VFMA: Topographic Analysis of Sensitivity Data From Full-Field Static Perimetry.
OBJECTIVE
To analyze static visual field sensitivity with topographic models of the hill of vision (HOV), and to characterize several visual function indices derived from the HOV volume.


METHODS
A software application, Visual Field Modeling and Analysis (VFMA), was developed for static perimetry data visualization and analysis. Three-dimensional HOV models were generated for 16 healthy subjects and 82 retinitis pigmentosa patients. Volumetric visual function indices, which are measures of quantity and comparable regardless of perimeter test pattern, were investigated. Cross-validation, reliability, and cross-sectional analyses were performed to assess this methodology and compare the volumetric indices to conventional mean sensitivity and mean deviation. Floor effects were evaluated by computer simulation.


RESULTS
Cross-validation yielded an overallR2of 0.68 and index of agreement of 0.89, which were consistent among subject groups, indicating good accuracy. Volumetric and conventional indices were comparable in terms of test-retest variability and discriminability among subject groups. Simulated floor effects did not negatively impact the repeatability of any index, but large floor changes altered the discriminability for regional volumetric indices.


CONCLUSIONS
VFMA is an effective tool for clinical and research analyses of static perimetry data. Topographic models of the HOV aid the visualization of field defects, and topographically derived indices quantify the magnitude and extent of visual field sensitivity.


CONCLUSIONS
VFMA assists with the interpretation of visual field data from any perimetric device and any test location pattern. Topographic models and volumetric indices are suitable for diagnosis, monitoring of field loss, patient counseling, and endpoints in therapeutic trials.
Casey Eye Institute Oregon Retinal Degeneration Center, Oregon Health & Science University, Portland, OR, USA.
Richard G
RG
Weleber
Casey Eye Institute Oregon Retinal Degeneration Center, Oregon Health & Science University, Portland, OR, USA.
Travis B
TB
Smith
Casey Eye Institute Oregon Retinal Degeneration Center, Oregon Health & Science University, Portland, OR, USA ; Department of Public Health and Preventative Medicine, Division of Biostatistics, Oregon Health & Science University, Portland, OR, USA.
Dawn
D
Peters
Casey Eye Institute Oregon Retinal Degeneration Center, Oregon Health & Science University, Portland, OR, USA.
Elvira N
EN
Chegarnov
Applied Brain, Inc., Portland, OR, USA.
Scott P
SP
Gillespie
Pacific Ophthalmology Consulting, Portland, OR, USA.
Peter J
PJ
Francis
Devers Eye Institute, Legacy Research Institute, Portland, OR, USA.
Stuart K
SK
Gardiner
Centre for Ophthalmology/Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
Jens
J
Paetzold
Centre for Ophthalmology/Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
Janko
J
Dietzsch
Centre for Ophthalmology/Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany ; Competence Centre "Vision Research", University of Applied Sciences, Aalen, Germany.
Ulrich
U
Schiefer
Department of Ophthalmology and Visual Sciences and the Institute for Vision Research, University of Iowa, Iowa City, IA, USA.
Chris A
CA
Johnson
clinical trial endpoints; retinitis pigmentosa; standard automated perimetry; visual fields; volumetric measures of the hill of vision