I have just examined a 25-year-old female who told me she is starting to have hearing problems with both ears and she keeps bumping into things, especially at night, and sometimes loses her balance. Her visual acuity in each eye was 6/5 and she was unsure about her family history. When I examined her retina, I could see some clumps of pigment in the periphery. What is going on?
Whenever a patient tells me they have hearing and vision problems, the first thing that comes into my mind is Usher syndrome. This is an inherited, genetic condition. There are four types of Usher syndrome.
Usher type 1
People with Usher type 1 are usually born with severe hearing loss in both ears. Balance problems are also common. Usher type 1 is associated with the development of night blindness, starting at around the age of 10, progressing to severe peripheral visual field loss and photophobia due to retinitis pigmentosa.
Usher type 2
People who have Usher type 2 are usually born with a mild to severe hearing loss in both ears, as with type 1, but type 2 is not associated with balance problems. Retinitis pigmentosa develops in the teens or early twenties.
Usher type 3
Usher type 3 is characterised by gradual sight and hearing loss, which occurs later in life after a person has learned to speak. Some people may develop severe hearing loss while others may not. People with Usher type 3 typically have problems with their balance, as in type 1.
Not everyone who has Usher syndrome fits into these three clinical types described above. People may have varying symptoms that are difficult to diagnose as a specific Usher type.
It sounds to me as if your patient has Usher syndrome type 3. She should be referred for further ocular investigation and genetic counselling.