Abstract
Purpose :
Retinal neurodegeneration is a major cause of vision loss, with limited progress in therapeutic options. Recent studies have explored low-intensity ultrasound (US) as a potential treatment to protect retinal ganglion cells from optic nerve damage. We conducted a whole RNA sequencing test to examine changes in a rat model following ultrasound stimulation.
Methods :
We applied low-frequency ultrasound at 3.3MHz to assess its reparative effects on the optic nerve. Initially, the optic nerve was lightly damaged using tweezers. Subsequently, ultrasound stimulation was administered for seven days. Retinal tissue was then harvested, and retinal ganglion cells (RGC) were isolated using magnetic cell separation strategies (MACS). RNA was extracted from these cells for sequencing analysis.
Results :
Fig a shows testing whether the ultrasound transducer is focused on the bottom of the retina. We determined the focus point of the ultrasound on the retina by checking if the distance between the two echoes in the pulse echo corresponds to the distance from the cornea to the fundus of the eye. Fig b uses COMSOL software to simulate the energy distribution of a 3.3MHz probe inside the eye, including the size of the focus point. Fig c presents the GO analysis of the ultrasound-treated group and the control group in the ONC (optic nerve crush) model. Compared to the control group, the ultrasound-treated group showed higher expression in response to cytokines and mechanical stimuli. Fig e displays a volcano plot of all gene expressions. Fig d details the gene analysis of the 'response to mechanical stimulus' group.
Conclusions :
Ultrasound stimulation appears to protect the optic nerve from degeneration. This is evident in the high expression of neuro regeneration-related GO groups. A possible mechanism for this effect may be the presence of piezo1 in RGC, which links ultrasound stimulation to neuron regeneration.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.