Development and validation of a computerized expert system for evaluation of automated visual fields from the Ischemic Optic Neuropathy Decompression Trial

Steven E. Feldon, Lori Levin, Roberta W. Scherer, Anthony Arnold, Sophia M. Chung, Lenworth N. Johnson, Gregory Kosmorsky, Steven A. Newman, Joanne Katz, Patricia Langenberg, P. David Wilson, Shalom E. Kelman, Kay Dickersin, John Kennerdell, Anna Bruchis, Dawn Govreau, John Holds, John Selhorst, Mark Malton, Amy RogersTimothy Saunders, Karen King, Tami Fecko, Deborah Ross, Kerry Zimmerman, Kathy Friedberg, Nahid Sadaati, Nancy J. Newman, Donna Loupe, Ted Wojno, Barry Skarf, Mark Croswell, Wendy Gilroy Clements, George Ponka, Rosa Tang, Melissa Hamlin, Jewel Curtis, Kirk Mack, Portia Tello, Janet Buckley, Robert Goldberg, Lynn Gordon, Howard Krauss, Robert Stalling, Wayne Cornblath, Barbara Michael, Gaye Baker, Coy Cobb, Sharon Turner, Brian Younge, Jacqueline Leavitt, Rebecca Nielsen, Barbara Eickhoff, James Garrity, Jacqueline Ladsten, Kathleen Lebarron, Thomas Link, Jay Rostvold, Karen Weber, Warren Felton, Tammy Anderson, George Sanborn, David Kaufman, Eric Eggenberger, Suzanne Bickert, Robert Granadier, Sandra Holliday, Thomas Moore, Deborah Friedman, Patricia Jones, Thomas Bersani, Jonathan Horton, Maeve Chang, Lou Anne Aber, Stuart Seiff, John Guy, Z. Suzanne Zam, Revonda Burke, James Goodwin, Allen Putterman, Robert Baker, Judy Beck, Michael Hanson, Toni Scoggins, Charlotte Frank, Rani Kalsi, Kakarla Chalam, Shirley Hackett, Kathleen Digre, Jolyn Erickson, Terrell Blackburn, Richard Anderson, Paul Langer, Paula Morris, Sandra Osborn, Bhupendra Patel, Sandra Staker, Judith Warner, Christine Evans, Carolyn Harrell, Helen Overstreet, James Scott, Lillian Tyler, John Linberg, Brian Ellis, Charlene Campbell, Gordon McGregor, Edward Cohn, Kristi Cummings, Patricia Manatrey, Sara Casey, Virginia Regan, David Roehr, Patricia Streasick, Michael Elman, Frank Hooper, Barbara Crawley, Cheryl Hiner, Lucy Howard, Olga Lurye, Janet Masiero, Robert McCarter, Sara Riedel, Michelle Sotos, Laureen Spioch, Joann Starr, Judy Urban, Mark Waring, Jie Zhu, Qi Zhu, Donald Everett, Marian Fisher, Phil Aitken, Roy Beck, Andrea LaCroix, Simmons Lessell, Reverend Kenneth MacLean, Stuart R. Seiff

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Abstract

Background: The objective of this report is to describe the methods used to develop and validate a computerized system to analyze Humphrey visual fields obtained from patients with non-arteritic anterior ischemic optic neuropathy (NAION) and enrolled in the Ischemic Optic Neuropathy Decompression Trial (IONDT). The IONDT was a multicenter study that included randomized and non-randomized patients with newly diagnosed NAION in the study eye. At baseline, randomized eyes had visual acuity of 20/64 or worse and non-randomized eyes had visual acuity of better than 20/64 or were associated with patients refusing randomization. Visual fields were measured before treatment using the Humphrey Field Analyzer with the 24-2 program, foveal threshold, and size III stimulus. Methods: We used visual fields from 189 non-IONDT eyes with NAION to develop the computerized classification system. Six neuroophthalmologists ("expert panel") described definitions for visual field patterns defects using 19 visual fields representing a range of pattern defect types. The expert panel then used 120 visual fields, classified using these definitions, to refine the rules, generating revised definitions for 13 visual field pattern defects and 3 levels of severity. These definitions were incorporated into a rule-based computerized classification system run on Excel® software. The computerized classification system was used to categorize visual field defects for an additional 95 NAION visual fields, and the expert panel was asked to independently classify the new fields and subsequently whether they agreed with the computer classification. To account for test variability over time, we derived an adjustment factor from the pooled short term fluctuation. We examined change in defects with and without adjustment in visual fields of study participants who demonstrated a visual acuity decrease within 30 days of NAION onset (progressive NAION). Results: Despite an agreed upon set of rules, there was not good agreement among the expert panel when their independent visual classifications were compared. A majority did concur with the computer classification for 91 of 95 visual fields. Remaining classification discrepancies could not be resolved without modifying existing definitions. Without using the adjustment factor, visual fields of 63.6% (14/22) patients with progressive NAION and no central defect, and all (7/7) patients with a paracentral defect, worsened within 30 days of NAION onset. After applying the adjustment factor, the visual fields of the same patients with no initial central defect and 5/7 of the patients with a paracentral defect were seen to worsen. Conclusion: The IONDT developed a rule-based computerized system that consistently defines pattern and severity of visual fields of NAION patients for use in a research setting.

Original languageEnglish (US)
Article number34
JournalBMC Ophthalmology
Volume6
DOIs
Publication statusPublished - Nov 20 2006

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ASJC Scopus subject areas

  • Medicine(all)

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