[In Vitro Evaluation of the Optical Quality of Segmental Refractive Multifocal Intraocular Lenses]. / In-vitro-Untersuchung zur optischen Qualität segmental refraktiver multifokaler Intraokularlinsen.

OBJECTIVES: In customised patient care, it is important to know the optical quality of different intraocular lenses (IOL). In this study, the optical quality of three segmental intraocular lenses were compared. MATERIALS AND METHODS: The LENTIS Comfort LS-313 MF15, LENTIS Mplus X LS-313 MF30 and LENTIS High Add IOL LS-313 MF80 (Oculentis, Berlin, Germany) with a far power of + 21 D were analysed at the optical bench OptiSpheric IOL PRO (Trioptics GmbH, Wedel, Germany). The lenses have almost the same optical design but differ in the power of the near segment. The MF15 has a + 1.5 D addition to improve vision in intermediate distances, the MF30 has a near addition of + 3 D and the MF80 has a near addition of + 8 D. The modulation transfer function area (MTFa) and the Strehl ratio were examined for apertures of 3 mm (photopic) and 4.5 mm (mesopic). RESULTS: The MTFa values for the far focus are 33.34/30.80/51.53 (MF15/MF30/MF80) with an aperture of 3 mm and 25.38/22.52/43.15 for 4.5 mm. The MTFa values for the intermediate focus are 29.85/16.21/6.25 for a 3 mm aperture and 23.92/8.05/3.08 for 4.5 mm. The MTFa values for the near focus are 9.75/21.49/33.12 for an aperture of 3 mm and 4.95/22.70/31.68 for 4.5 mm. The Strehl ratio of the far focus is 0.34/0.30/0.52 for an aperture of 3 mm and 0.24/0.22/0.43 for 4.5 mm. For the intermediate focus, the Strehl ratio is 0.30/0.17/0.07 for an aperture of 3 mm and 0.24/0.08/0.03 for 4.5 mm. The Strehl ratio of the near focus is 0.10/0.22/0.33 for an aperture of 3 mm and 0.05/0.23/0.32 for 4.5 mm. CONCLUSION: We confirmed that the addition influences the optical quality of segmental bifocal intraocular lenses. For the far focus, the results of the MF15 and MF30 are similar. In intermediate distances, the MF15 achieves the best results. For near distances, the MF30 achieves better optical values than the MF15. The lens MF80, which has been designed for patients with maculopathies, achieves good results for far and near distances.

In vitro comparative optical bench analysis of a spherical and aspheric optic design of the same IOL model.

BACKGROUND: To analyse objective optical properties of the spherical and aspheric design of the same intraocular lens (IOL) model using optical bench analysis. METHODS: This study entailed a comparative analysis of 10 spherical C-flex 570 C and 10 aspheric C-flex 970 C IOLs (Rayner Intraocular Lenses Ltd., Hove, UK) of 26 diopters [D] using an optical bench (OptiSpheric, Trioptics, Germany). In all lenses, we evaluated the modulation transfer function (MTF) at 50 lp/mm and 100 lp/mm and the Strehl Ratio using a 3-mm (photopic) and 4.5-mm (mesopic) aperture. RESULTS: At 50 lp/mm, the MTF values were 0.713/0.805 (C-flex 570 C/C-flex 970 C) for a 3-mm aperture and 0.294/0.591 for a 4.5-mm aperture. At 100 lp/mm, the MTF values were 0.524/0.634 for a 3-mm aperture and 0.198/0.344 for a 4.5-mm aperture. The Strehl Ratio was 0.806/0.925 and 0.237/0.479 for a 3-mm and 4.5-mm aperture respectively. A Mann-Whitney U test revealed all intergroup differences to be statistically significant (p < 0.01). CONCLUSION: The aspheric IOL design achieved higher MTF values than the spherical design of the same IOL for both apertures. Moreover, the differences between the two designs of the IOL were more prominent for larger apertures. This suggests that the evaluated IOL provides enhanced optical quality to patients with larger pupils or working under mesopic conditions.

In vitro optical quality measurements of three intraocular lens models having identical platform.

BACKGROUND: With recent advances in technology and introduction of new intraocular lens (IOL) models, surgeons today have the opportunity to choose from various optical designs, which can influence the postoperative quality of vision. In our laboratory study, we compared the optical quality of three different IOLs that use the identical platform and are produced by the same manufacturer. The study included two diffractive multifocal IOLs, a bifocal and a trifocal one, as well as a monofocal IOL. METHODS: Three IOL models: monofocal CT ASPHINA 409 M, diffractive bifocal AT LISA 809 M, and diffractive trifocal AT LISA Tri 839MP (Carl Zeiss Meditec AG, Germany) were assessed for optical quality by measuring modulation transfer function (MTF) and Strehl Ratio (SR) values at pupil sizes of 3.0 and 4.5 mm on the OptiSpheric® IOL PRO (Trioptics GmbH, Germany). The United States Air Force (USAF) Target images were also recorded to comfirm the optical performance qualitatively. RESULTS: For far focus at 50 lp/mm and 3.0 mm pupil size, MTF value of the monofocal lens (MTF = 0.798) was 1.8-fold and 2.1-fold better than the bifocal (MTF = 0.446) and the trifocal (MTF = 0.382) IOLs, respectively. For near focus, bifocal IOL (MTF = 0.265) was 1.4-fold better than trifocal IOL (MTF = 0.187), while for intermediate focus, the trifocal IOL (MTF = 0.148) was 1.7-fold better than the bifocal IOL (MTF = 0.086). For the same pupil size, total sum of light loss amounted to 5.2% for the monofocal, 16.0% for the bifocal and 6.0% for the trifocal IOL. For a larger pupil, the amount of light loss increased significantly for the multifocal IOLs. CONCLUSIONS: The monofocal IOL performed the best for far, the bifocal IOL for near and the trifocal IOL for intermediate focus. While the monofocal IOL created the least amount of light loss for both pupil sizes, the trifocal IOL created less than half the amount of light loss than the bifocal IOL for small pupil. For large pupil, however, less light scatter was observed for the bifocal than the trifocal IOL.

[Impact of Near Addition on the Optical Quality of Diffractive Multifocal Intraocular Lenses - a Laboratory Study Using an Optical Bench]. / Auswirkungen der Nahaddition auf die optische Qualität von diffraktiven multifokalen Intraokularlinsen ­ eine Laborstudie an der optischen Bank.

Purpose To analyse the optical quality of diffractive multifocal intraocular lenses (IOLs) with different near additions in a laboratory study. Methods We analysed the AcrySof® IQ ReSTOR® + 2.5 D SV25T0 (Alcon Laboratories inc., Fort Worth, USA), the AcrySof® IQ ReSTOR® + 3.0 D SN6AD1 (Alcon, USA) and the TECNIS® ZMA00 and ZMB00 (Abbott Medical Optics, USA) with a power of 21D for the distance, using the OptiSpheric® IOL PRO optical bench (TRIOPTICS, Wedel, Germany). The lenses have a similar optical design but different near additions: The ReSTOR + 2.5 D has a near addition of + 2.5 D, the ReSTOR + 3.0 D has a near addition of + 3.0 D and both TECNIS IOLs have a near addition of + 4.0 D. We evaluated the modulation transfer function area (MTFA) and the Strehl ratio. Additionally the optical qualities of the IOL were compared using USAF (United States Air Force)-Target pictures. Results The MTFA at the far focus (ReSTOR + 2.5 D/ReSTOR + 3.0 D/TECNIS) was 47.85/42.06/33.57. The MTFA was 11.05/9.54/8.60 for intermediate distances. MTFA at the near focus was 20.11/29.50/33.39. The Strehl ratio was 0.48/0.42/0.29 at the far focus, 0.11/0.10/0.09 at the intermediate focus and 0.20/0.30/0.34 at the near focus. The USAF Target pictures correlated with these measurements. Conclusion At the near focus, the TECNIS ZMA00 and ZMB00 performed the best, while the ReSTOR + 2.5 D performed the worst. At the intermediate distance, all IOLs achieved similar results. At the far focus, the ReSTOR + 2.5 D performed the best. Surgeons can choose the right IOL for the patients' individual needs, because a broad range of near additions in diffractive multifocal IOLs is available these days.