Blindness & Visual Impairment Support Group
Blindness is the condition of lacking visual perception due to physiological or psychological factors. This is the group to discuss living with blindness, sharing experiences, and for those that may be facing the prospect of a life without sight. Find support and answers among people who know what you're going through.
As for the vitamin A, I don't take it specifically but do take a supplement called Perfect Eyes. I would guess that the liver function tests would have to do with taking vitamin A. I would ask your retinal specialist to be more specific in regards to that supplement if he is advising you to take it.
I often experience temporary changes in my vision. I think I've had the same effect you're describing at times. I don't know why it happens either and the doctors are no wiser in that regard. I'm just relieved when it stops..and thankfully it always does. It's a scary diagnosis due to all the unknowns. I can relate to your fear. Try to be positive..it will help you to control your stress which can effect RP to some degree. :)