Progressive Retinal Atrophy

I took Kel, 12-1/2, to the vet for his six month physical and one concern I have is that he seems to be going blind. He can see better in the daylight but still seems to have problems. At night he has mega-problems, like he has night blindness. If he wanders into my backyard (the streetlight is broken in the back) and out of range of the streetlight in front, he gets "lost". I have to send Mac back to find him and "herd" him back out front. During the day he's fine going into the backyard and making his way out front without problems.

For the past 9 months or year he's had a brown discharge from his eyes, especially in the morning and after eating. He has a hard time focusing to take a treat from my fingers even in bright daylight, but can take one easily if placed in my outstrached hand.

His vet said he may have Progressive Retinal Atrophy, however, he doesn't have anything obviously wrong when she looks into his eyes. His rehab vet agreed with this diagnosis.

I've looked this condition up on several web sites and his symptoms follow the description of this condition, BUT most sites say dogs get it from puppyhood up to 7 years of age (this is why I'm posting here and not on the SENIOR forum). I know there are exceptions so maybe this is one, but I just don't know.

All the sites agree there is nothing that can be done to prevent the blindness.

Kel has numerous health issues including sever arthritis, especially in his elbows, liver problems caused by an unknown underlying problem, digestive problems, etc., etc., etc.

If he were younger I'd take him to an opthomologist for a definite diagnosis, but right now I'm not sure I want to put him thru any more procedures, especially if nothing can be done. Unless there's a miracle, I don't see him having much time left (a few weeks? a couple months?) My goal is to give him a quality life for whatever time he has, and I just don't know if taking him to an eye doctor would improve his quality of life.

Does anyone have any experience with this condition? Recommendations? Suggestions?
http://www.animaleyecare.net/diseases/pra.htm
http://www.peteducation.com/article.cfm?cls=2&cat=1606&articleid=343
http://www.gopetsamerica.com/dog-health/progressive-retinal-atrophy.aspx