I have just examined a 25-year-old female who has recently been diagnosed with retinitis pigmentosa. She asked me what would happen to her sight as she got older. I wasn’t sure what to say.

Retinitis pigmentosa (RP) is a group of inherited eye conditions. The rod and cone cells gradually stop working and depending on the type of RP symptoms may start in early childhood or later, between the ages of 10 to 30.

The first symptom is not seeing well in dim light, such as outside at dusk, or at night. There may also be problems with seeing things in the peripheral vision.

RP is a progressive condition, which means that sight will continue to get worse over the years. Often, changes in sight can happen suddenly over a short period of time. However, a certain level of vision may be maintained for long periods of time.

As RP progresses, peripheral sight is lost, leaving a central narrow field of vision that can remain until the 50s, 60s, or older. However, advanced RP will eventually affect central vision causing problems with reading and/or recognising faces.