Comparison Of Rotational Stability Of Two Aspheric Toric Intraocular Lenses (Iols): Preliminary Results Of A Randomised Controlled Study

To evaluate the rotational stability of two monofocal toric intraocular lenses (IOLs), the Eyhance Toric II IOL and the Alcon IQ SN6ATX IOL using slit lamp photography image analysis.

University Hospital, Guy’s and St. Thomas NHS Foundation trust.

Patients with bilateral cataracts and corneal astigmatism of over 1.25 dioptres, and no significant ophthalmic problems were randomised to receive either bilateral insertion of Alcon SN6ATX or the Eyhance Toric II IOL with micro-monovision. Digital photography was performed on day of surgery and at 6 weeks and 6 months for one eye per patient.  Toric IOL axis marker positions were measured against iris and scleral landmarks, for assessment of Toric IOL rotation. IOL position was compared with intended insertion position at 6 weeks after surgery.

Six patients in Alcon SN6ATX group (1M:5F, mean age 68.93 yrs), and 10 patients to the Eyhance Toric group (1M:9F, mean age 66.77yrs) have completed 6 week follow-up. Mean initial angle deviation in the Alcon SN6ATX group was 6.357˚  (3.25-10.23; SD 2.370), and 5.453˚ (0.96-10.68; SD 3.637) in the Eyhance Toric group (p= 0.60). No statistically significant differences were found between the two groups.  Mean 6 week angle deviation in the Alcon SN6ATX group was 1.351˚  (0.36-3.187; SD 1.00), and 0.77˚  (0.96-10.68; SD 3.637) in the Eyhance Toric group (p=0.14).  

There were  acceptable levels of Toric IOL rotational stability in both IOL groups, and non-inferiority of the Eyhance Toric II IOL when compared to the Alcon Toric IOL. We aim to present further data, with larger groups and 6 month follow-up data.