Innovative facility at the San Raffaele Institute in Milan
In journalistic language we often speak of 'bionic eye' to designate so-called 'artificial retinas', i.e. sub-retinal electrode implants capable of partially restoring visual function in people suffering from severe retinal degeneration.
A major success was recorded last February in Italy with an innovative implant performed in a blind woman at the Ophthalmology Unit of the IRCCS Ospedale San Raffaele.
 The Alpha AMSI prosthesisThe extremely delicate operation lasted more than 10 hours and was performed by a team led by Dr. Marco Codenotti, head of the Vitreoretinal Surgery Service at the IRCCS San Raffaele Hospital, assisted for the extraocular part by Dr. Antonio Giordano Resti, head of the Ophthalmoplastic Surgery Service at the same hospital.
The grafted prosthesis is innovative compared to previous implanted prostheses, both in Italy and abroad, in that it does not require a camera to be attached to glasses or other external aids.
The microchip, called Alpha AMSis produced by the German company Retina Implant. This device, intended for people who have lost their sight during adulthood due to severe genetic retinal diseases such as retinitis pigmentosa, can restore the perception of light and the silhouettes of certain surrounding objects and/or people.
The principle of operation is based on the replacement of the retinal photoreceptors, i.e. the specialised cells (the cones and rods) responsible for translating light into bioelectric signals that reach the brain via the optic nerve. The no longer functioning photoreceptors are replaced by a photodiode, a microscopic electronic apparatus capable of transforming light into an electrical stimulus.
The microchip measures about three millimetres and contains 1600 sensors. The device is inserted below the retina, at the macula, in order to stimulate the nerve circuit that naturally connects the eye to the brain: in this way it replaces the activity of retinal cells that are no longer able to function properly.
The prosthesis is very expensive and the surgery was only possible thanks to the support of Banca Mediolanum, which fully financed the operation.
"Following the surgery, we expect retinal stimulation that will gradually lead to the patient learning to see again." commented Dr Marco Codenotti, who adds: "The surgery was the most complicated I have ever performed. Every step is crucial and delicate and the success of the surgery can be compromised at any moment. Seeing the microchip placed correctly was a great emotion for me, a dream come true.
To provide as much information as possible to patients, doctors decided to open a dedicated mailbox: retina.artificiale@hsr.it
No new interventions are planned at the moment, however, people suffering from blindness due to hereditary-degenerative retinal diseases, such as retinitis pigmentosa and retinal dystrophies of the rods and cones, can write an e-mail to get all the information they are interested in.
However, the operation is not indicated in the case of visual impairment caused by glaucoma or in patients blind from birth.
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Dr. Carmelo Chines
Direttore responsabile
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