Iris-fixated anterior chamber phakic intraocular lens for myopia moves posteriorly with mydriasis.

Purpose: To elucidate the physiological characteristics of eyes implanted with iris-fixated anterior chamber phakic intraocular lenses (pIOLs), which are increasingly being used for the correction of higher myopic and hyperopic refractive errors.

Methods: In a case series of 20 patients (39 eyes), the position of the pIOL to the natural lens and the cornea was evaluated under photopic (135 lux) and low mesopic (< 1 lux) circumstances with anterior segment optical coherence tomography.

Results: The distance between the pIOL and the natural lens decreased, and congruently, the distance from the pIOL to the corneal endothelium increased under low mesopic circumstances.

Conclusions: The distance between the pIOL and the corneal endothelium increases when the pupil dilates under dark circumstances, contributing to the already excellent safety data available on pIOL implantation.