Pharmacological Accommodative Changes of the Anterior Segment and Its Impact on the Vault in Implantable Collamer Lens Implantation.

Abstract

To estimate the accommodative changes of the anterior segment and its impact on the central and peripheral vaults after Visian Implantable Collamer Lens (ICL) (STAAR Surgical) implantation. Eighty eyes of 40 consecutive patients (mean age: 28.05 years; range: 19 to 42 years) were examined 3 months after ICL implantation. Eyes were randomly divided into a mydriasis group and a miosis group. Anterior chamber depth (ACD) to crystalline lens (ACD-L), anterior chamber depth to ICL (ACD-ICL), central distance from endothelium to sulcus to sulcus (ASL), central distance from sulcus to sulcus to crystalline lens (STS-L), central distance from ICL to sulcus to sulcus (STS-ICL), and central (cICL-L), midperipheral (mICL-L), and peripheral (pICL-L) vaults were measured by ultrasound biomicroscopy at baseline and after induction with tropicamide or pilocarpine. After tropicamide treatment, cICL-L, mICL-L, and pICL-L decreased from 0.531 ± 0.200, 0.419 ± 0.173, and 0.362 ± 0.150 mm to 0.488 ± 0.171, 0.373 ± 0.153, and 0.311 ± 0.131 mm, respectively. The values decreased from 0.540 ± 0.185, 0.445 ± 0.172, and 0.388 ± 0.149 mm to 0.464 ± 0.199, 0.378 ± 0.156, and 0.324 ± 0.137 mm after pilocarpine administration, respectively. The ASL and STS showed a significant increase in the mydriasis group (all P ≤ .038), but a decrease in the miosis group (all P < .001). The ACD-L increased and STS-L decreased in the mydriasis group (all P < .001), indicating the backward shift of the crystalline lens, whereas crystalline lens forward shift was observed in the miosis group. Additionally, the STS-ICL decreased in both groups (all P ≤ .021), suggesting the ICL backward shift. Both central and peripheral vaults decreased during the pharmacological accommodation process, and the ciliaris-iris-lens complex contributed to the changes. [J Refract Surg. 2023;39(6):414-420.].