Multifocal intraocular lenses (IOLs) have been increasingly preferred in patients receiving cataract removal for the convenience brought to daily life. Diffractive bifocal IOLs comprise concentric rings that form two primary focal points for distance and near vision, whereas new models of trifocal IOLs form three focal distances, providing correction for near, intermediate, and distance vision.1 The visual performance related to the two types of IOLs has become a matter of concern. There have been some clinical reports about the comparison of implantation with a bifocal or trifocal IOL,2–9 but the visual performance of apodized diffractive bifocal and trifocal IOLs from the same manufacturer with identical IOL platforms (including lens design, material, and profile) has not been compared. Moreover, the AT LISA 839MP IOL (Carl Zeiss Meditec, Jena, Germany) has been described to achieve a useful third focus for intermediate vision in vitro.10–13 Vega et al.12 reported similar optical imaging quality in the distance and near foci for the AT LISA 809M IOL (Carl Zeiss Meditec) and the AT LISA tri 839MP IOL, whereas Son et al.13 showed the AT LISA 809M IOL had a better image quality for near foci than the AT LISA 839MP IOL. These results concerning the two IOLs seem to be somewhat different.
Our study aimed to evaluate and compare the visual acuity and objective and subjective optical quality after implantation of the bifocal and trifocal IOLs from the same manufacturer using identical IOL platforms.
Patients and Methods
This prospective, non-randomized, controlled study was performed at Shandong Eye Institute and approved by its institutional review board. Practices and research were conducted in accordance with the tenets of the Declaration of Helsinki. All patients signed an informed consent before participation.
The involved patients did not have any ocular disease except age-related cataract and experienced uneventful cataract extraction and IOL implantation, with corneal astigmatism of less than 1.00 diopter (D). Patients with a history of ocular surgery, irregular corneal astigmatism, corneal disease, glaucoma, retinal detachment, macular degeneration, retinopathy, or ocular inflammation were excluded from this study.
The characterization and price of both bifocal and trifocal IOLs and the condition of the eyes were explained to each patient. The same type of IOL (bifocal AT LISA 809M or trifocal AT LISA tri 839MP) selected according to the patient's need was implanted in both eyes. A total of 110 consecutive eyes (55 patients) receiving phacoemulsification and IOL implantation surgery were enrolled from March 2016, and the follow-up was completed in July 2017.
The AT LISA tri 839MP IOL is a single-piece, four-haptic, apodized diffractive trifocal preloaded IOL with a 6-mm biconvex optic, an overall length of 11 mm, and a posterior surface with asphericity of −0.18 µm. This IOL is trifocal within an IOL diameter of 4.3 mm and bifocal between 4.3 and 6 mm. In the central 4.3-mm area, the IOL provides a near addition of +3.33 D and an intermediate addition of +1.66 D, both calculated at the IOL plane. The addition power between the diameters of 4.3 and 6 mm is +3.75 D. In theory, light is distributed with 50% for a distance focus, 20% for an intermediate focus, and 30% for a near focus.
The AT LISA 809M IOL is a single-piece four-haptic apodized diffractive bifocal IOL with a biconvex optic diameter of 6 mm, an overall diameter of 11 mm, and a posterior surface with asphericity of −0.18 µm. This IOL is bifocal within an IOL diameter of 6 mm, and the near addition at the lens plane is 3.75 D. Theoretically, the incident light is distributed with 65% for a distance focus and 35% for a near focus.
Preoperatively, all patients underwent a complete examination, including visual acuity, Goldmann applanation tonometry, slit-lamp microscopy, axial length, corneal power, anterior chamber depth (ACD) measured by the IOLMaster 500 (Carl Zeiss Meditec), and funduscopy. The Holladay 2 and SRK/T formulas were used to calculate the power of the IOL to be implanted. Two experienced examiners performed the calculation to reduce any operating errors. Target refraction was emmetropia in all cases. The method reported by Holladay et al.14 was used to optimize the A-constant.
All surgeries were performed by the same experienced surgeon (YH) using a standard phacoemulsification technique of sutureless micro-coaxial 2.2-mm phacoemulsification. The Callisto Eye System (Carl Zeiss AG, Dublin, CA) was used to guide the corneal incisions at the steep axis and to set up the center location and 5.5-mm size of the capsulorhexis. Postoperatively, levofloxacin (Santen, Osaka, Japan) and prednisolone acetate (Allergan; Irvine, CA) eye drops were topically administered four times a day for 1 week and diclofenac sodium eye drops (Cisen, Jining, China) were used four times a day for 4 weeks.
At 3 months, the following were evaluated: refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuity at 4 m, uncorrected (UIVA) and corrected (CIVA) intermediate visual acuity at 80 cm, uncorrected (UNVA) and corrected (CNVA) near visual acuity at 40 cm, distance-corrected near (DCNVA) (40 cm) and intermediate (DCIVA) visual acuity (80 cm), objective optical quality measured by a wavefront aberrometer (i-Trace; Tracey, Houston, TX) for assessment of modulation transfer functions (MTFs) and higher-order aberrations (HOAs), quality of life with the National Eye Institute Visual Functioning Questionnaire-14 (VF-14),15 the level of perceived visual disturbances,16 overall patient satisfaction, and spectacle independence. For the evaluation of defocus curves, the patient wore the correction providing the best distance visual acuity in both eyes, and the Early Treatment of Diabetic Retinopathy Study charts were used at a distance of 4 m. Different levels of defocus were introduced in 0.50-D steps from +1.00 to −4.00 D, and visual acuity values were recorded.
All statistical analyses were performed using SPSS statistical software (version 19.0; SPSS, Inc., Chicago, IL). The chi-square or Fisher's exact test was used to compare qualitative variables between groups. The Kruskal–Wallis test was used to check the normality of the quantitative variables distribution. When normality was achieved, the Student's t test for unpaired data was used for the comparison between groups; when normality was not achieved, the Mann–Whitney U test was used. Differences with a P value of less than .05 were considered to be statistically significant.
Thirty patients (60 eyes) had bilateral implantation of the bifocal IOL and 25 patients (50 eyes) received the trifocal IOL. No intraoperative complications occurred. No corneal decompensation, glaucoma, posterior capsular opacification, or cystoid macular edema was observed during the follow-up period. There was no significant difference in age, gender, preoperative vision, corneal astigmatism, axial length, ACD, IOL power, target spherical equivalent (SRK/T), or postoperative spherical equivalent between groups (Table A, available in the online version of this article).
Clinical and Demographic Data of Patients Implanted With Trifocal or Bifocal IOLs
No statistically significant difference was found in UDVA (P = .41) or CDVA (P = .16) between groups at 3 months after surgery, with all eyes achieving 0.03 logMAR (20/20 Snellen) or better in UDVA. In contrast, UIVA, CIVA, and DCIVA measured at 80 cm were significantly better in the trifocal IOL group (mean: 0.08 logMAR or 20/25 in UIVA) compared to the bifocal IOL group (mean: 0.26 logMAR or 20/40 in UIVA) (all P < .01). In both groups, all patients had UNVA, CNVA, and DCNVA of 0.15 logMAR (20/32) or better (P = .22, .05, and .15, respectively) (Table 1). The refractive outcomes are shown in Figure 1.
3-Month Postoperative Visual Acuities of Patients Implanted With Trifocal or Bifocal IOLs
Graphs of refractive outcomes for bifocal and trifocal intraocular lenses: (A) uncorrected distance visual acuity (UDVA); (B) UDVA vs corrected distance visual acuity (CDVA); (C) spherical equivalent refraction accuracy; (D) postoperative refractive cylinder. D = diopters
Figure 2 shows the mean defocus curves obtained in the two groups. The difference in visual acuities corresponding to the levels of defocus simulating the intermediate vision was significant between groups. Specifically, the visual acuity was much better in the trifocal IOL group compared to the bifocal IOL group for the defocus levels of −1.00 D (P < .01), −1.50 D (P < .01), and −2.00 D (P < .01).
Mean defocus curve in the bifocal (blue line) and trifocal (orange line) intraocular lens groups. D = diopters
Optimization of A-Constant
We summarized the postoperative spherical equivalent (mean: −0.19 D) and target spherical equivalent (mean: 0.15 D) for 50 eyes with the AT LISA tri 839MP IOL and optimized A-constant from 118.9 to 118.6. The postoperative spherical equivalent (mean: 0.03 D) and target spherical equivalent (mean: 0.16 D) for 60 eyes with the AT LISA 809M IOL were also evaluated with A-constant optimized from 118 to 117.8.
Figure 3 displays the corneal, internal, and ocular aberrometic data in the two groups at 3 months after surgery. Postoperatively, no statistically significant difference in corneal, internal, or ocular optics was found at the 4-mm pupil diameter (P ≥ .08). In both groups, the mean total HOAs in corneal, internal, and ocular optics were 0.16 µm or lower, 0.14 µm or lower, and 0.17 µm or lower, respectively. The low ocular spherical aberration values (0.02 µm for bifocal IOLs and 0.01 µm for trifocal IOLs) resulted from negative internal spherical aberration values (−0.03 µm for both IOLs) compensating for the positive corneal spherical aberration values (0.05 µm for bifocal IOLs and 0.04 µm for trifocal IOLs).
Distribution of postoperative corneal, internal, and ocular higher-order aberrations in the bifocal (dark blue bars) and trifocal (light blue bars) intraocular lens groups.
Figure 4 demonstrates the mean MTFs obtained in the two groups. At the 4-mm pupil diameter, equivalent levels of MTFs were obtained in both types of IOLs and there was no statistically significant difference in MTFs between groups from 5 to 30 cycles per degree (P ≥ .54).
Mean modulation transfer functions (MTFs) in the bifocal (blue line) and trifocal (orange line) intraocular lens groups. cpd = cycles per degree
The VF-14 questionnaire yielded a mean value of 93.58 (range: 67.86 to 98.21) in the trifocal IOL group and 90.09 (range: 75 to 100) in the bifocal IOL group (P = .04) for evaluation of the difficulty in performing vision-related activities. Most patients with the trifocal IOLs reported no or little difficulty, whereas the bifocal IOL group complained of mild or moderate difficulty in doing fine handwork, cooking, and playing card games, which was significant (P ≤ .04) (Table B, available in the online version of this article).
Mean Values on the Postoperative National Eye Institute Visual Functioning Questionnaire-14,
Satisfaction and Visual Disturbances
Only 1 patient (4%) with trifocal IOLs had spontaneous complaints about visual disturbances. The halos were more frequent than glare in both groups (Figure 5). The halos were present in 84% of the eyes with a trifocal IOL and 86.7% of the eyes with a bifocal IOL (P = .69). In the trifocal IOL group, 40% of the eyes showed glare compared to 33.3% in the bifocal IOL group (P = .38). Twenty-six patients (86.7%) with the bifocal IOLs and 22 patients (88%) with the trifocal IOLs were not bothered at all or only slightly bothered (P = 1.00). In the trifocal IOL group, more than 22 patients (88%) reported no need of spectacles for any distance; in the bifocal IOL group, more than 26 patients (86.7%) were spectacle independent for near and far distances and 24 patients (80%) needed spectacles for intermediate distance (Figure 6). Overall, 92% of the patients with trifocal IOLs were satisfied, compared to 90% of the patients with bifocal IOLs (P = .81).
Frequencies of halos and glare after the implantation of the bifocal and trifocal intraocular lenses.
Rates of spectacle independence at different distances.
In the current study, the bifocal AT LISA 809M IOLs and the trifocal AT LISA tri 839MP IOLs with an identical IOL platform design were used to compare the visual outcomes, as well as subjective and objective optical quality. Preoperatively, there was no significant difference in age, gender, axial length, ACD, keratometry, or IOL power between eyes with the two types of IOLs. The difference in postoperative UDVA and CDVA was insignificant between the two groups, just as reported in previous series.7,17 There was also no significant difference in UNVA, CNVA, or DCNVA between the two groups, which is not coincident with the results of the study by Mojzis et al.,7 in which the near visual acuities were better in the trifocal IOL group. They used IOLs from the same manufacturer, but the lens shape and length were different. In our series, the same IOL platform was used in the surgery. In many comparative studies about the bifocal and trifocal diffractive IOLs, no significant difference was observed in distance or near visual outcomes between different IOL models.2,3,6 Vega et al.12 reported similar optical imaging quality between the AT LISA and AT LISA tri IOLs in distance and near foci in vitro.
In this study, the intermediate vision was much better than expected in the eyes with the trifocal IOL, which was evidenced by the defocus curve results, showing the significant difference across the intermediate distance range of vision. This finding was similar to previous reports about the trifocal IOLs. Gundersen and Potvin2 and Mojzis et al.7 found that the AT LISA tri 839MP IOLs achieved better visual acuity at −0.50, −1.00, and −1.50 D compared with the ReSTOR SV25T0/SN6AD1 and AT LISA 801 IOLs, respectively. The trifocal FineVision IOLs were reported to perform better at −1.00, −2.00, and −2.50 D compared with the ReSTOR SV6AD2/SN6AD1 IOLs by Bilbao-Calabuig et al.4; at −1.00, −1.50, −2.00, and −2.50 D compared with Tecnis ZMB00 by Cochener6; at −1.50 D only compared with the ReSTOR SND1T by Gundersen and Potvin5; at −1.00 and −1.50 D compared with the ReSTOR SN6AD1 by Plaza-Puche and Alió8; and at −1.00 D only under photopic and mesopic circumstances compared with the ReSTOR SN6AD1 by Jonker et al.3 It was demonstrated recently that a new trifocal IOL (PanOptix, Alcon Laboratories, Inc.) performed better at −1.50 and −2.00 D than the FineVision IOL.18 The trifocal IOLs had two peaks of CDVA at distance and near, whereas there was no distinct peak in the intermediate zone of vision, as observed in our study and previous reports.2,7 At vergences of −1.00, −1.50, and −2.00 D (corresponding to viewing distances from 1 m to 50 cm), the vision with the AT LISA tri IOL was significantly better than the AT LISA IOL.
A decrease in contrast sensitivity is a side effect of diffractive multifocal IOLs compared with monofocal IOLs.9,19,20 HOAs and MTFs were measured by the i-Trace based on ray tracing and compared between groups in this study to evaluate the potential effect on the visual and ocular optical quality. The level of HOA is difficult to express when aberrometry is performed for multifocal lenses,21 and ray tracing seems to be the most adequate platform.22 The threshold of 0.30 µm is admitted to be the level of vision impairment for the total induced HOAs. MTFs, assimilated to contrast sensitivity, which is not really the case, were obtained based on the wavefront measurement in the current study. Equivalent levels of MTFs were acquired in both groups, and the levels of ocular, corneal, and internal HOAs at a 4-mm pupil diameter were not significantly different. In the two groups, the mean total HOAs in corneal, internal, and ocular optics were below 0.17 µm. Moreover, the negative internal spherical aberration values compensated for the positive corneal spherical aberration values and the ocular spherical aberration values were low, which were consistent with the results in previous reports.7,23 Chen et al.24 found no significant difference between the bifocal (Tecnis ZMB00) and monofocal (Tecnis ZCB00) IOLs in MTF cut-off frequency measured by the Optical Quality Analysis System. Mojzis et al.7 displayed similar contrast sensitivity outcomes using the CSV-1000, finding no significant difference in corneal, internal, and ocular aberrometric terms using the OPA-Scan III between trifocal (AT LISA tri 839MP) and bifocal (AT LISA 801M) IOLs. Cochener et al.6 also observed no significant difference in contrast sensitivity tested by the VCTS-6500 chart and in aberrometry detected by the WaveScan wavefront aberrometer between the trifocal (FineVision MicroF) and bifocal (Tecnis ZMB00) IOLs. The performance of different diffractive bifocal and trifocal IOLs detected using different devices proved that the generation of a third focal point does not necessarily decrease the postoperative ocular optical quality. The values of HOAs obtained in this study were of the same magnitude or better than the outcomes reported previously.6,7
Photic phenomena were considered a major concern after multifocal IOLs were introduced. De Vries et al.25 reported that the major complaint of 38.2% of dissatisfied patients was the perception of photic phenomena and subjective complaints included glare and halos. In the study of Mendicute et al.,16 more than 80% of patients perceived some level of halos and more than 40% perceived glare after implantation of the AT LISA tri IOL, but 75% said they were not bothersome. Law et al.26 found a progressive decrease in photic phenomena and a high level of satisfaction after implanting the AT LISA tri IOL. Cochener6 demonstrated that 92% of patients with the FineVision IOL and 67% of patients with the Tecnis ZMB00 IOL presented halos, whereas 58% and 50% of them, respectively, had glare but more than 92% in the two groups reported being satisfied. In the current series, none of the IOLs had to be explanted due to problems with halos or glare. Only one patient spontaneously complained of visual disturbances, and others did not realize they had halos and glare until they were directly questioned. Halos were present in more than 84% of patients and glare in less than 40% in the two groups. However, in the report by Vryghem and Heireman,27 68% of patients with a mean age of 70 years did not see halos, and no patients with the FineVision IOL experienced glare. The difference in age-related visual need may be attributed to the difference in the perception of halos and glare. In the current study, 88% of patients in the trifocal group and 86.7% in the bifocal group were not bothered or only slightly bothered, which was in accordance with previous reports.16,26,27 We also found a similar incidence of halos and glare in the two groups, but Cochener6 reported a higher incidence of halos and glare in the trifocal IOL group than in the bifocal IOL group. The reason may be the difference in IOL models. Moreover, the phenomena decreased with time in other reports,16,26 which might be attributed to pupil miosis and neural adaption.
In the current series, the value of the VF-14 was higher in the trifocal IOL group, especially when intermediate distance vision was required for fine hand-work, cooking, and card games, than in the bifocal IOL group. A high level of spectacle independence and a high rate of patient satisfaction were also displayed in the trifocal IOL group, which is consistent with previous studies.16,26–28 Although 80% of patients were spectacle dependent at intermediate distance in the bifocal IOL group, the level of overall satisfaction was high. This may be a reflection of adequate preoperative communication, careful patient selection, and less expense. It may also be associated with the improved intermediate vision, which was approximately 0.26 logMAR UIVA in this study. The levels of spectacle independence and patient satisfaction in the bifocal group were consistent with the previous reports.3,6
Because of the potential limitations of the study, it should be noted that a pupil size larger than 4 mm to measure the objective optical quality is also important. However, it is difficult to naturally dilate the pupil to become larger in older patients under dark conditions. If the patient's pupil is dilated with medication, it will not be the natural physiological condition. Moreover, the trifocal IOLs built in the trifocal concept in the central area with a diameter of 4.34 mm and built in the bifocal concept in the peripheral ring of 4.34 to 6 mm. To compare the bifocal and trifocal components, the diameter of 4 mm was chosen for analysis.
The trifocal diffractive IOLs provided better intermediate vision without affecting distance or near vision and did not induce extra qualitative vision disturbances when compared to the bifocal diffractive IOLs. However, the evaluation of these parameters requires a larger study population and a longer follow-up period. The trifocal IOL seems to be an optimal option over the bifocal diffractive IOL, but the patient's need should be followed. The bifocal IOLs present equivalent levels of visual performance in distance and near, and are preferred by patients who do not need excellent intermediate vision. The cost of a trifocal IOL is much higher than that of a bifocal IOL, which is also one of the factors that affects the selection of patients.
- Kook D, Kampik A, Dexl AK, et al. Advances in lens implant technology. F1000 Med Rep. 2013;5:3. doi:10.3410/M5-3 [CrossRef]
- Gundersen KG, Potvin R. Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses. Clin Ophthalmol. 2016;10:805–811.
- Jonker SM, Bauer NJ, Makhotkina NY, Berendschot TT, van den Biggelaar FJ, Nuijts RM. Comparison of a trifocal intraocular lens with a +3.0 D bifocal IOL: results of a prospective randomized clinical trial. J Cataract Refract Surg. 2015;41:1631–1640. doi:10.1016/j.jcrs.2015.08.011 [CrossRef]
- Bilbao-Calabuig R, Gonzalez-Lopez F, Amparo F, Alvarez G, Patel SR, Llovet-Osuna F. Comparison between mix-and-match implantation of bifocal intraocular lenses and bilateral implantation of trifocal intraocular lenses. J Refract Surg. 2016;32:659–663. doi:10.3928/1081597X-20160630-01 [CrossRef]
- Gundersen KG, Potvin R. Comparison of visual outcomes after implantation of diffractive trifocal toric intraocular lens and a diffractive apodized bifocal toric intraocular lens. Clin Ophthalmol. 2016;10:455–461.
- Cochener B. Prospective clinical comparison of patient outcomes following implantation of trifocal or bifocal intraocular lenses. J Refract Surg. 2016;32:146–151. doi:10.3928/1081597X-20160114-01 [CrossRef]
- Mojzis P, Kukuckova L, Majerova K, Liehneova K, Piñero DP. Comparative analysis of the visual performance after cataract surgery with implantation of a bifocal or trifocal diffractive IOL. J Refract Surg. 2014;30:666–672. doi:10.3928/1081597X-20140903-06 [CrossRef]
- Plaza-Puche AB, Alió JL. Analysis of defocus curves of different modern multifocal intraocular lenses. Eur J Ophthalmol. 2016;26:412–417. doi:10.5301/ejo.5000780 [CrossRef]
- Plaza-Puche AB, Alió JL, Sala E, Mojzis P. Impact of low mesopic contrast sensitivity outcomes in different types of modern multifocal intraocular lenses. Eur J Ophthalmol. 2016;26:612–617. doi:10.5301/ejo.5000777 [CrossRef]
- Carson D, Hill WE, Hong X, Karakelle M. Optical bench performance of AcrySof((R)) IQ ReSTOR((R)), AT LISA((R)) tri, and FineVision((R)) intraocular lenses. Clin Ophthalmol. 2014;8:2105–2113.
- Gatinel D, Houbrechts Y. Comparison of bifocal and trifocal diffractive and refractive intraocular lenses using an optical bench. J Cataract Refract Surg. 2013;39:1093–1099. doi:10.1016/j.jcrs.2013.01.048 [CrossRef]
- Vega F, Alba-Bueno F, Millan MS, Varon C, Gil MA, Buil JA. Halo and through-focus performance of four diffractive multifocal intraocular lenses. Invest Ophthalmol Vis Sci. 2015;56:3967–3975. doi:10.1167/iovs.15-16600 [CrossRef]
- Son HS, Tandogan T, Liebing S, et al. In vitro optical quality measurements of three intraocular lens models having identical platform. BMC Ophthalmol. 2017;17:108. doi:10.1186/s12886-017-0460-0 [CrossRef]
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- Postolache C, Postolache O. Comparation of refractive results with bifocal implants AT LISA 809 and trifocal AT LISA Tri839. Rom J Ophthalmol. 2015;59:100–2.
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3-Month Postoperative Visual Acuities of Patients Implanted With Trifocal or Bifocal IOLs
| Mean ± SD||0.04 ± 0.10||0.02 ± 0.09|
| Range||−0.10 to 0.20||−0.10 to 0.20|
| Mean ± SD||−0.01 ± 0.08||−0.04 ± 0.07|
| Range||−0.10 to 0.10||−0.10 to 0.10|
|logMAR UIVA||< .01|
| Mean ± SD||0.26 ± 0.13||0.08 ± 0.10|
| Range||0.00 to 0.50||−0.10 to 0.30|
|logMAR DCIVA||< .01|
| Mean ± SD||0.21 ± 0.12||0.06 ± 0.08|
| Range||0.00 to 0.40||−0.10 to 0.20|
|logMAR CIVA||< .01|
| Mean ± SD||0.10 ± 0.07||0.02 ± 0.05|
| Range||0.00 to 0.20||−0.10 to 0.10|
| Mean ± SD||0.15 ± 0.13||0.11 ± 0.11|
| Range||0.00 to 0.40||−0.10 to 0.30|
| Mean ± SD||0.09 ± 0.07||0.07 ± 0.08|
| Range||0.00 to 0.20||−0.10 to 0.30|
| Mean ± SD||0.06 ± 0.08||0.02 ± 0.09|
| Range||−0.10 to 0.20||−0.10 to 0.20|
|UDVA ≥ logMAR 0.1||26 (86.7%)||23 (92.0%)||1.00|
|UIVA ≥ logMAR 0.1||6 (20.0%)||20 (80.0%)||< .01|
|UNVA ≥ logMAR 0.1||16 (53.3%)||17 (68.0%)||.41|
Clinical and Demographic Data of Patients Implanted With Trifocal or Bifocal IOLs
|Age (y)||50.5 ± 7.7||49.7 ± 12.6||.06|
|Preoperative VA (logMAR)||0.80 ± 0.34||0.76 ± 0.19||.71|
|Corneal astigmatism (D)||0.61 ± 0.50||0.72 ± 0.34||.94|
|AL (mm)||23.34 ± 1.09||24.02 ± 1.31||.06|
|ACD (mm)||3.16 ± 0.52||3.35 ± 0.40||.19|
|IOL power (D)||19.76 ± 3.01||18.77 ± 3.31||.30|
|Target SE (SRK/T)||0.16 ± 0.16||0.15 ± 0.18||.41|
|Postoperative SE (D)||0.03 ± 0.37||−0.19 ± 0.36||.09|
Mean Values on the Postoperative National Eye Institute Visual Functioning Questionnaire-14a,b
|Activity||Trifocal IOL||Bifocal IOL||P|
|1. Reading small print, such as medicine bottle labels, a telephone book, or food labels||3.59 ± 0.64||3.65 ± 0.66||.76|
|2. Reading a newspaper or book||3.78 ± 0.51||3.74 ± 0.51||.79|
|3. Reading a large-print book or large-print newspaper or numbers on a telephone||3.96 ± 0.19||3.94 ± 0.25||.64|
|4. Recognizing people when they are close to you||3.96 ± 0.19||3.81 ± 0.40||.07|
|5. Seeing steps, stairs, or curbs||3.96 ± 0.19||3.97 ± 0.18||.92|
|6. Reading traffic signs, street signs, or store signs||3.93 ± 0.27||3.97 ± 0.18||.48|
|7. Doing fine handwork like sewing, knitting, crocheting, or carpentry||3.15 ± 0.67||2.84 ± 0.52||.04|
|8. Writing checks or filling out forms||3.40 ± 0.57||3.32 ± 0.48||.54|
|9. Playing games such as bingo, dominos, card games, or mahjong||3.89 ± 0.32||3.10 ± 0.54||< .01|
|10. Taking part in sports like bowling, handball, tennis, or golf||3.93 ± 0.27||3.78 ± 0.50||.07|
|11. Cooking||3.93 ± 0.27||3.68 ± 0.48||.02|
|12. Watching television||3.89 ± 032||3.90 ± 0.30||.86|
|13. Driving during the day||3.93 ± 0.27||3.84 ± 0.37||.32|
|14. Driving at night||3.11 ± 0.51||3.13 ± 0.43||.88|