Vault Changes Caused by Light-Induced Pupil Constriction and Accommodation in Eyes With an Implantable Collamer Lens

PURPOSE: An appropriate vault after implantation of a posterior chamber phakic intraocular lens with a central hole (ICL KS-AP) is important for successful long-term outcomes. In the present study, we used anterior segment optical coherence tomography (AS-OCT) to examine dynamic pupil and vault changes under photopic and scotopic conditions and during accommodation in eyes with ICL KS-AP. METHODS: This retrospective study included patients at an outpatient ophthalmology clinic who underwent ICL KS-AP implantation >1 month before enrollment. All patients underwent dynamic AS-OCT imaging under photopic and scotopic conditions. Patients aged <40 years also underwent imaging in the accommodative and nonaccommodative states. Primary outcome measures were the pupil size and vault at the maximum and minimum pupil sizes. RESULTS: This study included 91 eyes of 47 patients (35.5 ± 8.6 years, 21 men). Accommodation was examined in 51 eyes of 26 patients (28.9 ± 5.0 years, 10 men) younger than 40 years. The pupil size was significantly smaller under photopic conditions (3.64 ± 0.77 mm) than under scotopic conditions (4.91 ± 0.75 mm, P < 0.001) and during accommodation (3.88 ± 0.64 vs. 4.10 ± 0.61 mm, P < 0.001). Vault was also significantly lower under photopic conditions (476.1 ± 219.6 μm) than under scotopic conditions (521.1 ± 220.4 μm, P < 0.001) and during accommodation (454.8 ± 224.9 vs. 481.6 ± 219.1 μm, P < 0.001). CONCLUSIONS: Vault can be significantly lowered by light-induced pupil constriction and accommodation in eyes with ICL KS-AP.