Comparisons of the in-the-bag stabilities of single-piece and three-piece intraocular lenses for age-related cataract patients: a randomized controlled trial

Abstract

BackgroundTo compare the in-the-bag stability and visual function of single-piece intraocular lenses (IOLs) and three-piece IOLs.MethodsA total of 65 patients with age-related cataracts (80 eyes) were enrolled and randomly assigned to receive in-the-bag implantation of either a single-piece IOL (40 eyes) or a three-piece IOL (40 eyes). Follow-up visits were conducted at 1 week, 1 month and 3 months postoperatively. Visual acuity, refraction and total aberration were examined. IOL position stability (including axial movement, decentration and tilt) was measured using a Scheimpflug imaging system.ResultsAt the 3-month follow-up visit, single-piece IOLs did not exhibit significant axial movement (0.07 ± 0.30 mm, p = 0.13) compared with their axial position at 1 week postoperatively, whereas three-piece IOLs displayed forward axial movement of −0.22 ± 0.23 mm (p < 0.0001). The mean manifest spherical equivalence (SE) of eyes with single-piece IOL was 0.15 ± 0.18D, whereas in eyes with three-piece IOLs, the mean manifest SE was −0.34 ± 0.15D (p < 0.001). There was no statistically significant difference in IOL decentration, tilt, uncorrected visual acuity, best-corrected visual acuity or total spherical aberration between the two groups.ConclusionsThree months after implantation, single-piece IOLs exhibit better axial stability and more stable refractive outcome than three-piece IOLs, but both IOLs perform equally well in terms of decentration, tilt, visual acuity and total aberration.Trial registrationClinicalTrial.gov, NCT02609997, 11/18/2015, retrospectively registered.Electronic supplementary materialThe online version of this article (doi:10.1186/s12886-016-0283-4) contains supplementary material, which is available to authorized users.

Effect of Intraocular Lens Tilt and Decentration on Visual Acuity, Dysphotopsia and Wavefront Aberrations

“…In multifocal IOLs, decentration might result in a different light distribution between the distance focus and near focus [ 18 ]. With regards to IOL design, 1-piece and 3-piece, hydrophobic and hydrophilic IOLs have been reported to perform equally well in terms of decentration and tilt [ 11 , 19 ].…”

Evaluation of the anterior segment parameters after Nd: YAG laser Capsulotomy: Effect the design of intraocular lens Haptic

“…Zhong reported 1-piece IOLs exhibits better axial stability and more stable refractive outcomes after three months in the bag. 11 …”

“…The characteristics of the IOLs implanted in the capsular bag effect anterior segment parameters by the time. 11 Design of the IOL (i.e., whether it is 1-piece or 3-piece model) may be the most important characteristic. Haptic of the 1-piece IOLs have the same material with optics and they are in soft manner.…”

Influence of material and haptic design on the mechanical stability of intraocular lenses by means of finite-element modeling

“…Chang 15 found that the silicone plate haptics have a higher incidence of rotation than hydrophobic C-loop. Zhong et al 16 found that single-piece IOLs exhibit better axial stability and more stable refractive outcome than three-piece IOLs. Rotation occurs most frequently in the early postoperative period, before anterior and posterior capsules fuse together with the lens.…”

“…There are several methods to measure IOL decentration and tilt once it is implanted inside the pseudophakic eyes. These include slit lamp assessment, 21 retroillumination photography, 22 Scheimpflug imaging, 16 optical coherence tomography, [23][24][25] and measurements using Purkinje reflections. [26][27][28] But before the implant injection into the eye, a study on reliable prediction of the visual outcome of the implantation needs to be performed.…”