Usher syndrome is the combination of having Retinitis Pigmentosa (RP), but also having hearing loss or deafness, which can cause balance issues as well. Usher is a different inherited disease that is often diagnosed in infants or children. The hearing loss is caused by abnormal development of the receptor cells in the inner ear. Hearing aids can be used for some, but others rely on cochlear implants.
Cochlear implants consist of a microphone, speech processor, a transmitter and receiver, and an electrode array. The microphone picks up the sound. The speech processor organizes the sounds. The transmitter turns the sounds to electrical impulses, bypassing the damaged parts of the ear, sending the impulses to the array. The array then sends the impulses to the auditory nerve. The process does not replace hearing, but gives the person information to be able to distinguish speech and environmental sounds.
The Retinitis Pigmentosa part of Usher syndrome progresses in the same way as explained above. It starts out as night blindness, progressing to tunnel vision, and eventually to total blindness. Other eye issues such as cataracts or macular cysts affect the remaining vision. As with RP itself, there is currently no cure for Usher syndrome.
Image taken from https://www.nidcd.nih.gov/health/cochlear-implants
This inherited disease is sometimes called juvenile macular dystrophy. It is basically the opposite of Retinitis Pigmentosa in that the peripheral vision is not affected. The central vision is affected here. As children, teens or young adults, central vision starts to become blurry or dark. Ofttimes colors are difficult to distinguish. A sensitivity to light is often present as well, leading to more frequent sunglass use.
Progression of Stargardt can vary. It can sometimes speed up and get worse more quickly, then level off and stabilize. UV rays affect this, and cigarette smoke, even secondhand, had been said to cause more issues. Many times, people who have Stargardt disease were never able to see well enough to drive a car.
Macular degeneration (dry most commonly) is normally found in older people, usually age 50 or more. In this disease, the macula, the part of the retina at the back of the eye, becomes thinner, and the person tends to have "spots" in the central part of their vision. It can affect only one eye, or both. Symptoms include visual distortions, reduced central vision, difficulty adjusting to dimly lit areas such as buildings, having blurry spots in people's faces making it hard to identify some people, and difficulty reading due to the blurriness. Most people will not lose all of their sight, but if it is untreated, it could turn into Wet Macular Degeneration.
Wet Macular Degeneration is mostly the same, but has advanced to where the blood vessels in the eye or eyes start to leak blood or fluid into the macula. This will make the condition deteriorate more rapidly. People have also been known to have visual hallucinations. However, there are ways to help prevent and possibly treat symptoms before they get worse.
Macular Degeneration issues are most commonly found in Caucasian people. It is also usually an inherited trait, so learn your family history. There are also environmental factors such as smoking, obesity and diet that affect whether you get Macular Degeneration. Cardiovascular disease has also been linked to Macular Degeneration. The best way to prevent this is to make sure you are healthy and have your eyes checked every year, Stay consistent with your ophthalmologist or optometrist so that they can see changes in your eyes each year. If you notice something strange in your central vision, the best thing to do is to go see your eye professional as soon as possible.