Figure 1. Consort Diagram of Participant Randomization, Allocation, Follow-up, and Analysis.

CYP2D6 indicates cytochrome P450 2D6 isozyme; HHT, hereditary hemorrhagic telangiectasia.

^aThe liver enzyme that metabolizes timolol, CYP2D6, was tested in the first 5 patients. This participant had the low metabolizing phenotype and was removed from the study for safety reasons. After multiple ambiguous genetic test reports, the CYP2D6 testing was eliminated from the protocol.