Three-dimensional retinal electrodes in a convex Braille shape partially restore sight

Key Takeaways

• A research team has successfully developed three-dimensional retinal electrodes that resemble convex Braille.
• By stimulating the remaining normal nerve cells in the retina, the electrodes may someday be used to partially restore vision to patients with blindness.

One of the main causes of blindness is damage to photoreceptor cells in the retina due to diseases such as diabetic retinopathy,  macular degeneration and retinitis pigmentosa. Damage to photoreceptors, which convert light information from the eye into electrical signals, is irreversible and may cause decreased vision and even blindness.

Retinal implants are devices that restore vision by replacing damaged photoreceptors and transmitting electrical signals to normal nerve cells in the retina, enabling the signals to reach the brain along the optic nerve. Many traditional retinal implants adopt simple two-dimensional electrodes, which encounter difficulty in adhering to cells. The three-dimensional electrodes several research groups have developed resemble pointed needles or have angled edges that could damage normal cells.

A research team led by Professor Sohee Kim of the Daegu Gyeongbuk Institute of Science & Technology has successfully developed a technology that forms three-dimensional electrodes in a convex Braille shape on thin, flexible films. The electrodes’ characteristics improve retinal implants’ efficiency by minimizing the distance to cells, thereby reducing the current required for stimulation and preventing unnecessary current leakage. Notably, they have a rounded shape that does not damage cells.

The research team used the Braille-shaped retinal electrodes to stimulate the retina and induce visual responses in mice and primates. In addition, in collaboration with Professor Yong-sook Goo of Chungbuk National University, the team also conducted the rarely reported procedure of electrical stimulation in the primate degenerative retina. The results were published in the journal Advanced Materials Technologies.

The researchers are hopeful that the electrodes will be useful in partially restoring sight in patients with blindness. Professor Kim said, “We have developed a technology that allows electrodes to closely adhere along the retinal curvature to ensure a wide field of view. We hope that this retinal stimulation technology will be commercialized in Korea and help many blind patients.”

Edited by Miriam Kaplan, PhD

Source: Daegu Gyeongbuk Institute of Science and Technology (DGIST), Medical Xpress, May 7, 2024; see source article