Anatomical and functional outcomes of toric intraocular lens implantation

Background: To minimize the residual refractive correction, toric intraocular lens (TIOL) is being increasingly used in cases undergoing cataract surgery with preexisting corneal astigmatism of >= 1.0 D. Aims: The aim of this study is to evaluate anatomical and functional outcomes of TIOL implantation in cases undergoing cataract surgery with significant corneal astigmatism using conventional manual marking of target axis and to see for any difference in outcomes based on the power of TIOL. Methodology: It is a prospective observational study. Consecutive patients with cataract and astigmatism of >1.0 D with adequate pupil dilation and no significant ocular or systemic comorbidity scheduled to undergo phacoemulsification with TIOL implantation were enrolled. Results: The mean improvement in postoperative uncorrected distance visual acuity (UDVA) over preoperative corrected distance visual acuity was 0.51 +/- 0.54 logarithm of the minimum angle of resolution (95% confidence interval CI: 0.30-0.70), equivalent to 4 Snellen lines. The mean postoperative spherical equivalent is 0.38 +/- 0.27; 77.4% showed within 0.50 D and the rest were within 1 D. The mean deviation of postoperative TIOL alignment from intended intraoperative TIOL alignment is 3 degrees +/- 2 degrees (range: 0 degrees -6 degrees). Both the groups (low- and medium-power TIOLs) had similar postoperative UDVA, residual astigmatism, and deviation of target axis. Conclusions: There was an effective correction of preoperative corneal astigmatism and good visual outcomes with TIOL implantation. Fairly accurate TIOL alignment is achievable with manual marking of target axis. The power of TIOL did not influence postoperative UDVA, residual astigmatism, or deviation of TIOL from target axis.