Retinitis pigmentosa, what therapies US, EU, Canada), if any, are efficient in slowing it down or stopping its progression? Is advanced cupping of the optic nerve caused by RP? My intraocular pressure is 17 in both eyes. How serious is this cupping? Can it actually affect my optic nerve? I am a female 65 years old of age and can see and go around pretty well. Thank you.