Retinitis pigmentosa (RP) is an eye disease caused by genetic changes, known as mutations. These mutations lead to the breakdown of rod photoreceptors, which help us see in low light, causing night blindness. Over time, this affects cone photoreceptors too, leading to tunnel vision. A medicine called N-acetylcysteine (NAC) may help. NAC is an antioxidant, meaning it can reduce damage from oxidative stress, which contributes to vision loss in RP. In animal studies, NAC slowed the damage to cones, and in early human trials, it slightly improved vision. The NAC Attack study will test if taking NAC for several years helps people with RP. The study takes place in the US, Canada, Mexico, and Europe.

• The study lasts for several years, and you must be able to attend all visits.
• Participants should be between 18 and 65 years old.
• Excludes those with certain health conditions or who have used NAC recently.