[Rotational stability in intraocular lenses with C-loop haptics versus Z haptics in cataract surgery. A prospective...

The aim of the study was to compare the rotational stability of intraocular lenses (IOLs) with C-loop haptics and those with Z haptics. A total of 50 patients with cataracts were prospectively randomised in equal numbers using a design equivalent to IOL MS 612 S (C-loop haptic) and MS 6120 (Z haptic, both HumanOptics, Erlangen). Complete ophthalmological examinations were performed including assessment of the IOL rotation after 1 day, 1 month and 3 months postoperatively. The significances between the groups were evaluated using the Wilcoxon test. The Fisher exact test was used for the primary finding of the study (rotation of at least 10 degrees ). The IOL group with the C-loop haptics showed a median lens rotation of 0 degrees on the first day and 2 degrees clockwise after 1 month and 3 months. In the Z haptic group, there was no median rotation in the IOL group. Moreover, the range of IOL rotation of the C-loop haptics was broader (3 months postoperatively: maximum in the C-loop haptics: 21 degrees with 15.5 degrees in the Z haptics). There was no significant difference at any time. At 3 months postoperatively, 32% of the C-loop haptic IOL and 16% of the Z haptic IOL rotated at least 10 degrees (P=0.32). In 59% of the IOL with C-loop haptics, the direction of the rotation was clockwise. This was 40% for the IOL with Z haptics (P=0.33). At 3 months postoperatively, both IOLs demonstrated good rotational stability with a low mean deviation from the target axis. IOLs with Z haptics showed a tendency to greater rotational stability than C-loop haptics but without any significant difference. There was no significant difference in visual rehabilitation.