Increased pressure after paracentesis of the rabbit eye is completely accounted for by prostaglandin synthesis and release plus pupillary block.

Paracentesis of the anterior chamber of the rabbit eye results in hyperemia, increased protein in the aqueous, elevated intraocular pressure, and miosis. Aspirin does not affect miosis but attenuates the pressure and protein response by about 60%. Pupillary block resulting from miosis aggravates the rise in intraocular pressure (as does mydriasis). Pretreatment with aspirin plus iridectomy virtually eliminates the elevation of intraocular pressure consequent to paracentesis.