Abstract
Purpose:
The aim of this thesis is to investigate the effects of vision training on accommodation and myopia progression. The short term effect of vision training on accommodation and of altered spherical aberration on accommodative facility rates was investigated. The longitudinal effects of vision training for accommodative facility on accommodation and myopia progression rates was then be investigated as part of the Cambridge Anti-Myopia Study (CAMS).
Methods:
A short term study of the effects of vision training on static and dynamic accommodation was made. The effect of altering spherical aberration with soft contact lenses on dynamic accommodation was investigated. A longitudinal study of the effect of a vision training programme on static and dynamic accommodation was made in 116 fourteen to twenty-one year olds over a one year period. The association between accommodation and myopia progression rates was then examined.
Results:
Myopes had lower distance accommodative facility rates and longer positive accommodation response times than emmetropes. Vision training improved facility rates and the improvements were not related to the initial facility rates. Altering spherical aberration did not significantly change accommodative facility rates but did affect the relative duration of the positive and negative components of the facility cycle. The longitudinal study did not show a significant difference in myopia progression between vision training treatment and control groups. Accommodative facility rates and static accommodative responses to negative lens-induced blur improved in all participants.
Conclusion:
Vision training to improve the dynamics of the accommodation system did not affect static accommodation responses to targets in real space. No effect of vision training on myopia progression rates was shown but any difference in myopia progression rate could have been diluted by the improvements in accommodation dynamics in the control group resulting from repeated testing.
The aim of this thesis is to investigate the effects of vision training on accommodation and myopia progression. The short term effect of vision training on accommodation and of altered spherical aberration on accommodative facility rates was investigated. The longitudinal effects of vision training for accommodative facility on accommodation and myopia progression rates was then be investigated as part of the Cambridge Anti-Myopia Study (CAMS).
Methods:
A short term study of the effects of vision training on static and dynamic accommodation was made. The effect of altering spherical aberration with soft contact lenses on dynamic accommodation was investigated. A longitudinal study of the effect of a vision training programme on static and dynamic accommodation was made in 116 fourteen to twenty-one year olds over a one year period. The association between accommodation and myopia progression rates was then examined.
Results:
Myopes had lower distance accommodative facility rates and longer positive accommodation response times than emmetropes. Vision training improved facility rates and the improvements were not related to the initial facility rates. Altering spherical aberration did not significantly change accommodative facility rates but did affect the relative duration of the positive and negative components of the facility cycle. The longitudinal study did not show a significant difference in myopia progression between vision training treatment and control groups. Accommodative facility rates and static accommodative responses to negative lens-induced blur improved in all participants.
Conclusion:
Vision training to improve the dynamics of the accommodation system did not affect static accommodation responses to targets in real space. No effect of vision training on myopia progression rates was shown but any difference in myopia progression rate could have been diluted by the improvements in accommodation dynamics in the control group resulting from repeated testing.
| Original language | English |
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| Qualification | PhD |
| Awarding Institution |
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| Award date | 31 Jul 2007 |
| Publication status | Published - 31 Jul 2007 |