Comparison of Clinical Outcomes, Visual Quality and Visual Function of Two Presbyopia-Correcting Intraocular Lenses Made from the Same Material, but with Different Design and Optics

Abstract

This semi-prospective, parallel, comparative investigation evaluated the clinical outcomes and quality of vision (contrast sensitivity, visual function, dysphotopsia, spectacle use, overall satisfaction) after mono- or bilateral implantation of two presbyopia-correcting intraocular lenses (IOL)-the Liberty^® 677MY or the AT LISA^® tri 839M-in 50 eyes of 25 cataract patients. Clinical outcomes were assessed 3 and 12 months postoperatively. Eighty-nine percent of eyes implanted with the Liberty IOL and 59% of eyes implanted with the AT LISA IOL achieved a refractive outcome ±0.5 diopters of the target (emmetropia). Refractive outcomes were stable with both lenses. The proportions of eyes with 20/20 uncorrected distance visual acuity (UDVA) and 20/20 uncorrected near visual acuity (UNVA) were higher in the Liberty group than in the AT LISA group (UDVA: 56% vs. 41%; UNVA: 83% vs. 66%). Optical quality assessment results were comparable for the two IOLs. Superior photopic contrast sensitivity was found with the Liberty lens. The rate of Nd:YAG capsulotomy at the 12-month follow-up was 16.7% in the Liberty group and 40.6% for the AT LISA IOL. Considering that both lenses are made from the same material, we propose that the noted differences in clinical outcomes may derive from differences in design and optical surface between the two IOLs.

Keywords: 677MY; 839M; cataract; contrast sensitivity; dysphotopsia; multifocal intraocular lenses (MIOL); posterior capsule opacification; presbyopia; visual function; visual outcomes.

Figure 1

Postoperative spherical equivalent refractions and residual cylindrical refractions measured 12 months postoperatively. (a) Postoperative SEQ Liberty group; (b) postoperative SEQ AT LISA tri group; (c) residual astigmatism Liberty group; (d) residual astigmatism AT LISA tri group.

Figure 2

Cumulative Snellen uncorrected and corrected visual acuities for distance and near vision, measured 12 months after surgery. (a) Cumulative distance visual acuities for the Liberty group. (b) Cumulative distance visual acuities for the AT LISA tri group. (c) Cumulative near visual acuities for the Liberty group. (d) Cumulative near visual acuities for the AT LISA tri group. (e) Difference between UDVA and CDVA in Snellen lines for the Liberty group. (f) Difference between UDVA and CDVA in Snellen lines for the AT LISA tri group. UDVA: uncorrected distance visual acuity. CDVA: corrected distance visual acuity. UNVA: uncorrected near visual acuity. CNVA: corrected near visual acuity.

Figure 3

Monocular defocus curves of the two IOL models, plotted 12 months after surgery. Pairwise comparisons showed a significant difference only at the −2.0 D defocus value (*), while the area under curve analysis confirmed superior near vision performance for the Liberty IOL (p = 0.0004; ****).

Figure 4

Contrast sensitivity, measured in different light conditions at 12 months postoperatively. (a) In photopic conditions. (b) In photopic conditions with glare. (c) In mesopic conditions (measurements not obtained at 18 cpd). cpd = cycles per degree.

Figure 5

Mean responses for (a) dysphotopsia and (b) visual function assessment using a modified visual function questionnaire completed at 12 months postoperatively. 1 = No difficulties; 2 = minor difficulties; 3 = moderate difficulties; 4 = major difficulties; 5 = cannot accomplish task. No significant differences between the two lenses could be revealed.

Figure 6

Distribution of responses given by the patients regarding difficulties caused by (a) blurred far vision, and (b) glare/flare. Subjective assessment was performed using a modified visual function questionnaire completed at 12 months postoperatively.

Figure 7

Overall satisfaction reported by patients at 12 months after surgery. 10 = highest ranking; 1 = lowest ranking.