Abstract

Photorefractive (PR) screening of children is currently used for detection of specific vision problems. We have used three-dimensional ray tracing and several published models of the human eye to investigate the ability to predict photorefractive results. Specifically, by using the optical design of an actual photorefractive instrument and using a monochromatic source as an example, we demonstrate the methodology of computing the relative spatial irradiance at its detector surface. The variation of the irradiance at the detector is computed for several eye models for a range of refractive errors. The results showed that the basic physics of photorefraction is described simply using the width and the center of the dark zone (CDZ) of retinal reflex images. Refractive parameters of a subject can be directly determined from these values of CDZ, and the contribution of monochromatic and chromatic aberrations upon the CDZ is derived.

© 2003 Optical Society of America

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References

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  1. G. lennerstrand, P. Jakosson, G. Kvarnstrom, �??Screening for ocular dysfunction in children: approaching a common program,�?? Acta. Ophthalmol. 214 (Suppl): 39-40, (1995).
  2. M. Stayte, B. Reeves, C. Wortham, �??Ocular and vision defects in preschool children,�?? Br. J. Ophthalmol. 77, 228-32, (1993).
    [CrossRef] [PubMed]
  3. Simons K, �??Preschool vision screening: Tationale, methodology and outcome.�?? Surv. Ophthalmol. 41, 3-30, (1996).
    [CrossRef]
  4. BD. Moore, �??Epidemiology of ocular disorders in young children,�?? In: Moore BD, ed. Eye Care for Infants and Children. (Boston: Butterworth-Heinemann, 21-9 1997).
  5. J. Atkinson, O. Braddick, B. Robier, et al. �??Two infant vision screening programs: prediction and prevention of strubiamus and amblyopia from photo- and videorefractive screening,�?? Eye 10 (Pt 2) 189-98 (1996).
    [CrossRef]
  6. M. R. Angi, V. Pucci, F. Forattini, P. A. Formentin. �??Results of photorefractometric screening for amblyogenic defects in children aged 20 months,�?? Behav. Brain. Res. 49, 91-7, (1992).
    [CrossRef] [PubMed]
  7. M. Choi, S. Weiss, F. Schaeffel, A. Seidemann, H. Howland, B. Wilhelm, H. Wilhelm, �??Laboratory, clinical, and kindergarten test of a new eccentric infrared photorefractor (PowerRefractor),�?? Optom. Vis. Sci. 77, 537-48, (2000).
    [CrossRef] [PubMed]
  8. A. Roorda, M. Campbell, �??Slope-based eccentric photorefraction: theoretical analysis of different light source configurations and effects of ocular aberrations,�?? J. Opt. Soc. Am. A 14, 2547-56, (1997).
    [CrossRef]
  9. M. Campbell, W. Bobier, A. Roorda, �??Effect of monochromatic aberrations on photorefractive patterns,�?? J. Opt. Soc. Am. A 12, 1637-46, (1995).
    [CrossRef]
  10. A. Roorda, M. Campbell, W. Bobier, �??Geometric theory to predict eccentric photorefraction intensity profiles in human eye,�?? J. Opt. Soc. Am. A 12, 1647-56, (1995).
    [CrossRef]
  11. W. Bobier, �??Eccentric photorefraction: Optical analysis and empirical measures.�?? Am. J. of Optom. & Physiol. Optics 62, 614-620, (1985).
    [CrossRef]
  12. F. Gekeler, F. Schaeffel, H. Howland, J. Wattam-Bell, �??Measurement of astigmatism by automated infrared photoretinoscopy,�?? Optom. Vis. Sci. 74, 472-82, (1997).
    [CrossRef] [PubMed]
  13. H. Howland, �??Optics of photoretinoscopy: results from ray tracing,�?? Am. J. Optom. Physiol. Opt. 62, 621-625, (1985).
    [CrossRef] [PubMed]
  14. R. Kusel, U. Oechsner, W. Wasemann, S. Russlies, E. Irmer, B. Rassow, �??Light-intensity distribution in eccentric photorefraction crescents,�?? J. Opt. Soc. Am. A 15, 1500-11, (1998).
    [CrossRef]
  15. W. Wasemann, A. Norcia, D. Allen, �??Theory of eccentric photorefraction (photoretinoscopy): astigmatic eyes,�?? J. Opt. Soc. Am. A 8, 2038-47, (1991).
    [CrossRef]
  16. A. Gullstrand, �??The optical system of the eye,�?? Appendices to part 1. In: Von Helmholtz H. Physiological Optics. 3rd ed. Vols 1 and 2. (Hamburg, Voss, 350-8, 1909).
  17. H. Von Helmholtz, Physiological Optics. 3rd ed. Vols 1 and 2. (Hamburg, Voss, 91-121, 1909).
  18. Y. Le Grand, Optique physiologique. T. 1. Dioptrique de l�??oeil er sa correlations. English translation by El Hage SG. (Berlin, Springer-Verlag, 64-7, 1980).
  19. W. Lotmar, �??Theoretical eye model with aspherics,�?? J. Opt. Soc. Am. 16, 1522-9, (1971).
    [CrossRef]
  20. R Navarror, J. Santamaria, J. Bescos, �??Accommodation-dependent model of the human eye with aspherics,�?? Opt. Soc. Am. (A) 2, 1273-81, (1985).
    [CrossRef]
  21. I. Escudero-Sanz, R. Navarro, �??Off-axis aberrations of a wide-angle schematic eye model,�?? J. Opt. Soc. Am. A Opt. Image Sci. Vis. 16, 1881-91, (1999).
    [CrossRef] [PubMed]
  22. S. Marcos, SA. Burns, PM. Prieto, R. Navarro, B. Baraibar, �??Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes,�?? Vision Res. 41, 3861-71, (2001).
    [CrossRef] [PubMed]
  23. L. N. Thibos, M. Ye, X. Zhang, A. Bradley, �??Spherical aberration of the reduced schematic eye with elliptical refracting surface,�?? Vis. Sci. 74, 548-556, (1997).
    [CrossRef]
  24. I. H. Al-Ahdali, M. A. El-Messiery, �??Examination of the effect of the fibrous structure of a lens on the optica characteristics of the human eye: a computer-simulated model,�?? Appl. Opt. 34, 5738-45, (1995).
    [CrossRef] [PubMed]
  25. H. Liou, N. Brenan, �??Anatomically accurate, finite model eye for optical modeling,�?? J. Opt. Soc. Am. A, 14, 1684-95, (1997).
    [CrossRef]
  26. Y.-L. Chen, J. W. L. Lewis, C. Parigger, "Human Eye Model Effects on Digital Retinascopic Diagnostic," in SESAPS annual meeting (Starkville, MI, DC1 2000).
  27. L. Zhu, D. U. Bartsch, W. R. Freeman, Sun PC, Fainman Y. �??Modeling human eye aberrations and their compensation for high-resolution retinal imaging,�?? Optom. Vis. Sci. 75, 827-39, (1998).
    [CrossRef] [PubMed]
  28. S. P. Donahue, T. M. Johnson, �??Age-based refinement of referral criteria for photoscreening,�?? Ophthalmol. 108, 2309-14, (2001).
    [CrossRef]
  29. R. Kennedy, D. Thomas �??Evaluation of the iScreen digital screening system for amblyogenic factors,�?? CANJ Opthalmol. 35. 258-62, (2000).
  30. J.E. Greivenkamp, J. Schwiegerling, J.M. Miller, M.D. Mellinger, "Visual Acuity Modeling Using Optical Raytracing of Schematic Eyes," Am. J. Ophthalmol. 120, 227-240, (1995).
    [PubMed]
  31. L. N. Thibos, M. Ye, X. Zang, and A. Bradley, �??The chromatic eye: a new reduced-eye model of ocular chromatic aberration in human,�?? Appl. Opt. 31, 3594-3600, (1992).
    [CrossRef] [PubMed]
  32. W. N. Charman and J. A. Jennings �??Objective measurements of the longitudinal chromatic aberration of the human eye,�?? Vision Res. 16, 999-1005. (1976).
    [CrossRef] [PubMed]
  33. R. E. Bedford, and G. Wyszecki, �??Axial Chromatic Aberration of the Human Eye,�?? J. Opt. Soc. Am. 47, 564�??565 (1957).
    [CrossRef] [PubMed]
  34. G. Wald and D. R. Griffin, �??The Change in Refractive Power of the Human Eye in Dim and Bright Light,�?? J. Opt. Soc. Am. 37, 321�??336 (1947).
    [CrossRef] [PubMed]
  35. P. Mouroulis, Visual instrumentation, (McGraw-Hill, 1999), Chap. 4.

Acta. Ophthalmol. (1)

G. lennerstrand, P. Jakosson, G. Kvarnstrom, �??Screening for ocular dysfunction in children: approaching a common program,�?? Acta. Ophthalmol. 214 (Suppl): 39-40, (1995).

Am. J. of Optom. & Physiol. Optics (1)

W. Bobier, �??Eccentric photorefraction: Optical analysis and empirical measures.�?? Am. J. of Optom. & Physiol. Optics 62, 614-620, (1985).
[CrossRef]

Am. J. Ophthalmol. (1)

J.E. Greivenkamp, J. Schwiegerling, J.M. Miller, M.D. Mellinger, "Visual Acuity Modeling Using Optical Raytracing of Schematic Eyes," Am. J. Ophthalmol. 120, 227-240, (1995).
[PubMed]

Am. J. Optom. Physiol. Opt. (1)

H. Howland, �??Optics of photoretinoscopy: results from ray tracing,�?? Am. J. Optom. Physiol. Opt. 62, 621-625, (1985).
[CrossRef] [PubMed]

Appl. Opt. (2)

Behav. Brain. Res. (1)

M. R. Angi, V. Pucci, F. Forattini, P. A. Formentin. �??Results of photorefractometric screening for amblyogenic defects in children aged 20 months,�?? Behav. Brain. Res. 49, 91-7, (1992).
[CrossRef] [PubMed]

Br. J. Ophthalmol. (1)

M. Stayte, B. Reeves, C. Wortham, �??Ocular and vision defects in preschool children,�?? Br. J. Ophthalmol. 77, 228-32, (1993).
[CrossRef] [PubMed]

CANJ Opthalmol. (1)

R. Kennedy, D. Thomas �??Evaluation of the iScreen digital screening system for amblyogenic factors,�?? CANJ Opthalmol. 35. 258-62, (2000).

Eye (1)

J. Atkinson, O. Braddick, B. Robier, et al. �??Two infant vision screening programs: prediction and prevention of strubiamus and amblyopia from photo- and videorefractive screening,�?? Eye 10 (Pt 2) 189-98 (1996).
[CrossRef]

J. Opt. Soc. Am. (3)

J. Opt. Soc. Am. A (7)

Ophthalmol. (1)

S. P. Donahue, T. M. Johnson, �??Age-based refinement of referral criteria for photoscreening,�?? Ophthalmol. 108, 2309-14, (2001).
[CrossRef]

Opt. Soc. Am. (A) (1)

R Navarror, J. Santamaria, J. Bescos, �??Accommodation-dependent model of the human eye with aspherics,�?? Opt. Soc. Am. (A) 2, 1273-81, (1985).
[CrossRef]

Optom. Vis. Sci. (3)

F. Gekeler, F. Schaeffel, H. Howland, J. Wattam-Bell, �??Measurement of astigmatism by automated infrared photoretinoscopy,�?? Optom. Vis. Sci. 74, 472-82, (1997).
[CrossRef] [PubMed]

M. Choi, S. Weiss, F. Schaeffel, A. Seidemann, H. Howland, B. Wilhelm, H. Wilhelm, �??Laboratory, clinical, and kindergarten test of a new eccentric infrared photorefractor (PowerRefractor),�?? Optom. Vis. Sci. 77, 537-48, (2000).
[CrossRef] [PubMed]

L. Zhu, D. U. Bartsch, W. R. Freeman, Sun PC, Fainman Y. �??Modeling human eye aberrations and their compensation for high-resolution retinal imaging,�?? Optom. Vis. Sci. 75, 827-39, (1998).
[CrossRef] [PubMed]

Surv. Ophthalmol. (1)

Simons K, �??Preschool vision screening: Tationale, methodology and outcome.�?? Surv. Ophthalmol. 41, 3-30, (1996).
[CrossRef]

Vis. Sci. (1)

L. N. Thibos, M. Ye, X. Zhang, A. Bradley, �??Spherical aberration of the reduced schematic eye with elliptical refracting surface,�?? Vis. Sci. 74, 548-556, (1997).
[CrossRef]

Vision Res. (2)

S. Marcos, SA. Burns, PM. Prieto, R. Navarro, B. Baraibar, �??Investigating sources of variability of monochromatic and transverse chromatic aberrations across eyes,�?? Vision Res. 41, 3861-71, (2001).
[CrossRef] [PubMed]

W. N. Charman and J. A. Jennings �??Objective measurements of the longitudinal chromatic aberration of the human eye,�?? Vision Res. 16, 999-1005. (1976).
[CrossRef] [PubMed]

Other (6)

P. Mouroulis, Visual instrumentation, (McGraw-Hill, 1999), Chap. 4.

Y.-L. Chen, J. W. L. Lewis, C. Parigger, "Human Eye Model Effects on Digital Retinascopic Diagnostic," in SESAPS annual meeting (Starkville, MI, DC1 2000).

BD. Moore, �??Epidemiology of ocular disorders in young children,�?? In: Moore BD, ed. Eye Care for Infants and Children. (Boston: Butterworth-Heinemann, 21-9 1997).

A. Gullstrand, �??The optical system of the eye,�?? Appendices to part 1. In: Von Helmholtz H. Physiological Optics. 3rd ed. Vols 1 and 2. (Hamburg, Voss, 350-8, 1909).

H. Von Helmholtz, Physiological Optics. 3rd ed. Vols 1 and 2. (Hamburg, Voss, 91-121, 1909).

Y. Le Grand, Optique physiologique. T. 1. Dioptrique de l�??oeil er sa correlations. English translation by El Hage SG. (Berlin, Springer-Verlag, 64-7, 1980).

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Figures (9)

Fig. 1.
Fig. 1.

Longitudinal spherical aberration (LSA) and chromatic aberrations (LCA) in different eye models. The reference wavelength in the LCA plot is 589 nm.

Fig. 2.
Fig. 2.

Power of the virtual lens used to produce refractive prescription of model eye.

Fig. 3.
Fig. 3.

Simulated photorefraction images with pupil diameters from 7 mm to 3 mm (top to bottom). From left to right, the refractive errors are indicated at the bottom.

Fig. 4.
Fig. 4.

Comparison of CDZ shift in photorefraction with 4 published measurements of ocular chromatic aberration and eye model. All data are adjusted vertically to have a zero value at the reference wavelength of 589 nm.

Fig. 5.
Fig. 5.

Simulation results of photoretinoscope images using Navarro, Arizona, and Liou eye models. From left to right are eyes with refractive error of +10 to -10 diopters. The irradiance levels in all calculation results are related.

Fig. 6.
Fig. 6.

Slope profiles from the simulation results of Fig. 5. The forms, or shapes, and the magnitudes of the irradiance profiles are similar within the 3 models’ result except for the shifted in refractive power (CDZ position) and the width of insensitive zone (dark zone). These differences are results from the monochromatic aberrations inherited with the eye models.

Fig. 7.
Fig. 7.

Experimental data using iScreen photoretinoscope. Upper row: original photographs. The iris, pupil, and the 1st Purkinje image from cornea in each photograph are circled using a target-finding program. Second to forth row: Intensity distribution of the original data in red (2nd row), green (3rd row) and blue (4th row).

Fig. 8.
Fig. 8.

Experimental data taken from a Caucasian using iScreen photoretinoscope. Upper row: original photographs. The iris, pupil, and the 1st Purkinje image from cornea in each photograph are circled using a target-finding program. Second to forth row: Intensity distribution of the original data in red (2nd row), green (3rd row) and blue (4th row).

Fig. 9.
Fig. 9.

Tear waves appeared after blinking eyes may cause interference patterns in photorefraction measurement.

Tables (1)

Tables Icon

Table 1. Parameters used in the construction of the three eye models along with Gullstrand model.

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