To the Editor.
—The fact that cycloplegics may cause a significant elevation in the intraocular pressure of some normal eyes and some eyes with open-angle glaucoma in the absence of angle closure has received further documentation by the careful study reported by L. S. Harris (Cycloplegic-Induced Intraocular Pressure Elevations, Arch Ophthal79:242-246 [March] 1968).The effect of 10% phenylephrine, a commonly used mydriatic, upon intraocular pressure is less clearly defined. Several investigators1-4 have reported phenylephrine has no effect upon intraocular pressure in open-angle glaucoma.Conversely, Lee5 reported the "paradoxical" rise of intraocular pressure of some patients with open-angle glaucoma following instillation of 1% epinephrine or 10% phenylephrine. In these cases outflow facility was decreased without gonioscopically visible closure of the anterior chamber angle.In a personal study of 21 patients with open-angle glaucoma under medical treatment (pilocarpine, anticholinesterases, epinephrine bitartrate, and carbonic anhydrase inhibitors, singly or
Hill K. WHAT'S THE ANGLE ON MYDRIASIS?. Arch Ophthalmol. 1968;79(6):804. doi:10.1001/archopht.1968.03850040806032