The invention relates to the use of cyclopentane heptan(ene)oic acid, 2-heteroarylalk(en)yl derivatives as ocular hypotensives. The compounds used in accordance with the invention are represented by the following formula I: wherein the hatched segments represent &agr; bonds, the solid triangle represents a &bgr; bond, wavy line attachments indicate either the alpha (&agr;) or beta (&bgr;) configuration; dashed bonds represent a double bond or a single bond, R is a substituted hetero aryl radical having at least two pendant substituents selected from the group consisting of C1 to C6 alkyl; halogen; trifluoromethyl; COR1; COCF3; SO2NR1; NO2 and CN or at least one cyano group; R1 is hydrogen or a lower alkyl radical having up to six carbon atoms; X is selected from the group consisting of —OR1 and —N(R1)2; Y is ═O or represents 2 hydrogen radicals, and the 9, 11, or 15 alkyl esters thereof; provided, however, when said heteroaryl radical is a dichlorothienyl radical, said compound is not a 1-carboxylic acid or amide thereof.