Light- and drug-induced pupillary dynamics in eyes with a retropupillary iris-claw intraocular lens

Purpose: We evaluated the pupillary characteristics and response to light and drugs in eyes with posterior chamber (PC) placement of iris-claw intraocular lens (IC-IOL). Methods: In this cross-sectional, comparative study, we included adults with an IC-IOL implanted in the PC of a single eye. We excluded patients with ocular trauma, postoperative IC-IOL displacement or complications, and extended iris atrophy. We used anterior segment optical coherence tomography to perform light-controlled pupillography, measure the pupil diameter (PD), and estimated the pupil circularity under mesopic conditions. PD was also assessed under photopic, scotopic, pharmacological mydriasis, and miosis conditions. The results were compared to those of the fellow eye, phakic, or regular pseudophakic. Results: The IC-IOL and control groups included 30 eyes each. The most frequent reasons for IC-IOL implantation were complicated cataract (37%) and dislocated/luxated prior IOL (33%). Compared to the control group, the IC-IOL group had lower visual acuity, a smaller PD under scotopic conditions (p = 0.0010) and after pharmacological mydriasis (p < 0.0001), and a larger PD after pharmacological miosis (p < 0.0001). Mesopic pupil circularity was comparable between the groups. We also considered ongoing extraocular treatments with possible effects on iris motility. Conclusions: The pupillary size and profile were similar between the groups in mesopic light. Reduced mydriasis was noted in response to light and drugs, while the degree of miosis was reduced in response to inducing drugs in the IC-IOL compared to the control group. This study complements previous results concerning the PC placement of IC-IOLs by adding original observations on drug-induced pupil motility.