Cycloplegics may cause elevations of intraocular pressure in certain eyes in the absence of angle closure of any degree. The incidence of this response is 23% in a population with proven open-angle glaucoma and 2% in an apparently normal population. Consequently, any patient having a significant intraocular pressure elevation and open angles after routine dilatation with cycloplegics should be considered an open-angle glaucoma suspect.
Patients exhibiting this phenomenon respond to all of the potent cycloplegic agents and not at all to those with a minimal effect on accommodation. The mechanism of this phenomenon is discussed in relation to evidence from other investigations.
Harris LS. Cycloplegic-Induced Intraocular Pressure ElevationsA Study of Normal and Open-Angle Glaucomatous Eyes. Arch Ophthalmol. 1968;79(3):242-246. doi:10.1001/archopht.1968.03850040244004