Fixed combinations without beta blockers result in a ________mmHg when added to PGAs.

• A. 3.2
• B. 5.6
• C. 7.0
• D. 9.1

Answer: (B)

Adding a fixed combination without a beta blocker to a prostaglandin analog typically yields a modest, additional drop in intraocular pressure. Studies and practice data show this incremental effect is around 5 to 6 mmHg, with 5.6 mmHg being a representative average. The reason is that the second agent works through a different mechanism and provides extra outflow or production suppression, but the total pressure reduction has a ceiling in chronic therapy, so the gain from each non–beta-blocker combination is usually in the single-digit range. That’s why 5.6 mmHg best fits the observed add-on effect. The other values are either smaller or larger than the typical incremental benefit observed when the added fixed combination does not include a beta blocker.