Two-Year Follow-Up Of Implantable Collamer Lens Implantation In Low-Vault Cases: An Efficacy And Safety Assessment

The purpose of the study was to evaluate the efficacy and safety profile of ICL implantation in eyes with low-vault (< 250 μm) over a two-years follow-up period.

Posterior chamber implantable collamer lens (ICL) phakic intraocular lens (IOL) are usually the first choice for the surgical correction of moderate-to-high myopia. The proper postoperative vault has been considered between 250-750 μm, and low-vault has been associated with cataract formation and toric ICL misalignment. Incidence of complications are decreasing since the introduction of the central aquaport, and the intended postoperative vault value is decreasing.

Retrospective cohort study was designed and included all patients submitted to ICL V4c or V5 implantation for myopia correction at Hospital de Braga, that presented a low vault (< 250 μm) in the first postoperative evaluation (1 month) and had a minimum of 2-years follow-up. Patients with previous ocular surgery or pathologies that would affect visual outcomes were excluded.

Study enrolled 124 eyes who completed 2Y follow-up. Mean age of patients was 34±7Y old. ICL size distribution was 12.1(9,7%),12.6(66,9%),13.2(21,8%),and 13.7(1,6%).68,5% of lenses implanted were toric.2Y post-op, mean uncorrected visual acuity and corrected visual acuity was 0.06±0.11 and 0.02±0.07 logMAR respectively.Efficacy and safety index were >1.0. In terms of refractive outcomes, spherical equivalent decreased from -0.08±0.42D(1st post-op evaluation) to -0.31±0.42D(2Y). The post-op central vault reduced 147±61μm 1M post-op to 140±64μm at 24M follow-up. There was 3.8% mean central endothelial cell density loss.We had 1 case post-op ocular hypertension;4 cases of toric ICL rotation and 1 case of anterior subcapsular peripheral cataract

Our study suggests that ICL maintains high levels of efficacy and safety in low-vault cases. Further studies may change the perception of the current ideal vault concept.