Abstract
Purpose :
To evaluate the accuracy of reaching movements in a patient implanted with a suprachoroidal-transretinal stimulation (STS) retinal prosthesis.
Methods :
The subject was a 42-year-old man with advanced Stargardt disease with visual acuity of LP (right eye) and HM (left eye). An STS retinal prosthesis was implanted in his right eye after approval from the Institutional Review Board of Osaka University Medical School. In the localization test, a white square (visual angle; 10°) was displayed on a PC monitor at random positions, and the subject was instructed to touch the center of a target (n=20). We averaged (average deviation) the distance between the touched point and the center of a target with the STS system turned ON or OFF.
Results :
When the left eye was occluded, the average deviation was smaller with system turned ON than the system OFF for a low contrast target (85%; system ON, 7.6±4.3°; OFF, 17.2±9.6°; P<0.001). However, the average deviation with the system ON was not always significantly different from that with the system OFF for a high contrast target (96%). With system ON and a low contrast target, the average deviation was also significantly smaller with the right-eye occluded and with both-eyes open conditions. With system ON, the average touching time was shorter with the right-eye occluded and both eyes open than with left eye occluded (right eye occluded, 2.41 sec; both eyes open, 2.23 sec; left eye occluded, 8.45 sec; P<0.001 one way ANOVA)
Conclusions :
With an appropriate target contrast, the accuracy of reaching movements was better in a patient with a retinal prosthesis. A possibility exists that patients with retinal prosthesis can improve their visual performance using both prosthetic vision and residual natural vision.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.