title: Osmotic cavitation of elastomeric intraocular lenses.
abstract: In recent years, traditional rigid materials have been replaced with softer elastomers in intraocular lenses to minimize the size of the required surgical incision, thereby reducing patient recuperation time. However, water-filled cavities that may impact visual acuity are found in many of these new implants. We demonstrate that the cavitation observed in vivo can occur due to an osmotic pressure difference between the aqueous solution within the cavity and the external media in which the lens is immersed. By reducing the osmolarity of the external solution from 300 to 0mM, we observe an increase in cavity volume of almost a factor of 30. Further, we have developed a model for cavity growth assuming the controlling factor is diffusion of hydrophilic molecules from the polymer matrix into the cavity. We find that the experimental observations are consistent with the model and suggest that oligomeric species generated during polymerization are responsible for the observed cavitation.
authors.affiliation: Food and Drug Administration, 10903 New Hampshire Ave., Silver Spring, MD 20993, USA. david.saylor@fda.hhs.gov
authors.forename: David M
authors.initials: DM
authors.lastname: Saylor
authors.forename: D
authors.initials: D
authors.lastname: Coleman Richardson
authors.forename: Benita J
authors.initials: BJ
authors.lastname: Dair
authors.forename: Steven K
authors.initials: SK
authors.lastname: Pollack
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D020724:Elastomers / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007910:Lenses, Intraocular; D008422:Materials Testing; D008962:Models, Theoretical; D009997:Osmotic Pressure
chemical_list: D020724:Elastomers