Artificial Eye: Materials, Implantable Devices, and Cosmetic Prostheses

Study Notes

Artificial Eye: Prosthetic Eye Materials, Implantable Artificial Eyes, and Cosmetic Prosthetic Eyes

Prosthetic Eye Materials

Artificial eyes have evolved significantly over the years, with various materials being used to create them. One of the most widely used materials is polymethyl methacrylate (PMMA), an acrylic polymer that has been in use since the 1940s. PMMA visual prostheses are often custom-made to match the contours of the orbital tissues and replicate the iris color. However, they are not fitted until 6-8 weeks after surgery to allow for tissue recovery and suture absorption.

It is also common to use adhesive-retained silicone ocular prostheses as an alternative when linking with an orbital implant is not possible due to cost. Modern enucleation methods, such as the meticulous connection of extraocular muscles to the implant, have significantly improved the preservation of artificial eye movement and aesthetic results.

Implantable Artificial Eyes

Implantable artificial eyes, also known as bionic or visual prostheses, are designed to provide artificial vision to visually impaired individuals. These devices consist of micro-electrodes surgically placed in or near the eye, along the optic nerve, or in the brain. The micro-electrodes stimulate the remaining functional parts of the visual system, leading the person to perceive small spots of light called phosphenes.

The vision provided by a bionic eye is not like natural sight. It is a series of flashing spots and shapes that the person uses to interpret their environment through training. Currently, the vision provided by a bionic eye is very basic and can be used for tasks such as identifying the location of an object, detecting a person, or finding a doorway. Researchers hope that future bionic eye devices will provide higher resolution vision, but this poses inherent challenges.

Cosmetic Prosthetic Eyes

Cosmetic prosthetic eyes are designed to restore an appropriate cosmetic look after enucleation or evisceration, where an orbital implant is inserted within the scleral envelope. These prostheses are often custom-made to match the contours of the orbital tissues and replicate the iris color. While PMMA visual prostheses are widely used, other materials may be used in the future to enhance the sensitivity and spectral range of the artificial eye, allowing for other functions such as night vision.

In conclusion, artificial eyes have come a long way since the early days of glass prostheses, which were susceptible to migration, extrusion, and subsequent infection. Today, advancements in materials, implantable devices, and cosmetic prosthetic eyes continue to improve the quality of life for individuals who have lost their natural sight.

Description

Learn about the evolution of artificial eyes, including prosthetic eye materials like PMMA, implantable artificial eyes with micro-electrodes for vision, and cosmetic prosthetic eyes for a natural look. Discover how these advancements have improved the quality of life for visually impaired individuals.