Hemianopia and neglect are the two most common visual disorders complicating posterior brain injury (Corbetta et al., 2005; Rowe et al., 2019). While neglect is more likely to spontaneously improve over the first year post-injury than hemianopia, both have long-term effects on patients’ activities of daily living (Warren, 2009; Wee & Hopman, 2008). Several behavioural approaches to treating patients with persistent hemianopia have been successfully trialled. The most consistently effective therapies promote retraining of compensatory eye movements, by practising voluntary guided saccades (e.g., patients have to find a visual target amongst distractors, or find a target that has “jumped” to a new location in their blind field (Jacquin-Courtois et al., 2013; Schuett et al., 2012)). Eye-movement therapies have also been shown to be effective in treating the symptoms of neglect, although these rely on stimuli that induce smooth-pursuit eye movements (e.g., patients have to focus on targets that move towards their neglected side at a constant velocity (Hopfner et al., 2015; Kerkhoff et al., 2014)). We have previously reported on the clinical efficiency of Eye-Search (https://www.eyesearch.ucl.ac.uk/), a web-based therapy that improves visual search in patients with hemianopia, but in that study (n = 78) we left out patients with neglect (Ong et al., 2015). As hemianopia and neglect can co-occur (Muller-Oehring et al., 2003), the aim of this study was to investigate whether Eye-Search therapy works in patients with either neglect alone (“pure neglect” group) or hemianopia and neglect. We also extended the criteria for length of participation in the study from three time points (patients completed 800 therapy trials), to four (1200 therapy trials completed).
Materials and methods
All subjects’ data were collected using the Eye-Search browser-based app. This study was approved by the UCL Research Ethics Committee: 2681/001, and all participants consented to the use of their data. All data were anonymized and held securely on a UCL server. The Eye-Search app has five main data collecting components:
A test to identify hemianopia
A test to identify visual neglect
The therapy: a ramp-step paradigm, embedded in a game, that delivers the trial-by-trial eye-movement practice
An impairment-based outcome measure: a visual search task
A patient-reported outcome measure (PROM): a visual analogue scale for rating difficulty performing six activities of daily life
Subjects re-tested themselves on the two visual tests and two outcome measures before they started therapy (baseline) and then every time that they completed a block of 400 trials (T1 = after 400 trials, T2 after 800 and T3 after 1200).
Study population and selection criteria
The therapy took place at the discretion of the patient and on their personal computers. Due to the nature and delivery modality of the therapy, the patients are considered to be self-enrolled, rather than traditionally recruited. The data analysed in this study were collected from participants who used the Eye-Search website between July 2012 and February 2019. In this period, 1407 participants took part, out of which 426 fitted the inclusion criteria (see consort diagram Figure 1). Of these, 302 (71%) were male. The mean participant age was 60 years [SD 14.6]. Causative diagnosis was self-reported with 6% leaving the section blank. The remaining patients were divided as follows: 84% stroke; 5% head injury; 3% surgery; and, 2% reported other causes such as an abscess, CO poisoning and encephalitis. Time between the cause of their visual impairment and starting therapy was positively skewed, median 85 days [IQR = 44–210 days]. Progress through the therapy was self-paced. The time to get from baseline to T1 and T3 was also positively skewed with subjects taking a median time of 5 days [IQR = 2–12 days] and 20 days [IQR = 9–33 days], respectively.