Asymmetric vault of an accommodating intraocular lens

Abstract

We report a case of a new syndrome, late asymmetric vault of the AT45 Crystalens intraocular lens (IOL) (Eyeonics Inc.). The late vault, which occurred in 6 month after implantation of the IOL, caused a decrease in uncorrected distance and near acuities and minus-cylinder axis perpendicular to the haptics. Treatment with neodymium:YAG laser capsulotomy and fibrotic band release was successful.

Two cases of Z syndrome with the Crystalens after uneventful cataract surgery

“…To produce maximum accommodation amplitude, the ideal optic starting position is posterior to the capsule ( Figure 6). 4 Capsule fibrosis can impede the axial movement, which is necessary for accommodation in this type of hinged accommodating IOL. 5 In particular, asymmetric fibrosis can cause IOL decentration.…”

“…5 The haptic loops provide 4 points of fixation in the capsular bag to maintain the Crystalens' position and prevent subluxation and decentration. 4 Although this may be true in an optimum environment, in some cases the capsular bag can contract, potentially causing the optic to bend and leading to asymmetric vaulting. We are unaware of reports of asymmetric tilting of other types of IOLs.…”

“…The irregular capsule contraction caused 1 haptic to bow anteriorly while the other remained in the normal posterior position. The term Z syndrome was first used by Jardim et al 4 as the IOL configuration in the capsular bag, with the optic in the middle, resembles the letter Z (Figure 7). The asymmetrical tilting of the optic caused coma aberration and increased astigmatism in the first case and increased myopia in the second case.…”

Corrective techniques and future directions for treatment of residual refractive error following cataract surgery

“…Development of posterior capsular opacification (PCO) can result in postoperative visual complaints irrespective of what type of IOL is used, however, different types of IOLs require different considerations. Accommodating IOLs are susceptible to gradual haptic deformation resulting from capsule fibrosis, culminating in the so-called ‘z-syndrome’ [32, 33]. In general, patients that have multifocal IOLs have higher sensitivity to minor degrees of postsurgical ametropia [34].…”

Presbyopia-correcting Intraocular Lenses in Cataract Surgery—A Focus on ReSTOR® Intraocular Lenses

“…[22][23][24] Due to the flexible nature of the haptics, optical tilting may occur in normally implanted individuals resulting in a condition known as Z syndrome and leading to the loss of visual acuity (VA) at all distances. 25,26 The problem may be corrected by neodymium-doped yttrium aluminum garnet (Nd:YAG) laser posterior capsulotomy, 25,26 that may also be used to correct for post-operative opacification of the posterior capsule. 18 Three-piece foldable lenses with prolene haptics tend to undergo a myopic shift over time, and mild myopic shift can also be seen with the Crystalens ® at one year after surgery.…”