How Much Does Reduced Dosing of Latanoprost and Dorzolamide-timolol Affect Pressure?

IOP effect of half-dose latanoprost dorzolamide-timolol will be compared to full dose. Further comparison will be made timolol-brimonidine-dorzolamide-bimatoprost. Dry eye effects of the different treatments will be assessed.

Subjects will have baseline IOP measurements (7-9 am and 3-5 pm) after using using latanoprost every other day and dorzolamide-timolol every morning. They will then randomly be assigned in phase 2 to either: double the frequency to latanoprost daily and dorzolamide-timolol twice daily; or use every morning compounded timolol-brimonidine-dorzolamide-bimatoprost. IOP measurements will be repeated 3 weeks after using the phase 2 medications. For phase 3, subjects will use the treatment to which they were not assigned in phase 2, and IOP measurements will again be repeated 3 weeks later. At each study visit, dry eye signs will be assessed and brief dry eye survey will be administered.