Toshifumi Mihashi1,2, Yoko Hirohara1,2, Kenichiro Bessho1, Naoyuki Maeda3, Tetsuro Oshika4, Takashi Fujikado5. 1. Department of Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan. 2. Technical Research Institute, Topcon Corporation, Tokyo, Japan. 3. Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan. 4. Department of Ophthalmology, University of Tsukuba, Tsukuba, Japan. 5. Department of Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan. fujikado@ophthal.med.osaka-u.ac.jp.
Abstract
PURPOSE: A clinical investigation of novel methods for evaluating light scattering using a Hartmann-Shack aberrometer. METHODS: Aberrometry was performed on normal eyes (n=7; patient age, 26.7+/-2.5 years, mean+/-SD), eyes with keratoconus (n=22; patient age, 26.1+/-8.1 years), and eyes with cataract (n=17; patient age, 56.5+/-16.9 years) using a Hartmann-Shack wavefront aberrometer. We introduced two methods: (1) a contrast method, in which we calculated the inverse of contrast of the local images around 12 spots in a Hartmann-Shack image, and (2) a difference of point spread function (PSF) method, in which we analyzed the difference between the width of the PSF computed with aberration information and the width of the measured PSF, which contains both aberration and light scattering information. RESULTS: The inverse contrast in cataractous eyes (5.04+/-3.06 inverse contrast units) was significantly larger than that in normal eyes (1.57+/-0.56) or keratoconic eyes (1.83+/-0.79). The difference of PSF in cataractous eyes (81.8+/-65.2 microm) was also significantly larger than that in normal eyes (9.3+/-4.3 microm) or keratoconic eyes (30.0+/-20.1 microm). The inverse contrast and the difference in the PSF were highly correlated (r=0.89, P<0.0001). CONCLUSIONS: The two methods introduced here successfully distinguished cataractous eyes from normal and keratoconic eyes. After the results were analyzed by a discriminant analysis, the separation of the three categories proved to be excellent. Copyright (c) Japanese Ophthalmological Society 2006.
PURPOSE: A clinical investigation of novel methods for evaluating light scattering using a Hartmann-Shack aberrometer. METHODS: Aberrometry was performed on normal eyes (n=7; patient age, 26.7+/-2.5 years, mean+/-SD), eyes with keratoconus (n=22; patient age, 26.1+/-8.1 years), and eyes with cataract (n=17; patient age, 56.5+/-16.9 years) using a Hartmann-Shack wavefront aberrometer. We introduced two methods: (1) a contrast method, in which we calculated the inverse of contrast of the local images around 12 spots in a Hartmann-Shack image, and (2) a difference of point spread function (PSF) method, in which we analyzed the difference between the width of the PSF computed with aberration information and the width of the measured PSF, which contains both aberration and light scattering information. RESULTS: The inverse contrast in cataractous eyes (5.04+/-3.06 inverse contrast units) was significantly larger than that in normal eyes (1.57+/-0.56) or keratoconic eyes (1.83+/-0.79). The difference of PSF in cataractous eyes (81.8+/-65.2 microm) was also significantly larger than that in normal eyes (9.3+/-4.3 microm) or keratoconic eyes (30.0+/-20.1 microm). The inverse contrast and the difference in the PSF were highly correlated (r=0.89, P<0.0001). CONCLUSIONS: The two methods introduced here successfully distinguished cataractous eyes from normal and keratoconic eyes. After the results were analyzed by a discriminant analysis, the separation of the three categories proved to be excellent. Copyright (c) Japanese Ophthalmological Society 2006.
Authors: Stefan Schramm; Bernd-Ulrich Seifert; Patrick Schikowski; Jürgen Prehl; Kathleen S Kunert; Marcus Blum; André Kaeding; Jens Haueisen Journal: Graefes Arch Clin Exp Ophthalmol Date: 2013-06-29 Impact factor: 3.117
Authors: Nikole L Himebaugh; Jayoung Nam; Arthur Bradley; Haixia Liu; Larry N Thibos; Carolyn G Begley Journal: Optom Vis Sci Date: 2012-11 Impact factor: 1.973