Scanning electron microscopic analysis of acrylic intraocular lenses for microincision cataract surgery.

Purpose: To analyze the surface quality before and after folding of 2 intraocular lens (IOL) models designed for microincision cataract surgery.
Setting: Eye Clinic and Department of Human Pathology and Oncology, University of Florence, Florence, Italy.
Methods: Two IOL models now available for sub-2.0 mm microincision were studied: UltraChoice 1.0 Rollable ThinLens (ultrathin lens by ThinOptX) and AcriSmart (foldable lens by AcriTec). Eight IOLs of each model were examined. Scanning electron microscopy (SEM) was performed before and after IOL folding with a dedicated injector. Special attention was given to the optic surface and edges, the optic-haptic junction, and the haptic itself.
Results: Initially, the surface quality of IOLs was evaluated before folding. On SEM, smooth and homogeneous optic and haptic surfaces were revealed in both IOL models with no surplus material or molding flashes; edge finish of all optics showed no evidence of ridges. The IOL surfaces were evaluated after insertion into their injectors and after ejection at room temperature. After folding, the microincision IOLs showed no sign of surface alteration, probably because of their high water content, which makes these IOLs soft and flexible.
Conclusions: Visual results and long-term biocompatibility of the IOLs are influenced by surface properties. In recent years, there has been a trend toward microincision cataract surgery. Our study shows that the 2 IOL models now available for sub-2.0 mm microincision have acceptable surface properties.