**1. Introduction**

Cataract surgery is one of the most frequently performed procedures around the world. Intraocular lenses (IOLs) have developed significantly in recent years. IOLs are used in cataract surgery to replace a cloudy lens and in refractive lens exchange (RLE). The most common implanted lenses are monofocal lenses, which provide good acuity to one type of vision correction, mainly for a far distance. In addition to monofocal lenses, premium lenses, which have a more advanced structure and different optical properties are available. These lenses correct presbyopia, i.e., insufficient accommodation that occurs

**Citation:** Dołowiec-Kwapisz, A.; Piotrowska, H.; Misiuk-Hojło, M. Evaluation of Visual and Patient— Reported Outcomes, Spectacle Dependence after Bilateral Implantation with a Non-Diffractive Extended Depth of Focus Intraocular Lens Compared to Other Intraocular Lenses. *J. Clin. Med.* **2022**, *11*, 5246. https://doi.org/10.3390/jcm11175246

Academic Editor: Nobuyuki Shoji

Received: 18 July 2022 Accepted: 3 September 2022 Published: 5 September 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

physiologically after the age of 40. Premium lenses include multifocal intraocular lenses (MIOLs), extended depth of focus lenses (EDOF) and accommodative lenses. These lenses improve visual acuity after cataract surgery and allow for full or partial independence from spectacle correction. Both the extension of life expectancy, lifestyle changes and greater professional activity of the elderly contribute to the willingness to become independent from eyeglass correction not only in the distance, but also in the near and intermediate distance [1].

MIOLs allow for the greatest degree of independence from eyeglass correction, but they have a lower contrast sensitivity and a higher rate of photic phenomena, such as halo and glare. The eligibility criteria for implantation in this group of lenses are the most stringent, and the eyes should be free of any pathology so that patients can achieve the best possible postoperative results [2].

EDOF lenses can be positioned between monofocal and multifocal lenses. They provide good uncorrected distance and intermediate visual acuity; however, visual acuity without near correction may be insufficient. They work by creating a single, elongated focus to increase the depth of field. The elongated focus is designed to eliminate the close-up and distance overlap that occurs with multifocal lenses, thus eliminating the halo effect. In addition, EDOF lenses provide a continuous focus range, without the power distribution being unevenly divided, and thus avoiding secondary out-of-focus images [3,4]. Compared to multifocal lenses, they do not lower contrast sensitivity and cause less dysphotopsia [5].

There are different methods of creating these lenses. One of them is the use of spherical aberration, however, it differs from patient to patient in the population and is influenced by pupil width [6,7]. Another way is to use diffraction optics to obtain the EDOF effect. However, this can lead to the development of a dysfunction similar to those seen after multifocal lens implantation, and uncorrected near vision acuity may not be satisfactory [8]. Another method may be the use of a circular mask, as with the IC-8 lens, a small-aperture EDOF lens. However, this can reduce the amount of light entering through the diaphragm and is typically used in the non-dominant eye [9].

An increasing number of patients presenting for cataract surgery want to be independent from eyeglass correction, and at the same time are afraid of the photic phenomena after the procedure. There has been a growing number of patients after refractive surgery in the past who would like to regain independence from eyeglass correction and do not qualify for multifocal lens implantation. The same applies to patients with ocular diseases who would like to choose premium lenses. For these patients, EDOF lenses provide a chance to improve uncorrected acuity at all distances. Due to the fact that the EDOF Vivity lens (Alcon Laboratories, Inc., Fort Worth, TX, USA) has a unique, non-diffractive optical part; it allows patients to see well from near to distance. It is based on the non-diffractive X-wave technology, which modifies the wave front and creates one elongated focus without splitting the light. Thanks to these properties, the lens reduces the risk of dysphotopsia and does not worsen the contrast sensitivity. In the construction of the lens, two zones can be distinguished: the transition zone 1 is responsible for stretching the wave front and creating a continuous elongated focus, while the transition zone 2 is responsible for shifting the wave front from hyperopia to short-sighted in order to use all the light energy. It has 1.5 D defocusing and negative asphericity of the anterior surface ( −0.2 μm) [10–12]. Moreover, the extended depth of focus, such as that seen in the Vivity lens, can "forgive" the imperfection of IOL power selection caused by the difficulty in calculating IOL power (especially in patients who have undergone refractive surgery in the past) [10].

To date, few articles have been published on postoperative outcomes in patients with non-diffractive EDOF lens implantation, including one in patients with ocular pathologies. This paper additionally includes patients with a history of refractive surgery, who will be increasingly more numerous in the future and would like to choose a premium lens. To the best of our knowledge, there are currently no publications on the comparison of the Vivity lens with monofocal and multifocal lenses. This work may provide some insight into lens selection, especially for patients with ocular pathologies and after refractive

surgery who are ineligible for MIOLs or are worried about their side effects. The aim of the article is to evaluate the postoperative results, spectacle dependence, the occurrence of the photic phenomena in patients after cataract surgery using a non-diffractive EDOF–Vivity intraocular lens compared to multifocal and monofocal intraocular lenses.

#### **2. Patients and Methods**

#### *2.1. Study Design*

This single-center, prospective, comparative study was conducted at the Ophthalmology Department of the Hospital in Zgorzelec in line with the Helsinki Declaration and approved by the Bioethics Committee at the Medical University of Wroclaw. Written consent was obtained from all patients.

#### *2.2. Study Population*

The study group in which the Vivity lens was implanted (DFT015 or the toric version of the lens-called the EDOF group) consisted of 70 eyes in 35 patients. The control groups consisted of 52 eyes in 26 patients in whom a Panoptix multifocal lens (TNTFOO or the toric version of the lens-called the MULTI group) was implanted and 52 eyes in 26 patients with implanted monofocal lens (SA60WF or the toric version SN6AT3-7-called the MONO group). All lenses implanted in the patients involved in our study are single-piece, aspheric, are constructed of the same material-hydrophobic, and are based on the same platform-Acrysof (Alcon Laboratories, Inc., Fort Worth, TX, USA) [10,11,13–15]. The EDOF and multifocal lens were donated by the Alcon Company for the purpose of this study.

The study included patients aged 35–75 diagnosed with bilateral cataracts in whom the removal of the cataract was planned by phacoemulsification.

Exclusion criteria included: patients under the age of 35, over the age of 75, pregnant, after a corneal transplant, with a history of past eye injuries, diseases of the anterior and posterior segmen<sup>t</sup> of the eye that may have significantly reduced the quality of vision after surgery, such as: advanced glaucomatous neuropathy, advanced diabetic retinopathy, amblyopia, corneal scarring and dystrophy, exudative age-related macular degeneration (AMD), post-posterior vitrectomy condition or elective surgery, and clinically significant severe dry eye syndrome. Patients after cerebral events that could have affected visual acuity were also excluded from the study.

#### *2.3. Preoperative Assessment*

The pre-operative examination consisted of: anterior and posterior segmen<sup>t</sup> examination in a slit lamp, intraocular pressure examination, refraction examination (NIDEK ARK-510A-Nidek Co. Ltd., Gammagori, Aichi, Japan), monocular visual acuity examination in logarithm of the minimum angle of resolution (logMAR) scale: uncorrected distance visual acuity (UCDVA) at 4 m, best corrected distance visual acuity (BCDVA), uncorrected intermediate visual acuity (UCIVA) at 80 cm, best corrected intermediate visual acuity (BCIVA), uncorrected near visual acuity (UCNVA) with 40 cm, best corrected near visual acuity (BCNVA), monocular contrast sensitivity at 40 cm (Pelli-Robson test, GIMA charts, Gessate, Italy), biometry using an Argos SS-OCT optical biometer (Movu, Inc., Kamaki, Japan) and IOL Master 500 (Carl Zeiss Meditec AG, Jena, Germany), Oculazer ™ WaveLight® II corneal tomography and topography (Alcon Laboratories, Inc., Fort Worth, TX, USA), posterior segmen<sup>t</sup> optical coherence tomography (OCT) (OCT III, Carl Zeiss Meditec AG, Jena, Germany). A standardized ETDRS chart at 4 m, 80 cm, and 40 cm was used to measure visual acuity (VA).

In the study, the refractive result was written as a spherical equivalent, defined as the sum of the spherical power and half of the cylindrical power [16]. The results obtained were classified as myopia, emmetropia or hyperopia. For myopia there was a spherical equivalent less than −0.5 D, for emmetropia-a spherical equivalent in the range of −0.5 and +0.5 D, and in the case of hyperopia, a spherical equivalent greater than +0.5 D. This division was adopted in accordance with other large cross-sectional and dynamic studies [16–18].

#### *2.4. Postoperative Assessment*

Controls were performed 2 weeks, 2 months (6–8 weeks) and 6 months after cataract surgery. Controls included: anterior and posterior segmen<sup>t</sup> examination in a slit lamp, an intraocular pressure test, manifest refraction expressed as mean refractive spherical equivalent (MRSE), monocular visual acuity test in the logMAR scale: UCDVA, BCDVA, UCIVA, BCIVA, UCNVA, BCNVA, monocular contrast sensitivity and the postoperative questionnaire.

Six months after the second eye surgery, binocular visual acuity was assessed: UCDVA, UCIVA, UCNVA.

Measurements were performed under photopic conditions (250–300 lumens/mm2) in all cases. The preoperative and postoperative examinations were carried out by the same person.

#### *2.5. Subjective Visual Quality Questionnaire*

Patients were asked "yes/no" questions regarding independence from glasses, the occurrence of postoperative dysphotopsia such as halo, glare, starburst, was assesed on a scale from 1 to 5 in increments of 1 (1-slight, 5-very high). In addition, patients were asked to rate their satisfaction with the procedure (scale from 1 to 5).

#### *2.6. Surgical Technique*

All cataract surgery with implantation of an appropriate intraocular lens was performed by the same surgeon (H.P.). All the procedures were uneventful. They were performed under drip (Alcaine) and intraocular (Mydriane) anesthesia. The lenses were implanted through a 2.2 mm corneal incision into the lens bag. At the end of the procedure, in accordance with European standards, cefuroxime solution was administered into the anterior chamber.

Implant power for the Vivity lens was calculated on an Argos optical biometer using Barret's formula, setting postoperative results to either emmetropia (18 patients, 36 eyes) or minimonovision (17 patients, non-dominant eye set to target ~ −0.75D). Eye dominance was determined by taking the Mile's test. For Panoptix lenses, the Argos biometer and Barret's formula were used, setting postoperative results to emmetropia. Implant power of monofocal lenses was calculated using an IOL Master 500 or Argos biometer, using the SRK/T formula or the Barret formula by setting the target to emmetropia. With axial length <22 mm, the Haigis formula was used. In the case of patients after previous radial keratotomy, measurements were made on an Argos biometer using the Barret true K formula.

#### *2.7. Statistical Analysis*

All analyses were performed in statistical environment R, version 4.1.3. Quantitative variables were compared between groups with the Kruskal-Wallis test or with ANOVA analysis and between measurements—with the Friedman's test (for more than two measurements) or Wilcoxon's test for dependent samples (for two measurements). These tests were chosen because all variables' distributions significantly differed from the normal distribution (checked with Shapiro-Wilk's test). Median differences with 95% confidence intervals were given when comparing two measurements. Dependencies for qualitative variables were analyzed with the chi-square test or the Fisher's exact test. Significance level in the analysis equalled α = 0.05.

## **3. Results**

Pre- and postoperative data of 174 eyes (87 patients) were included in the analysis. A total of 35 patients (70 eyes) received the Vivity IOL (19 toric and 51 non-toric), 26 patients (52 eyes) underwent the implantation of monofocal (12 toric and 40 non-toric) lens, and 26 patients (52 eyes) the PanOptix lens (10 toric and 42 non-toric).

#### *3.1. Demographics and Preoperative Data*

Detailed demographic characteristics, biometry values, mean preoperative refractive errors and visual acuity (VA), contrast sensitivity, and intraocular pressure from the three groups are presented in Table 1.

**Table 1.** Demographics and preoperative characteristics (refractive and monocular VA (logMAR) data, ocular pathologies) of the three groups.



Qualitative variables were described as n (%) and quantitative variables—as median with quartile 1 and 3 or mean with standard deviations. Dependencies between groups and qualitative variables were made using chi-square test or Fisher's exact test 1. Comparisons of quantitative variables' level were made with Kruskal-Wallis test or with ANOVA 2 analysis. *p*—*p* value for main analyses; *p* value for post-hoc analyses: p1—EDOF vs. MONO p2—EDOF vs. MULTI, p3—MONO vs. MULTI. Abbreviations: mm—milimiters, IOL—intraocular lens, AMD—age-related macular degeneration, PEX—pseudoexfoliation syndrome, MRSE—mean refraction spherical equivalent, Ddiopters, mmHg—millimetres of mercury, UCDVA—uncorrected distance visual acuity at 4 m, BCDVA—best corrected distance visual acuity, UCIVA—uncorrected intermediate visual acuity at 80 cm, BCIVA—best corrected intermediate visual acuity, UCNVA—uncorrected near visual acuity at 40 cm, BCNVA—best corrected near visual acuity.

Among the MULTI group there was a smaller proportion of eyes with myopia than in the other groups (23% vs. 44% for EDOF and 52% for MONO) and a higher proportion of eyes with emmetropia (17% vs. 7% for EDOF and 4% for MONO) or with hyperopia (60% vs. 49% for EDOF and 44% for MONO), *p* = 0.012. The analysis comparing quantitative variables was significant for: UCDVA (*p* = 0.017), BCDVA (*p* = 0.004), BCNVA (*p* = 0.014) and ACD (*p* = 0.012). Post-hoc analyses showed that patients from the MULTI group had a lower level of UCDVA variable than EDOF and MONO groups and lower level of BCNVA than the MONO group. Patients from the MONO group were characterized by a higher level of BCDVA than two remaining groups and by a lower level of ACD than patients from EDOF group (*p* < 0.050 for all post-hoc analyses), Table 1.

#### *3.2. Refractive and Visual Outcomes*

Monocular and binocular visual acuity and MRSE 6 months after the procedure were compared between EDOF, MONO and MULTI groups. All main analyses, except for comparisons of UCDVA (both monocular and binocular) level, were significant (*p* < 0.050). Post-hoc analyses showed that the level of: MRSE, BCDVA and BCIVA was higher among MULTI group than among EDOF group (*p* < 0.010 for all post-hoc analyses). Contrast sensitivity was lower among MULTI group than among EDOF group. The level of UCIVA (both monocular and binocular visual acuity) was higher in the MONO group than in the EDOF and MULTI groups (*p* < 0.001 for all post-hoc analyses) and higher in the MULTI group than in the EDOF group (*p* < 0.050 for both post-hoc analyses). The level of UCNVA (both monocular and binocular visual acuity) was higher in the MONO group than in the EDOF and MULTI groups (*p* < 0.001 for all post-hoc analyses) and higher in the EDOF group than in the MULTI group (*p* < 0.001 for both post-hoc analyses). The level of BCNVA was higher among MULTI group than among MONO group (*p* = 0.007), Table 2.


**Table 2.** Comparison of postoperative data (6 months after cataract surgery) between three groups.


**Table 2.** *Cont*.

Variables were described as median with range of scores (min–max). Comparisons of quantitative variables' level were made with Kruskal-Wallis test. *p*—*p* value for main analyses; *p* value for post-hoc analyses: p1—EDOF vs. MONO, p2—EDOF vs. MULTI, p3—MONO vs. MULTI.

When the EDOF group is divided into two subgroups: (1) patients with target set to emmetropia, (2) patients with minimonovision (non-dominant eye set to target ca. −0.75 D) the results of binocular uncorrected visual acuity 6 months after surgery are as follows, Table 3.

**Table 3.** Comparison of uncorrected binocular acuity at all distances between four groups (EDOF group divided into 2 subgroups: emmetropia i minimonovision).


Variables were described as median with quartile 1 and 3. Comparisons of quantitative variables' level were made with Kruskal-Wallis test.

#### Refractive and Visual Outcomes in Baseline and after 6 Months in Each Group

In the EDOF group at the baseline the level of: UCDVA (MD 95% CI = 0.70 (0.63; 0.82); *p* < 0.001), BCDVA (MD 95% CI = 0.25 (0.30; 0.35); *p* < 0.001), UCIVA (MD 95% CI = 0.75 (0.64; 0.80); *p* < 0.001), BCIVA (MD 95% CI = 0.20 (0.25; 0.35); *p* < 0.001), UCNVA (MD 95% CI = 0.40 (0.45; 0.60); *p* < 0.001), BCNVA (MD 95% CI = 0.30 (0.25; 0.40); *p* < 0.001) and IOP (MD 95% CI = 2.85 (1.90; 3.00); *p* < 0.001) was higher than after 6 months. The level of contrast was lower at the baseline than after 6 months (MD 95% CI = −0.20 (−0.35; −0.20); *p* < 0.001).

In the MONO group almost all comparisons between baseline and after 6 months were significant (except of the MRSE level). At the baseline the level of: UCDVA (MD 95% CI = 0.70 (0.55; 0.75); *p* < 0.001), BCDVA (MD 95% CI = 0.25 (0.30; 0.38); *p* < 0.001), UCIVA (MD 95% CI = 0.30 (0.30; 0.50); *p* < 0.001), BCIVA (MD 95% CI = 0.30 (0.24; 0.33); *p* < 0.001), UCNVA (MD 95% CI = 0.20 (0.13; 0.33); *p* < 0.001), BCNVA (MD 95% CI = 0.40 (0.30; 0.40); *p* < 0.001) and IOP (MD 95% CI = 2.80 (0.85; 2.45); *p* < 0.001) was higher than after 6 months. The level of contrast sensivity was lower at the baseline than after 6 months (MD 95% CI = −0.30 (−0.35; −0.25); *p* < 0.001).

All analyses were significant in the case of the MULTI group. At the baseline the level of: MRSE (MD 95% CI = 0.87 (0.00; 1.37); *p* = 0.043), UCDVA (MD 95% CI = 0.40 (0.40; 0.57); *p* < 0.001), BCDVA (MD 95% CI = 0.25 (0.25; 0.28); *p* < 0.001), UCIVA (MD 95% CI = 0.60 (0.60; 0.80); *p* < 0.001), BCIVA (MD 95% CI = 0.20 (0.15; 0.25); *p* < 0.001), UCNVA (MD 95% CI = 0.70 (0.65; 0.80); *p* < 0.001), BCNVA (MD 95% CI = 0.20 (0.20; 0.25); *p* < 0.001) and IOP (MD 95% CI = 2.90 (1.55; 2.50); *p* < 0.001) was higher than after 6 months. The level of contrast sensivity was again lower at the baseline than after 6 months (MD 95% CI = −0.10 (−0.20; −0.15); *p* < 0.001)

#### *3.3. Evaluation of Dysphotopsia*

Halo and glare after 6 months were experienced more often among subjects form the MULTI group than among subjects from the two other groups (65% of eyes in MULTI group vs. 6% of eyes in the EDOF group and 0% of eyes in the MONO group; *p* < 0.001 for halo and 10% of eyes in the MULTI group vs. 3% of eyes in the EDOF group and 0% of eyes in the MONO group; *p* = 0.045). No other significant difference was detected between groups and between the occurrence of photic phenomena 6 months after the procedure, Table 4.

**Table 4.** Comparison of occurrence of photic phenomena 6 months after the procedure between three groups.


Variables were described as n (%). Dependencies between groups and qualitative variables were made using chi-square test 2 or Fisher's exact test.

#### *3.4. Spectacle Dependence and Patient Satisfaction*

Glasses were needed by 35% of subjects from the EDOF group, by 96% of subjects from the MONO group and by no one from the MULTI group (this was a statistically significant dependency—*p* < 0.001). Every patient from every group was satisfied (both for the right and left the eye). Most of subjects from each group rated their satisfaction (both for right and left eye) with a number 5 (97% for right eye and 86% for left eye in the EDOF group; 92% for right eye and 81% for left eye in the MONO group; 77% for right eye and 85% for left eye in the MULTI group; *p* = 0.552 for the dependency between groups and level of satisfaction for right eye and *p* > 0.999 for the dependency between groups and level of satisfaction for left eye). Among the MULTI group, there was a greater proportion of subjects that rated their satisfaction for the right eye with the number 4 than in two other groups (23% vs. 3% in EDOF and 8% in MONO; *p* = 0.038), Table 5.


**Table 5.** Number of patients needing glasses and satisfaction rating broken down by groups.

Dependencies were calculated using chi-square test 2 or Fisher's exact test.

## **4. Discussion**
