Comparison of toric intraocular lens alignment error with different toric markers

Purpose: To compare the error in intraocular lens (IOL) toric alignment of 2 toric markers. Setting: Sir Charles Gairdner Hospital, Perth, Western Australia, Australia. Design: Retrospective case series. Methods: Two consecutive groups of patients had cataract surgery with implantation of an AcrySof SN6A toric IOL (versions T2–T8) by the same surgeon at 2 public hospitals. The only difference in the toric alignment method between the groups was the toric maker used (Group 1: Barrett dual axis toric marker; Group 2: Mendez gauge). A mobile phone application (toriCAM) was used in both groups to determine the reference meridian. The primary outcome measure was the error in toric IOL alignment in degrees at 1 month. The secondary outcome measure was the percentage of eyes achieving a manifest refraction astigmatism within ±0.50 diopter (D) at 1 month. Results: Seventy-two eyes of 56 patients were included (Group 1: 36 eyes of 35 patients; Group 2: 36 eyes of 25 patients). The mean absolute toric alignment error (intended versus achieved axis of alignment) was 4.0 degrees ± 2.9 (SD) in Group 1 and 8.4 ± 6.5 degrees in Group 2 (P =.0015). Twenty-nine eyes (80.6%) in Group 1 and 21 eyes (53.8%) in Group 2 achieved a manifest refractive astigmatism of 0.50 D or less (P <.05). Conclusion: Toric IOL alignment using the mobile phone application was more accurate with the Barrett dual axis toric marker than with the commonly used Mendez gauge, with a significantly higher percentage of eyes achieving a manifest refraction astigmatism within ±0.50 D.