gms | German Medical Science

Purpose: Anatomical axis of the bulb mismatches visual axis. A nasal pupil decentration is seen to be a physiological adaptation for the mentioned mismatching. Lens crystallina is mostly centrated and well positioned IOL in the bag has the centre in the anatomical axis. Sothat visual axis pass by the periphery of the IOL optic and the picture on the retina is misshaped. Particular subjective problems come by the implantation of a standard bifocal IOL with the concentric ring construction. Aim of our work was to find a way of the surgical innovation.

Methods: In the group of 15 healthy volunteers (the staff of our department) we have used Pentacam for measurement of a physiological nasal pupil decentration. An IOL nasal decentration during phaco cataract surgery was induced partly in well centered CCC and partly in the goal directed 0.5 mm nasal decentration of the CCC. Facility and stability of decentration were evaluated.

Results: The nasal pupil decentration of 0.5 mm is independent on cone and scotopic vision. It disappears in the artificial mydriasis. A nasal decentration with tilt of any IOL can be induced by the temporal “out of the bag” position of the IOL optic. In this case the effect of the “square edge” is lost. En face the nasal 0.5 mm decentration of CCC combined with the IOL nasal decentration in the bag is seen by us the optimal solution. Only hydrophobic (an adhesive effect on the capsule) one piece IOLs with “knee modified” haptics (Acrysof SA linie, Tecnis etc.) have fixed nasal decentred position after surgery.

Conclusions: We have introduced the new surgical method of the nasal IOL decentration combined with the nasal CCC decentration. New method is useful especially during implantation of a hydrophobic bifocal IOL with the standard concentric ring construction and the fine “knee modified” haptics.