Abstract
Purpose::
To understand the relationship between various types of whole-eye wavefront aberration and degree of pseudophakic accommodation with non-accommodating intraocular lens implants.
Methods::
This pilot study consisted of 11 subject eyes at UCSF. Subjects were recruited from UCSF ophthalmologic visits. Selection criteria included 20/20 best corrected visual acuity and at least one year post-op after cataract extraction and intraocular lens implantation. Subjects who did not have a minimum pupil size of 4mm were given a drop of phenylephrine and pupil size was remeasured after 20 minutes, requiring minimum 4mm pupils to participate. Accommodative amplitude was assessed by slowly bringing the near card away from the eye until the 20/40 line could be read. This distance was converted to diopters. Wavefront aberration was then measured in that eye using the Alcon Ladarwave Aberrometer. All tests were performed with uniform lighting and uniform pupillary dilation.
Results::
The age of subjects ranged from 16 to 77 years with a mean of 59 years. Accommodative amplitude was correlated with spherical aberration (Pearsons r=0.70, p=0.002). Age negatively correlated significantly with both accommodative amplitude and spherical aberration (r=-0.60, p=0.051 and r=-0.88, p=0.0004, respectively). Pupil size was also associated with both accommodative amplitude and spherical aberration (r=0.51, p=0.105 and r=0.66, p=0.028). Although not statistically significant, coma (r=0.41, p=0.214), higher order aberration (r=0.59, p=0.054), and defocus (r=0.39, p=0.236) also had a positive association with accommodative amplitude.
Conclusions::
This small pilot study suggests that spherical aberration correlates with pseudophakic accommodation. Age and pupil size may be confounders. Future studies will control for both age and pupil size. In addition, assessing intraocular lens tilt along with these parameters may reveal a physical link between particular whole eye wavefront types and increased accommodation. Such a link could explain pseudophakic accommodation and provide future strategies for accommodating intraocular lens design.
Keywords: presbyopia • intraocular lens