Persistence of Glaucoma Patients With Web-Browser-Based Visual Field Test

Andrew Pouw, MD

Overview

The goal of this clinical trial is to assess patient persistence and adherence with a 6-month period of at-home visual field testing, using a novel web-based visual field test (EyeSimplify, M\&S Technologies, Niles, IL). The main questions this clinical trials aims to answer are: 1. How adherent patients are to biweekly testing at home for 6 months, and 2. How patients feel the ease of user experience of the test was, and 3. Whether the EyeSimplify platform is able to detect any worsening of glaucoma-related visual field performance that can be corroborated by standard of care, office-based testing. Participants will be given iPads with links to the EyeSimplify visual field test, and asked to take the EyeSimplify tests at home biweekly for six months. The test takes between 10 to 15 minutes to do and participants will have no additional responsibilities between tests. Researchers will send reminders for patients to complete the at-home tests at periodic intervals, and if worsening on the at-home test platform is suggested by test results, researchers will arrange for return visits to the office to compare the EyeSimplify test results to standard-of-care, office-based testing. At the conclusion of the study, participant adherence to the 6-month biweekly testing schedule will be assessed and participants will be surveyed for their perceptions regarding the EyeSimplify platform's ease of usability and user experience.

The purpose of this prospective study is to assess patient persistence and adherence with a 6-month period of at-home visual field testing using an iPad with a novel web-browser-based visual field test, the EyeSimplify platform (M\&S Technologies, Niles, IL). Use of this test is intended to supplement, but not replace, regular clinic visits. The proposed study will be conducted at the University of Iowa Hospitals and Clinics. We estimate 50 subjects will be recruited to participate in the study. Data collected will not include patient identifiers, but will instead be coded. The research will involve prospective collection of visual field tests. Patients with suspected, mild, moderate, or severe glaucoma will be included. Clinical data including age, gender, ethnicity, visual acuity, intraocular pressure, severity of disease, past and comparative Humphrey HFA-III visual field test performance, EyeSimplify visual field test performance, and EyeSimplify usability survey will be recorded. Following study recruitment, subjects will be asked to take EyeSimplify visual field tests at home biweekly for six months. They will have no additional responsibilities between tests. Subjects will access the EyeSimplify web browser on an iPad provided by the research team, using a link and login credentials provided to them by a research assistant. Upon logging into the EyeSimplify web browser, subjects will click the "Start Test" button found along the left side of the window and follow the prompts presented on screen to calibrate their screen. Screen calibration involves holding a driver's license/credit card/ID to the screen to ensure the test window is the appropriate dimensions. Following screen calibration, subjects will follow the test prompts presented on screen to complete their visual field test. Test results are automatically sent to the research assistant who issued the exam, so subjects may exit the browser after each test. Upon study completion, subjects will be asked to fill out a brief user experience survey. M\&S Technologies is the developer of the EyeSimplify visual field test platform. As the developers, M\&S Technologies maintains a secure, encrypted, HIPAA-compliant database of test participants. This database includes patient profiles containing unique subject IDs (de-identified), birth year (but not specific date), and visual field testing results. Outside of this testing information, M\&S Technologies does not have access to any additional patient information.

Outcomes

Primary Outcomes

EyeSimplify Self-Test Adherence

For the purposes of this study, adherence is defined as number of times a subject self-tests divided by the number of times they are expected to self-test during the six-month study period. There will be a total of 14 expected self tests. Adherence will be evaluated at the conclusion of the six-month study period.

Time frame: Subjects will be asked to self-test once every two weeks for six months.

EyeSimplify Self-Test Persistence

For the purposes of this study, persistence is defined as the number of consecutive self-tests a subject completes without a lapse. Persistence will be evaluated at the conclusion of the six-month study period.

Time frame: Subjects will be asked to self-test once every two weeks for six months.

Secondary Outcomes

Visual Field Reliability Metric #1 - False Positive Rate

In perimetry (visual field testing), a "false positive error" occurs when a subject/patient records a response when no stimulus is presented. This is one metric by which the reliability of a visual field test is measured. The measurement is reported as a percentage.

Time frame: This measurement will automatically be reported upon conclusion of each visual field test. Visual field testing is estimated to take 5-15 minutes for each visual field test. Testing will occur every two weeks for the six-month study period.

Visual Field Reliability Metric #2 - False Negative Rate

In perimetry (visual field testing), a "false negative error" occurs when a subject/patient fails to record a response to a stimulus that is brighter than one they had previously responded to in the same visual location. This is one metric by which the reliability of a visual field test is measured. The measurement is reported as a percentage.

Visual Field Reliability Metric #3 - Fixation Loss Rate

In perimetry (visual field testing), a "fixation loss" occurs when a subject/patient records a response to a stimulus presented in the physiologic blind spot. If the patient responds, it indicates their gaze is not fixed straight ahead. This is one metric by which the reliability of a visual field test is measured. The measurement is reported as a percentage.

Visual Field Performance Metric #1 - Mean Deviation

Mean deviation indicates how much, on average, an entire visual field deviates from the age-normal value. It is the center-weighted average of the decibel deviations at each point tested in the visual field test. The measurement is reported in decibels.

Visual Field Performance Metric #2 - Pattern Standard Deviation

Pattern standard deviation reflects irregularities in a visual field, such as those caused by localized defects. This metric shows sensitivity losses after adjusting for generalized depression or elevation in the overall hill of vision (e.g. cataracts). The measurement is reported in decibels.

Visual Field Performance Metric #3 - Total Deviation

Total deviation probability plots identify test locations that are outside normal limits. Threshold sensitivity levels are compared to age-corrected normal values at each test location to produce a total deviation map. Each measurement is reported in decibels.

Visual Field Performance Metric #4 - Foveal Threshold

Foveal threshold is the minimum amount of luminance increment on a uniform background that can be detected by a subject/patient at the center of fixation. The measurement is reported in decibels.

Visual Field Loss Trend Metric #1 - Guided Progression Analysis Trend Analysis

Guided Progression Analysis (GPA) is a visual field analysis aid used to quantify visual field progression. This analysis aid is specific to Humphrey perimeters. The GPA Trend Analysis component quantifies the observed rate of change of the visual field. This metric is reported as percent loss per year (VFI) OR estimated mean deviation decibel loss per year, along with confidence limits for the slope estimate.

Time frame: This measurement will automatically be generated after five Humphrey visual field tests and is updated with each subsequent test. Subjects will only complete one Humphrey visual field during the study, so this metric will be taken from historic data.

Visual Field Loss Trend Metric #2 - EyeSimplify Mean Deviation Progression Trend

The EyeSimplify Progression Trend is a visual field analysis aid used to quantify visual field progression. This analysis aid is specific to EyeSimplify and quantifies the observed rate of change of subjects' mean deviation. This metric is reported as estimated decibel loss per year.

Time frame: This measurement will automatically be generated after five EyeSimplify visual field tests and is updated with each subsequent test. This metric will be recorded upon completion of the six-month study period.

EyeSimplify User Experience Question #1 - "Please select what type of device you used to take your EyeSimplify visual field tests."

Response options will include "Laptop", "Tablet", "Smartphone", and "Other".