Abstract
Purpose :
In the clinical setting with technician guidance, the iPad based app (Melbourne Rapid Fields, MRF) is able to produce perimetric results with high correlations with Humphrey Field Analyzer (HFA) outcomes. In this study we examined whether patients were able to perform self-directed MRF tests reliably at home.
Methods :
Forty-four patients with either controlled glaucoma (n=40) or normal eye (n=4) were recruited into a 6 week longitudinal home monitoring study. Each patient had visual field assessment using the HFA and the MRF app in clinic. They were then given a 20 minute training session on performing self directed testing at home. Viewing distance was fixed with a specially designed viewing hood. Each patient was then asked to perform the MRF test at home on a weekly basis for 6 weeks using a loan iPad. Testing was assisted by pre-recorded voice instructions. Weekly reminder was sent to the patients in the form of mobile phone message or email. Exclusion criteria were: inability to understand English instructions given by the iPad, visual acuity worse than 6/12, intraocular surgery in past 6 months. Comparisons were made by establishing correlations (Pearson's) and using Bland-Altman methods (Bias, 95% Limits of Agreement, LoA) for the summary statistics (Mean Deviation, MD, Pattern Deviation, PD).
Results :
The average number of tests performed over the 6 week period was 5.1±2.2, with 70% of patients (n=31) completing ≥4 test at home. Six patients (14%) were unable to perform a single test at home due to technical or social reasons. The MD in the study eye ranged from -28.77dB to +0.95 dB (average 6.23 dB). Pearson’s correlation for MD between MRF performed in clinic and HFA was R=0.80. Pearson’s correlation for
average MD for self directed MRF performed at home and HFA was R=0.83. Correlation for average MD for self directed MRF performed at home and MRF performed in clinic was R=0.72. 95% LoA for variability of MD values obtained by MRF test at home was ±4.38 dB. There is a tendency for greater test variability in patients with worse visual field defect as indicated by MD (R=0.52).
Conclusions :
This study finds good compliance and test-retest reliability in the short term for self directed visual field testing at home. Future longer term clinical trials are required to determine the ability of visual field home monitoring in detecting glaucoma progression.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.