Optical resolution of foldable intraocular lenses.
Recently manufactured intraocular lenses (IOLs) (STAAR AA 4203 made of silicone and IOGEL PC-12 made of polyHEMA) were tested before and after implantation simulation for axial optical resolution (model eye), for optical surface quality (photokeratoscope), and for surface microtrauma (scanning electron microscopy). At a 3 mm pupillary opening, both lens types achieved a mean axial resolution of 1.25 (range 1.0 to 1.5) on an optotype analogous resolution target. When the pupillary opening was increased to 6 mm, polymacon IOLs showed only a moderate resolution decrease (up to one line) and loss of contrast (up to 30%); silicone IOLs showed almost no decrease. Photokeratoscopic evaluation revealed that a circular optical nonhomogeneity at the peripheral optical zone of the hydrogel IOLs is the source of this impairment. Groove-like surface deformities occasionally observed by scanning electron microscopy did not detectably decrease resolution or contrast.
Kulnig
W
W
First Department of Ophthalmology, University of Vienna Medical School, Austria.
Skorpik
C
C
D006801:Humans; D007431:Intraoperative Complications; D007910:Lenses, Intraocular; D008689:Methacrylates; D008855:Microscopy, Electron, Scanning; D008953:Models, Anatomic; D055095:Optics and Photonics; D012828:Silicones; D013499:Surface Properties
D008689:Methacrylates; D012828:Silicones; C005044:hydroxyethyl methacrylate