Transient changes of intraocular pressure and anterior segment configuration after diagnostic mydriasis with 1% tropicamide in children

Background: This study investigated the association of transient changes in intraocular pressure (IOP) with changes in the anterior chamber configuration in children after diagnostic mydriasis with 1% tropicamide. Methods: In this prospective case- control study, 163 hospital clinic- based samples of unrelated children with or without myopia were enrolled. Complete ophthalmological examinations, including visual acuities, cycloplegic refraction, slitlamp examination, fundus examination, IOP, axial length measurement and Pentacam examination were performed. Results: Lens thickness in emmetropic children was significantly greater than in myopic children of both genders, both before and after mydriasis. In a comparison of the biometric differences before and after mydriasis, IOP was not different, but the lens thickness after mydriasis was significantly less in myopic and emmetropic children of both genders. The mean anterior chamber angle, anterior chamber depth and anterior chamber volume significantly increased after mydriasis in myopic and emmetropic children of both genders. These parameters were not related to the changes of IOP under multiple regression analysis. There were no statistically significant differences between groups in either biometric parameters or anterior chamber configurations. Conclusion: While the present findings do not show a significant change in IOP following mydriasis, there was wide inter- individual variation, with some children showing an increase in IOP of up to 8.0 mmHg and some showing a decrease of a similar amount. This variation suggests that IOP should be monitored when mydriatics or cycloplegics are used in children.