Artificial Polymer Retina for Macular Degeneration Treatment

As millions receive knee, hip, shoulder, and even heart replacements, researchers continue to advance in the science of artificial retina replacement as well. For several decades micro/nano retinal implant technologies have been helping restore vision to many patients with debilitating macular degeneration. However, detailed factors need to line up just right for a retinal replacement to be successful and it is often difficult to make happen due to obstacles such as limited space, complex electrical circuitry, and precise neural modifications. 

Recently, a new material has been developed as an artificial polymer retina for macular degeneration offering more flexibility and less invasiveness than other materials. It is another leap that has currently been approved for human use which may someday bring macular degeneration to a screeching halt. 

Through the Back of the Eye

Many treatments used to slow age-related macular degeneration (AMD) are administered through the front of the eye. Often injected directly into the sclera (white of the eye) or just adjacent to it. It can be painful, risk infection, and require many visits to maintain control of macular degeneration progress, particularly abnormal blood vessel growth. 

Knowable magazine reported on how a retinal replacement might work for retinitis pigmentosa (which can parallel macular degeneration) stating, 

“The disease does minimal damage to the retina’s many other neurons, which process signals from the rods and cones and convey the results to the optic nerve. So in principle, fixing vision is just a matter of going in through the very back of the eye, where the ravaged rods and cones originally formed a layer just 100 micrometers thick, and replacing them with a device that will generate electrical pulses in response to light. Pulses from various points on the device can then communicate with the retina’s surviving neurons in a natural way.”

This procedure also correlates with being applied to those suffering from AMD. Targeting the back of the eye where the most important visual functioning takes place, goes directly to the source as opposed to temporary oral pharmaceutical or injectable treatments.

Smartphone Polymer Applied

As technology advances in so many industries, we are seeing more crossover applications. When it comes to macular degeneration and other eye diseases, high tech polymer plastics often found in our digital devices are showing great promise.

The new material being used for artificial retina replacement is described by Knowable, 

“These polymers are best known for their use in some types of organic light-emitting diode (OLED) displays, the richly colored screens found in millions of smartphones….When light hits the polymer sheet, it triggers a localized pulse of electrical activity about 80 to 100 micrometers across. Because this is roughly comparable to the spacing of rod and cone cells outside the densely packed fovea, where the eye’s visual acuity is the highest, the polymer prosthesis would allow a resolution akin to a person’s natural peripheral vision.”

This is called a biomimetic application which is a synthetic method that mimics biochemical processes. Physicist Guglielmo Lanzani of the Italian Institute of Technology (IIT) in Milan explained to Knowable that, “Because semi-conductive polymers bend and flex like natural tissues, [] ‘they are biocompatible’. In tests in the lab and in animals, the polymer retina seems to coexist with them quite happily, with no adverse reactions at all.”

This is yet another example of the meshing of human-made materials with systemic biology. More and more, the future of homo sapiens health may be part human and part synthetic material.

Bio-Hybrid Implants

Researcher Edward Bloch and associates at Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, had their study, ‘Advances in retinal prosthesis systems’ published in Therapeutic Advances in Ophthalmology which concluded that,

“The field of visual restorative therapy is rapidly advancing and holds great promise for the introduction of real, measurable treatments of blinding conditions in the near future. [] It is likely that the future will see integration of prosthetic devices with regenerative medicine technologies, in the form of ‘biohybrid’ implants.”

According to Merriam-Webster dictionary, biohybrid is defined as:

“containing biomaterial and especially non-biological biomaterial; of a prosthesis: integrating synthetic material with human tissue (such as muscles, nerves, or bone)”

At this point, it may seem like the stuff of sci-fi movie cyborgs (part human, part machine) is beginning to morph into reality. 

Another Artificial Retina Already In the Works

As the polymer material becomes more applicable for artificial retina testing, other materials have been in the works since being reported by the Medical Device Network (MDV) in 2018. Researchers from the University of Texas at Austin, US and Seoul National University in South Korea collaborated on a project that consisted of an artificial retina made from multilayered 2D material. This material now replaces the silicon models which are flat, rigid, and weak making it difficult to replicate the natural curvature of the retina. 

MDV reports that Dr Dae-Hyeong Kim from Seoul National University developed a thinner, more flexible alternative to current retinal devices that could better mimic the shape and function of a natural retina. 

This 2D material is made from, 

“graphene and molybdenum disulfide, as well as thin layers of gold, alumina and silicon nitrate to create the flexible, high-density and curved sensor technology. The retina resembles the surface of a flattened football and conforms to the size and shape of a natural retina without any mechanical influence.”

Dr. Kim’s work was presented at the 256th National Meeting & Exposition of the American Chemical Society (ACS) which is the world’s largest scientific society.

These advances in artificial retina technology prove the major steps being taken by researchers which show considerable promise to eradicating such optical diseases as macular degeneration and retinitis pigmentosa. It also shows how humans may soon be walking around with more hardware in them than ever before. From organ and joint replacements to something as tiny as a retina replacement, the merging of synthetics and biology is just the beginning of a biohybrid society.