What everyday challenges is my patient likely to face? Even in 2021 we remain remarkably ill-equipped to answer this question. Clinical measures of basic visual function (acuity, visual fields, etc.) are surprisingly poor at predicting quality of life, and, historically, there has been no practical way to observe 'real-world' task performance directly. Virtual reality (VR) may provide a solution: allowing us to quantify patients' ability to perform the sorts of real-world tasks they really care about, in simulated environments that are safe and replicable. But is VR really capable of delivering clinically meaningful insights?
Is VR really capable of delivering clinically meaningful insights?
To address this question, Lam et al. gave 98 glaucoma patients, and 50 controls, five simulated tasks to perform (identifying products on a supermarket shelf, navigating a street at night, etc.). They measured performance in terms of completion time and number of errors.
As one might predict, glaucoma patients performed significantly more poorly than controls; for example taking 15 seconds (34%) longer to identify ten products on a supermarket shelf, and making more collisions in the navigation task. There were also encouraging associations with more basic visual function measures (e.g., navigation times increasing by 8.4 seconds for each 1 dB decrease in binocular visual field sensitivity), and a modest-but-respectable association with patient-reported quality of life (VFQ-25: R2 = 0.21).
These findings are consistent with - and substantively extend - previous findings from independent research groups. For example, Goh et al. (TVST, 2018), who used a smartphone- based virtual reality device to similarly assess activity limitation in glaucoma, and Jones et al. (NPJ Digital Medicine, 2020), where we used augmented reality to assess the 'real-world' impact of simulated glaucoma.
Overall, Lam et al.'s work represents an exciting proof-of-principle. It suggests that new digital technologies may indeed be capable of providing novel and meaningful insights into the challenges a particular patient may face, as well as into the effects of sight loss more generally. However, key practical hurdles remain, such as the fact that current-generation VR headsets are bulky, and not particularly comfortable to wear. In that respect, it is perhaps telling that the mean patient age in the present study was just 49.8 years, and that 16% of participants reported motion sickness when using the device.