Clinical management of a nonoptimal vault and unexpected postoperative refraction in a patient implanted with a phakic intraocular lens

Abstract

Introduction: This case reports the management of a bilateral toric implantable collamer lens (ICL) surgery with low vaulting and unilateral reduction in visual acuity (VA) associated with a combined effect of surgically induced astigmatism (SIA) and toric-ICL rotation. This case expands the common management of toric-ICL rotation, by adding surgically induced corneal changes. Patient and Clinical Findings: The patient presented with moderate myopia and high astigmatism and was implanted with a toric-ICL, resulting in bilateral low vault <150 mm and unilateral VA reduction (20/40) because of postoperative oblique astigmatism, observed at the 4-week follow-up. Diagnosis, Intervention and Outcomes: The lowICL vaulting was associated with a high crystalline lens rise and underestimation of the sulcus-to-sulcus distance. The VA reduction resulted from a combined effect of ∼1.0 diopter SIA and 8-degree ICL rotation. The authors associate the high SIA to abnormal corneal biomechanics indexes and the toric-ICL rotation to a lack of stability resultant from a small ICL size. The left eye toric-ICL has exchanged with one with larger size and the power recalculated using vectorial analysis. The toric ICL exchange increased the vault 75 mm and improved VA. Conclusions: Detailed anterior chamber morphometry and corneal biomechanics may assist in improving the refractive outcome in toric-ICL surgery.