Abstract
Purpose:
To assess the validity of a ray tracing system in determining the alignment of toric intraocular lenses (IOLs) in undilated pupil
Methods:
: This prospective, consecutive interventional study comprised of 30 eyes of 22 patients who have undergone cataract surgery with implantation of toric IOLs for correction of preexisting corneal astigmatism seen at post operative six weeks. The toric IOL axis was measured undilated by using ray tracing aberrometer. The pupil was then dilated and IOL axis was measured by rotating the slitlamp beam to align with the IOL axis indicator marks. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, residual refractive sphere, and residual keratometric and refractive cylinders were also measured.
Results:
The mean IOL misalignment measured by slit-lamp was 2.2± 3.5 degrees and 2.5± 4.8 degrees by ray tracing system. The mean difference between the two methods was 0.11degrees with 96.4% of the values falling with the limits of agreement on the Bland Altman plot
Conclusions:
: The ray tracing system is a reliable and predictable method of assessing IOL alignment. It can be used for analyzing the axis of toric IOLs even in non dilating pupil with good reliability
Keywords: 445 cataract •
567 intraocular lens •
682 refractive surgery: other technologies