Evaluation of pigment location in tinted soft contact lenses.pdfVIP

Contact Lens and Anterior Eye 39 (2016) 210–216 Contents lists available at ScienceDirect Contact Lens and Anterior Eye journal homepage: /locate/clae Evaluation of pigment location in tinted soft contact lenses Ji Won Junga,b,1, Sun Hyup Hana,1, Sang ah Kima, Eung Kweon Kima,c, Kyoung Yul Seoa, Tae-im Kima,* a The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea b Department of Ophthalmology and Inha Vision Science Laboratory, Inha University School of Medicine, Incheon, South Korea c Corneal Dystrophy Research Institute, Severance Biomedical Science Institute, and Brain Korea 21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea ARTICLE INFO Article history: Received 6 June 2015 Received in revised form 18 November 2015 Accepted 20 January 2016 Keywords: Tinted soft contact lenses Focused ion beam scanning electron microscopy Atomic force microscopy Pigment location Surface roughness ABSTRACT Purpose: The purpose of this study was to investigate ef?cient methods to evaluate the pigment layer location of tinted soft contact lenses and to assess various lens products on the market using those methods. Methods: Two types of tinted soft contact lenses with known pigment location embedded or back surface were manufactured and examined. Light microscopy (LM), focused ion beam milling and scanning electron microscopy (FIB-SEM), and Fourier-domain optical coherence tomography (FD-OCT) were used to examine the pigment layer. Lens surface roughness was also measured using atomic force microscopy. In the second part of the experiment, pigment location and surface roughness of a clear lens (Lens A) and eight commercially-available tinted soft contact lenses (Lens B-I) were evaluated using FIB-SEM and FDOCT. Results: Pigment location could be reliably determined with FIB-SEM and FD-OCT. With LM, 40% of the lens sections were broken or deformed during slide preparation.