SCANNING ELECTRON-MICROSCOPIC CHARACTERISTICS OF SMALL-INCISION INTRAOCULAR LENSES

Purpose: To evaluate the surface characteristics of commonly used, sma ll-incision, intraocular lenses (IOLs). Methods: Representative sample s of five groups of foldable IOLs (4 silicone and 1 acrylic) underwent surface and edge-finish examination using a slit lamp. The IOLs were folded using a folding block and forceps. All the IOLs then were exami ned using a scanning electron microscope. A one-piece polymethylmethac rylate IOL was used for comparing surface-finish characteristics. The IOLs were examined for optic surface quality, edge finish, haptic, hap tic/optic junction, and possible post-folding modifications. Results: Slit-lamp evaluation of the surface quality of all of the silicone len ses demonstrated a smooth finish of the optic surface, edge, and hapti cs. Scanning electron microscopic analysis of the IOLs demonstrated ad equately finished haptics or footplates and optics, Excess molding fla sh was seen on the edges of the some of the silicone IOLs, and no mold ing flash was observed on others. The acrylic IOL had a somewhat sharp er optic edge. Irregular finish of the haptic/optic junctions of some of the IOLs (both silicone and acrylic) was noted. Conclusions: Curren tly available foldable IOLs have demonstrated adequate lens finish. Ho wever, irregularities of the haptic/optic junctions and molding flash are present on most IOLs evaluated, indicating room for improvement in the finish of foldable IOLs. Phacoemulsification with capsular bag IO L placement may decrease the clinical significance of these relatively subtle lens finish irregularities.