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Virtual Journal for Biomedical Optics

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  • Editor: Gregory W. Faris
  • Vol. 4, Iss. 12 — Nov. 10, 2009
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Fast scanning photoretinoscope for measuring peripheral refraction as a function of accommodation

Juan Tabernero and Frank Schaeffel  »View Author Affiliations


JOSA A, Vol. 26, Issue 10, pp. 2206-2210 (2009)
http://dx.doi.org/10.1364/JOSAA.26.002206


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Abstract

A new device was designed to provide fast measurements (4 s) of the peripheral refraction (90° central horizontal field). Almost-continuous traces are obtained with high angular resolution (0.4°) while the subject is fixating a central stimulus. Three-dimensional profiles can also be measured. The peripheral refractions in 10 emmetropic subjects were studied as a function of accommodation (200 cm, 50 cm, and 25 cm viewing distances). Peripheral refraction profiles were largely preserved during accommodation but were different in each individual. Apparently, the accommodating lens changes its focal length evenly over the central 90° of the visual field.

© 2009 Optical Society of America

1. INTRODUCTION

It has been hypothesized that hyperopic defocus in the periphery might promote foveal myopia [1

1. J. Wallman and J. Winawer, “Homeostasis of eye growth and the question of myopia,” Neuron 43, 447–468 (2004). [CrossRef] [PubMed]

, 2

2. E. L. Smith III, C. Kee, R. Ramamirtham, Y. Qiao-Grider, and L. Hung, “Peripheral vision can influence eye growth and refractive development in infant monkeys,” Invest. Ophthalmol. Visual Sci. 46, 3965–3972 (2005). [CrossRef]

]. Therefore, it is of interest to determine under which conditions hyperopic defocus is imposed in the center and in the periphery and how it could be prevented. At present, measurements of peripheral refraction profiles are demanding and provide data at discrete angular positions (streak retinoscopy [3

3. F. Rempt, J. Hoogerheide, and W. P. H. Hoogenboom, “Peripheral retinoscopy and the Skiagram,” Ophthalmologica 162, 1–10 (1971). [CrossRef] [PubMed]

, 4

4. L. Hung, R. Ramamirtham, J. Huang, Y. Qiao-Grider, and E. L. Smith, “Peripheral refraction in normal infant rhesus monkeys,” Invest. Ophthalmol. Visual Sci. 49, 3747–3757 (2008). [CrossRef]

], autorefractometers [5

5. M. Millodot, “Effect of ametropia on peripheral refraction,” Am. J. Optom. Physiol. Opt. 58, 691–695 (1981). [PubMed]

, 6

6. D. O. Mutti, R. I. Sholtz, N. E. Friedman, and K. Zadnik, “Peripheral refraction and ocular shape in children,” Invest. Ophthalmol. Visual Sci. 41, 1022–1030 (2000).

, 7

7. N. S. Logan, B. Gilmartin, C. F. Wildsoet, and M. C. Dunne, “Posterior retinal contour in adult human anisomyopia,” Invest. Ophthalmol. Visual Sci. 45, 2152–2162 (2004). [CrossRef]

, 8

8. D. A. Atchison, N. Pritchard, and K. L. Schmid, “Peripheral refraction along the horizontal and vertical visual fields in myopia,” Vision Res. 46, 1450–1458 (2006). [CrossRef]

], double-pass method [9

9. A. Guirao and P. Artal, “Off-axis monochromatic aberrations estimated from double pass measurements in the human eye,” Vision Res. 39, 207–217 (1999). [CrossRef] [PubMed]

], Hartmann–Shack aberrometry [10

10. L. Lundström, P. Unsbo, and J. Gustafsson, “Off-axis wave front measurements for optical correction in eccentric viewing,” J. Biomed. Opt. 10, 034002 (2005) [CrossRef] [PubMed]

, 11

11. A. Mathur, D. A. Atchison, and D. H. Scott, “Ocular aberrations in the peripheral visual field,” Opt. Lett. 33, 865–863 (2008). [CrossRef]

, 12

12. D. A. Berntsen, D. O. Mutti, and K. Zadnik, “Validation of aberrometry-based relative peripheral refraction measurements,” Ophthalmic Physiol. Opt. 28, 83–90 (2008). [CrossRef] [PubMed]

], photoretinoscopy [13

13. A. Seidemann, F. Schaeffel, A. Guirao, N. Lopez-Gil, and P. Artal, “Peripheral refractive errors in myopic, emmetropic, and hyperopic young subjects,” J. Opt. Soc. Am. A 19, 2363–2373 (2002). [CrossRef]

, 14

14. R. Schippert and F. Schaeffel, “Peripheral defocus does not necessarily affect central refractive development,” Vision Res. 46, 3935–3940 (2006). [CrossRef] [PubMed]

]). The subject has to fixate at different angular positions across the visual field, imposing some subjectivity, or the operator has to move the instrument to angular different positions.

Recently, a device was introduced to scan the peripheral refraction with a hot mirror in combination with a custom-designed infrared photoretinoscope [15

15. J. Tabernero and F. Schaeffel, “More irregular eye shape in low myopia than in emmetropia,” Invest. Ophthalmol. Visual Sci. 50, 4516–4522 (2009). [CrossRef]

]. The scanning hot mirror projects the light from the infrared photoretinoscope into the eye under different angles, ranging from −45° to 45° from the fovea. The subject has to maintain steady fixation at a central target, which simplifies the procedure and makes it much faster. Still, due to mechanical limitations of the stepping motors that moved the hot mirror, the scanning time was still long (around 22 s for a full scan), which is too slow for measuring the effects of sustained accommodation on peripheral refraction.

Accommodation is assumed to be linked to the etiology of myopia [1

1. J. Wallman and J. Winawer, “Homeostasis of eye growth and the question of myopia,” Neuron 43, 447–468 (2004). [CrossRef] [PubMed]

]. The lag of accommodation and/or the excess of near work have been associated with the onset of myopia [16

16. J. Gwiazda, F. Thorn, J. Bauer, and R. Held, “Myopic children show insufficient accommodative response to blur,” Invest. Ophthalmol. Visual Sci. 34, 690–694 (1993).

, 17

17. J. Gwiazda, L. Hyman, T. T. Norton, M. E. M. Hussein, W. Marsh-Tootle, R. Manny, Y. Wang, and D. Everett, “Accommodation and related risk factors associated with myopia progression and their interaction with treatment in COMET children,” Invest. Ophthalmol. Visual Sci. 45, 2143–2151 (2004). [CrossRef]

]. It is not well known how accommodation affects the peripheral refraction, relative to the fovea, and whether there may be the risk of more relative hyperopia in the periphery during accommodation. With improved mechanics in our scanning photoretinoscope, the measurement time could be reduced to 4 s. This new setup was used to study this question. In addition, the new device was used to measure three-dimensional (3-D) maps of the refraction in the vertical pupil meridian.

2. MATERIALS AND METHODS

2A. Fast Scanning Infrared Photoretinoscope

2B. Subjects and Measurements

Ten young emmetropic students (20–25 years of age) with no ocular pathologies served as subjects for these measurements. Subjects were selected after a detailed subjective refraction performed by an experienced and certified optometrist that proved that they had spherical and cylindrical refractive errors less than 0.5 D. The measurements were approved by the Ethics Commission of the Faculty of Medicine of the Eberhart-Karls-University of Tübingen. In all subjects, peripheral refraction was measured at three accommodation levels (fixation distances 2 m, 0.5 m, and 0.25 m). The fixation target was a Maltese cross subtending 1.5°. Only right eyes were measured. Accommodation was stimulated monocularly through the right eyes (the left eyes were covered with a patch during the measurements). Monocular fixation offered the advantage that the fixation targets could be presented behind one another along a defined axis. Prior to the measurements, the subjects had to align the angular positions of the near and far targets for the right eyes. This procedure guaranteed that the refraction profiles measured for different accommodation levels were normalized to a fixed angular position. At least six full scans (±45°) of the peripheral refraction were performed for every subject at each of the three accommodation levels. In one subject, additional measurements of peripheral refraction were taken while the subject fixated a far stimulus (2 m) at seven different angular elevations (−10°, −8°, −4°, 0°, 4°, 8°, 12°). These data were later used to reconstruct a 3-D map of the peripheral refraction.

3. RESULTS

In this section, the results of measurements of peripheral refraction, determined in the vertical pupil meridian, from several subjects are presented. Figure 2 shows a 3-D reconstruction of the peripheral refractions from one of the subjects covering a field of 90°V × 22°H. The area of the optic disc head (at around 10° in the nasal retina) shows up as a more myopic region, due to the excavation of the optic disk. Apart from this fact, it seems that across the 22° in elevation the refraction remained similar in this subject.

Effects of accommodation on peripheral refraction patterns are summarized in Fig. 3 . The plots show refraction in diopters (D) (ordinate) versus the angular eccentricity (°) (abscissa) for each of the10 subjects. The three different curves show the refractions for three different accommodation levels: 0.5 D (black), 2 D (red/dark gray), and 4 D (green/light gray). In general, these curves show that with increasing accommodation, the shape of the refraction profile does not change. It is striking that each subject shows a typical pattern of peripheral refractions, from very flat (subjects 3, 4, and 10) to more parabolic (subjects 2 and 5). Other subjects show a centrally flat pattern with a steep increase in hyperopia in the periphery (subjects 1, 6, and 7). Similarly to the 3-D reconstruction map in Fig. 2, the excavation of the optic nerve shows up as the area of more myopia on the nasal side of the retina (positive eccentricity from the fovea).

To determine the gain of accommodation, the baseline refractions at 0.5 D accommodation effort were simply subtracted from the 2 D and 4 D curves. Results are shown in Fig. 4 . The small data points in bright red/dark gray represent the refractive changes from 0.5 D to 2 D, and the data points in light gray represent the changes from 0.5 D to 4 D. Expected changes in accommodation were −1.5 D and −3.5 D. For the sake of comparability, two thick dashed lines were added in Fig. 4 to illustrate these values. Data points above these lines represent a lag of accommodation (more hyperopic refraction), and data below represent a lead of accommodation (more myopic refraction) at a particular angular position. Data plotted in green/light gray filled circles show the averages of the 10 subjects, obtained by clustering the refractions across the field in intervals of 10° from −45° to 45°. The error bars in the circles represent the standard deviation of the average data. No statistically significant differences between expected and measured accommodation were observed. There were higher variations in the case of the 3.5 D accommodation change. This could be attributed to less-stable refractions with higher accommodation efforts or to the fact that photorefraction becomes more variable for higher refractive errors.

4. DISCUSSION

4A. Fast Scanning Infrared Photoretinoscope

At present, the major limitation of the scanning mirror system is that only the vertical meridian is refracted and information on astigmatism is lost. A solution would be to use a rotating photoretinoscope as in the PowerRefractor [20

20. M. Choi, S. Weiss, F. Schaeffel, A. Seidemann, H. C. Howland, B. Wilhelm, and H. Wilhelm, “Laboratory, clinical, and kindergarten test of a new eccentric infrared photorefractor (PowerRefractor),” Optom. Vision Sci. 77, 537–548 (2000). [CrossRef]

], although this would also slow down the sampling rate.

Using a mirror that also scans the vertical direction, a complete 3-D map of spheres, cylinders, and axes could be obtained. Again the scanning time would be increased, and in the end, the question remains as to whether such extended data sets would help us to understand the relationship between peripheral refractions and myopia development—currently one of the major goals of such studies.

4B. Inter-Individual Variability of Peripheral Refractions

In 1971, Rempt et al. [3

3. F. Rempt, J. Hoogerheide, and W. P. H. Hoogenboom, “Peripheral retinoscopy and the Skiagram,” Ophthalmologica 162, 1–10 (1971). [CrossRef] [PubMed]

] published a paper describing how they classified different types of peripheral refraction in a population of 442 subjects. Refractions were measured in both the horizontal and the vertical pupil meridian every 20°, from −60 to 60 across the horizontal visual field. For the refractions in the vertical meridian, the most common condition was increasing hyperopia to the periphery (found in 201 of 217 emmetropes). In the remaining cases, the refractions in the vertical meridian remained “flat” across the visual field. This type of refraction was named type V. Their description would fit to the data of subject 3 and perhaps subjects 4 and 10, shown in Fig. 3. The descriptions by Rempt et al. [3

3. F. Rempt, J. Hoogerheide, and W. P. H. Hoogenboom, “Peripheral retinoscopy and the Skiagram,” Ophthalmologica 162, 1–10 (1971). [CrossRef] [PubMed]

] were limited by the angular sampling intervals of 20°. Using more-continuous sampling as shown in Fig. 3, it can be seen that, although most of the subjects show more hyperopic refractions in the far periphery, they follow different patterns. Subjects 1, 6, and 7 display a central area with little change in refraction, but hyperopia increases rapidly beyond 30°. In contrast, in subjects 8 and 9 the increase of hyperopia follows a more linear function (V-shape). A different pattern is observed in subjects 2 and 5, where the refraction changes according to a more parabolic function. To evaluate the potential to predict myopia from the peripheral refractions, a more extensive evaluation of the peripheral refraction patterns may become necessary, in a larger sample of subjects.

4C. Changes of Peripheral Refraction with Accommodation

In myopic subjects, the patterns are even more variable. Some found no change [25

25. L. N. Davies and E. A. H. Mallen, “Influence of accommodation and refractive status on the peripheral refractive profile,” Br. J. Ophthamol. 93, 1186–1190 (2009). [CrossRef]

, 26

26. L. Lundstrom, A. Mira-Agudelo, and P. Artal, “Peripheral optical errors and their change with accommodation differ between emmetropic and myopic eyes,” J. Vision 9, 1–11 (2009). [CrossRef]

] in peripheral refraction with accommodation, while others found a small hyperopic shift of around 0.5 D that was restricted to the temporal retina at 30° [24

24. R. Calver, H. Radhakrishnan, E. Osuobeni1, and D. O’Leary, “Peripheral refraction for distance and near vision in emmetropes and myopes,” Ophthalmic Physiol. Opt. 27, 584–593 (2007). [CrossRef] [PubMed]

, 27

27. T. W. Walker and D. O. Mutti, “The effect of accommodation on ocular shape,” Optom. Vision Sci. 79, 424–430 (2002). [CrossRef]

]. Another study found a myopic shift of around 0.5 D at 40° of eccentricity [28

28. A. Whatham, F. Zimmermann, A. Martinez, S. Delgado, P. Lazon de la Jara, P. Sankaridurg, and A. Ho, “Influence of accommodation on off-axis refractive errors in myopic eyes,” J. Vision 9, 1–13 (2009). [CrossRef]

]. In conclusion, given that the differences between central and peripheral refraction at different states of accommodation are variable and quite small, it seems unlikely that these differences have a major effect on foveal refractive development and myopia.

4D. Conclusions

Measurements of continuous peripheral refraction profiles in 10 emmetropic subjects did not reveal any changes between center and peripheral refractions during accommodation. The new scanning mirror infrared photoretinoscope proved to be very useful for gathering these data: fast scanning (4 s from −40° to +40°), near-continuous traces (0.4° of angular resolution), and only a single fixation point for the subject. Different types of peripheral refraction profiles were identified, and their high angular resolution will make it possible to further classify peripheral refraction patterns and their potential relationship to myopia progression.

ACKNOWLEDGMENTS

This study was supported by a postdoctoral fellowship of the Marie Curie Research Training Network (RTN) “MyEuropia” of the European Community (http://www. my-europia.net/) to Juan Tabernero. We thank the mechanical workshop of the Ophthalmic Research Institute (Head: Mr. Hubert Willmann) for building the mechanical components for the scanning mirror linear stage.

Fig. 1 Setup with the scanning mirror infrared photoretinoscope.
Fig. 2 3D peripheral refraction map for an emmetropic subject. The optic nerve excavation on the nasal side of the temporal retina (positive horizontal eccentricity) is clearly seen as an area of more myopia.
Fig. 3 Peripheral refraction profiles of the 10 subjects participating in the study for the three different accommodation levels.
Fig. 4 The gain in accommodation calculated as the subtraction of the 4 D and 2 D profiles from the 0.5 D profile. Data in red/dark gray correspond to the gain obtained for the theoretical value of 1.5 D. The data in light gray account for the gain corresponding to the value of 3.5 D. The filled circles are the averages of the experimental data. Error bars denote standard deviation of the average. The thick dashed lines correspond to the 1.5 D and 3.5 D values as a reference to check for lags or leads of accommodation.
Fig. 5 Normalized gain in accommodation and comparison with theoretical predictions. The gray data on the background represent the gain normalized to the values of −1.5 D and −3.5 D at 0° eccentricity. Filled circles and error bars show the averages of the experimental data and their standard deviations (clustered every 10° of eccentricity). The red/dark gray dashed lines correspond to the theoretical gain from the ray-tracing calculations, also normalized to the −1.5 D and −3.5 D refraction in the fixation axis.
1.

J. Wallman and J. Winawer, “Homeostasis of eye growth and the question of myopia,” Neuron 43, 447–468 (2004). [CrossRef] [PubMed]

2.

E. L. Smith III, C. Kee, R. Ramamirtham, Y. Qiao-Grider, and L. Hung, “Peripheral vision can influence eye growth and refractive development in infant monkeys,” Invest. Ophthalmol. Visual Sci. 46, 3965–3972 (2005). [CrossRef]

3.

F. Rempt, J. Hoogerheide, and W. P. H. Hoogenboom, “Peripheral retinoscopy and the Skiagram,” Ophthalmologica 162, 1–10 (1971). [CrossRef] [PubMed]

4.

L. Hung, R. Ramamirtham, J. Huang, Y. Qiao-Grider, and E. L. Smith, “Peripheral refraction in normal infant rhesus monkeys,” Invest. Ophthalmol. Visual Sci. 49, 3747–3757 (2008). [CrossRef]

5.

M. Millodot, “Effect of ametropia on peripheral refraction,” Am. J. Optom. Physiol. Opt. 58, 691–695 (1981). [PubMed]

6.

D. O. Mutti, R. I. Sholtz, N. E. Friedman, and K. Zadnik, “Peripheral refraction and ocular shape in children,” Invest. Ophthalmol. Visual Sci. 41, 1022–1030 (2000).

7.

N. S. Logan, B. Gilmartin, C. F. Wildsoet, and M. C. Dunne, “Posterior retinal contour in adult human anisomyopia,” Invest. Ophthalmol. Visual Sci. 45, 2152–2162 (2004). [CrossRef]

8.

D. A. Atchison, N. Pritchard, and K. L. Schmid, “Peripheral refraction along the horizontal and vertical visual fields in myopia,” Vision Res. 46, 1450–1458 (2006). [CrossRef]

9.

A. Guirao and P. Artal, “Off-axis monochromatic aberrations estimated from double pass measurements in the human eye,” Vision Res. 39, 207–217 (1999). [CrossRef] [PubMed]

10.

L. Lundström, P. Unsbo, and J. Gustafsson, “Off-axis wave front measurements for optical correction in eccentric viewing,” J. Biomed. Opt. 10, 034002 (2005) [CrossRef] [PubMed]

11.

A. Mathur, D. A. Atchison, and D. H. Scott, “Ocular aberrations in the peripheral visual field,” Opt. Lett. 33, 865–863 (2008). [CrossRef]

12.

D. A. Berntsen, D. O. Mutti, and K. Zadnik, “Validation of aberrometry-based relative peripheral refraction measurements,” Ophthalmic Physiol. Opt. 28, 83–90 (2008). [CrossRef] [PubMed]

13.

A. Seidemann, F. Schaeffel, A. Guirao, N. Lopez-Gil, and P. Artal, “Peripheral refractive errors in myopic, emmetropic, and hyperopic young subjects,” J. Opt. Soc. Am. A 19, 2363–2373 (2002). [CrossRef]

14.

R. Schippert and F. Schaeffel, “Peripheral defocus does not necessarily affect central refractive development,” Vision Res. 46, 3935–3940 (2006). [CrossRef] [PubMed]

15.

J. Tabernero and F. Schaeffel, “More irregular eye shape in low myopia than in emmetropia,” Invest. Ophthalmol. Visual Sci. 50, 4516–4522 (2009). [CrossRef]

16.

J. Gwiazda, F. Thorn, J. Bauer, and R. Held, “Myopic children show insufficient accommodative response to blur,” Invest. Ophthalmol. Visual Sci. 34, 690–694 (1993).

17.

J. Gwiazda, L. Hyman, T. T. Norton, M. E. M. Hussein, W. Marsh-Tootle, R. Manny, Y. Wang, and D. Everett, “Accommodation and related risk factors associated with myopia progression and their interaction with treatment in COMET children,” Invest. Ophthalmol. Visual Sci. 45, 2143–2151 (2004). [CrossRef]

18.

F. Schaeffel, L. Farkas, and H. C. Howland, “Infrared photoretinoscope,” Appl. Opt. 26, 1505–1509 (1987). [CrossRef] [PubMed]

19.

J. Tabernero, D. Vazquez, A. Seidemann, D. Uttenweiler, and F. Schaeffel, “Effect of myopic spectacle correction and radial refractive gradient spectacles on peripheral refraction,” Vision Res. 49, 2176–2186 (2009). [CrossRef] [PubMed]

20.

M. Choi, S. Weiss, F. Schaeffel, A. Seidemann, H. C. Howland, B. Wilhelm, and H. Wilhelm, “Laboratory, clinical, and kindergarten test of a new eccentric infrared photorefractor (PowerRefractor),” Optom. Vision Sci. 77, 537–548 (2000). [CrossRef]

21.

R. Navarro, J. Santamaria, and J. Bescos, “Accommodation-dependent model of the human eye with aspherics,” J. Opt. Soc. Am. A 2, 1273–1281 (1985). [CrossRef] [PubMed]

22.

I. Escudero-Sanz and R. Navarro, “Off-axis aberrations of a wide-angle schematic eye model,” J. Opt. Soc. Am. A 16, 1881–1891 (1999). [CrossRef]

23.

G. Smith, M. Millodot, and N. McBrien, “The effect of accommodation on oblique astigmatism and field curvature of the human eye,” Clin. Exp. Optom. 71, 119–125 (1988). [CrossRef]

24.

R. Calver, H. Radhakrishnan, E. Osuobeni1, and D. O’Leary, “Peripheral refraction for distance and near vision in emmetropes and myopes,” Ophthalmic Physiol. Opt. 27, 584–593 (2007). [CrossRef] [PubMed]

25.

L. N. Davies and E. A. H. Mallen, “Influence of accommodation and refractive status on the peripheral refractive profile,” Br. J. Ophthamol. 93, 1186–1190 (2009). [CrossRef]

26.

L. Lundstrom, A. Mira-Agudelo, and P. Artal, “Peripheral optical errors and their change with accommodation differ between emmetropic and myopic eyes,” J. Vision 9, 1–11 (2009). [CrossRef]

27.

T. W. Walker and D. O. Mutti, “The effect of accommodation on ocular shape,” Optom. Vision Sci. 79, 424–430 (2002). [CrossRef]

28.

A. Whatham, F. Zimmermann, A. Martinez, S. Delgado, P. Lazon de la Jara, P. Sankaridurg, and A. Ho, “Influence of accommodation on off-axis refractive errors in myopic eyes,” J. Vision 9, 1–13 (2009). [CrossRef]

OCIS Codes
(330.4460) Vision, color, and visual optics : Ophthalmic optics and devices
(330.5370) Vision, color, and visual optics : Physiological optics
(330.7322) Vision, color, and visual optics : Visual optics, accommodation
(330.7327) Vision, color, and visual optics : Visual optics, ophthalmic instrumentation

ToC Category:
Vision, Color, and Visual Optics

History
Original Manuscript: July 8, 2009
Revised Manuscript: August 21, 2009
Manuscript Accepted: August 21, 2009
Published: September 21, 2009

Virtual Issues
Vol. 4, Iss. 12 Virtual Journal for Biomedical Optics
October 8, 2009 Spotlight on Optics

Citation
Juan Tabernero and Frank Schaeffel, "Fast scanning photoretinoscope for measuring peripheral refraction as a function of accommodation," J. Opt. Soc. Am. A 26, 2206-2210 (2009)
http://www.opticsinfobase.org/vjbo/abstract.cfm?URI=josaa-26-10-2206


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References

  1. J. Wallman and J. Winawer, “Homeostasis of eye growth and the question of myopia,” Neuron 43, 447-468 (2004). [CrossRef] [PubMed]
  2. E. L. Smith III, C. Kee, R. Ramamirtham, Y. Qiao-Grider, and L. Hung, “Peripheral vision can influence eye growth and refractive development in infant monkeys,” Invest. Ophthalmol. Visual Sci. 46, 3965-3972 (2005). [CrossRef]
  3. F. Rempt, J. Hoogerheide, and W. P. H. Hoogenboom, “Peripheral retinoscopy and the Skiagram,” Ophthalmologica 162, 1-10 (1971). [CrossRef] [PubMed]
  4. L. Hung, R. Ramamirtham, J. Huang, Y. Qiao-Grider, and E. L. Smith, “Peripheral refraction in normal infant rhesus monkeys,” Invest. Ophthalmol. Visual Sci. 49, 3747-3757 (2008). [CrossRef]
  5. M. Millodot, “Effect of ametropia on peripheral refraction,” Am. J. Optom. Physiol. Opt. 58, 691-695 (1981). [PubMed]
  6. D. O. Mutti, R. I. Sholtz, N. E. Friedman, and K. Zadnik, “Peripheral refraction and ocular shape in children,” Invest. Ophthalmol. Visual Sci. 41, 1022-1030 (2000).
  7. N. S. Logan, B. Gilmartin, C. F. Wildsoet, and M. C. Dunne, “Posterior retinal contour in adult human anisomyopia,” Invest. Ophthalmol. Visual Sci. 45, 2152-2162 (2004). [CrossRef]
  8. D. A. Atchison, N. Pritchard, and K. L. Schmid, “Peripheral refraction along the horizontal and vertical visual fields in myopia,” Vision Res. 46, 1450-1458 (2006). [CrossRef]
  9. A. Guirao and P. Artal, “Off-axis monochromatic aberrations estimated from double pass measurements in the human eye,” Vision Res. 39, 207-217 (1999). [CrossRef] [PubMed]
  10. L. Lundström, P. Unsbo, and J. Gustafsson, “Off-axis wave front measurements for optical correction in eccentric viewing,” J. Biomed. Opt. 10, 034002 (2005) [CrossRef] [PubMed]
  11. A. Mathur, D. A. Atchison, and D. H. Scott, “Ocular aberrations in the peripheral visual field,” Opt. Lett. 33, 865-863 (2008). [CrossRef]
  12. D. A. Berntsen, D. O. Mutti, and K. Zadnik, “Validation of aberrometry-based relative peripheral refraction measurements,” Ophthalmic Physiol. Opt. 28, 83-90 (2008). [CrossRef] [PubMed]
  13. A. Seidemann, F. Schaeffel, A. Guirao, N. Lopez-Gil, and P. Artal, “Peripheral refractive errors in myopic, emmetropic, and hyperopic young subjects,” J. Opt. Soc. Am. A 19, 2363-2373 (2002). [CrossRef]
  14. R. Schippert and F. Schaeffel, “Peripheral defocus does not necessarily affect central refractive development,” Vision Res. 46, 3935-3940 (2006). [CrossRef] [PubMed]
  15. J. Tabernero and F. Schaeffel, “More irregular eye shape in low myopia than in emmetropia,” Invest. Ophthalmol. Visual Sci. 50, 4516-4522 (2009). [CrossRef]
  16. J. Gwiazda, F. Thorn, J. Bauer, and R. Held, “Myopic children show insufficient accommodative response to blur,” Invest. Ophthalmol. Visual Sci. 34, 690-694 (1993).
  17. J. Gwiazda, L. Hyman, T. T. Norton, M. E. M. Hussein, W. Marsh-Tootle, R. Manny, Y. Wang, and D. Everett, “Accommodation and related risk factors associated with myopia progression and their interaction with treatment in COMET children,” Invest. Ophthalmol. Visual Sci. 45, 2143-2151 (2004). [CrossRef]
  18. F. Schaeffel, L. Farkas, and H. C. Howland, “Infrared photoretinoscope,” Appl. Opt. 26, 1505-1509 (1987). [CrossRef] [PubMed]
  19. J. Tabernero, D. Vazquez, A. Seidemann, D. Uttenweiler, and F. Schaeffel, “Effect of myopic spectacle correction and radial refractive gradient spectacles on peripheral refraction,” Vision Res. 49, 2176-2186 (2009). [CrossRef] [PubMed]
  20. M. Choi, S. Weiss, F. Schaeffel, A. Seidemann, H. C. Howland, B. Wilhelm, and H. Wilhelm, “Laboratory, clinical, and kindergarten test of a new eccentric infrared photorefractor (PowerRefractor),” Optom. Vision Sci. 77, 537-548 (2000). [CrossRef]
  21. R. Navarro, J. Santamaria, and J. Bescos, “Accommodation-dependent model of the human eye with aspherics,” J. Opt. Soc. Am. A 2, 1273-1281 (1985). [CrossRef] [PubMed]
  22. I. Escudero-Sanz and R. Navarro, “Off-axis aberrations of a wide-angle schematic eye model,” J. Opt. Soc. Am. A 16, 1881-1891 (1999). [CrossRef]
  23. G. Smith, M. Millodot, and N. McBrien, “The effect of accommodation on oblique astigmatism and field curvature of the human eye,” Clin. Exp. Optom. 71, 119-125 (1988). [CrossRef]
  24. R. Calver, H. Radhakrishnan, E. Osuobeni1, and D. O'Leary, “Peripheral refraction for distance and near vision in emmetropes and myopes,” Ophthalmic Physiol. Opt. 27, 584-593 (2007). [CrossRef] [PubMed]
  25. L. N. Davies and E. A. H. Mallen, “Influence of accommodation and refractive status on the peripheral refractive profile,” Br. J. Ophthamol. 93, 1186-1190 (2009). [CrossRef]
  26. L. Lundstrom, A. Mira-Agudelo, and P. Artal, “Peripheral optical errors and their change with accommodation differ between emmetropic and myopic eyes,” J. Vision 9, 1-11 (2009). [CrossRef]
  27. T. W. Walker and D. O. Mutti, “The effect of accommodation on ocular shape,” Optom. Vision Sci. 79, 424-430 (2002). [CrossRef]
  28. A. Whatham, F. Zimmermann, A. Martinez, S. Delgado, P. Lazon de la Jara, P. Sankaridurg, and A. Ho, “Influence of accommodation on off-axis refractive errors in myopic eyes,” J. Vision 9, 1-13 (2009). [CrossRef]

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