Inclusion Criteria:  Over 18 years of age Using physician-prescribed timolol as directed The ability to read, understand, and sign informed consent for blood draw and release of medical information forms For wound group: documented chronic wound (greater than 30 days, with minimal improvement), with any type of wound. For glaucoma group: diagnosed with ocular hypertension or open-angle glaucoma.  Exclusion Criteria:  Patient is not currently prescribed timolol or currently taking oral metoprolol History of any type of heart block History of bradycardia (heart-rate less than 60 beats per minute (bpm)) History of documented hypotension History of asthma or chronic obstructive pulmonary disease.