This invention relates to potent selective agonists of the EP4 subtype of prostaglandin E2 receptors, their use or a formulation thereof in the treatment of glaucoma and other conditions which are related to elevated intraocular pressure in the eye of a patient. Further there is a sensor and a CPU. A power supply potential is supplied to the output terminal of the shift register circuit through the transistor. The collar has a shoulder portion extending at least around the opening and a neck portion integral with the shoulder portion and projecting radially from the opening. The invention also relates to a method for determining the measured quantity and to a corresponding system. The invention also relates to a corresponding fabrication method.