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

BACKGROUND: To compare the in-the-bag stability and visual function of single-piece intraocular lenses (IOLs) and three-piece IOLs. METHODS: A 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. RESULTS: At 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. CONCLUSIONS: Three 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 REGISTRATION: ClinicalTrial.gov, NCT02609997, 11/18/2015, retrospectively registered. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12886-016-0283-4) contains supplementary material, which is available to authorized users.