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Isabella Baur Isabella Baur Follow Oct 12, 2021 · 3 mins read
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Clinical outcomes of a new hybrid monofocal IOL with extended depth of focus

Heidelberg, Tuesday 12 October 2021. In the September edition of the Journal of Refractive Surgery, we were pleased to see our report published on the visual function of a group of cataract patients after the implantation of a new enhanced monofocal IOL.

The exact lens: xact

The xact Mono-EDoF ME4 is a single-piece IOL with a biconvex, aspheric design with four diffractive rings. The lens is CE-marked and it meets the ISO standards for a monofocal IOL. The lens material is glistening-free hydrophobic acrylate containing a blue light filter.

What we did

47 IOLs were implanted in 28 patients, who underwent cataract surgery and implantation of the xact Mono-EDoF ME4 intraocular lens in one (9 patients) or both eyes (19 patients). Postoperative examinations included visual acuity testing (monocular and binocular; uncorrected distance visual acuity [UDVA], corrected distance visual acuity [CDVA], uncorrected intermediate visual acuity [UIVA], distance corrected intermediate visual acuity [DCIVA]), defocus curve and contrast sensitivity testing and finally we evaluated the patients’ experiences of dysphotopsia.

What we found

  • Mean binocular UDVA was -0.02 ± 0.09 logMAR and mean binocular CDVA was -0.09 ± 0.09 logMAR
  • We found a binocular UIVA (70 cm) of 0.09 ± 0.12 logMAR and binocular DCIVA (70 cm) of 0.13 ± 0.11 logMAR.
  • Defocus curve testing demonstrated a functional defocus of 1.25 diopters at 0.2 logMAR for monocular and 1.50 diopters at 0.2 logMAR for binocular testing.

Figure 1: Postoperative spherical equivalent refraction at 3, 6 and 9 months. The percentage of patients who achieved a certain range of spherical equivalent is shown for the three follow-up visits.

Figure 2: The percentage of patients with a defined Postoperative Refractive Cylinder is shown at the 3, 6 and 9 months examinations.

Figure 3: This figure shows the percentage of patients who achieved a certain Snellen visual acuity level at 3, 6 and 9 months postoperatively.

Figure 4: Defocus curves at the 3-month visit: mean CDVA values and standard deviation are shown in logMAR for monocular and binocular testing.

Figure 5: Defocus curves at 6 months: mean values for monocular and binocular CDVA (logMAR) and standard deviation are shown.


Low levels of photic phenomena

  • Patients reported a low level of photic phenomena when asked to simulate any halos or other unwanted images using a simulator.

Figure 6: This image, generated by the Halo & Glare simulator (Eyeland Design Network GmbH, Vreden, Germany), is the result of entering the mean values for size and intensity for the halo and glare parameters (see Table 4 in our paper).

Our conclusion

The xact Mono-EDoF ME4 IOL showed good functional results for far and intermediate distance visual acuity while inducing a low level of photic phenomena.

But more research is needed because our study group had only a small number of patients and we did not enrol a control group. We should verify our results in a future randomised controlled trial.

Read and cite this article

Baur ID, Khoramnia R, Weindler J, Naujokaitis T, Poompokawat P, Auffarth GU. Clinical Outcomes of a New Hybrid Monofocal IOL With Extended Depth of Focus. J Refract Surg. 2021 Sep;37(9):601-608. doi: 10.3928/1081597X-20210610-03. Epub 2021 Sep 1. PMID: 34506236.

Isabella Baur
Written by Isabella Baur Follow
Dr. med. Isabella Baur is a guest contributor at the AppleLab website. She is an Ophthalmologist at the University Eye Clinic Augsburg, Germany and formerly Ophthalmology resident at the University Eye Clinic Heidelberg.