Randomized trial comparing visual outcomes of toric intraocular lens implantation using manual and digital marker

Purpose: The aim of this study was to compare the visual outcome of participants undergoing toric intraocular lens (IOL) implantation after cataract extraction using manual marking versus digital marking for intraoperative guidance. Methods: Randomized controlled trial of participants with cataract and corneal astigmatism of 1.00 D-4.50 D. The eyes were grouped into manual marking (Group 1) and digital marking (Group 2). Preoperative Uncorrected distance visual acuity (UDVA), Corrected distance visual acuity (CDVA), and corneal astigmatism were determined. IOL power and axis of alignment were determined using Barrett toric calculator. Eyes were marked by bubble marker and Mendez ring in group 1 and by VERION (Alcon, Fort Worth, Texas) digital overlay in Group 2. Postoperatively, UDVA, CDVA, residual refractive cylinder and IOL misalignment were determined (iTrace system, Tracey technologies) at 1 week, 6 weeks, and 3 months. Results: A total of 61 eyes of 50 participants, 31 in Group 1 and 30 in Group 2, were studied. The mean postoperative cylindrical error was 0.50 +/- 0.39 D in Group 1 and 0.29 +/- 0.34 D in Group 2 (P = 0.03). 67.74% (n = 21) and 93.55% (n = 29) eyes achieved a residual astigmatism of <= 0.50 D and <= 1.00 D, respectively, in Group 1, whereas 83.33% (n = 25) and 100% (n = 30) eyes achieved a residual astigmatism of <= 0.50 D and <= 1.00 D, respectively, in Group 2 at 3 months postoperatively. Toric IOL misalignment was 4.71 +/- 3.12 degrees in Group 1 and 4.03 +/- 2.99 degrees in Group 2 (P = 0.39). Conclusion: Accurate manual marking and digital marking are equally effective guides for toric IOL alignment, intraoperatively.