The retina is a specialized tissue that transforms the light into a signal comprehensible to the brain. It is located in the posterior part of the eye, in the opposite position respect to the pupil.
The retina has a stratified structure composed by many layers of cells having different functions. The most external layer is composed by photoreceptors; a special kind of cells that absorb the light and transform it in a signal transmitted to the neurons which they are connected to.
The layer in contact with photoreceptors is composed by bipolar and horizontal cells. Both the types of cells are neurons specialized in the interpretation of the signal sent by the photoreceptors and perform a first elaboraton of the same.
The retina is a specialized tissue that transforms the light into a signal comprehensible to the brain. It is located in the posterior part of the eye, in the opposite position respect to the pupil.
The retina has a stratified structure composed by many layers of cells having different functions. The most external layer is composed by photoreceptors; a special kind of cells that absorb the light and transform it in a signal transmitted to the neurons which they are connected to.
The layer in contact with photoreceptors is composed by bipolar and horizontal cells. Both the types of cells are neurons specialized in the interpretation of the signal sent by the photoreceptors and perform a first elaboraton of the same.
The signal transformed by these neurons is then forwarded to another layer of cells, called ganglions. The main role of these cells is to transmit the signal to the optic nerve and then to the brain.
The light perception system involves then a multistep process to allow the transmission of a signal that starts in the photoreceptors.
The signal transformed by these neurons is then forwarded to another layer of cells, called ganglions. The main role of these cells is to transmit the signal to the optic nerve and then to the brain.
The light perception system involves then a multistep process to allow the transmission of a signal that starts in the photoreceptors.
Retinitis pigmentosa generally indicates a group of rare ilnesses of genetic nature. All these illnesses lead to a slow degeneration of the retina which consquences are the loss of nocturnal and peripheric vision first and eventually complete blindness.
During the course of the condition, the main responsible of the vision loss is the death of the photoreceptors.
Generally, this degenration is limited only to that kind of cells and all the other neurons of the retina remain alive. This means that there is only one non-working component in the vision mechanism and all the rest of the process can potentially still work. That’s also the reason why patients affected by retinitis pigmentosa can still perceive flashes of light when, for example, retina is electrically stimulated.
Considering USA, Europe, and Japan, retinitis pigmentosa affect about 250.000 people. 30.000 of those people are legally blind and today no definitive cures exist. There only are some advanced treatments in experimentation.
Retinitis pigmentosa generally indicates a group of rare ilnesses of genetic nature. All these illnesses lead to a slow degeneration of the retina which consquences are the loss of nocturnal and peripheric vision first and eventually complete blindness.
During the course of the condition, the main responsible of the vision loss is the death of the photoreceptors.
Generally, this degenration is limited only to that kind of cells and all the other neurons of the retina remain alive. This means that there is only one non-working component in the vision mechanism and all the rest of the process can potentially still work. That’s also the reason why patients affected by retinitis pigmentosa can still perceive flashes of light when, for example, retina is electrically stimulated.
Considering USA, Europe, and Japan, retinitis pigmentosa affect about 250.000 people. 30.000 of those people are legally blind and today no definitive cures exist. There only are some advanced treatments in experimentation.