Ji Won Jung1, Sun Hyup Han2, Sang Ah Kim2, Eung Kweon Kim3, Kyoung Yul Seo2, Tae-Im Kim4. 1. The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea; Department of Ophthalmology and Inha Vision Science Laboratory, Inha University School of Medicine, Incheon, South Korea. 2. The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea. 3. The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea; 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. 4. The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea. Electronic address: tikim@yuhs.ac.
Abstract
PURPOSE: The purpose of this study was to investigate efficient 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 FD-OCT. 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. The pigment particles in Lens B were buried below the front surface and there were no significant differences of roughness between the front and back surfaces. However, all tinted lenses with surface pigment had significant difference of roughness between front and back surfaces at the pigmented area. CONCLUSION: The FIB-SEM and FD-OCT could reliably locate the pigment layer of tinted soft contact lenses. In addition, lens surface roughness was influenced by pigment layer location.
PURPOSE: The purpose of this study was to investigate efficient 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 FD-OCT. 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. The pigment particles in Lens B were buried below the front surface and there were no significant differences of roughness between the front and back surfaces. However, all tinted lenses with surface pigment had significant difference of roughness between front and back surfaces at the pigmented area. CONCLUSION: The FIB-SEM and FD-OCT could reliably locate the pigment layer of tinted soft contact lenses. In addition, lens surface roughness was influenced by pigment layer location.
Authors: Timur M Yildirim; Ramin Khoramnia; Michael Masyk; Hyeck-Soo Son; Gerd U Auffarth; Christian S Mayer Journal: PLoS One Date: 2020-08-13 Impact factor: 3.240