Evaluation of an enhanced monofocal intraocular lens

News
Article
Ophthalmology Times EuropeOphthalmology Times Europe April 2024
Volume 20
Issue 3
Pages: 26 - 27

Three IOLs are evaluated in a randomised study

Introduced in 2019, the Tecnis Eyhance IOL (Johnson & Johnson
Vision) was the first of a new generation of “enhanced monofocal” or “monofocal plus” IOLs. At the University Eye Clinic of Trieste, Italy, we performed a randomised, controlled clinical trial comparing this lens to two high-quality standard monofocal IOLs, the Clareon Monofocal (Alcon) and the Tecnis 1-Piece (Johnson & Johnson Vision).

Figure. The Tecnis Eyhance IOL is an enhanced monofocal. Due to the higher-order aspheric profile on the anterior surface of the optic, power gradually increases from the periphery to the centre of the lens. (Image courtesy of Johnson & Johnson Vision)

Figure. The Tecnis Eyhance IOL is an enhanced monofocal. Due to the higher-order aspheric profile on the anterior surface of the optic, power gradually increases from the periphery to the centre of the lens. (Image courtesy of Johnson & Johnson Vision)

The enhanced monofocal lens has a higher-order aspheric profile on the anterior surface of the optic, with power gradually increasing from the periphery to the center of the lens (Figure). The standard monofocal IOLs have both been proven to provide excellent distance visual acuity. They filter UV light and, in the case of Clareon, also blue light. The Tecnis 1-Piece, in particular, serves as an excellent control lens to determine if there is any benefit from the enhanced monofocal, because it is made from the same material as the enhanced monofocal, with the same compensation for spherical aberration.

The enhanced monofocal IOL as well as the control IOLs don’t require any specific patient selection criteria and are suitable for implantation in most eyes, including those with glaucoma, macular degeneration, corneal scars, and other pathologies.

However, for this study, eyes with pathology that could have a significant effect on outcomes were excluded to reduce the risk of biases.

In this randomised, controlled, single-masked trial, we evaluated 180 eyes of 90 patients. Participants were randomly assigned 1:1:1 to bilateral implantation of one of the three IOLs and evaluated 3 months after surgery.1 Monocular and binocular corrected and uncorrected visual acuities were assessed for far, intermediate and near distances. Defocus curves were calculated using the best corrected distance visual acuity (CDVA) and introducing defocus in 0.5-D steps from +2.00 to –4.00 D. The Catquest-9SF questionnaire was administered before cataract surgery and at 3 months postoperatively to assess change in patient quality-of-life variables.

Visual acuity results

All eyes were targeted for emmetropia. The preoperative mean pupil size was similar for all three groups.

All the IOLs performed very well for distance, with no statistically significant differences among the groups in CDVA or uncorrected distance visual acuity. No significant differences were observed between the two standard monofocal IOLs at any distance. The enhanced monofocal IOL performed better at near and intermediate distances (distance corrected and uncorrected) than either of the standard monofocal IOLs. At intermediate distance (70 cm), mean binocular uncorrected visual acuity (UIVA) was 0.17 plus/minus0.12 for the enhanced monofocal, compared to 0.32 plus/minus 0.11 for the Tecnis 1-Piece monofocal and 0.31 plus/minus 0.09 for the Clareon monofocal (P < .001). Mean binocular distance-corrected intermediate visual acuity (DCIVA) was 0.13 plus/minus 0.11 for the enhanced monofocal vs. 0.29 plus/minus 0.01 for the Tecnis 1-piece monofocal and 0.29 plus/minus 0.09 for the Clareon monofocal (P < .001).

The defocus curve revealed that the enhanced monofocal provided better visual acuity across the range of –1.50 D to –4.00 D of defocus.

A table shows the add power required for patients with three lenses: Tecnis 1-piece, Tecnis Eyhance and Clareon Monofocal.

We observed that the required add power for near vision was lower in eyes implanted with the enhanced monofocal. The add power required for patients with the enhanced monofocal was 1.40 D, compared with >2.00 D for those with either of the standard monofocal IOLs (Table). Importantly, an add is still required for near vision—the lens is by no means a presbyopia-correcting IOL. However, for daily activities like cooking or seeing prices on goods while shopping, the enhanced range of vision could provide more functional vision. A lower add power may also be more tolerable for patients who wear progressive spectacles and/or provide less blur in the downward gaze when walking.

Patient-reported outcomes

There were no statistically significant differences among the three IOL groups on patient-reported outcomes scores, based on Rasch
analysis. On the Catquest questionnaire, patients were asked about difficulty with specific tasks (e.g., reading, recognising faces, seeing prices, walking around on uneven ground), difficulty with vision and their degree of satisfaction. The survey was designed to measure change from baseline after cataract surgery. Unfortunately, it is not designed to distinguish between satisfaction with and without correction, and we suspect that muted any perceived differences between the IOL groups, which is a limitation of our study. New questionnaires are needed that are specifically designed to evaluate results with extended depth of focus (EDOF) and newer-generation IOLs.

Patient selection and counseling

Intermediate vision is essential for common tasks such as using a computer and seeing the car dashboard, so improvements in intermediate vision can be beneficial for patients. The enhanced monofocal lens we studied should not be recommended for patients who want spectacle independence after surgery. Patients should be counseled that while the lenses may provide better functional vision,2 the improvement will likely not be sufficient to perform many tasks without reading glasses.

On the other hand, the Tecnis Eyhance is a safe and easy alternative to a standard monofocal. Patients achieved better intermediate vision and lower add power requirements with the enhanced monofocal IOL, without detriment to distance vision, quality of vision or quality of life. Unlike presbyopia-correcting EDOF and multifocal IOLs, where we have to perform an extensive examination and consider factors including pupillary diameter, patient personality, tolerance for dysphotopsia, and preferred reading distance, this enhanced monofocal can simply be implanted in anyone who is a suitable monofocal IOL candidate without a lot of extra patient counseling. In countries where there is an additional charge for an enhanced monofocal, it may be most suitable for those who do limited near work and simply want better functional vision for sports and other intermediate distance activities. Patients with naturally small pupils can exploit the optics of this lens to perhaps achieve good near vision.

In the past 10 years, most of the advancements in IOLs have been targeted at presbyopia-correcting IOLs, so it is nice to see the development of better monofocal IOLs for patients who are not good candidates for or cannot afford presbyopia-correcting IOLs.

References

1. Giglio R, Vinciguerra AL, Presotto M, et al. Visual outcomes and patient satisfaction after bilateral implantation of an enhanced monofocal intraocular lens: a single-masked prospective randomized study. Int Ophthalmol. 2024; 44(1):112. doi:10.1007/s10792-024-02946-9
2. Ribeiro F, Cochener B, Kohnen T, et al. Definition and clinical relevance of the concept of functional vision in cataract surgery ESCRS Position Statement on Intermediate Vision: ESCRS Functional Vision Working Group. J Cataract Refract Surg. 2020;46(suppl 1):S1-S3. doi:10.1097/j.jcrs.0000000000000096

Rosa Giglio, MD | E: giglio.rosam@gmail.com

Dr Giglio is an ophthalmologist at the University Eye Clinic of Trieste in Trieste, Italy.

Daniele Tognetto, MD | E: tognetto@units.it

Prof Tognetto is a full professor and head of the University Eye Clinic of Trieste in Trieste, Italy.

The study discussed was supported by an unrestricted grant from Johnson & Johnson Vision.

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