Therapeutic agents

A method of treating glaucoma, the method comprising administering to a subject in need thereof a therapeutically effective amount of at least one compound having the structure:

• or a pharmaceutically acceptable salt thereof, wherein:
• Ar is aryl, heteroaryl, substituted aryl, or substituted heteroaryl, wherein substituents are selected from alkyl, alkenyl, alkynyl, hydroxyalkyl, hydroxyl, alkoxy, halogen, —CN, —CF3, —C(O)R1, —C(O)OR1, —C(O)CF3, —SO2N(R1)2, —SO2NH2, or —NO2;
• L is C1-C6 alkylene;
• A is arylene or heteroarylene;
• E is —CO2R1, —CH2OR1, —C(O)N(R1)2, or tetrazol-5-yl;
• each R1 is independently H, C1-C6 alkyl, phenyl, or biphenyl;
• and
• n is 0 or 1.