Mathias, J. K. Kistler, and P. J. Donaldson, “The lens circulation,” J. Membr. Biol. 216(1), 1–16 (2007).
[Crossref]

J. Opt. Soc. Am. A (3)

Journal of vision (1)

S. Kasthurirangan, E. L. Markwell, D. A. Atchison, and J. M. Pope, “MRI study of the changes in crystalline lens shape with accommodation and aging in humans,” Journal of vision 11(3), 19 (2011).
[Crossref]

Lancet (1)

P. A. Asbell, I. Dualan, J. Mindel, D. Brocks, M. Ahmad, and S. Epstein, “Age-related cataract,” Lancet 365(9459), 599–609 (2005).
[Crossref]

OncoTargets Ther. (1)

B. K. Pierscionek, M. Bahrami, M. Hoshino, K. Uesugi, J. Regini, and N. Yagi, “The eye lens: age-related trends and individual variations in refractive index and shape parameters,” OncoTargets Ther. 6(31), 30532–30544 (2015).
[Crossref]

Ophthalmology (1)

A. Glasser and P. L. Kaufman, “The mechanism of accommodation in primates1,” Ophthalmology 106(5), 863–872 (1999).
[Crossref]

Optometry and Vision Science (1)

A. C. Kingston and I. G. Cox, “Predicting through-focus visual acuity with the eye’s natural aberrations,” Optometry and Vision Science 90(10), 1111–1118 (2013).
[Crossref]

Physiological measurement (1)

E. Vaghefi, B. P. Pontre, P. J. Donaldson, P. J. Hunter, and M. D. Jacobs, “Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI,” Physiological measurement 30(10), 1061–1073 (2009).
[Crossref]

Prog. Retinal Eye Res. (2)

P. J. Donaldson, A. C. Grey, B. M. Heilman, J. C. Lim, and E. Vaghefi, “The physiological optics of the lens,” Prog. Retinal Eye Res. 56, e1–e24 (2017).
[Crossref]

B. K. Pierscionek and J. W. Regini, “The gradient index lens of the eye: opto-biological synchrony,” Prog. Retinal Eye Res. 31(4), 332–349 (2012).
[Crossref]

Vision Res. (6)

C. E. Jones, D. A. Atchison, R. Meder, and J. M. Pope, “Refractive index distribution and optical properties of the isolated human lens measured using magnetic resonance imaging (MRI),” Vision Res. 45(18), 2352–2366 (2005).
[Crossref]

M. Dubbelman and G. Van der Heijde, “The shape of the aging human lens: curvature, equivalent refractive index and the lens paradox,” Vision Res. 41(14), 1867–1877 (2001).
[Crossref]

G. Smith, M. J. Cox, R. Calver, and L. F. Garner, “The spherical aberration of the crystalline lens of the human eye,” Vision Res. 41(2), 235–243 (2001).
[Crossref]

B. K. Pierscionek, G. Smith, and R. C. Augusteyn, “The refractive increments of bovine α-, β-and γ-crystallins,” Vision Res. 27(9), 1539–1541 (1987).
[Crossref]

B. A. Moffat, D. A. Atchison, and J. M. Pope, “Age-related changes in refractive index distribution and power of the human lens as measured by magnetic resonance micro-imaging in vitro,” Vision Res. 42(13), 1683–1693 (2002).
[Crossref]

L. Thaler, A. C. Schütz, M. A. Goodale, and K. R. Gegenfurtner, “What is the best fixation target? The effect of target shape on the stability of fixational eye movements,” Vision Res. 76, 31–42 (2013).
[Crossref]

Other (3)

D. A. Atchison and G. Smith, “Optics of the Human Eye” (Butterworth-Heinemann,2000).

V. Vezhnevets and V. Konouchine, “GrowCut: Interactive multi-label ND image segmentation by cellular automata,” in proc. of Graphicon, 2005), 150–156.

M. Tocci, “How to model the human eye in ZEMAX,” Opt. Design Eng.23 (2007).

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Figures (8)

Fig. 1.
Fig. 1. Study design. The flowchart demonstrates the steps involved in our study. Consenting participants came to Auckland University Optometry Clinic on the first visit and underwent an ophthalmic examination. After ensuring participants met all inclusion criteria, they were invited to undertake two sessions of MRI scan. The scan included TSE and MSE pulse sequences for lens geometry and T2 (GRIN) measurements, respectively. The lens geometry and GRIN obtain by MRI were then combined with ocular biometric data acquired using LenStar to build accurate optical models of the right eye of each participant using the optical modelling software ZEMAX. Participants refractive errors predicted from ZEAMX were then compared with that obtained from the clinical examination.
Fig. 2.
Fig. 2. Extraction of lens geometry from raw MRI images. (A) A cropped raw MRI image of the human eye to show the lens. The orange circle indicates lens outer cortex. (B) Image of the same lens after histogram equalisation has been applied to enhance edge contrast of the lens edge. (C) The anterior (blue curve) and posterior (red curve) surfaces of the enhanced image are then fitted with two conic equations.
Fig. 3.
Fig. 3. T2 imaging of the lens to extract the GRIN. (A) A sequence of 6 representative MSE images obtained using different TEs. Six representative nominal TE selected from the all images were presented here. (B) Three pixels were labelled to represent three lens regions (nucleus, inner cortex and outer cortex), and their exponential curves were displayed. The lens tissue from these three regions have different relaxation behaviour and thus, different T2 values. (C) Raw T2 images are then processed to generate T2 maps of the lens. Coloured markers on the lens mark the same regions used for curve fitting process in panel (B). (D) T2 values were converted to refractive index values (n) to produce a GRIN map.
Fig. 4.
Fig. 4. Formation of participant-specific optics of the human eye. (A) The anatomical image is matched to the T2/GRIN image of the same lens, and the optical centre (dotted red line) is marked as the centre of connecting all vertices of contour (black *). This connected path is used to separate the lens anterior and posterior sections. (B) Geometrical parameters of the lens include anterior radius and thickness (Ra and Ta), posterior radius and thickness (Rp and Tp) and full lens thickness (Tap). (C) Sagittal GRIN profiles taken from the GRIN maps are fitted into ZEMAX GRIN3 formula. The optical centre is used to split GRIN profiles to avoid discontinuity. (D) Schematic drawing of the eye model in ZEMAX combining respective geometry and GRIN. The lens is modelled as a doublet split around the optical centre into anterior and posterior surfaces. The spectacle surface was used to estimate the spherical equivalent error.
Fig. 5.
Fig. 5. Accuracy and repeatability of measurements of lens geometry. (A) Correlation plot (left panel) comparing the measurements of lens thicknesses obtained from MRI and LenStar, and the two methods were assessed by Bland & Altman equity plot right panel confirming that the two techniques gave measures of lens thickness that lay within the 95% confidence limits (dashed lines). (B&C) Correlation plots (left panels) comparing the measurements lens radius (B: Ra blue; Rp red) and thickness (C: Ta blue; Tp red) taken at the first and second visit for each participant and the associated Bland & Altman equity plots (right panels).
Fig. 6.
Fig. 6. Trend analysis and repeatability of T2 measurements. (A) T2 map showing the optical centre from which line plots were extracted along the anterior, posterior, proximal and distal axes. (B) The extracted line plots along each axis were fitted with Eq. (4) and the exponents c from the first and second visit were displayed on a correlation (left panel) and Bland-Altman equity (right panel) plots to assess inter-day repeatability. In the correlation plot, the black line shows the unity line. The 95% limit of agreement is indicated as two dash lines.
Fig. 7.
Fig. 7. Anterior and posterior lens T2 measurements and repeatability. (A) A representative T2 map divided into eight regions of interest that represent the outer cortex (OC), middle cortex (MC), inner cortex (IC) and nucleus (N) of the anterior and posterior sections of the lens. Due to the partial volume effect and “non-lens” pixels, the OC region was excluded in this analysis. (B&C) The inter-day repeatability of anterior (B) and posterior (C) sections were analyzed by correlation plot (left panel) and Bland-Altman analysis (right panel). The 95% limit of agreements are indicated as two dash lines.
Fig. 8.
Fig. 8. ZEMAX modelling of the eye accurately predicts the refractive error. (A) Correlation plot (left panel), and Bland & Altman analysis (right panel) show that the ZEMAX model can predict the spherical equivalent error measured clinically for each participant. (B) Correlation plot and Bland (left panel) & Altman analysis (right panel) show that our methods can estimate lens power with comparable results with the lens power obtained from the modified Bennet method. The black line indicates the equity plot and the dashed lines indicate the 95% limit of agreements.

Tables (1)

Tables Icon

Table 1. Summary of the optical measurements from ZEMAX modelling.

Equations (6)

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

S = S 0 e T E T 2 ; S ( T E ) > σ
n = 1.3554 + 1.549 × 10 3 ( 1 T 2 ) 6.34 × 10 6 ( 1 T 2 ) 2
y = c ( x x 0 ) 2 1 + 1 k c 2 ( x x 0 ) 2 + y 0
P L = 1000 n ( S c v + K ) 1000 n ( A C D + c 1 T ) ( S c v + K ) + 1000 n c 2 T + V C D
S c v = S E 1 0.14 S E
T 2 = a + b x c

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