Abstract
Purpose :
To provide novel display modalities of visual field loss progression over time as a function of Amsler grid contrast for threshold Amsler grid tests when performing subsequent repeat exams of subjects.
Methods :
Employing the Ceeable Visual Field Analyzer (CVFA), f.k.a. 3D Computer-automated Threshold Amsler Grid (3D-CTAG, Fink & Sadun, JBO 2004), visual field loss is recorded as missing areas on Amsler grids of various contrast levels.
Results :
Two display modalities were devised. Display modality #1 (Fig. 1, top) displays the respective percentage of visual field area not seen as a color-coded (according to Amsler grid contrast levels tested, Fig. 2) horizontal bar of a length proportional to that percentage. This modality displays as many color-coded bars as there are contrast levels tested in a CVFA exam. A normal visual field is displayed as a single vertical line of no width. Absolute scotomas are represented as horizontal bars of equal length. Hence a time progression over subsequent exams will always exhibit horizontal bars of equal length if the absolute scotoma character is preserved. The overall magnitude can change, e.g., due to disease or treatment. Relative scotomas are presented as horizontal bars of differing length, i.e., the length is proportional to the respective percentage of vision loss. Hence a time progression of subsequent exams will always exhibit horizontal bars of differing lengths. Display modality #2 (Fig. 1, bottom) displays the respective percentage of visual field area not seen as a mono-color horizontal bar within a box of fixed length (i.e., corresponding to 100%) per contrast level tested. A normal visual field is displayed as a series of empty boxes. Absolute scotomas are represented as horizontal bars of equal length in the respective boxes for all exams over time, but the overall magnitude can change. Relative scotomas are presented as horizontal bars of differing length inside each box, i.e., the length is proportional to the respective percentage of vision loss. Hence a time progression of subsequent exams will always exhibit horizontal bars of differing lengths.
Conclusions :
Both display modalities are intuitive. Display modality #2, while simpler, requires the added information of tested contrast levels, whereas modality #1 has this information already color-encoded. Both modalities express visual field changes over time due to disease or treatment.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.