There are numerous diseases and processes that could potentially affect the optic nerve, as well as the retina. These could include ischemic disease or vascular disease, degenerative disease, and infectious or inflammatory disease. Depending upon how damaged the eye becomes during each type of illness will determine the targeting for the prosthesis.
What Damages Could Occur to the Eye?
Following a diagnosis of diseases to the eye, the processes could begin to cause selectively damage to certain areas of the optic or retinal nerve. If there is a need for a prosthetic device to be worn by the patient, the damage caused by the disease could potentially cause design implications for the potential use of this therapeutic visual device.
What Are the Types of Diseases of the Outer Retinal Nerve?
There are conditions that are specific to the outer retinal nerve and they include pathologic myopia, age-related macular degeneration, and retinitis pigmentosa. Despite the fact that there is the potential for the retinal photoreceptors becoming lost, patients can rest assured that their inner retina is still preserved relatively well with regards to these diseases. Therefore, they could still be targets for retinal prosthetic devices.
What Are the Types of Diseases of the Inner Retinal Nerve?
There are diseases that are specific to the inner retinal nerve, and they include such vascular diseases such as retinal venous occlusive disease, diabetic retinopathy, and retinopathy of prematurity. Other retinal layers could become affected by other retinal diseases such as ocular infections (retinitis, endophthalmitis). Prosthetic devices created for the stimulation of the inner retina might not be effective due to the destruction of the inner retinal cells, including of the retinal ganglion cells, during these diseases.
What Are the Most Common Diseases?
There are some eye diseases that are more frequent than others. Some of the most common diseases with regards to the optic nerve are glaucoma, ischemic optic neuropathy, and optic neuritis. When these diseases occur, the ganglion nerve cells themselves become damaged. This means that, for these diseases, the prosthetics will need to emphasize the visual cortex or another targeted area of the visual pathway.
When choosing a visual prosthetic device, it is clear how crucial it is to have a sound understanding of optic and retinal nerve disease pathophysiology. This is particularly true with regards not only to the selection of the prosthetics, but to the design of the optimal visual device as well.