Abstract
Purpose :
The Argus II retinal prosthesis restores ultra low-resolution visual perception to late blind patients.It has been shown that structural changes occur in the brain due to late-onset blindness, including cortical thinning in visual regions of the brain.Following vision restoration, it is not yet known whether these visual regions are reinvigorated and regain a normal cortical thickness or retain the diminished thickness caused by blindness.
Methods :
We evaluated the cortical thicknesses and subcortical volumes of Argus II patients (N = 6), blind patients (N = 10), and sighted participants (N = 4) with a Siemens 3T MRI scanner at USC. Age-matched sighted controls (N = 6) from the Lifespan Human Connectome Project Aging (HCP-A) database were also included (Siemens 3T MRI scanner).
We compared the cortical thicknesses of the occipital lobe regions delineated by the Desikan-Killiany atlas between the participant groups.
Results :
The visual regions in the two sighted participant groups (USC and HCP-A) did not show a significant difference in cortical thickness, and therefore are included in one sighted group.
The blind patients were shown to have a reduced cortical thickness in the left Cuneus Cortex, the left Lingual Gyrus, and the left Lateral Occipital Cortex, and a reduced volume of the right Lateral Geniculate Nucleus (LGN) relative to the sighted controls. The Argus II patients had a reduced cortical thickness in the left Lingual Gyrus, and a reduced volume in the right LGN relative to the sighted controls. However, the Argus II patients had a thicker left Lateral Occipital Cortex relative to the blind patients.
Conclusions :
Overall, the Argus II patients did not show a reversal of the blindness-driven thinning of grey matter in early visual regions. However, Argus II patients’ cortical thickness was rejuvenated in one higher visual region.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.