Chen Wang1, Flavia Brancusi1, Zaheer M Valivullah2, Michael G Anderson3,4, Denise Cunningham5, Adam Hedberg-Buenz3,4, Bradley Power1, Dimitre Simeonov6, William A Gahl1, Wadih M Zein5, David R Adams1, Brian Brooks5. 1. a Section on Human Biochemical Genetics , National Human Genome Research Institute, National Institutes of Health , Bethesda , Maryland , USA. 2. b Undiagnosed Diseases Program, NIH Common Fund, Office of the Director , National Human Genome Research Institute, National Institutes of Health , Bethesda , Maryland , USA. 3. c Department of Molecular Physiology and Biophysics , University of Iowa , Iowa City , Iowa , USA. 4. d Center for the Prevention and Treatment of Visual Loss , Iowa City Veterans Affairs (VA) Health Care System , Iowa City , Iowa , USA. 5. e National Eye Institute , National Institutes of Health , Bethesda , Maryland , USA. 6. f Department of Human Biochemical Genetics , University of California, San Francisco , San Francisco , California , USA.
Abstract
PURPOSE: To develop a sensitive scale of iris transillumination suitable for clinical and research use, with the capability of either quantitative analysis or visual matching of images. METHODS: Iris transillumination photographic images were used from 70 study subjects with ocular or oculocutaneous albinism. Subjects represented a broad range of ocular pigmentation. A subset of images was subjected to image analysis and ranking by both expert and nonexpert reviewers. Quantitative ordering of images was compared with ordering by visual inspection. Images were binned to establish an 8-point scale. Ranking consistency was evaluated using the Kendall rank correlation coefficient (Kendall's tau). Visual ranking results were assessed using Kendall's coefficient of concordance (Kendall's W) analysis. RESULTS: There was a high degree of correlation among the image analysis, expert-based and non-expert-based image rankings. Pairwise comparisons of the quantitative ranking with each reviewer generated an average Kendall's tau of 0.83 ± 0.04 (SD). Inter-rater correlation was also high with Kendall's W of 0.96, 0.95, and 0.95 for nonexpert, expert, and all reviewers, respectively. CONCLUSIONS: The current standard for assessing iris transillumination is expert assessment of clinical exam findings. We adapted an image-analysis technique to generate quantitative transillumination values. Quantitative ranking was shown to be highly similar to a ranking produced by both expert and nonexpert reviewers. This finding suggests that the image characteristics used to quantify iris transillumination do not require expert interpretation. Inter-rater rankings were also highly similar, suggesting that varied methods of transillumination ranking are robust in terms of producing reproducible results.
PURPOSE: To develop a sensitive scale of iris transillumination suitable for clinical and research use, with the capability of either quantitative analysis or visual matching of images. METHODS: Iris transillumination photographic images were used from 70 study subjects with ocular or oculocutaneous albinism. Subjects represented a broad range of ocular pigmentation. A subset of images was subjected to image analysis and ranking by both expert and nonexpert reviewers. Quantitative ordering of images was compared with ordering by visual inspection. Images were binned to establish an 8-point scale. Ranking consistency was evaluated using the Kendall rank correlation coefficient (Kendall's tau). Visual ranking results were assessed using Kendall's coefficient of concordance (Kendall's W) analysis. RESULTS: There was a high degree of correlation among the image analysis, expert-based and non-expert-based image rankings. Pairwise comparisons of the quantitative ranking with each reviewer generated an average Kendall's tau of 0.83 ± 0.04 (SD). Inter-rater correlation was also high with Kendall's W of 0.96, 0.95, and 0.95 for nonexpert, expert, and all reviewers, respectively. CONCLUSIONS: The current standard for assessing iris transillumination is expert assessment of clinical exam findings. We adapted an image-analysis technique to generate quantitative transillumination values. Quantitative ranking was shown to be highly similar to a ranking produced by both expert and nonexpert reviewers. This finding suggests that the image characteristics used to quantify iris transillumination do not require expert interpretation. Inter-rater rankings were also highly similar, suggesting that varied methods of transillumination ranking are robust in terms of producing reproducible results.
Authors: Je Hyun Seo; Young Suk Yu; Jeong Hun Kim; Ho Kyung Choung; Jang Won Heo; Seong-Joon Kim Journal: Ophthalmology Date: 2007-03-06 Impact factor: 12.079
Authors: Colleen M Trantow; Adam Hedberg-Buenz; Sachiyo Iwashita; Steven A Moore; Michael G Anderson Journal: PLoS Genet Date: 2010-07-01 Impact factor: 5.917
Authors: Karen Grønskov; Christopher M Dooley; Elsebet Østergaard; Robert N Kelsh; Lars Hansen; Mitchell P Levesque; Kaj Vilhelmsen; Kjeld Møllgård; Derek L Stemple; Thomas Rosenberg Journal: Am J Hum Genet Date: 2013-02-07 Impact factor: 11.025