Effect of folding on the multifocal silicone intraocular lens: Scanning electron microscopic study

Purpose: To evaluate whether the surface of the refractive zonal multifocal silicone intraocular lens (IOL) is altered by different folding and implan tation instruments and is more sensitive to manipulation during folding tha n the surface of a monofocal IOL. Setting: Department of Ophthalmology, University Hospital, Kiel, Germany. Methods: Evaluated were the refractive multifocal silicone IOL (SA-40N, Arr ay) and an otherwise identical monofocal IOL (SI-40NB) from the same manufa cturer (Allergan Inc.). Different folding devices (folding blocks, folding and implantation forceps, and an injector system) were used. The IOLs were kept folded for 60 seconds; 24 hours later, scanning electron microscopy (S EM) was performed. In addition, the cartridges of the injector system were examined by SEM. Results: Overall, regardless of the folding and implantation instruments us ed, both the multifocal and monofocal IOLs had discrete surface alterations . The cartridges of the injector system had a rough surface at the tip, whi le the proximal portion appeared smooth Conclusion: There were no signs of lesions particularly affecting the surfa ce of multifocal IOLs. J Cataract Refract Surg 1999; 25. 1505-1509 (C) 1999 SCRS and ESCRS.