title: Magnetically adjustable intraocular lens.
abstract: OBJECTIVE
  To provide a noninvasive, magnetic adjustment mechanism to the repeatedly and reversibly adjustable, variable-focus intraocular lens (IOL).
  
  
  METHODS
  University of Missouri-Rolla, Rolla, and Eggleston Adjustable Lens, St. Louis, Missouri, USA.
  
  
  METHODS
  Mechanically adjustable IOLs have been fabricated and tested. Samarium and cobalt rare-earth magnets have been incorporated into the poly(methyl methacrylate) (PMMA) optic of these adjustable lenses. The stability of samarium and cobalt in the PMMA matrix was examined with leaching studies. Operational force testing of the magnetic optics with emphasis on the rotational forces of adjustment was done.
  
  
  RESULTS
  Prototype optics incorporating rare-earth magnetic inserts were consistently produced. After 32 days in solution, samarium and cobalt concentration reached a maximum of 5 ppm. Operational force measurements indicate that successful adjustments of this lens can be made using external magnetic fields with rotational torques in excess of 0.6 ounce inch produced. Actual lenses were remotely adjusted using magnetic fields.
  
  
  CONCLUSIONS
  The magnetically adjustable version of this IOL is a viable and promising means of handling the common issues of postoperative refractive errors without the requirement of additional surgery. The repeatedly adjustable mechanism of this lens also holds promise for the developing eyes of pediatric patients and the changing needs of all patients.
authors.affiliation: University of Missouri-Rolla, St. Louis, MO 65409, USA.
authors.forename: Michael Wayne
authors.initials: MW
authors.lastname: Matthews
authors.forename: Harry Conrad
authors.initials: HC
authors.lastname: Eggleston
authors.forename: Steven D
authors.initials: SD
authors.lastname: Pekarek
authors.forename: Greg Eugene
authors.initials: GE
authors.lastname: Hilmas
mesh_terms: D001672:Biocompatible Materials; D003035:Cobalt; D006801:Humans; D007910:Lenses, Intraocular; D008280:Magnetics; D019904:Polymethyl Methacrylate; D011474:Prosthesis Design; D017755:Prosthesis Fitting; D012029:Refraction, Ocular; D012493:Samarium
chemical_list: D001672:Biocompatible Materials; D003035:Cobalt; D012493:Samarium; D019904:Polymethyl Methacrylate