Clinical Utility of Web-based Office and Home Peristat for the Detection of Visual Field Defects in Patients with Glaucoma

Abstract

 

Purpose

 

To investigate the performance of a new virtual perimetry device for online office-based and home-based detection of scotomas. This is a pilot study to characterize the reliability, sensitivity and specificity of self-administered Peristat screening and compare to office-based testing under clinical supervision.

 

Methods

 

Nineteen patients undergoing routine examinations for glaucoma were enrolled from the University of California, San Francisco Medical Center and the Byers Eye Institute at Stanford University. All patients performed Peristat testing under two sets of conditions: once in the office under clinical supervision and once individually at home. Visual field results from each tested eye were divided into four quadrants, each of which was independently scored as normal or abnormal. A quadrant was defined as abnormal if it contained a cluster of ≥ 3 adjacent points with ≥ 6.7 dB loss from background or ≥ 2 adjacent points with ≥ 10 dB loss from background. Peristat findings were deemed reliable for tests with ≤ 33% rate for false positives, false negatives, and fixation loss.

 

Results

 

Of the 19 enrolled patients, 11 (57.9%) obtained valid results for both office- and home-based Peristat. A total of 16 eyes represented 64 visual field quadrants, 52 (81.3%) of which consistently identified possible defects as abnormal or within normal range. For 3 (4.7%) quadrants, normal office-based findings were subsequently graded as abnormal at home. For 9 (14.1%) quadrants, abnormal office-based findings were subsequently graded as normal at home. Comparing all office versus home Peristat quadrants, the Cohen's kappa coefficient was 0.750. No significant difference was observed between the groups with respect to fixation loss (p = 0.2225), false negatives (p = 0.1093), or false positives (p = 0.3519) during the tests.

 

Conclusions

 

Self-administered home-based Peristat shows comparable efficacy in detecting scotomas as office-based testing under clinical supervision. Peristat has the potential to be used as a self-administered home screening perimetric test.

 

 

Online Peristat identifies scotomas by interrogating four quadrants of a visual field.

 

Keywords: 758 visual fields • 465 clinical (human) or epidemiologic studies: systems/equipment/techniques