Multifocal and Trifocal Lenses in Post-Lasik Eyes

EDITORIAL SPOTLIGHT

Courtesy of Cyres Keiki Mehta, MD - CATARACT & REFRACTIVE SURGERY TODAY EUROPE

JUNE 2017 D, FEBO h In patients with a visually significant cataract, the onlythe cataract, significant visually a with patients In tolens of power which is cases these in conundrum The Typically, we can exercise two options in these cases. Incases. these in options two exercise can we Typically, Figure 2. Injecting the FineVision trifocal IOL. trifocal FineVision the Injecting 2. Figure focus by increasing spherical aberration. The difficulty with thiswith difficulty The aberration. spherical increasing by focus distance excellent had having patients, some that is approach distance;for blurred eye one want not do years, these all vision orphones their on whether print, fine read to want also they younger. were they when did they as books, in or devices oftenmost I Today, IOL. multifocal a implant to is option (Carltri LISA AT design—the trifocal a patients these offer (PhysIOL;trifocal FineVision the or 1) Figure Meditec; Zeiss IOLSymfony vision of range extended the 2)—or Figure byjoined be will lenses These Vision). Johnson & (Johnson myin available is it once (Alcon) PanOptix IQ AcrySof the ver toric a in available is tri LISA AT the India, In country. thanmore with patients In not. is FineVision the but sion, lens. toric a for opt always I cylinder, D 0.50 THE CONUNDRUM emmetropiato close as is result final the that so implant presbyopes, we can lift the LASIK flap and perform laserperform and flap LASIK the lift can we presbyopes, blendedLaser strategy. laser excimer another or vision blended dominantthe wherein monovision, creates essentially vision toeye nondominant the and D -0.50 to corrected is eye ofdepth increased provides also ablation The D. -1.50 to -1.25 - -

- - - B D The conundrum in post-LASIK cases is post-LASIK in conundrum The IOL power. appropriate the determining By Cyres Keiki Mehta, MD par surgery, refractive of advent the With Postoperative Astigmatism: Astigmatism: Postoperative IOLs Multifocal of Enemy The

C A The most frequent comment anterior segment surgeonssegment anterior comment frequent most The Figure 1. AT LISA tri: Preloaded (A) and in the injector (B).injector the in and (A) Preloaded tri: LISA AT 1. Figure theAligning (C). overlay toric with tri LISA AT the Injecting (D). system overlay markerless the with IOL toric

surgery; what are my options?” or, in the case of presbyopes,of case the in or, options?” my are what surgery; all.” at glasses reading wear to want don’t “I desire to be spectacle-free. be desireto presby or cataract of subgroup this counseling when hear cataractafter glasses wear to want don’t “I is, patients opic have since developed presbyopia, and some have devel have some and presbyopia, developed since have mul a or trauma, diabetes, aging, to due cataract oped their maintain still they However, causes. other of titude ticularly LASIK, in the 1990s, patients finally gained access gained finally patients 1990s, the in LASIK, ticularly indepen spectacle achieve to option painless and safe a to population patient early this in individuals Many dence. BY CYRES KEIKI MEHTA, MD; AND PETER MOJZIS, MD, P MOJZIS, MD, MEHTA, MD; AND PETER KEIKI CYRES BY Considerations for implanting premium IOLs in patients with previous refractive surgery. in patients with previous for implanting premium IOLs Considerations LENSES LENSES IN POST-LASIK EYES MULTIFOCAL AND TRIFOCAL AND MULTIFOCAL TRIFOCAL Courtesy of Cyres Keiki Mehta, MD Mehta, Keiki Cyres of Courtesy EDITORIAL SPOTLIGHT 16

CATARACT & REFRACTIVE SURGERY TODAY EUROPE CATARACT &REFRACTIVE SURGERY corneal surface and those caused by cataract formation. neal aberrations and can distinguish between those on the Technologies) can provide additional information about cor central corneal power. noted in the literature to be a useful tool for measuring Corneal Topography System (Carl Zeiss Meditec) has been tion formulas. Simulated K is of less relevance. The Atlas power, and this value can be used in IOL power calcula topography can also reasonably estimate central corneal astigmatism—the enemy of multifocal IOLs. Corneal sion on the steep axis and, thus, minimize postoperative measurements allow the surgeon to place the phaco inci ing workup. for presbyopia, post-LASIK eyes should undergo the follow PREOPERATIVE ASSESSMENTS SRK-T method, but it is now rare. common in the past after IOL calculation with the standard with an error between 1.50 and 3.00 D, or even more, was surprise, in which the patient presents after cataract surgery tive refractive outcome is a hyperopic error. result, the IOL power is underestimated, and the postopera the actual anterior chamber depth does not change. As a underestimated because of the flattened cornea, whereas K reading. In eyes with previous myopic LASIK, the ELP is chamber depth, which is geometrically determined by the The ELP is estimated as a function of the presumed anterior under the assumption that the cornea has a spherical shape. in IOL power in these eyes can be significant. mulas such as the SRK-T and Hoffer-Q, the underestimations calculation formulas. With third-generation theoretical for shape, so IOL power is underestimated by standard power tral area is higher than at the center; it resembles a tabletop to oblate. In an oblate cornea, the K reading in the paracen asphericity of the anterior cornea is changed from prolate terior corneal curvatures is also altered. Simultaneously, the than in a normal eye. The ratio between anterior and pos atometry (K) readings for this flatter cornea are thus lower corneal surface flatter than that in an untreated eye. The ker laser ablation for a myopic correction makes the anterior vious myopic excimer laser surgery are unpredictable. The Refractive outcomes after cataract surgery in eyes with pre ditional IOL power calculation formulas no longer apply. aberration after myopic LASIK. aspheric IOL helps to compensate for the increased spherical after myopic LASIK, degrading overall image quality. An Studies show that spherical aberration increases significantly as possible. All of the lenses mentioned here are aspheric. Ray-tracing software such as that of the iTrace (Tracey Ray-tracing software such as that of the iTrace (Tracey Corneal topography. Before cataract surgery or refractive lens exchange (RLE) These formulas calculate the effective lens position (ELP) In planning for cataract surgery in post-LASIK eyes, tra 6

Accurate corneal topography 1 4,5

JUNE 2017 3 This hyperopic This hyperopic 2 ------biometry (Axis; Quantel Medical) or optical biometry with biometry (Axis; Quantel Medical) or optical biometry with in manifest refraction when those data are not entered. internal regression formula to calculate an estimated change refraction (change in manifest refraction) because it uses an with or without considering the surgically induced change in history is available (no-history formula). It can also be used predict the required power of the IOL when no refractive postlaser refraction values. The Barrett True K formula can RK, and it requires the measured K reading and the pre- and patients whohavehadmyopicorhyperopicLASIKPRK or Universal II formula. It calculates a modified K value for with previous myopic LASIK or PRK. ASCRS online calculator for predicting IOL power in eyes equal to or better than alternative methods available on the compared with laser interferometry in the IOLMaster 500. it uses swept-source OCT for axial length measurement as many more keratometric points than the IOLMaster 500, and the software of the IOLMaster 700. The IOLMaster 700 has Haigis-L formula (myopic or hyperopic), which is included in use the excimer laser for a postoperative adjustment. power calculation goes awry and we have to lift the flap and of the stromal bed. This technology is also helpful if the lens the exact corneal thickness, LASIK flap thickness, and quality should be used to evaluate the macula in these patients. should be avoided. In addition to dilated fundus exam, OCT related macular degeneration, multifocal IOL implantation the macula, such as an impending macular hole or dry age- directly to errors in IOL power. measurement is important because errors in axial length lead (Haag-Streit) should be used to calculate axial length. This the IOLMaster 700 (Carl Zeiss Meditec) or the Lenstar Figure 3. Presbyopic RLE. Accurate axiallengthmeasurement. The Barrett True-K formula is based on the Barrett The Barrett True-K formula is based on the Barrett The Barrett True-K formula has been shown to be either IOL powercalculation. Anterior segmentOCT. Dilated fundusexamination. Typically, I prefer to use the Typically, I prefer to use the Anterior segment OCT can reveal Anterior segment OCT can reveal If there are problems at If there are problems at Immersion A-scan Immersion A-scan

7 Courtesy of Cyres Keiki Mehta, MD Mehta, Keiki Cyres of Courtesy EDITORIAL SPOTLIGHT 18

CATARACT & REFRACTIVE SURGERY TODAY EUROPE CATARACT &REFRACTIVE SURGERY 4. HofferKJ.Intraocularlenspower calculationafterpreviouslaserrefractivesurgery. myopic laserrefractivesurgery. 3. AlioJL,PineroD,MuftuogluO.Cornealwavefront-guided retreatmentsforsignificantnightvisionsymptomsafter LASIK. 2. WangL,BoothMA,KochDD.Comparisonofintraocularlens powercalculationmethodsineyesthathaveundergone aspheric andsphericalintraocularlenses:acomparativestudy. 1. TzelikisPF,AkaishiL,TrindadeFC,BoteonJE.Sphericalaberration andcontrastsensitivityineyesimplantedwith exchange the lens always exists. IOL power calculation goes grossly wrong, the option to dilated fundus examination, and anterior segment OCT. If corneal topography, accurate axial length measurement, Before cataract surgery, post-LASIK eyes should undergo because the IOL position was not accurately predicted. because the surgical corneal power is underestimated or CONCLUSION will be perfect in every case. not available; further, the capsulorrhexis position and size be used to perform limbal relaxing incisions if a toric IOL is femtosecond laser is an efficient tool in this setting, as it can surgery will be immediately picked up by the patient. The who have 20/20 CDVA and N5 CNVA. Any shortcoming in byopic RLE. Remember that you are operating on patients -1.00 D will be happier without surgery. the procedure in low myopes; for example, a patient with and halos is tolerable. It is advisable to avoid performing presbyopic RLE must consent that some amount of glare FACP, FACS, FRCS(Ed), FRCOphth). Patients undergoing (personal communication from Sheraz M. Daya, MD, is unacceptably high in this young group of presbyopes the rate of retinal detachment after Nd:YAG capsulotomy their residual accommodation was better. Additionally, the procedure often feel that their preoperative vision with have a sufficient degree of presbyopia and, therefore, after justify the procedure. Patients aged 43 or 44 years do not or older; below this, the degree of presbyopia does not PRESBYOPIC RLE and OCT. input from a Scheimpflug device (Pentacam; Oculus) Barrett True-K and the Potvin-Hill formula, which uses revised to include new, innovative formulas such as the online calculator. This online calculator has recently been Refractive surprises after monovision LASIK can occur Refractive surprises after monovision LASIK can occur The happiest patients after lens surgery for presbyopia are: Surgeons should exercise caution when performing pres For presbyopic RLE (Figure 3), patients must be 48 years For all postrefractive surgery cases, I use the ASCRS Ophthalmology • • • reasons and are presbyopic before surgery. Patients who refuse to wear spectacles for cosmetic as the improvement in vision is gratifying; and Patients with cataracts and poor vision preoperatively, near can be achieved; Hyperopes, as spectacle independence for far and . 2004;111:1825-1831. Am JOphthalmol . 2008;145:65-74. Am JOphthalmol

JUNE 2017 . 2008;145:827-833. JCararactRefractSurg . 2009;35:759-765. - 2008;34:1658-1663. 7. HaigisW.Intraocularlenscalculationafterrefractivesurgeryformyopia:Haigis-Lformula. 2010;36:1466-1473. of CataractandRefractiveSurgeonsPost-KeratorefractiveIntraocularLensPowerCalculator. 6. WangL,HillWE,KochDD.EvaluationofintraocularlenspowerpredictionmethodsusingtheAmericanSociety 2000;26:142-144. 5. GimbelH,SunR,KayeGB.Refractiveerrorincataractsurgeryafterpreviousrefractivesurgery. This is done by looking for evidence of central steepening This is done by looking for evidence of central steepening is identifying the type of LASIK correction they received. LASIK. Thus, the first step in planning cataract/IOL surgery even know whether they underwent hyperopic or myopic ent without any preoperative data. Often, they do not EVALUATING PREVIOUSLASIK are an ideal surgical solution in these challenging cases. visual acuity across all distances. In my experience, trifocal IOLs are of presbyopic age, and seek options for improving their matically. These patients are familiar with refractive procedures, for cataract surgery with a history of LASIK has increased dra HOAs was high at 0.179. implantation, measured in a 4-mm pupil. The Strehl ratio for with previous myopic LASIK scheduled for trifocal IOL Figure 4. MTF (A) and PSF (B) corneal values in a patient Many patients with a history of refractive surgery pres Over the past decade, the number of patients who present n n n n Cyres Keiki Mehta, MD A Mumbai, India Financial disclosure:Noneacknowledged [email protected] Director, CKMEyeSpecialitiesPvtLtd Surgical Chief,Dr.CyresMehta’sInternationalEyeCentre, These lenses can provide excellent These lensescanprovide excellent The Ideal Surgical Solution By Peter Mojzis, MD, PhD, FEBO PhD, MD, Mojzis, Peter By the post-LASIK eye. sacrificing distanceandnearvision in intermediate visualacuitywithout spectacle independence and improve B J CataractRefractSurg JCataractRefractSurg J CataractRefractSurg

- . .

- . Courtesy of Peter Mojzis, MD, PhD, FEBO PhD, MD, Mojzis, Peter of Courtesy EDITORIAL SPOTLIGHT 20

CATARACT & REFRACTIVE SURGERY TODAY EUROPE CATARACT &REFRACTIVE SURGERY

Courtesy of Peter Mojzis, MD, PhD, FEBO ular corneal astigmatism. To minimize postoperative refractive ular corneal astigmatism. To minimize postoperative refractive tation is planned (Figure 5). using wavefront aberrometry before multifocal IOL implan size and severity of corneal aberrations should be evaluated other factors, ablation profile, flap quality, and pupil size. The or glare. The magnitude of HOAs is determined by, among and cause symptoms of double vision, blurred vision, halos, cal IOL in an aberrated cornea could worsen optical quality cornea and can change or induce HOAs. Use of a multifo surgery. Corneal refractive surgery modifies the shape of the degrees of HOAs can decrease optical performance after lens contrast when light passes through an optical system (Figure 4). in the image of a point source, and MTF evaluates the loss of tion transfer function (MTF). PSF measures the intensity of light cornea by looking at point spread function (PSF) and modula quality of the whole optical system, the lens, and especially the Additionally, I find it useful to assess the preoperative optical mainly coma and spherical aberration—and angle kappa. phy, LASIK flap centration, higher-order aberrations (HOAs)— myopic LASIK). (indicating hyperopic LASIK) or central flattening (indicating myopic LASIK, measured in a 4-mm pupil. Corneal topography shows a well-centered optical zone. Figure 5. Low induced HOAs, coma, and spherical aberration are demonstrated in this eye after Figure 6. A trifocal toric IOL centered in the capsular bag in a patient with previous hyperopic LASIK. An abnormal corneal shape can also induce regular or irreg Decentered LASIK flaps, postoperative ectasia, and high I use the OPD-Scan III (Nidek) to evaluate corneal topogra

JUNE 2017 - - - - - myopic LASIK, this calculation overestimates corneal curvature myopic LASIK, this calculation overestimates corneal curvature with a normal anterior:posterior corneal curvature ratio. After calculations in post-LASIK eyes arises from the use of a formula ablation may lead to miscalculations. The main error in IOL corneal curvature induced by flap creation and excimer laser less predictable than in virgin eyes. Alterations of the anterior IOL CALCULATION (Figure 7). an excellent solution for patients with large angle kappa tri has a large central optical zone of 1.04 mm, which is Purjkinje image, which is close to visual axis. The AT LISA in patients with a high degree of angle kappa is the first axis. The best point for perfect multifocal IOL centration angle kappa, wherein the visual axis is close to the pupillary method for centering a multifocal IOL in patients with small to produce miosis. Induced miosis is a simple and effective intracameral carbachol intraocular solution may be used and corneal reflexes. In some cases, at the end of surgery, the lens should be centered halfway between the pupillary in patients with large angle kappa after hyperopic LASIK, recommend centering a trifocal lens on the corneal vertex; IOL calculation in patients with previous refractive surgery is IOL calculation in patients with previous refractive surgery is In patients with a small angle kappa after myopic LASIK, I kappa values. I conduct tend to have large angle increased glare and halos. decentration, resulting in in postoperative lens play a significant role high angle kappa can and pupillary axes. A angle between the visual ANGLE KAPPA component (Figure 6). trifocal IOL with a toric astigmatism, I implant a high degree of corneal error in an eye with a 0.2 mean angle kappa was and in 10 myopic eyes, kappa was 0.34 tropic eyes, mean angle 0.43 mean angle kappa was In 42 hyperopic eyes, in 60 eyes (30 patients). kappa was measured ed a study in which angle Hyperopes especially Hyperopes especially Angle kappa is the ± ± 0.1. 0.1. 0.18; in six emme ± 0.12; 0.12; - - EDITORIAL SPOTLIGHT

CATARACT & REFRACTIVE SURGERY TODAY EUROPE

JUNE 2017

Courtesy of Peter Mojzis, MD, PhD, FEBO - - - (CP is the value CP , where the blue point the pupil center. pupil the point blue the Figure 7. An eye with a largea with eye An 7. Figure point white The kappa. angle vertex andindicates the corneal - n Medical Director, Premium Clinic Teplice, Czech Republic [email protected] Financial disclosure: None acknowledged In my experience, the AT LISA tri and AT LISA tri toric andtoric tri LISA AT and tri LISA AT the experience, my In Cataract surgery in patients with previous myopic or hyper or myopic previous with patients in surgery Cataract Regarding surgical approach, the placement of incisionsof placement the approach, surgical Regarding Hyperopic LASIK modifies the peripheral cornea, increasingcornea, peripheral the modifies LASIK Hyperopic Many methods havemethods Many n n n Peter Mojzis, MD, PhD, FEBO MD, Mojzis, Peter near vision in post-LASIK patients. These lenses are stable,are lenses These patients. post-LASIK in vision near normalprovide they and bag, capsular the in well center they complexthese in advantages notable sensitivity—all contrast scenarios. surgical the Alsafit trifocal and Alsafit trifocal toric (both from Alsanza) from (both toric trifocal Alsafit and trifocal Alsafit the improveand independence spectacle excellent provide can without sacrificing distance and acuity visual intermediate astigmatism, angle kappa, and preoperative optical quality arequality optical preoperative and kappa, angle astigmatism, results.postoperative excellent obtaining for factors key all opic LASIK is challenging for a number of reasons. Precisereasons. of number a for challenging is LASIK opic cornealHOAs, of assessments and essential, is calculation IOL aged LASIK flap. LASIK aged CONCLUSION placed outside the flap to minimize damage by means of means by damage minimize to flap the outside placed bal of instillation accidental or cannulas and/or tip phaco postoperativeevent the In OVD. or solution saline anced dam the lifting problem no is there needed, is fine-tuning reports, I exclusively use the hyperopic Haigis-L formula. Haigis-L hyperopic the use exclusively I reports, beshould incisons Corneal flap. LASIK the avoid should hyperopic LASIK are easier than those after myopic LASIK,myopic after those than easier are LASIK hyperopic myIn modified. is curvature corneal central the which in medical previous their to access without patients in practice, in the center of the axial topography map.topography axial the of center the in aftercalculations thus, radius; corneal anterior:posterior the using the Wang-Koch- the using is formula The simple: is method This method. Maloney power = estimated corneal - 6.1 x 1.114) cursorthe placing upon obtained power corneal central of been presented to helpto presented been morepower IOL calculate recommendI precisely. previously myopic patientsmyopic previously dissatisfied.highly are shift. Residual hyperopiaResidual shift. allat acuity visual worsens event,an such In distances. tion of an IOL with too with IOL an of tion andpower dioptric low hyperopicresultant a and leads to implanta to leads and