This advanced 3D printing technology is expected to be used to help create realistic prosthetic eyes for the 8 million people worldwide who either have abnormal or missing eyes due to birth defects, or who need at least one prosthetic eye because they have lost one.
According to the new technology, it takes just 90 minutes to create a prosthetic eye, compared to the eight hours it usually takes a skilled technician or ophthalmologist to create a prosthetic eye by hand. The results show that the labor required to manufacture 3D printed eyes is five times less than traditional methods.
Johann Reinhard, lead author of the study, said: "Patients are very conscious about wearing prosthetics because they don't want to draw attention to themselves. Having these more lifelike eyes might help them become more socially engaged." He stressed that the advantage of this technology is to provide patients with more comfortable and realistic prosthetic eyes, which is expected to improve their confidence and participation in society.
Further research on 3D printing technology in artificial eyes
So far, the approach has been successfully applied to more than 200 adult patients at Moorfields Eye Hospital (MEH) in London, including the 10 patients detailed in the new study, Reinhard said.
Typically, ophthalmologists use a soft molding material to temporarily fill the cavity and make a mold of the patient's eye socket. The material is then removed and used as a template to make a wax impression that fits the human eye socket. The wax is smoothed, tested and reshaped until it fits comfortably and is then used to make a plastic version. The final plastic eyes are hand-painted to match the patient's healthy eyes.
In addition, this traditional manufacturing method results in artificial eyes that typically need to be replaced every five to ten years, in part due to wear and tear of the plastic. However, since this is a manual process, subsequent prosthetic eyes made for the same person may be slightly different in appearance and shape.
Instead, the new 3D printing method takes specialized images of empty eye sockets and healthy eyes taken from patients, which are then processed and used to draft blueprints, which are then sent to a lab for 3D printing. This printing process usually takes only about 90 minutes, but can be sped up if multiple eyes are printed at the same time, for example, printing 100 prosthetic eyes in 10 hours, Reinhard said.
These 3D-printed eyes can nearly replicate the color, size, and structure of a patient's healthy eye, and are particularly good at capturing the colored part of the eye (i.e. the iris) and the white part (i.e. the sclera). Once the eye is made, it only takes 15 to 30 minutes for it to be installed by an ophthalmologist.
In theory, about 80 percent of adults who need prosthetic eyes could be fitted this way, the team said. However, this is not possible for all patients, such as those with very complex eye sockets, because the software cannot find a matching shape for the prosthetic eye. In addition, more data is needed to determine whether this technology can also be used to make prosthetic eyes for children, which requires more regulation.
In the future, the team intends to test this approach in more clinics. Sometime this year, they hope to publish the results of a clinical trial that explores the long-term performance of these 3D-printed eyes in 40 patients with MEH, compared to hand-made prosthetic eyes.