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Abstract #47971 Published in IGR 13-4
A method to measure and predict rates of regional visual field decay in glaucoma
Caprioli J; Mock D; Bitrian E; Afifi AA; Yu F; Nouri-Mahdavi K; Coleman ALInvestigative ophthalmology & visual science 2011; 52: 4765-4773
This study was conducted to measure the rate of visual field (VF) decay in glaucoma, to separate faster and slower components of decay, and to predict the rate of VF decay. Patients who had primary glaucoma and 6 or more years of follow-up were included. Thresholds at each VF location were regressed with linear, quadratic, and exponential models. The best model was used to parse the VF into slower and faster rate components. Two independent cohorts (glaucoma [n = 87] and cataract [n = 38]) were used to determine the technique's ability to distinguish areas of glaucomatous VF changes from those caused by cataract. VF forecasts, derived from the first half of follow-up, were compared with actual VF thresholds at the end of follow-up. The mean ((plus or minus)SD) years of follow-up and number of VFs for the main cohort (389 eyes of 309 patients) were 8.2 ((plus or minus)1.1) years and 15.7 ((plus or minus)3.0), respectively. The proportions of best fits were linear 2%, quadratic 1%, and exponential 97%. Proportions of eyes with exponential rates of decay (greater-than or equal to)10% for the entire visual field (VF), faster components, and slower components were 20%, 56%, and 4%, respectively. The difference in decay rates between the faster and slower components was greater in the independent glaucoma cohort (19% (plus or minus) 10%) than in the cataract cohort (5% (plus or minus) 5%; P < 0.001). Test location forecasts significantly correlated with measured values (r(2) = 0.67; P < 0.001). This method isolates faster and slower components of VF decay in glaucoma, can identify patients who are fast progressors, and can predict patterns of future VF loss with appropriate confidence intervals. (ClinicalTrials.gov number, NCT00000148.).
J. Caprioli. Jules Stein Eye Institute, University of California at Los Angeles School of Medicine, Los Angeles, California 90025, USA. Email: caprioli@ucla.edu
Classification:
6.20 Progression (Part of: 6 Clinical examination methods)
6.6.2 Automated (Part of: 6 Clinical examination methods > 6.6 Visual field examination and other visual function tests)
