Part 3: Optimizing outcome precision with leading edge advanced lens technology

Data collected in the ESCRS Clinical Trends Surveys show that since the polling was first conducted in 2016, the percentage of total cases performed using a presbyopia-correcting IOL has increased significantly.¹ The results also show that throughout the history of the survey, a trifocal IOL was the technology most commonly used for patients wanting presbyopia correction (Figure 1).¹ The latter finding is not surprising considering that compared with other options, trifocal IOLs may be most likely to provide patients good uncorrected vision spanning from far to intermediate to near.²

Figure 1. ESCRS Clinical Trends Survey Results 2016 to 2022

3.1 The ZEISS AT ELANA 841P – Design details & optical performance testing

Gerd U Auffarth

The AT ELANA® 841P from ZEISS is a recent entry into the category of trifocal IOLs. The optic of the ZEISS AT ELANA is based on the optic of the hydrophilic AT LISA® tri 839MP from ZEISS, a trifocal lens with clinical performance proven in over 170 peer-reviewed papers.^3,4 However, the diffractive structure of the ZEISS AT ELANA differs in a few ways. First, its increased overall light transmission efficiency due to an improved diffractive structure and a higher proportion of light allocated towards near vision, lead to an enhanced near-to-intermediate vision without compromising distance vision*. The ZEISS AT ELANA optic also stays fully trifocal over its entire optical zone. In addition, the aspheric optic of the AT ELANA is aberration-neutral whereas the AT LISA tri 839MP aspheric optic is an aberration-correcting design.

For its haptic platform, the ZEISS AT ELANA uses the same rigid optic-haptic junction and step-vaulted C-loop haptics as the CT LUCIA® 621P from ZEISS, which are features that enable centration and maximize capsular contact to provide positional stability and resistance to posterior capsule opacification (PCO).^5.6 In addition, the AT ELANA is made of the same biomaterial as the CT LUCIA 621P, which is a glistening-free** hydrophobic acrylic with a heparin-coated*** surface that allows smooth and controlled unfolding. The material also delivers good clarity.

We conducted a series of in vitro evaluations to assess the optical performance of the ZEISS AT ELANA and to compare it with the ZEISS AT LISA tri 839MP.^2,7 First, we found that visual acuity (VA) values and defocus curves simulated from bench testing measurements of modulation transfer function (MTF) indicated that the AT ELANA is capable of delivering 0.1 logMAR or better VA at far, intermediate, and near distances.

Whether looking at the simulated VA or MTF results, the performance of the AT ELANA over an extended range of defocus was generally similar to that of the AT LISA tri 839MP, although the AT ELANA was slightly superior at near (Figure 2). Analyses of MTF data also showed that the optical performance of the AT ELANA was more resistant to decentration than the AT LISA tri 839MP, which can be attributed to the aberration-neutral aspheric design of the AT ELANA. MTF values for the AT ELANA remained stable over the tested decentration range of up to 1.0 mm.

Figure 2. Defocus curve with AT ELANA and AT LISA tri; simulated visual acuity based on optical bench MTF measurements; pupil size 3 mm; aberration-neutral cornea mode

In addition, we found that like the AT LISA tri 839MP, the AT ELANA has excellent pupil independent light utilization. Therefore, the AT ELANA might be expected to have the same profile of photic phenomena as the AT LISA tri 839MP (Video 1).

Video 1. In vitro evaluation of photopic phenomena and glistening of AT ELANA 841

3.2 ZEISS AT ELANA clinical outcomes

Peter Mojžiš

I began implanting the ZEISS AT ELANA as an investigator in a clinical trial. Findings from follow-up visits at 1 day, 3 months, and 5 months after surgery from the second patient enrolled in this study show the optical quality of the AT ELANA, its stability, and its potential to provide a full range of good uncorrected vision (Video 2).

Video 2. Outcome analysis for one patient case with ZEISS AT ELANA

Results from analysis of data collected in 10 patients who had bilateral implantation of the ZEISS AT ELANA demonstrate refractive predictability and excellent visual outcomes. We analyzed data from the first 10 patients who underwent bilateral implantation of the AT ELANA.IOL power was calculated with the ZEISS IOLMaster 700 using the Haigis and SRK/T formula for eyes with short axial length and the Hoffer Q or Barrett TK Universal formula for longer eyes. Mean implanted IOL power was 23.1±2.13 D (median 23.0 D; range 19.5 to 27.5 D).

At 1 month, the achieved refractive predictability was very high with 85% of the patients within ±0.5 D of target refraction and 100% within ±1.0 D. These results are impressive and far exceed criteria found in the Royal College of Ophthalmologists Cataract Surgery Guidelines that set benchmark standards for rates of achieved refraction of 55% for outcomes within ±0.5 D of target and 85% for eyes within ±1.0 D.

Monocular and binocular VA results for the 10 patients were consistent with the excellent refractive outcomes (Table 1). In all patients, uncorrected logMAR VA was 0.1 or better at distance (ETDRS 4 m), intermediate (80 cm), and near (40 cm).

Table 1. Visual acuity (logMAR) and refractive outcomes 1 month after implantation of the ZEISS AT ELANA IOL

Abbreviations: SD, standard deviation; CDVA, corrected distance visual acuity;
UDVA, uncorrected distance visual acuity; UIVA, uncorrected intermediate visual acuity;
DCIVA, distance-corrected intermediate visual acuity; UNVA, uncorrected near visual acuity;
DCNVA, distance-corrected near visual acuity; SEQ, spherical equivalent of autorefraction; D, diopter; na, not applicable)

Even more importantly, and as expected, the excellent refractive and functional results corresponded with a high level of patient satisfaction with their vision and improved visual function. We are seeking to formally validate the benefits of the ZEISS AT ELANA for enabling spectacle independence by having patients complete the Catquest-9SF questionnaire preoperatively and one month after their second eye surgery.This validated instrument includes two general questions about difficulty and satisfaction with sight and seven questions about difficulty with specific daily life activities. Data from our first 10 patients clearly show their satisfaction with and benefit gained from surgery with the trifocal AT ELANA (Figure 3).

Figure 3. Patient satisfaction before and after surgery (Catquest 9SF Questionnaire)

Video 3. Findings from optical bench tests evaluating the ZEISS AT ELANA

Findings from optical bench tests evaluating the ZEISS AT ELANA (Video 3) and clinical experience are positive and support its potential to provide patients with an extended range of good uncorrected vision. (Video 4). In addition, implantation of the fully preloaded AT ELANA IOL is easy and controlled, and this IOL is demonstrating excellent postoperative stability, refractive predictability, and functional outcomes. Furthermore, comments received during follow-up visits along with subjective questionnaire results show a very high level of patient satisfaction.

Video 4. Findings from clinical experience are positive and support its potential to provide patients with an extended range of good uncorrected vision

With the introduction of the AT ELANA 841P, outstanding trifocal IOL technology from ZEISS is available on two distinct platforms. Therefore, regardless of their personal preference for lens biomaterial or haptic design, all cataract surgeons now have the opportunity to satisfy their patients seeking presbyopia correction with clinically proven technology.

* Compared to ZEISS LISA tri in photopic conditions in virtual implantations and optical bench test results

** Grade 1 (traces) or better for 85% of the patients up to and including 12 months according to Christiansen scale and based on internal clinical trial outcomes and on published clinical data.

*** Fragment of heparin used in IOL surface coating with no pharmacological, immunological or metabolic action.

References

1. ESCRS Clinical Trends Survey 2022 results. Supplement to EuroTimes. September 2022. https://www.escrs.org/media/5cbb4kx4/2022_escrs_clinical-survey-supplement.pdf. Accessed February 21, 2024.
2. Łabuz G, Yan W, Khoramnia R, Auffarth GU. Optical-quality analysis and defocus-curve simulations of a novel hydrophobic trifocal intraocular lens. Clin Ophthalmol. 2023;17:3915-3923.
3. Mojžiš P, Majerova K, Plaza-Puche AB, Hrckova L, Alio JL. Visual outcomes of a new toric trifocal diffractive intraocular lens. J Cataract Refract Surg. 2015;41(12):2695-706.
4. Mojžiš P, Kukuckova L, Majerova K, Ziak P, Piñero DP. Postoperative visual performance with a bifocal and trifocal diffractive intraocular lens during a 1-year follow-up. Int J Ophthalmol. 2017;10(10):1528-1533.
5. Borkenstein AF, Borkenstein EM. Long-term clinical results and scanning electron microscopic analysis of the aspheric, hydrophobic, acrylic intraocular lens CT LUCIA 611P(Y). Clin Ophthalmol. 2018;12:1219-1227.
6. Borkenstein AF, Borkenstein EM. Geometry of acrylic, hydrophobic IOLs and changes in haptic-capsular bag relationship according to compression and different well diameters: A Bench study using computed tomography. Ophthalmol Ther. 2022;11(2):711-727.
7. Łabuz G, Yan W, Khoramnia T, Auffarth G. Comparing optical quality and simulated defocus curves: a head-to-head analysis of hydrophilic and hydrophobic trifocal intraocular lenses. Personal Communication, 2023

Supported by ZEISS
The statements of the authors reflect only their personal opinions and experiences and do not necessarily reflect the opinion of any institution with whom they are affiliated with. The authors alone are responsible for the content of their experience reported and any potential resulting infringements. Carl Zeiss Meditec AG and its affiliates do not have clinical evidence supporting the opinions and statements of the authors nor accept any responsibility or liability of the authors’ content.
The authors Gerd Auffarth and Peter Mojžiš have a contractual or other financial relationship with Carl Zeiss Meditec AG and its affiliates.

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