Abstract
Background
To prospectively evaluate binocular visual outcomes after implantation of trifocal intraocular lenses (IOLs) with high-water-content hydrophobic acrylic material in Japanese patients.
Methods
In 59 patients (mean age 65.1 ± 7.9 years), Clareon PanOptix (CNWTT0: Alcon) with a high-water-content hydrophobic acrylic material was implanted bilaterally. Three months postoperatively, binocular uncorrected visual acuity (BUCVA) and distance-corrected visual acuity (BDCVA) at distances of 5 m, 80, 60, and 40 cm, binocular defocus curves, and binocular photopic contrast sensitivity were examined. Subjective symptoms (night vision disturbance, glare, halos, haze, or blurry vision) were also assessed.
Results
The mean postoperative BUCVA/BDCVA at 5 m, 80 cm, 60 cm, and 40 cm were − 0.115/-0.163, -0.052/-0.047, -0.054/-0.075, and − 0.043/-0.067 logMAR, respectively. A smooth defocus curve, contrast sensitivity within the normal range, and acceptable subjective symptom rates were obtained.
Conclusions
The trifocal IOL, composed of a high-water-content hydrophobic acrylic material, provides good continuous binocular vision from distance to near.
Trial registration
This investigator-initiated study was registered in the Japan Registry for Clinical Trials (identifier: jRCTs032220042) on April 26, 2022.
Keywords: Trifocal intraocular lens, Water-content, Hydrophobic acrylic, Binocular visual acuity, Binocular contrast sensitivity
Background
Diffractive trifocal intraocular lenses (IOLs) have been used to correct presbyopia in near, intermediate, and far vision by utilizing three or more focal points. In the AcrySof IQ PanOptixⓇ IOL (Alcon), the diffractive optics design in the central 4.5-mm area in the optical zone enables multiple foci with added powers of + 2.17 D (for intermediate) and + 3.25 D (for near). Uncorrected visual acuity from near to far distances has been evaluated in previous publications [1, 2]. Recently, this material was replaced with a new one, ClareonⓇ, comprising hydroxyethyl methacrylate instead of phenylethyl methacrylate. The water content was increased to 1.5% at 35 °C and the glass transition temperature was decreased to 9.1 °C, to improve the clarity of IOL [3] and effectively suppress glistenings and surface light scattering, which are frequently observed in the use of AcrySofⓇ IOLs [4]. The effectiveness and safety of this new material were experimentally evaluated [3], then ClareonⓇ monofocal IOLs were clinically evaluated with long-term observations [5, 6]. Although differences in the material are considered to affect the optical and mechanical properties, the clinical outcomes of Clareon PanOptixⓇ have been rarely evaluated [7, 8]. This prospective non-comparative study aimed to examine the visual performance of eyes with a diffractive trifocal IOL composed of this new material.
Methods
Participants
This investigator-initiated prospective study was approved by a local Certified Review Board (Shinanozaka Clinic/Hattori Clinic CRBs, Tokyo, Japan) and registered with the Japan Registry for Clinical Trials (identifier: jRCTs032220042). This study was conducted in accordance with the tenets of the Declaration of Helsinki and Clinical Trials Act of Japan (Act No. 16, 2017). Written informed consent was obtained from all the patients. Patients who underwent bilateral cataract surgery with implantation of multifocal IOLs were recruited from four sites: Totsuka-ekimae Suzuki Eye Clinic (Yokohama, Japan), Zengyo Suzuki Eye Clinic (Fujisawa, Japan), Yokohama Sky Eye Clinic (Yokohama, Japan), and Tokyo Dental College Suidobashi Hospital (Tokyo, Japan). The inclusion criteria were age of 45 to79 years, corneal astigmatism of 1.0 D or less, a target refraction of emmetropia, and potential postoperative corrected visual acuity of 10/20 or better. Patients with other ocular diseases influencing visual function, irregular corneal astigmatism, history of intraocular or corneal surgery, or other systemic or ophthalmic diseases unsuitable for this study were excluded.
Sample size determination
The sample size was determined to evaluate binocular distance-corrected visual acuity. In a previous study [9], the mean binocular distance-corrected visual acuities were − 0.04 (standard deviation [SD]: 0.11) in logMAR (logarithm of the minimum angle of resolution) at distance and 0.04 (SD: 0.12) at 60 cm in eyes with trifocal IOL TFNT00 (Alcon) of AcrySof material. As the minimum step of Landolt ring charts ranging from 0.8 to 1.2 in Snellen is 0.05 logMAR, sample sizes of 25 and 42 patients were required for detecting a difference of 0.06 logMAR, as reported previously, with a significance level of 0.05 and detection power of 90% (R version 3.6.1, package ‘pwr’ version 1. 3). A sample size of 60 patients was required, considering a dropout rate of 25%. With a sample size of 42, half of the two-sided 95% CI for the mean based on the t-statistic would extend 0.31 times of SD values from the observed mean.
Intraocular lenses and surgery
Clareon PanOptixⓇ CNWTT0 (Alcon) was a single-piece hydrophobic acrylic diffractive trifocal IOL, which is identical to AcrySof PanOptixⓇ TFNT00 (Alcon) except for the material. The new material introduced hydroxyethyl methacrylate instead of phenylethyl methacrylate, so that the water content and glass transition temperature were 1.5% at 35 °C and 9.1 °C, respectively. This material was also blue-light-blocked, and the IOL optics were aspheric with a diameter of 6 mm and a sharp edge on the posterior surface. The refractive index was 1.55 at 35 °C. The diffractive optics of 4.5 mm diameter on the anterior surface produced add powers of 2.17 and 3.25 D. The power of all IOLs was determined for emmetropia with the use of biometry and power calculation formula routinely used at each site.
Cataract surgeries were performed by a single experienced surgeon at each site. Cataracts were removed using phacoemulsification and aspiration techniques through 2.2–2.4 mm temporal corneal incisions, and IOLs were inserted in the capsular bag using specific injectors. Details of their procedure and technique were not standardized in four sites.
Postoperative examinations
Three months after surgery, the monocular and binocular visual acuities, manifest refraction spherical equivalent (MRSE), binocular photopic contrast sensitivity, and binocular defocus curves were examined.
Monocular and binocular uncorrected (UCVA and BUCVA, respectively) and distance-corrected (DCVA and BDCVA, respectively) visual acuities at distances of 0.4, 0.6, 0.8, and 5 m were measured using Landolt ring charts under photopic illumination (85–110 cd/m2). The MRSE was also measured during the DCVA measurements at 5 m. While the measured MRSE was corrected to infinity by adding − 0.20 D [10], DCVA and BDCVA were corrected with the measured values. The visual acuity was converted to logMAR for subsequent analyses.
Binocular photopic contrast sensitivity was measured using CSV-1000 (Vector Vision, Fairfield, CT) under distance correction with measured MRSE and photonic illumination (85 cd/m2) at a distance of 2.5 m. Logarithm contrast sensitivities at spatial frequencies of 3, 6, 12, and 18 cycle per degree (cpd) were obtained.
Binocular defocus curves between − 3.0 and + 1.5 D in a step of 0.5 D were measured under distance correction with measured MRSE.
Symptoms of night vision disturbance, glare, halos, hazy, or blurry vision at a distance under daily light conditions were assessed using a questionnaire, and the severity was graded on a 4-point scale: absent, mild, moderate, and severe. The questionnaire also asked about difficulties with vision in reading (newspapers and books), seeing computer screens, and recognizing people.
Results
Sixty participants were enrolled; one dropped out before surgery. Hence, 118 eyes of 59 participants (22 men and 37 women) were evaluated. Their demographic data are listed in Table 1. During the postoperative period, glistenings were not observed in all eyes with slit-lamp microscopy examinations.
Table 1.
Demographic data of participants
| Mean (SD) | Range | |
|---|---|---|
| Age, year | 64.9 (7.8) | 44–78 |
| Height, cm | 161.8 (7.8) | 148–178 |
| Arm length, cm | 50.7 (3.7) | 42–58 |
| Axial length, mm | 24.4 (1.7) | 21.5–29.5 |
| Corneal astigmatism, D | 0.60 (0.26) | 0.00–1.30 |
SD: standard deviation, D: diopter
The postoperative MRSE, BUCVA, BDCVA, UCVA, and DCVA values at distances of 0.4, 0.6, 0.8, and 5 m are listed in Table 2. Figure 1 shows the distributions of the MRSEs and refractive cylinders. In total, 81% of eyes were within ± 0.50 D of MRSE and the refractive cylinders of 92% of eyes were 1.0 D or less. Figure 2 shows the cumulative percentage of patients achieving BDCVAs and BUCVAs at distances of 5 m (far), 0.6 m (intermediate), and 0.4 m (near). A postoperative BDCVA of 20/20 or better was obtained in 90% or more of the participants at far, intermediate, and near distances, and similar results were found for BUCVAs.
Table 2.
Postoperative manifest refraction spherical equivalent (MRSE) and binocular uncorrected (BUCVA) and distance-corrected (BDCVA), and monocular uncorrected (UCVA) and distance-corrected (DCVA) visual acuities at distances of 0.4, 0.6, 0.8, and 5 m
| Mean (SD) | Range | |
|---|---|---|
| MRSE for infinity, D | 0.02 (0.39) | -1.27–1.11 |
| BUCVA, logMAR | ||
| at 0.4 m | -0.043 (0.093) | -0.176–0.398 |
| at 0.6 m | -0.054 (0.101) | -0.176–0.398 |
| at 0.8 m | -0.052 (0.122) | -0.176–0.523 |
| at 5 m | -0.115 (0.099) | -0.301–0.222 |
| BDCVA, logMAR | ||
| at 0.4 m | -0.067 (0.090) | -0.176–0.398 |
| at 0.6 m | -0.075 (0.091) | -0.176–0.301 |
| at 0.8 m | -0.047 (0.144) | -0.176–0.523 |
| at 5 m | -0.163 (0.087) | -0.301–0.000 |
| UCVA, logMAR | ||
| at 0.4 m | 0.014 (0.106) | -0.176–0.398 |
| at 0.6 m | 0.011 (0.131) | -0.176–0.523 |
| at 0.8 m | 0.015 (0.143) | -0.176–0.699 |
| at 5 m | -0.050 (0.122) | -0.301–0.398 |
| DCVA, logMAR | ||
| at 0.4 m | -0.018 (0.103) | -0.176–0.398 |
| at 0.6 m | -0.017 (0.125) | -0.176–0.523 |
| at 0.8 m | 0.001 (0.162) | -0.176–0.699 |
| at 5 m | -0.131 (0.089) | -0.301–0.046 |
SD, standard deviation; D, diopters; logMAR, logarithm of minimum angle of resolution
Fig. 1.
Distributions of manifest refraction spherical equivalent (left) and postoperative refractive cylinder [10]
Fig. 2.
Cumulative percentage of eyes achieving binocular uncorrected and distance-corrected visual acuities (BUCVA and BDCVA, respectively) at far (left), intermediate (center), and near (right) distances [10]
After implantation, 53 of 59 participants (89.8%) were spectacle-independent, and one (1.7%) and five (6.8%) participants were always and sometimes, respectively. Spectacles were used for distance and near vision by only two (3.4%) and four (6.8%) participants, respectively.
Binocular photopic contrast sensitivity was measured in 58 participants. Figure 3 shows a box plot of contrast sensitivity and mean values (rhombus marks). The binocular contrast sensitivity was within the normal range.
Fig. 3.
Binocular contrast sensitivity. Rhombus denotes mean value.
Figure 4 shows the binocular defocus curves for all participants. The curve was smooth and a mean BDCVA of 0.0 logMAR or better (20/20 or better in Snellen notation) was achieved for defocus between − 3.0 and 0.0 D, which corresponded to distances between far and 33 cm.
Fig. 4.
Binocular defocus curves
Table 3 shows the rates of subjective symptoms of night vision disturbance, glare, halos, haze, and blurry vision. Over 90% of the participants did not experience severe symptoms. Halos were the most frequently reported symptom after Clareon PanOptix IOL implantation.
Table 3.
Number of participants reporting subjective symptoms and their severity
| Symptom | Absent, | Mild | Moderate | Severe |
|---|---|---|---|---|
| Night vision disturbance | 35 (59.3%) | 19 (32.2%) | 4 (6.8%) | 1 (1.7%) |
| Glare | 19 (32.2%) | 25 (42.4%) | 12 (20.3%) | 3 (5.1%) |
| Halos | 8 (13.6%) | 23 (39.0%) | 23 (39.0%) | 5 (8.5%) |
| Hazy or blurry vision | 43 (72.9%) | 13 (22.0%) | 2 (3.4%) | 1 (1.7%) |
Postoperatively, 23.7%, 16.9%, and 3.4% of the participants reported difficultes in reading, seeing a computer screen, and recognizing people, respectively.
Discussions
After binocular implantation of Clareon PanOptix IOLs (model: CNWTT0), a BDCVA of 20/20 or better at far, intermediate, and near distances was obtained in 90% or more of the participants, and a BUCVA of 20/20 or better was found in 86% or more. Consequently, the mean BDCVA values at all distances were acceptable. Table 4 lists a previous study’s results of mean BDCVAs in eyes implanted with the TFNT00 IOL [11–13], which is composed of AcrySof material, as well as the current results. Compared with outcomes from TFNT00, the current results were comparable. The rates of patients who achieved a BDCVA of 20/20 or better in eyes with TFNT00 IOLs were 95.1%, 73.8%, and 85.8% at far (N = 305), intermediate (N = 404), and near (N = 260) distances, respectively [12]. The current results were similar to or better than those reported previously. The binocular defocus curve in the current study was also similar to the pooled results [12]. The postoperative photopic contrast sensitivity of eyes with the TFNT00 IOL was examined using the CSV-1000, which was similar to the current results. Spectacle independence was achieved more than in a clinical trial in Japan [11].
Table 4.
Comparison of binocular distance-corrected visual acuities of eyes with AcrySof PanOptix IOLs
| Study | IOL |
N
(patient) |
BDCVA, mean (SD) in logMAR | ||
|---|---|---|---|---|---|
| Far | Intermediate | Near | |||
| Bissen-Miyajima et al. [11] | TFNT00 | 68 | -0.197 (0.076) | -0.112 (0.111) | -0.073 (0.111) |
| Modi et al. [13] | TFNT00 | 129 | -0.062 (0.066) | -0.007 (0.021) | 0.050 (0.038) |
| Pooled analysis [12] | TFNT00 | 260–404 | -0.088 (0.10) |
-0.017 (0.12) |
0.021 (0.11) |
| Current | CNWT00 | 59 | -0.115 (0.099) | -0.054 (0.101) | -0.043 (0.093) |
IOL, intraocular lens
Over a 3-month period, the current results revealed comparable visual acuity in eyes with AcrySof PanOptix IOLs. Previous experimental and clinical studies on monofocal Clareon IOLs have validated IOL clarity up to three years postoperatively, including the development of glistenings, surface light scattering, and postoperative capsule opacity [3, 6, 14]. Thus, a trifocal IOL made of the new material may be anticipated to sustain clarity in providing presbyopia-correcting functions. Long-term outcomes will have to be assessed to validate our findings.
Mild, moderate, and severe halos were reported in 39.0%, 39.0%, and 8.5% of participants, respectively. In the previous study of Japanese patients with AcrySof PanOptix IOLs, they were 56.7%, 13.4%, and 1.5%, 6 months postoperatively [11]. It was conceivable that awareness of moderate halo may reduce after three to six months.
Postoperatively, difficulties in reading, seeing a computer screen, and recognizing people were reported in 23.7%, 16.9%, and 3.4% of the participants, respectively. In the study of AcrySof PanOptix IOLs, 26.5%, 10.3%, and 14.7% of Japanese patients reported such difficulties [11]. The difference of MRSE (0.06 D in AcrySof PanOptix IOLs compared with 0.02D in Clareon IOLs) would be a factor of difficulties in seeing a computer screen and recognizing people. The percentage in reading was over 20% in both studies. Such a high percentage may be influenced by the complexity of the Chinese characters used in Japanese, Chinese characters require larger font sizes to achieve the same visual acuity for alphabet letters [15].
This study had some limitations. First, the observation period was until 3 months. Glistenings and surface light scattering are normally found after 6 months and 3 years after implantation of AcrySof IOLs [4] so a longer observation is required to confirm the suppression. Previous long-term assessments of Clareon monofocal IOLs demonstrated the suppressions [5, 6]. While the similar results were anticipated for the use of Clareon PanOptix, long-term evaluation is required. Next, the sample size was not sufficient for comparing outcomes with the use of AcrySof IOLs. With additional reporting of Clareon PanOptix IOL outcomes, further comparison would be obtained with the meta-analysis. Lastly, toric models were not available when the current study started in Japan. Corneal astigmatism sensitively influences the outcome of trifocal IOLs, and the use of a toric model is suggested for corneal astigmatisms of 0.75 D or more [16]. As there were 41 of 118 eyes in the current study, better outcomes could be anticipated if the toric model were available.
Acknowledgements
None.
Abbreviations
- BDCVA
Binocular distance-corrected visual acuity
- BUCVA
Binocular uncorrected visual acuity
- CRB
Certified Review Board
- cpd
Cycle per degree
- DCVA
Distance-corrected visual acuity
- IOL
Intraocular lens
- logMAR
Logarithm of the minimum angle of resolution
- MRSE
Manifest refraction spherical equivalent
- SD
Standard deviation
- UCVA
Uncorrected visual acuity
Author contributions
Design of the study (KM, KM); data collection (TS, YO, HS, SH, HBM); statistical analysis (KM); preparation of the manuscript (YO, KM); and critical revision (TS, HS, SH, HBM). All the authors have read and approved the final version of this manuscript.
Funding
This investigator-initiated study was supported by Alcon.
Data availability
The datasets used and/or analyzed in the current study are available from the corresponding author upon reasonable request.
Declarations
Ethics approval and consent to participate
This investigator-initiated prospective study was approved by a local Certified Review Board (Shinanozaka Clinic/Hattori Clinic CRBs, Tokyo, Japan) and registered with the Japan Registry for Clinical Trials (identifier: jRCTs032220042). This study was conducted in accordance with the tenets of the Declaration of Helsinki and Clinical Trials Act of Japan (Act No. 16, 2017). Written informed consent was obtained from all the patients.
Consent for publication
Not applicable.
Competing interests
All received research support from Alcon. HBM is consultant and speaker bureaus of Alcon. KM is an editorial board member of BMC Ophthalmology.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Tañá-Rivero P, Rodríguez-Carrillo MD, Tañá-Sanz P, Ruiz-Santos M, Tañá-Sanz S. Clinical outcomes of trifocal toric intraocular lenses. Eur J Ophthalmol. 2023;33:1773–85. [DOI] [PubMed] [Google Scholar]
- 2.Zhu D, Ren S, Mills K, Hull J, Dhariwal M. Rate of complete spectacle independence with a Trifocal Intraocular Lens: a systematic literature review and Meta-analysis. Ophthalmol Ther. 2023;12:1157–71. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Werner L, Thatthamla I, Ong M, Schatz H, Garcia-Gonzalez M, Gros-Otero J, Cañones-Zafra R, Teus MA. Evaluation of clarity characteristics in a new hydrophobic acrylic IOL in comparison to commercially available IOLs. J Cataract Refract Surg. 2019;45:1490–7. [DOI] [PubMed] [Google Scholar]
- 4.Werner L. Glistenings and surface light scattering in intraocular lenses. J Cataract Refract Surg. 2010;36:1398–420. [DOI] [PubMed] [Google Scholar]
- 5.Oshika T, Fujita Y, Inamura M, Miyata K. Mid-term and long-term clinical assessments of a new 1-piece hydrophobic acrylic IOL with hydroxyethyl methacrylate. J Cataract Refract Surg. 2020;46:682–7. [DOI] [PubMed] [Google Scholar]
- 6.Kinoshita K, Miyata K, Nejima R, Honbo R, Mori M, Minami Y. Surface light scattering from 1-piece hydrophobic acrylic intraocular lenses with hydroxyethyl methacrylate: contralateral observation for 7 years. J Cataract Refract Surg. 2021;47:702–5. [DOI] [PubMed] [Google Scholar]
- 7.Khoramnia R, Naujokaitis T, Baur ID, Hassel O, Henningsen N, Reitemeyer E, Chychko L, Łabuz G, Auffarth GU. Functional outcomes after refractive Lens Exchange with Implantation of a glistening-free Diffractive Trifocal intraocular Lens. Am J Ophthalmol. 2024;268:296–305. [DOI] [PubMed] [Google Scholar]
- 8.Jo E, Kim B, Kim TI, Kim MK, Choi CY. Clinical outcomes of a new hydrophobic trifocal intraocular Lens with Hydroxyethyl Methacrylate in cataract surgery: a prospective Multicenter Study. Korean J Ophthalmol. 2024;38:212–20. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Kohnen T, Marchini G, Alfonso JF, Bala C, Cochener B, Martinez A, Carreño E. Innovative trifocal (quadrifocal) presbyopia-correcting IOLs: 1-year outcomes from an international multicenter study. J Cataract Refract Surg. 2020;46:1142–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Fernández J, Ribeiro FJ, Rodríguez-Vallejo M, Dupps WJ Jr, Werner L, Srinivasan S, Kohnen T. Standard for collecting and reporting outcomes of IOL-based refractive surgery: update for enhanced monofocal, EDOF, and multifocal IOLs. J Cataract Refract Surg. 2022;48:1235–41. [DOI] [PubMed] [Google Scholar]
- 11.Bissen-Miyajima H, Ota Y, Hayashi K, Igarashi C, Sasaki N. Results of a clinical evaluation of a trifocal intraocular lens in Japan. Jpn J Ophthalmol. 2020;64:140–9. [DOI] [PubMed] [Google Scholar]
- 12.Kohnen T, Lapid-Gortzak R, Ramamurthy D, Bissen-Miyajima H, Maxwell A, Kim TI, Modi S. Clinical outcomes after bilateral implantation of a diffractive trifocal intraocular Lens: a Worldwide Pooled analysis of prospective clinical investigations. Clin Ophthalmol. 2023;17:155–63. 10.2147/OPTH.S377234. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Modi S, Lehmann R, Maxwell A, Solomon K, Cionni R, Thompson V, Horn J, Caplan M, Fisher B, Hu JG, Yeu E. Visual and patient-reported outcomes of a Diffractive Trifocal Intraocular Lens Compared with those of a Monofocal Intraocular Lens. Ophthalmology. 2021;128:197–207. [DOI] [PubMed] [Google Scholar]
- 14.Nuijts RMMA, Bhatt U, Nanavaty MA, Roberts TV, Peterson R, Teus MA. Three-year multinational clinical study on an aspheric hydrophobic acrylic intraocular lens. J Cataract Refract Surg. 2023;49:672–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Wang CX, Lin N, Guo YX. Visual requirement for Chinese reading with normal vision. Brain Behav. 2019;9:e01216. 10.1002/brb3.1216. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Hayashi K, Yoshida M, Igarashi C, Hirata A. Effect of refractive astigmatism on all-distance visual acuity in eyes with a trifocal intraocular lens. Am J Ophthalmol. 2021;221:279–86. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets used and/or analyzed in the current study are available from the corresponding author upon reasonable request.