Monofocal intraocular lens with enhanced intermediate function as substitute for multifocal intraocular lens in positive dysphotopsia

Managing dissatisfaction after multifocal intraocular lens implantation through lens exchange using monofocal or alternative multifocal IOLs

PURPOSE

To manage patient dissatisfaction following multifocal intraocular lens (MF-IOL) implantation by IOL exchange with either a monofocal or an alternative MF-IOL, and to compare outcomes in these two groups.

METHODS

MF-IOL exchange was performed in 32 patients (64 eyes) with neuroadaptation failure. The MF-to-MF group involved patients who had a MF-IOL exchanged with another MF-IOL of a different optical profile and the MF-to-MO group involved patients who had a MF-IOL exchanged to a monofocal IOL. Visual outcomes and complications were analysed. The Quality of Vision (QoV) questionnaire, Visual Function Index (VF-14) and its Rasch-revised version (VF-8R) were also used to assess outcomes.

RESULTS

There were no significant differences (p > 0.05) in the QoV scores between the two groups, both preoperatively and postoperatively. Preoperatively, there were no significant differences in VF-14 scores between both groups (p > 0.05). Postoperatively, there were statistically significant differences in VF-14 (total score, intermediate vision and near vision) in favour of the MF-to-MF group (p < 0.05). The postoperative VF-8R score in the MF-to-MF group was significantly better than the MF-to-MO group (p ≤ 0.001). Uncorrected and corrected near as well as corrected distance visual acuities were significantly better (p < 0.05) in the MF-to-MF group compared to the MF-to-MO group at 3 months.

CONCLUSION

Patient dissatisfaction and neuroadaptation failure following MF-IOL implantation can be managed by an IOL exchange with an alternative optical design of MF-IOL or a monofocal IOL. Although, in the current study, the MF-to-MF group showed some better postoperative results, both options are feasible solutions.

Analysis of a novel hydrophobic acrylic enhanced monofocal intraocular lens compared to its standard monofocal type on the optical bench

Introduction

The aim of this laboratory study is to objectively analyze the new hydrophobic, acrylic, enhanced monofocal intraocular lens Acunex Quantum (AN6Q) and compare it with the monofocal platform Acunex AN6. 

Methods

Two IOL models were analyzed (Acunex Quantum AN6Q and Acunex AN6, Teleon Surgical, Spankeren, Netherlands), each having the same refractive power of + 22.0 D, on the optical bench with the OptiSpheric IOL PRO 2. The measurements followed the guidelines of the International Standard Organization with following parameters: ISO 2 cornea (+ 0,28 µ), ISO 11979/2, lens placement in situ in NaCl with 35° temperature, 546 nm and selection of different aperture sizes (3.0 mm vs 4.5 mm). The aberrations of each IOL were evaluated by the WaveMaster IOL 2, a high-resolution Shack-Hartmann sensor in reverse projection setup. An in-situ model eye was used according to ISO 11979 in NaCl (n = 1.337) with 546 nm, mask width 4.51. Zernike polynomials up to 10th order were determined by means of the measured wavefront that describe the optical properties of the IOL.

Results

Through frequency modulation transfer function (mean) at 50 lp/mm (AN6Q/AN6 centered) was 0.687/0.731 (3.0 mm aperture) and 0.400/0.509 (4.5 mm aperture). The SR (mean) was 0.592/0.809 (3.0 mm) and 0.332/0.372 (4.5 mm). The MTF (mean) at 50 lp/mm (AN6Q/AN6 decentered by 1 mm) was 0.413/0.478 (3.0 mm) and 0.257/0.229 (4.5 mm). The SR (mean) was 0.393/0.404 (3.0 mm) and 0.183/0.212 (4.5 mm). The MTF (mean) at 50 lp/mm (AN6Q/AN6 tilted by 5°) was 0.508/0.710 (3.0 mm) and 0.337/0.513 (4.5 mm). The SR (mean) was 0.508/0.760 (3.0 mm) and 0.235/0.2372 (4.5 mm). AN6Q showed MTF peak of 0.55 with an enlarged depth of power of about 2.5 D and two cusps in the MTF curve. The spherical aberration Z 4–0 was about -0.21 µm and the secondary spherical aberration Z 6–0 was about 0.16 µm. No other relevant aberration showed up.

Conclusion

The new, enhanced monofocal AN6Q provides an extended range of focus with only slight decrease in contrast quality. Both types of the hydrophobic, acrylic Acunex IOL platform have its particular advantages in clinical settings and therefore its importance, respectively.