Purpose
Eccentric viewing training with microperimetry biofeedback (MBF) is a rehabilitation technique aim to improve fixation stability in patients with central scotoma and unstable fixation. However home-based exercises under controlled environment are difficult to implement due to the cost of technology. The current pilot study explored the use of Augmented Reality Eyewear (ARE) to perform eccentric viewing exercises on patients with large central scotoma after MBF.
Methods
Fixation stability was measured in 10 patients with bilateral central geographic atrophy. Patients performed a MAIA microperimetry to evaluate the position of the preferred retinal locus (PRL) and measure fixation stability. Secondly, all patients underwent 2 weekly MBF sessions during 2 weeks. In 5 patients, home-based exercises were performed using the VIZUX eyewear (Rochester, N.Y.) to perform vision exercises during 1 month, three times a week, 10 minutes per session. The ARE, connected to an iPad, showed 2 screens with a horizontal red line crossing the field of view. Such line was positioned superiorly or inferiorly from the horizontal meridian of the visual field corresponding to the PRL selected on the MAIA during the MBF training. On the center of the screen, 2 different targets were shown: a black dot, and a 5 letters word. Patients were advised to move their gaze towards the horizontal line to attempt fixation on the central target. The other 5 patients did not perform any exercise during 1 month as a control group. All patients performed a last MBF session to evaluate the consistency of fixation stability outcomes. The MAIA P1 fixation stability index was used to evaluate fixation performance.
Results
In the control group, the MAIA P1 fixation stability index on the 5th MBF session showed a decrease of stability (mean = -13%) when compared to the 4th MBF session. On the contrary the group with ARE, showed the same, or slightly improved fixation stability on the 5th MBF session (mean = +9.8%).
Conclusions
The results of this pilot study, suggest that augmented reality eyewear with a dedicated home-based vision training application, may help maintaining fixation stability outcomes obtained during eccentric viewing training in vision centers with microperimetry and biofeedback.