The Effect of Peripheral Defocus on Axial Growth and Modulation of Refractive Error in Hyperopes

Abstract

Despite the known visual and pathological implications of hyperopia, there has been inertia to
address the modulation of refractive error in these individuals.


Imposing relative peripheral hyperopic defocus using centre-near multifocal contact
lenses accelerates axial growth in isohyperopic children.
Axial growth and refractive error did not change during the 6 months prior to intervention in the
intervention or control group. Axial growth across the 2-year period of intervention was 0.17
mm in the intervention group versus 0.06 mm in the control group. Refractive error change
across the same period was -0.26 D in the intervention group and +0.01 D in the control group.
Axial growth and refractive error during the final 6 months without intervention did not change
in either group. The overall difference in axial growth between groups was significant whereas
the change in refractive error was not.


Imposing relative peripheral hyperopic defocus using centre-near multifocal contact
lenses does not accelerate axial growth nor reduce refractive error in anisohyperopic
children.
In this paired eye study, axial growth and refractive error did not change during the 6 months
prior to intervention in either eye. Axial growth across the 2-year period of intervention was
0.11 mm in the intervention eye versus 0.15 mm in the control eye. Refractive error change
across the same period was -0.23 D in the intervention eye and -0.27 D in the fellow eye. Axial
growth and refractive error during the final 6 months without intervention did not change in
either group. The overall change in axial growth was greater in the control eye than the
intervention eye, whereas the reduction in refractive error was comparable.


Axial length measures are comparable and repeatable under pre- and post-cycloplegic conditions.


Refractive error measures are comparable and repeatable at discrete time intervals after the instillation of a cycloplegic agent.

Date of Award	2021
Original language	English
Awarding Institution	Aston University
Supervisor	Nicola Logan (Supervisor) & Leon Davies (Supervisor)