|Year : 2014 | Volume
| Issue : 3 | Page : 166-170
Multifocal intraocular lens: Current scenario
Rajesh Sinha, Vijay K Sharma, Tarun Arora, Namrata Sharma, Jeewan S Titiyal
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
|Date of Submission||03-Jun-2014|
|Date of Acceptance||03-Jun-2014|
|Date of Web Publication||16-Aug-2014|
Dr. Rajesh Sinha
Cornea, Lens and Refractive Surgery Services, 474, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sinha R, Sharma VK, Arora T, Sharma N, Titiyal JS. Multifocal intraocular lens: Current scenario. J Clin Ophthalmol Res 2014;2:166-70
|How to cite this URL:|
Sinha R, Sharma VK, Arora T, Sharma N, Titiyal JS. Multifocal intraocular lens: Current scenario. J Clin Ophthalmol Res [serial online] 2014 [cited 2023 Jan 31];2:166-70. Available from: https://www.jcor.in/text.asp?2014/2/3/166/138866
Improvement in medical technology and surgical techniques along with patients' increasing expectations has fuelled the quest for superior vision. This has led to rapid evolution in the field of intraocular lens (IOL) manufacture. Multifocal IOLs have been designed to solve the problem of presbyopia after cataract extraction, so that the patient does not need reading glasses. These IOLs provide high levels of spectacle independence and their mechanism of action is independent of the ciliary body function. They are currently the most reliable lens for attaining both distance and near vision. This review aims at exploring the various indications, contraindications, outcome, complications, patient selection criteria and further evolving trends for multifocal IOLs.
| Indications|| |
Cillino et al. (Ophthalmology 2014;121:34-44) compared visual outcomes, reading performance, and quality of life (QoL) of working-age cataractous patients bilaterally implanted with three different diffractive multifocal intraocular lenses (MIOLs) in a randomized, prospective, and double-masked study. Sixty-three consecutive patients (126 eyes) were randomized to receive the ReSTOR SN6AD3 (Alcon Laboratories, Inc., Irvine, CA, USA) (20 patients, group A), ReSTOR SN6AD1 (Alcon Laboratories, Inc.) (21 patients, group B), or TECNIS ZMA00 (Abbott Medical Optics, Santa Ana, CA, USA) (22 patients, group C) MIOL. They concluded that newer-generation aspheric diffractive MIOLs, especially low-add hybrid apodized or full diffractive, are highly suited for working-age cataractous patients in terms of visual outcomes, reading performance, and QoL. Intrinsic optical differences, such as optimization for computer or dim-light working, or night driving, could be useful tools to customize the IOL in each single case.
Jacobi et al. (Ophthalmology 2002;109:2315-24) reported that secondary scleral-fixated multifocal IOL implantation was as successful as monofocal IOL implantation in achieving best corrected visual acuity (BCVA) comparable with preoperative BCVA. Moreover, stereopsis, uncorrected and distance-corrected near visual acuities were better in the multifocal patients than in the monofocal eyes making multifocal IOL a viable alternative in children and young patients with contact lens-intolerant aphakia.
Jacobi et al. (Ophthalmology 2001;108:1375-80) separately reported that multifocal IOL is a viable alternative to monofocal IOL in pediatric patients in the age group 2-14 years and in eyes with traumatic cataract.
Petermeier et al. (Br J Ophthalmol 2009;93:1296-301) reported that patients with anisometropic amblyopia may benefit from implantation of an AcrySof ReSTOR.
Souza et al. (J Refract Surg 2006;22:303-5) reported that in young patients with unilateral cataract, multifocal IOL implantation provides satisfactory visual acuity (VA).
| Diffractive Multifocal Intraocular Lenses|| |
Hayashi et al. (J Cataract Refract Surg 2009;35:2070-6) reported that the diffractive multifocal IOL with a low add power (ReSTOR SN6AD1* IOL with a +3.0 D add) provided significantly better intermediate and near VA than the monofocal (AcrySof IQ SN60WF) IOL. Contrast sensitivity (CS) with and without glare was reduced with multifocal IOL, and all-distance VA was independent of pupil diameter.
Castillo-Gómez et al. (J Cataract Refract Surg 2009;35:1244-50) compared visual quality after bilateral implantation of AcriLISA 366D, Carl Zeiss Meditec, Jena, Germany (group A) or Tecnis ZM900 (group B) multifocal IOLs. They reported that both diffractive multifocal IOLs improved functional visual capacity at a distance and near and were comparable.
Alfonso et al. (Eur J Ophthalmol 2009;19:748-53) implanted multifocal IOL (AcrySof ReSTOR Natural SN60D3*) and reported good VA and CS for both distance and near, with and without distance correction in eyes with high and low myopia. Better results were seen in low myopic eyes compared to high levels of myopia. They also reported a better VA and CS for both distance and near, with and without distance correction in eyes with low hyperopia compared to high levels of hyperopia after implantation of the same IOL.
Cionni et al. (J Cataract Refract Surg 2009;35:1033-9) reported that although unilateral implantation of apodized diffractive (Acrysof ReSTOR*) multifocal IOL provided patients with high levels of spectacle freedom and good CS, overall clinical results favored bilateral implantation for stereopsis, uncorrected near VA, and BCVA for near and intermediate distance.
| Refractive Multifocal Intraocular Lenses|| |
Kawamorita et al. (J Refract Surg 2009;25:467-9) reported that ReZoom refractive multifocal IOL gave better image quality than the array refractive multifocal IOL, particularly at distant focus. For good near vision, the desired pupil size should be at least 3.45 mm.
Fernandez-Vega et al. (Am J Ophthalmol 2009;148:214-20) reported that bilateral implantation of the Acri.LISA 366D IOL provided a satisfactory full range of vision in patients with high hyperopia (IOL power 25-36 D) comparable with that obtained in patients with low to moderate hyperopia.
Hayashi et al. (Ophthalmology 2009;116:401-8) observed that the refractive multifocal IOL (Hoya SFX MV1 Hoya Medical Europe, Frankfurt/Main, Germany) with minimal added power provided significantly better intermediate and near VA than a monofocal IOL.
Alió et al. (J Cataract Refract Surg 2012;38:978-85) compared the visual outcomes and intraocular optical quality in patients with a low-addition (add) power multifocal refractive IOL with rotational asymmetry and a single-optic accommodating IOL in a prospective comparative nonrandomized consecutive case series. Of the 66 eyes (40 patients; age 61-81 years), 31 were in the multifocal group and 35 were in the accommodating group. Postoperatively, both groups had a significant improvement in the uncorrected and corrected distance VAs and uncorrected near visual acuity (UNVA) and corrected near visual acuity (CNVA) (P < 0.01). Distance-CNVA was significantly better in the multifocal group postoperatively (P ≤ 0.04). No significant differences in UNVA and CNVA were detected postoperatively (P ≥ 0.09). In the defocus curve, the multifocal group had significantly better visual acuities at several defocus levels. The accommodating group had better CS under photopic conditions at all spatial frequencies (P ≤ 0.04). The multifocal group had significantly higher postoperative intraocular tilt (P < 0.01). Hence, they concluded that both IOLs restored distance vision. The refractive multifocal IOL provided better near visual rehabilitation.
| Diffractive and Refractive Multifocal Intraocular Lenses: 'Mix and Match'|| |
Hutz et al. (Eur J Ophthalmol 2009) reported that the combination of a far dominant refractive (ReZoom) multifocal IOL (with better distance performance) in one eye with a near dominant diffractive (Tecnis ZM900) multifocal IOL (with better near vision) in the other eye proved to be very suitable to help meet cataract patients' visual needs.
Chen et al. (Acta Ophthalmol 2009) reported that the combined implantation of refractive and diffractive multifocal (ReZoom and Tecnis MF) IOLs improved reading ability and near stereoacuity with a good visual quality.
Ortiz et al. (J Cataract Refract Surg 2008;34:755-62) implanted a refractive multifocal IOL (ReZoom) in their dominant eye and a diffractive multifocal IOL (Tecnis) in their nondominant eye and reported good visual outcomes with this "mix and match" approach.
Gierek-Ciaciura et al. (Graefes Arch Clin Exp Ophthalmol 2009) compared the patients' visual results after bilateral implantation of three groups of MIOLs: ReZoom NXG1, Acrysof ReSTOR SA60D3 and Tecnis MF ZM900. The results were comparable with regard to BCVA, glare, and halo.
Zelichowska et al. (J Cataract Refract Surg 2008;34:2036-42) implanted refractive (ReZoom) or apodized diffractive multifocal IOLs (AcrySof ReSTOR) and noted that both IOLs provided good visual performance at a distance and near under photopic conditions. The HOA, in particular coma and SA, and photopic CS were significantly higher in the ReZoom group (P < 0.001).
Alfonso et al. (J Cataract Refract Surg 2008;34:1848-54) reported that diffractive multifocal IOLs provided good and comparable VA at a distance and near when implanted in patients with previous myopic laser in-situ keratomileusis. However, the aspheric Acri.LISA IOL gave better intermediate VA than the spherical AcrySof ReSTOR IOL.
Cillino et al. (Ophthalmology 2008;115:1508-16) performed a randomized prospective clinical trial comparing visual performance after bilateral implantation of the multifocal refractive Array SA40N, multifocal refractive ReZoom, multifocal diffractive pupil-independent Tecnis ZM900 and monofocal IOLs. The monofocal IOL group exhibited a lower uncorrected and best distance-CNVA than the multifocal IOL groups (P < 0.0005). New-generation, diffractive, pupil-independent multifocal IOLs provided better near vision, equivalent intermediate vision with less unwanted photic phenomena, and greater spectacle independence than either monofocal or refractive multifocal IOLs.
Ortiz et al. (J Cataract Refract Surg 2008;34:755-62) reported that multifocal refractive IOLs resulted in higher intraocular aberrations. The hybrid refractive-diffractive IOL was least affected by pupil diameter in terms of intraocular aberrations.
Martínez Palmer et al. (J Refract Surg 2008;24:257-64) evaluated the visual function of three types of multifocal IOLs: symmetric diffractive multifocal Tecnis ZM900; zonal refractive multifocal ReZoom; and asymmetric diffractive multifocal TwinSet (Acri.Tec) IOLs with Tecnis monofocal IOL as the control group in a prospective, randomized, and controlled clinical study of 114 patients. They reported that the monofocal IOL showed better visual function and lesser photic phenomena than multifocal IOLs but patients were spectacle dependent. ReZoom provided better distance BCVA than the TwinSet diffractive model. Patients with Tecnis and TwinSet diffractive multifocal IOLs were more spectacle independent than patients with ReZoom. Patients with TwinSet had less favorable CS scores. Patients with Tecnis diffractive ZM900 IOL reported more photic phenomena.
| Outcome and Complications|| |
Schmickler et al. (Br J Ophthalmol 2013;97:1560-4) evaluated multifocal aspheric diffractive IOL (ZMB00 1-Piece Tecnis multifocal IOL) in 104 eyes of 52 patients. The residual refractive error was 0.01 ± 0.47 D with 56% of eyes within ±0.25 D and 97% within ±1.0 D. Uncorrected visual acuity (UCVA) was 0.02 ± 0.10 log of the minimum angle of resolution (logMAR) at a distance and 0.15 ± 0.30 logMAR at near, only reducing to 0.07 ± 0.10 logMAR at a distance and 0.21 ± 0.25 logMAR at near in mesopic conditions. The defocus curve showed a near addition between 2.5 and 3.0 D allowing a reading acuity of 0.08 ± 0.13 logMAR. Spectacle independence was 100% for distance and 88% for near, with high levels of satisfaction reported. Overall rating of vision without glasses could be explained (r = 0.760) by preoperative best corrected distance acuity, postoperative reading acuity and postoperative uncorrected distance acuity in photopic conditions (P < 0.001). Only two minor adverse events occurred. They concluded that ZMB00 1-Piece Tecnis multifocal IOL provides a good visual outcome at a distance and near with minimal adverse effects.
Liu et al. (Int J Ophthalmol 2013;6:690-5) studied visual function and higher order aberration after implantation of aspheric and spherical MIOLs and overall findings indicated that aspheric multifocal IOL and spherical multifocal IOL provided similar VA at near and distance. Patients implanted with aspheric multifocal IOL had less spherical aberration and higher order aberration than patients with spherical multifocal IOL.
de Vries et al. (J Cataract Refract Surg 2011;37:859-65) studied dissatisfaction after implantation of MIOLs and 76 eyes of 49 patients were included in the study. Blurred vision (with or without photic phenomenon) was reported in 72 eyes (94.7%) and photic phenomena (with or without blurred vision) in 29 eyes (38.2%). Both symptoms were present in 25 eyes (32.9%). Residual ametropia and astigmatism, posterior capsule opacification (PCO), and a large pupil were the three most significant etiologies. Sixty-four eyes (84.2%) were amenable to therapy, with refractive surgery, spectacles, and laser capsulotomy the most frequent treatment modalities. IOL exchange was performed in three cases (4.0%).
Woodward et al. (J Cataract Refract Surg 2009;35:992-7) analyzed the reasons for patient dissatisfaction after multifocal IOL implantation. Thirty-two patients (43 eyes) reported unwanted visual symptoms after multifocal IOL implantation, that included 28 eyes (65%) with an AcrySof ReSTOR IOL and 15 (35%) with a ReZoom IOL. Thirty patients (41 eyes) reported blurred vision, 15 (18 eyes) reported photic phenomena, and 13 (16 eyes) reported both. Causes of blurred vision included ametropia (12 eyes, 29%), dry eye syndrome (6 eyes, 15%), and unexplained etiology (1 eye, 2%). Causes of photic phenomena included IOL decentration (2 eyes, 12%), retained lens fragment (1 eye, 6%), PCO (12 eyes, 66%), dry eye syndrome (1 eye, 2%), and unexplained etiology (2 eyes, 11%). Three eyes (7%) required IOL exchange. The authors recommended that neodymium-doped yttrium aluminum garnet (Nd:YAG) capsulotomy should be delayed until it has been determined that IOL exchange will not be necessary.
Jendritza et al. (J Refract Surg 2008;24:274-9) studied wavefront-guided excimer laser vision correction after multifocal IOL implantation in a prospective, nonrandomized case series in 27 eyes of 19 patients (Tecnis diffractive IOL, n = 20; ReSTOR diffractive IOL, n = 4; ReZoom refractive IOL, n = 3). In the Tecnis group, results before (after) laser in situ keratomileusis (LASIK) were: sphere +1.06 ± 0.77 D (−0.03 ± 0.28 D; P = 0.0001), cylinder −1.13 ± 0.73 D (−0.14 ± 0.25 D; P = 0.00004), distance UCVA 20/45 ± 0.09 (20/29 ± 0.16; P = 0.00004), near UCVA 20/30 ± 0.24 (20/25 ± 0.16; P = 0.001), and higher order aberrations (4-mm pupil) 0.14 ± 0.05 micron (0.18 ± 0.03 micron; P = 0.02). Distance and near best spectacle-corrected visual acuity (BSCVA) did not change. In the ReSTOR group, results before (after) LASIK were: sphere +0.75 ± 0.56 D (+0.13 ± 0.22 D), cylinder −1.50 ± 0.47 D (−0.13 ± 0.22 D), distance UCVA 20/40 ± 0.07 (20/26 ± 0.07), near UCVA 20/44 ± 0.05 (20/25 ± 0.0), and higher order aberrations (4-mm pupil) 0.14 ± 0.03 μm (0.20 ± 0.02 μm). Distance and near BSCVA did not change. In the ReZoom group, results before (after) LASIK were: sphere +0.08 ± 1.20 D (0.00 D), cylinder −0.83 ± 0.120 D (0.00 D), distance UCVA 20/40 ± 0 (20/25 ± 0), near UCVA 20/60 ± 0.09 (20/150 ± 0.18), and higher order aberrations (4-mm pupil) 0.43 ± 0.04 μm (0.39 ± 0.03 μm). Patients lost one line of distance BSCVA and two lines of near BSCVA. They concluded that wavefront-guided LASIK is safe and effective in diffractive multifocal IOLs to correct residual refractive error but higher order aberrations did not improve. It is not recommended in refractive multifocal IOLs, as these cannot be measured reliably with current wavefront sensors.
Leyland and Zinicola (Ophthalmology 2003;110:1789-98) reported reduced CS and subjective experience of halos around lights with these IOLs.
Gauthier et al. (J Cataract Refract Surg 2010;36:1195-200) studied Nd:YAG laser rates after bilateral implantation of hydrophobic or hydrophilic MIOLs in a 24-month retrospective comparative study.
This study included patients with cataract or clear lenses who had bilateral implantation of AcrySof ReSTOR hydrophobic or Acri.LISA hydrophilic acrylic multifocal IOLs between May 2004 and June 2009. The hydrophobic IOL group comprised 80 patients and the hydrophilic IOL group, 76 patients. There were significantly more men in the hydrophobic group (51.3%) than in the hydrophilic group (30.7%) and patients were significantly younger in the hydrophobic group (63.0 years vs. 65.8 years) (both P < 0.01). Eighteen months postoperatively, 4.4% of eyes in the hydrophobic group and 14.6% of eyes in the hydrophilic group required Nd:YAG laser capsulotomy. After 24 months, the respective rates were 8.8% and 37.2% (P < 0.0001). Eyes in the hydrophilic group had a 4.50-fold (2.28 vs. 8.91) higher risk for Nd:YAG laser capsulotomy (P < 0.0001) that persisted after adjusting for age (relative risk 4.64, 2.32-9.29) (P < 0.0001). Patients younger than 63.5 years in the hydrophilic group were more likely to require Nd:YAG laser capsulotomy. They concluded that capsulotomy was significantly less frequent after hydrophobic IOL implantation than after hydrophilic IOL implantation 24 months postoperatively.
Ito and Shimizu (J Cataract Refract Surg 2009;35:1501-4) reported that the reading ability after bilateral cataract surgery was better in patients who had pseudophakic monovision than patients who had refractive multifocal IOL implantation.
Hofmann et al. (J Refract Surg 2009;25:485-92) reported that patients with diffractive IOL had significantly more glare for all light conditions, especially at night.
Negishi et al. (Jpn J Ophthalmol 2005;49:281-6) reported that up to 1.0 mm of decentration of a monofocal and multifocal IOL would not greatly affect the retinal image quality.
Elgohary et al. (J Cataract Refract Surg 2007;33:342-7) reported opacification of two silicone multifocal IOLs.
Inoue et al. (J Cataract Refract Surg 2009;35:1239-43) reported aberrations with diffractive multifocal IOLs and attributed it to the optical design of the IOLs.
Auffarth and Dick (Ophthalmologe 2001;98:127-37) in their review opined that earlier multifocal IOLs were associated with decentration, surgically-induced astigmatism, reduced CS and increased glare. The newer multizonal, progressive refractive IOLs combined with improved surgical techniques have overcome those problems.
| Neuroadaptation|| |
Palomino Bautista et al. (Eur J Ophthalmol 2009;19:762-8) in their study with multifocal Tecnis IOL in 250 eyes observed that most patients required a neuroadaptation period of nearly 6 months to experience full visual benefits of the lens.
Kaymak et al. (J Refract Surg 2008;24:287-93) investigated the efficacy of a special visual training program on the postoperative visual performance with ReSTOR and Tecnis IOLs and reported an accelerated visual performance by a specific 2-week training program. This effect was sustained over a 6-month period.
Marjan Farid, et al. (Am J Ophthalmol 2014, article in press) evaluated mean deviation values in automated perimetry in eyes with multifocal compared to monofocal IOL implants in a prospective, age-matched, and comparative analysis.
A total of 37 healthy eyes in 37 patients with bilateral multifocal (n - 22) or monofocal (n - 15) IOL implants were studied. Humphrey visual field 10-2 testing was performed on all patients. Mean deviation (MD) and pattern standard deviation (PSD) numerical values were evaluated and compared between groups. They concluded that multifocal IOL implants cause significant nonspecific reduction in MD values on Humphrey visual field 10-2 testing that does not improve with time or neuroadaptation. Multifocal IOL implants may be inadvisable in patients where central visual field reduction may not be tolerated, such as macular degeneration, retinal pigment epithelium changes, and glaucoma.
Wilkins et al. (Ophthalmology 2013;120:2449-55) compared spectacle independence in patients randomized to receive bilateral MIOLs or monofocal IOLs with the powers adjusted to produce monovision. They studied a total of 212 patients with bilateral, visually significant cataract and concluded that patients randomized to bilateral implantation with the diffractive multifocal Tecnis ZM900 were more likely to report being spectacle independent but also more likely to undergo IOL exchange than those randomized to receive monofocal implants (Akreos AO) with the powers adjusted to give low monovision.
Gundersen and Potvin (Clin Ophthalmol 2013;7:1979-85) studied comparative visual performance of ReSTOR +2.5 D apodized diffractive multifocal IOL, monofocal AcrySof IQ lens and the ReSTOR +3.0 D IOL. The data indicate that the ReSTOR +2.5 D IOL provided good intermediate and functional near vision for patients who did not want to accept a higher potential for visual disturbances associated with the ReSTOR +3.0 D IOL, but wanted more near vision than a monofocal IOL generally provides. Quality of vision was not significantly different between the multifocal IOLs, but patient self-selection for each lens type may have been a factor. Postoperative VA data showed that the ReSTOR +2.5 D provided much better intermediate and near vision than a monofocal IOL, but the near vision was not as good as the ReSTOR +3.0 D lens. The preferred reading distance for subjects with the ReSTOR +2.5 D IOL implanted was about 50 cm, slightly further out than the 40 cm distance of the ReSTOR +3.0 D, consistent with the lens design. Near VA at the preferred reading distance was equivalent to the VA provided by the ReSTOR +3.0 D IOL and significantly better than that provided by the AcrySof IQ monofocal. Again, as a measure of usable near vision, the data indicate that the ReSTOR +2.5 D IOL is an effective improvement over a monofocal lens. The tradeoff for the ReSTOR +2.5 D design relative to the ReSTOR +3.0 D design in terms of retaining more light for distance vision was expected to be better distance VA and lower levels of visual disturbance for the former lens. Distance VA for all three tested lenses was excellent, so no significant differences were observed. However, lower contrast VA provided some indication that the ReSTOR +2.5 D IOL design provided distance VA closer to a monofocal lens than to the ReSTOR +3.0 D lens, though the results were not statistically significant.
| Future - Conquering Presbyopia|| |
Patel et al. (J Refract Surg 2008;24:294-9) compared the visual outcomes of two IOLs (AcriSmart [multifocal] and AT-45 [accommodative]) for correction of distance and near VA with LASIK procedure for presbyopia (presbyLASIK) and a control group fitted with a standard distance-correcting monofocal IOL (Acrysof). The distance and near acuities improved with presbyLASIK and AcriSmart IOLs when compared with controls. In those patients treated with the AT-45 IOL, average VA improved for distance but not for near.
Sandstedt et al. (Trans Am Ophthalmol Soc 2006;104:29-39) assessed the feasibility of creating customized multifocal and aspheric patterns onto a light-adjustable lens (LAL) using a digital light delivery (DLD) system. Silicone LALs were placed in a wet cell and irradiated in vitro using the DLD. Spatial intensity patterns were designed and generated to create a multifocal optic with customized power and diameter and simultaneously correct defocus and spherical aberration. In addition, the LALs were adjusted in vivo for defocus and spherical aberration using a rabbit model. In vitro creation of multifocal patterns demonstrated ability to reproducibly customize zone diameter and power. Both bull's-eye bifocal and annular patterns were successfully created on LAL. Spherical aberration was reduced simultaneously with correction of hyperopia and myopia, both in vitro and in vivo. In addition, these customized spatial intensity profiles can be written onto an LAL that is first adjusted to emmotropia. The ability to readjust the LAL was demonstrated.
Lichtinger et al. (Eur Ophthalmic Rev 2012;6:108-11) reviewed the design, development and clinical results of the LAL. Evolution in techniques, biometry, and IOL power calculation have improved outcomes and increased expectations after cataract surgery. Nevertheless, imprecise IOL power determinations, preexisting and surgical-induced astigmatism, and previous corneal refractive surgery continue to limit postoperative uncorrected vision. The LAL was designed to provide a stable, precise correction of refractive errors with a safe, noninvasive postoperative procedure. The concept behind the LAL is based on photochemistry and diffusion. The adjustment occurs when all nonattached solutes equally distribute themselves throughout the optic after irradiation with ultraviolet light that causes the photosensitive macromers to polymerize in the irradiated region. Clinical results have been positive, with the largest series (122 eyes) showing 97% of patients within 0.25 D of attempted spherical equivalent and 100% uncorrected vision 20/25 or better.