Xalatan and xalatan

My mother is currently using Alphagan-P to lower her IOP. Her doctor has recommended that she switch to Xalatan or add it as a second drop at bedtime. I want to be especially cautious given that she is monocular and 90% of her optic nerve is damaged ( she seem to be progressively losing her perpheral vision despite an IOP of 13-17 ), and she has some macular degenerative problems. I understand with Xalatan, there could potentially be macular side effects. I would appreciate it if anyone has used Xalatan or Alphagan-P to comment on side effects that they may have experienced or efficacy and also if anyone may have some insight or perhaps personal experience related to this. I would be so very, very thankful for your help.

lance67@bellsouth.net
I have experienced blurred vision and a shadow of objects and letters that is faint and just below the object or letter. For example, people will appear to have two sets of eyes. My Doctor stopped the Xalatan and assured me that the blurred vision would clear up, but it has been approximately 3 years and it seems to be getting worse. How many others have experienced this problem?? Nancy Dunaway, Oak Ridge, Tenn.