A retinal implant is a microchip or a tiny computer device that is surgically inserted in the retina of the eye. It stimulates the light receptors contained in the retina in order to restore eyesight. The retina is found at the back portion of the eye, and transmits signals to the brain about the images it receives. For patients with degenerative eye conditions and other age-related eye disorders, light receptors in the retina often malfunction, die or decrease in number. These often lead to the progressive decline of vision and eventually, to blindness.
Subretinal implant and epiretinal implant are the two types of retinal implants. A subretinal implant is mainly inserted beneath the retina. An epiretinal implant, on the other hand, is placed above the retina. Either of them work in restoring vision by powering light-sensitive cells in the retina and allowing the transmission of messages from the eyes to the brain.
Retinal implant patients are generally between 18 and 78 years old, often diagnosed with degenerative eye conditions such as retinitis pigmentosa, choroideremia, or macular degeneration. Retinitis pigmentosa is an inherited eye problem resulting in the progressive destruction of the retina. Choroideremia is also an inherited eye disease affecting mainly men, while macular degeneration is often a result of old age. These patients have been blind for less than 20 years, but they also had use of their vision for at least 12 years.
Placement of a retinal implant is usually done by an ophthalmologist. An ophthalmologist is a medical doctor who specializes in the treatment of eye diseases. He is also capable of performing eye operations to help improve the vision of his patients.
After a retinal implant procedure, patients are often encouraged to make regular medical check-up visits for evaluation of their sight. Patients who have retinal implant surgery are sometimes able to see their surroundings, count their fingers, and recognize faces. They also are sometimes able to read large print or letters with the use of other visual aids.
Not all loss of vision can be treated with the use of retinal implants, however. Conditions of the eye that cannot be helped by a retinal implant are blindness which occurred since birth, blood circulation disorders in the retina, and glaucoma, which is caused by the build up of pressure in the eye. Blindness caused by stroke and diabetes mellitus also cannot be treated with retinal implants.