Abstract
Purpose: :
To investigate the impact of phenylephrine and cyclopentolate on wavefront refraction and investigate the relationship between paralysis of accommodation and the optical aberrations on paediatric eyes.
Methods: :
15 healthy children between 4 up 11 years old were enrolled. Each 28 eyes underwent optical aberration measurement with natural pupil condition (group 1) at first sight, with pharmacological dilation (phenylephrine) (group 2) and at least with dilatation and cycloplegia (cyclopentolate 1%) (Group 3) 30 minutes after the instillation of cyclopentolate 1% to investigate the effect of paralysis of accommodation. Monochromatic optical aberrations and pupil size were measured with a Hartmann-Shack wavefront sensor under monocular scotopic viewing conditions. Wavefront aberrations were expressed by Zernike expansion up to the sixth order.
Results: :
Spherical ametropia ranges from -1.75 to +8.25 diopters with mean pupil diameter was 7.74mm +/-0.73mm for group 1, 7.87+/-0.69mm for group 2 and 8.65+/-0.38mm for group 3. The total higher order RMS wavefront aberration did not increase. Group 1 and especially group 2 (phenylephrine) have increased fourth and sixth order aberrations. From an other side, paralysis of accommodation with cyclopentolate appeared to reduce higher-order aberrations, except on fifth order aberration showing characteristic changes. Cycloplegia increases fifth order much more than natural or pharmacological accommodative dilatation state. Unfortunately there were no eyes enough to conclude significantly.
Conclusions: :
Accommodative dilatation state with phenylephrine shows more higher-order aberration than cycloplegia or natural state except for the fifth order in children. The paralysis of accommodation reduces higher order aberration. Without bringing significant evidence, this series shows that accommodation raises higher order aberration. This can be explained by an asymmetrical ciliary bodies contraction.
Keywords: accomodation • aberrations • refractive surgery