Relationship of Angle Kappa With Diffractive Multifocal IOL Centration and Visual Acuity
Narrative Responses:
Purpose
To evaluate the relationship between angle kappa and centration of a 1-piece diffractive multifocal IOL and their relationship to early postoperative uncorrected visual acuity.
Methods
Retrospective single-surgeon, observational case series. Digital mesopic pupil images from 118 eyes implanted with the Tecnis Multifocal 1-piece IOL (ZMB00, Abbott Medical Optics) were analyzed. Computerized measurements were made to determine the location of the the coaxially-sighted corneal light reflex (CSCLR), the IOL center, and the pupil center. In all cases, attempt was made to align the IOL with the CSCLR intraoperatively.
Results
Preoperative angle kappa was a good predictor of postoperative angle kappa (R = 0.77). On postoperative day 1, mean decentration of the IOL was 0.15 ± 0.09 mm from the CSCLR and 0.21 ± 0.11 from the pupil center. The amounts of IOL decentration from the CSCLR and the pupil center were positively correlated with angle kappa (R = 0.27 and 0.48, respectively). Although weak, uncorrected visual acuity was negatively correlated with angle kappa (R = -0.07) and pupil center alignment (R = -0.05) and positively correlated with CSCLR alignment (R = 0.07).
Conclusion
Good centration of diffractive multifocal IOLs on the CSCLR is associated with better uncorrected visual acuity. Although small overall, decentration tends to be greater in eyes with a larger angle kappa.