www.eyeworld.org

The News Magazine of the American Society of Cataract and Refractive Surgery

“ Our goal as surgeons is clear, weshould use technology that targets zero higher order aberrations, such as spherical aberration, in order to providepatients with the best visual quality.”

Capt. Steven C. Schallhorn, M.D.

Evolving Corneal and Lens-Based Refractive SurgeryUnderstanding and selecting surgical solutions to maximize visual acuity, patient satifaction, and quality

I N S I D E :

• Achieving Spectacle Independence with Multifocal IOLs

• The Next Generation ofCustom Matching

• Monovision-New Options for Presbyopic Correction

• Update on Aspheric Ablations for Correction of Hyperopic Presbyopia

• Pseudophakic Refractive Management

• Iris Registration in Enhancements and Challenging Cases

• Wavefront-Guided Laser Vision Correction for Complex Retreatments

• Aspheric IOLs: Understanding the Clinical Differences Between Lenses

• Targeting Zero Spherical Aberration Post Lens Implantation

• Creating the Optimal SurgicalEnvironment for Success with Multifocal IOLs

• Understanding the Impact of Blocking Blue Light

CONTRIBUTORS

Steven J. Dell, M.D.H.L. “Rick” Milne, M.D.Angel López Castro, M.D.Colman R. Kraff, M.D.W. Bruce Jackson, M.D.Mounir A. Khalifa, M.D.Baha Toygar, M.D.Maj. Charles Reilly, M.D.Y. Ralph Chu, M.D.Capt. Steven C. Schallhorn, M.D.Martin A. Mainster, Ph.D., M.D., FRCOphth.Farrell “Toby” C. Tyson II, M.D., F.A.C.S.

Supported by a grant from AMO, Inc.

2 0 0 6 L A S V E G A S S H O W S U P P L E M E N T

November 2006

2 Las Vegas Show Supplement — Presbyopia Solutions

Patients can see well at all distances and arehappy with much less dependency on glasses

Maximizing Patient Satisfaction With Multifocal IOLs

by Doug Grayson, M.D.

Recent clinical experienceimplanting nearly 1500ReZoom (AdvancedMedical Optics, AMO,Santa Ana, Calif.) multifo-

cal IOLs shows patients areextremely satisfied with theirincreased vision at all distances andenjoy spectacle independence post-operatively.

My clinical experience, coupledwith the experiences of several othersurgeons, including Steven Dell(M.D., Austin, Texas) and Stephen M.Weinstock (M.D. Largo, Fla.), illus-trate that the majority of patientsenjoy a wide range of excellentvision and have much less dependen-cy on spectacles post-operatively.

Use of ReZoomOf the 1200 ReZoom lenses I haveimplanted, 90% have been bilateralReZoom implantations. Initially, Ievaluate the patient's pupil size todetermine whether he shouldreceive ReZoom or ReStor.Assuming the patient does nothave very myotic pupils, ReZoomwill always be my first choice.

Because we extensively discusspatient desires, visual needs, andexpectations prior to multifocalimplantation, most patients areextremely happy with their results.

Depending on reading abilityafter the first ReZoom implanta-tion, I consider mixing and match-ing ReZoom with other lens tech-nologies in some patients. If thepatient's reading ability is good(but not absolutely perfect), I willimplant another ReZoom becausepatients receive an added effectfrom having ReZooms in both eyes.In other cases, if the patients’ read-ing is very moderate because theyare not going into the full nearzone on the ReZoom, then theywill receive a ReStor in the othereye.

The reading level is not neces-sarily based on objective measure-ment, it is more subjective. Forexample, if patients can't read thenewspaper or they are just nothappy, then they will receive aReStor in the other eye. If thepatient's vision is good and thereare only a few things he cannotread, then he will receive anotherReZoom.

ResultsReZoom patients included in thiscombined group have excellentoverall spectacle independence (seetable). Ninety four percent of these

patients implanted with bilateralReZoom achieved spectacle inde-pendence at all ranges and 99%have spectacle independence at dis-tance. For near vision and interme-diate tasks such as prolonged read-ing or small print and craft andcomputer work, some patientschose to wear reading glasses. Forexample, some patients may use alight pair of reading glasses becausethey do not feel their near vision isgood enough to see the back of apill bottle.

The other main reason whypatients use any form of vision cor-rection post ReZoom lens implanta-tion is residual astigmatism.Astigmatism is the big wild card.For instance, some patients mayhave 2 D of astigmatism and theyare reduced to 1 D of astigmatismwith limbal-relaxing incisions(LRIs). They still are not totallyhappy, but they do not wantanother procedure.

Therefore, they chose to wearglasses for correcting that remain-ing astigmatism. This is related topost-operative astigmatism oranother post-operative refractivecomponent, not the ReZoom lens.

Post-operative EnhancementPost-operative enhancement is notneeded in the majority of cases. Inmy practice, less than 2% of bilat-eral ReZoom patients receive a sec-ondary procedure to manage resid-ual error post lens implantation.

I use LRIs at the time of the ini-tial procedure to manage preexist-

ing astigmatism. However, caseswith significant astigmatism mayrequire LASIK, unless the patientdecides the residual astigmatism isacceptable. If LASIK is required, thepatient receives laser vision correc-tion from my partner for an addi-tional fee.

For example, patients with morethan 1 D of preexisting astigmatismreceive an intra-operative LRI.Patients with more than 2 D of astig-matism they would receive more LRIor LASIK post-operative. Patientswith greater than 2.5 D of astigma-tism receive a staged procedure inwhich they receive the multifocalimplant and are scheduled for aplanned LASIK post-operatively.

Optimizing OutcomesConventional LASIK also is used bymy colleagues, including StephenWeinstock, to eliminate any refrac-tive surprises or astigmatism thatwas not corrected during the origi-nal procedures.

For surgeons such as StevenDell, wavefront-guided laserenhancements are helpful in opti-mizing patients' outcomes. He useswavefront-guided laser enhance-ments whenever high-quality wave-front diagnostic testing results areobtained because the wavefrontincreases the probability of reach-ing the refractive target. However,if the scans are poor, he would usetraditional laser vision correction.

Doug Grayson, M.D. is in private practice,Parsippany, N.J.

Figure 1: Results for patients implanted with the bilateral ReZoom show excellent overallspectacle independence.

“Ninety four percent of thesepatients implantedwith bilateralReZoom achievedspectacle inde-pendence for allranges ...”

Doug Grayson, M.D.

Presbyopia Solutions — Las Vegas Show Supplement 3

Patient counseling regarding visual needs andexpectations helps boost patient satisfaction

Pseudophakic Refractive Management with Multifocal IOLs

by Steven J. Dell, M.D.

Bilateral implantation withthe ReZoom (AdvancedMedical Optics, AMO,Santa Ana, Calif.) multifo-cal lenses provides excel-

lent post-operative vision at a vari-ety of distances. At our practice, weeducate all of our patients aboutvarious presbyopic IOL options anddiscuss with them realistic expecta-tions pre-operatively. We make useof patient questionnaires andhandouts to streamline this process(Figure 1). As a result, patientexpectations are set at an appropri-ate level, and post-operativepatient satisfaction is very high.

Patient SelectionThe best ReZoom patients are thosewith dense cataracts and a highrefractive error who do not domuch night driving and desiregood vision at all three workingdistances (distance, intermediate,and near). However, with appropri-ate pre-operative counseling, it is

possible to achieve good results inmany other patients who do notmeet this specific profile.

Surgeons can take a number ofsteps to help patients achieve thehighest level of satisfaction. Themost important things are to assessthe patient's visual demands andpersonality and match these to themost appropriate IOL. Patients alsoneed to be forewarned about thepossibility of halos or glare with allmultifocals. They must understandthat some residual spectacle use isa possibility with any IOL.

Clinical ExperienceI generally split most of my presby-opia correction IOL patientsbetween the ReZoom and the crys-talens. When I believe that a multi-focal is best for the patient, I typi-cally will use the ReZoom. I preferthis multifocal over the ReStor typ-ically because the ReZoom seems toprovide better overall visual func-tion for the patient in all threevision zones. It is a fairly forgivinglens, and it is the easier of the twoto use. In some cases, we mix andmatch these two multifocal IOLs.

We caution all patients thatthey might require spectacles forsome tasks after receiving any IOL,but for most tasks, virtually allpatients are spectacle free with theReZoom. Reading for prolongedperiods of time is the most typicalsituation in which ReZoompatients use any form of vision cor-rection. Most of these patientsenjoy complete spectacle inde-pendence for intermediate visionand distance vision.

To treat preexisting cornealastigmatism, I typically performlimbal-relaxing incisions (LRIs) atthe time of surgery first. This suc-cessfully addresses the majority ofastigmatism cases. However, somepatients with higher degrees ofastigmatism pre-operatively have abit of residual astigmatism andmight use some distance correctionon occasion. Laser touch-up or fur-ther LRIs are options for thosecases.

Post-Operative Enhancement Despite careful biometry and astig-matism management, multifocalIOL patients receive a secondaryprocedure to manage residualrefractive error post lens implanta-tion in about 5% of cases. Ourenhancement numbers are this lowbecause we do not promise totalspectacle elimination with any sur-

gical procedure. We explain thatthere are limits to the accuracy ofour measurements, and the patientshould anticipate the chance of asmall residual refractive error post-operatively. We also explain thatthere is an added charge for a sec-ondary procedure to manage thisresidual refractive error.

To correct astigmatism or resid-ual error in cataract or refractivelens exchange patients, I rely onone of several procedures, depend-ing on the case. Most receive wave-front-guided laser enhancement,but I also use conventional laserenhancement and supplementalLRIs. LRIs are reserved for cases inwhich the spherical equivalent isclose to zero. I use a wavefront-guided laser enhancement over atoric IOL to resolve astigmatismissues because the laser is moreaccurate.

In rare cases, I will choose piggy-backing IOLs for large ammetropiasor when corneal surgery is con-traindicated.

My secondary procedure ofchoice is wavefront-guided laserenhancements whenever we obtainhigh-quality wavefront diagnostic

testing results. We prefer not toinduce new aberrations into theequation. Also, a high percentageof my patients are referrals whohave had prior keratorefractive sur-gery, and I want to minimize post-operative aberrations in these casesespecially.

Wavefront raises the chances ofhitting our refractive target, whichis especially critical in these casesbecause patients may not be willingto let you perform a third proce-dure on them. The AdvancedCustomVue (Advanced MedicalOptics, AMO, Santa Ana, Calif.) sys-tem has been able to image themajority of multifocal and crystal-ens pseudophakes for treatment.

However, if the scans are poor,or other factors such as tissue con-servation limit our ability to usewavefront treatment, we will usetraditional laser vision correction.This still works well because therefractive errors involved are typi-cally small.

Steven J. Dell, M.D. is medical director, DellLaser Consultants, Austin, Texas.

“ I use a wavefront-guidedlaser enhance-ment over a toricIOL to resolveastigmatismissues becausethe laser is muchmore accurate.”

Steven J. Dell, M.D.

Figure 1: Patient questionnaires such as this can help clinicians streamline their patient andtreatment selection process.

4 Las Vegas Show Supplement — Presbyopia Solutions

A refractive multifocal in the dominant eye and a diffractive multifocalin the fellow eye provides patients with the broadest range of vision

Custom Matching Multifocal IOLs

by H.L. "Rick" Milne, M.D.

My initial experiencewith multifocal IOLswas with the AlconReStor lens, a diffrac-tive multifocal IOL.

Although the results were verygood, I noticed that a significantpercentage of these patients werenot totally satisfied with theirvision post-operatively. Given howmuch patients are paying out oftheir own pockets for a premiumIOL, my goal is always for them tofeel that they got what they paidfor.

Much of the dissatisfaction Iwas seeing was due to the lack ofintermediate vision. A diffractivelens provides very little intermedi-ate vision, so patients usually haveto put on glasses for computer workand many other common everydaytasks. I started combining theReStor with an AMO refractive

ReZoom multifocal IOL, hoping togive patients better intermediatevision and maximizing the advan-tages of both lenses.

Diffractive and refractive IOLshave complementary strengths indifferent lighting conditions. Thediffractive IOL performs better fornear in bright light and the refrac-tive IOL provides better near in dimlight. For distance, the opposite istrue. In addition, the refractive IOLprovides the intermediate visionthat patients were missing previ-ously.

Bilateral Versus Mix and Match I conducted a small study to com-pare the results of bilateral diffrac-tive lenses with this custom mix-and-match approach. Based on theresults, I no longer implant bilater-al ReStor at all.

In this study, all 68 patientswere followed for six months. Allof them achieved near vision of atleast J2 and distance acuity of20/40 or better, so, objectively, allhad good reason to be satisfiedwith the results of their multifocalIOL procedure.

Most importantly to me, thepercentage of patients who report-ed being completely spectacle inde-pendent went from 65% in thebilateral group to 90% in the cus-tom-match group. And of thosewearing glasses, no one wore glass-es for any type of task more than50% of the time. Satisfaction andspectacle independence ratesaround 95% are what I want andexpect to see with premium multi-focal IOLs (Table 1).

I have found that the eyes inthese custom-match cases summatebeautifully, often giving thepatients one or two lines bettervisual acuity improvement withboth eyes than they are able to seewith either eye individually.

Customizing the IOL decision processWhen I talk to prospective IOLpatients about their visual needsand expectations, the vast majorityof them want to have it all: near,intermediate, and distance visionwithout glasses. For these patients,I test for eye dominance andimplant the refractive ReZoom mul-tifocal in the dominant eye.

I don't plan for the second eyeimplant until I have evaluated theresults of the first eye. On the fol-low-up visit at two to three weekspost-operative, I ask patients how

they are functioning with the treat-ed eye.

When patients are happy withtheir vision after the first surgery, Iusually will implant the samerefractive multifocal IOL in the sec-ond eye. But if they perceive anylimitations in their near vision, Iimplant a diffractive multifocal–currently the ReStor IOL–in theirsecond eye. To date, I haveimplanted about 400 refractive/dif-fractive combinations, without anyexplantations.

I truly enjoy being able to pro-vide my cataract patients withgood uncorrected vision that letsthem reduce their dependence onglasses. Part of my job is to matchpatients with the best possible IOLfor their visual needs. And in mostcases, I believe it is the combina-tion of one refractive and one dif-fractive IOL that provides the high-est levels of satisfaction and specta-cle independence.

H.L. “Rick” Milne M.D. is in private practice atthe Eye Center in Columbia, S.C.

“ I have foundthat the eyes inthese mix-and-match casessummate beauti-fully, often givingthe patients oneor two lines bettervisual acuityimprovement …”

H.L. “Rick” Milne, M.D.

Table 1: Results of Custom-Match Approach Compared to BilateralDiffractive IOLs at Six Months Postoperative

Bilateral ReStor ReZoom - ReStor(n=23) (n=45)

Satisfied or very satisfied 74% 98%with distance vision

Satisfied or very satisfied 83% 98%with near vision

Completely spectacle 65% 90%independent

Halos during day 43% 18%

Halos at night 86% 73%

Would recommend the 65% 98%procedure to others

Would have the procedure 70% 98%again themselves

Maximizing Range of Vision for Cataract Patients Reading Acuity and Reading Speed With Diffractive Multifocal IOLs

A t the 2006 ESCRS meeting in London, Werner W. Hütz, M.D., (BadHersfeld Clinic, Germany) presented data from his study comparingthe reading acuity and reading speed of cataract patients implanted

bilaterally one of two MIOLs; the Tecnis ZM001 (n=20) and the AcrySofReSTOR (n=20). At six weeks post-operative, reading acuity and readingspeed were evaluated under bright (100 cd/m²) and dim light conditions (6cd/m²) using the standardized Radner reading charts.

Dr. Hütz and colleagues found that under bright light conditions, uncor-rected reading acuity of the patients with the Tecnis ZM001 lens was notsignificantly different from the Acrysof ReSTOR (P=0.2). However, underdim light conditions, the Tecnis ZM001 group achieved an uncorrected log-mar reading acuity of 0.275±0.096 compared to a poor score of0.435±0.162 (P<0.001) for the Acrysof ReSTOR.

In terms of reading speed without correction, Dr. Hütz reported thatunder bright light conditions, the Tecnis ZM001 group achieved a readingspeed of 174 ± 30 words/min compared to 138 ± 45 words/min for theAcrysof ReSTOR group. For dim light conditions, the Tecnis ZM001achieved a reading speed of 142 ± 43 w/min, which still outperformed thebright light condition reading results for the Acrysof ReSTOR group.

Both of these MIOLs provide distinctly different reading capabilities,and Dr. Hütz concluded that the Tecnis ZM001 outperformed the AcrysofReSTOR under all lighting conditions.

Presbyopia Solutions — Las Vegas Show Supplement 5

Combining aspheric diffractive and refractive IOLs maximizes patients’range of vision, improves satisfaction, and reduces night-vision complaints

Evaluating the Next Generation of Custom-Match IOLs

by Angel López Castro, M.D.

New technology IOLs offerus a wonderful opportuni-ty not only to implantthese lenses in cataract orrefractive lens exchange

patients bilaterally but to combinethe technologies, where appropri-ate, to maximize the patient’srange of vision.

There are many possible combi-nations, but the one that makesthe most sense to me and to manyothers is combining refractive anddiffractive multifocal IOLs. Most ofmy custom-match experience hasbeen with Advanced MedicalOptics’ (AMO, Santa Ana, Calif.)Tecnis multifocal and ReZoomIOLs. These two lenses comple-ment each other well, so integrat-ing their technological advantagesand optical properties offers anideal result for the patient.

The refractive ReZoom lensprovides the intermediate visionthat is missing in bilateral implan-tation of diffractive IOLs. In brightlight, it provides superior distancevisual acuity with no loss of lighttransmission, while the diffractivemultifocal Tecnis provides excel-lent near with the high quality ofvision we expect from the asphericTecnis platform.

In dim light, ReZoom providesreading capability in the middlerange of the pupil. Meanwhile, theouter portion of the Tecnis multifo-cal lens becomes dominant, pro-viding better distance vision anddecreasing nighttime photic phe-nomena. Thus, the combination of

both lenses provides a full range ofvision under most lighting condi-tions.

In my experience, healthy eyeshave no problem integrating thevisual input from two differentIOLs in their eyes. As with anymultifocal lens, there is a process ofneural adaptation that can take upto two or three months. Duringthis period, contrast sensitivity andnear vision continue to improve.

Study ResultsWe analyzed two groups ofpatients. Group 1 was comprised of36 patients with bilateral diffractivemultifocal IOLs with a one-year fol-low-up and laser vision correctiontouch-ups, as necessary. Group 2was comprised of 31 patients witha ReZoom refractive multifocal inthe dominant eye and a Tecnis dif-fractive multifocal in the other eye.

The comparison is a bit unfairto the mix-and-match groupbecause I had only three months offollow-up with this group andnone of them has yet had LASIKenhancements. Despite this, theresults clearly favor the mix-and-match group.

For example, in mesopic condi-tions, 85% of mix-and-matchpatients achieved J3 or better read-ing vision versus 70% in the bilat-eral diffractive group. The averagenear acuity for the mix-and-matchgroup is J2.4 compared to J4.1 forthe bilateral group. The differencewas statistically significant.

When it comes to intermediatevision, three times as many mix-and-match patients (60% versus20%) can see J3 or better in brightlight, and twice as many (60% ver-sus 30%) can see at least J5 in dimlight. Distance visual acuity wasvery good in both groups (Figure 1).

Quality of Vision and EnhancementsBecause multifocal IOLs cannotcorrect astigmatism, we still willneed to perform laser touch-ups,but the need for enhancement hasbeen significantly reduced with amix-and-match approach. Nearlyhalf (46%) of the bilateral diffrac-tive group needed a laser enhance-ment compared to only 33% of themix-and-match patients.

Overall, the mixed IOL groupmembers were more satisfied withtheir vision after surgery, with88.5% saying they would choosethese lenses again, compared to82.5% of the bilateral diffractivegroup. In the mixed IOL group,about 85% said they never wearglasses.

When we asked about photicdisturbances, 92% of mix-and-match patients said they experi-enced no glare or moderate glareversus 64% in the bilateral diffrac-tive group. Halos were the mostcommon complaint in bothgroups. However, none of the mix-and-match patients, versus 36% ofthe bilateral diffractive group,reported severe night-vision prob-lems.

Patient SatisfactionThis study shows that patients gainnear mesopic vision, distant pho-topic vision, and intermediate acu-ity at all light levels from a mix-and-match approach. Patients witha combination of refractive anddiffractive IOLs report high visualquality, with most (85%) achievingtotal freedom from spectacles evenbefore LASIK enhancement.

We observed significantly lowernight-vision complaints in themix-and-match patients, withfewer requests for LASIK enhance-ments. Patient satisfaction reportsshow that complementary IOLsoffer these patients the opportuni-ty to maximize their vision to meetall their lifestyle needs.

Angel López Castro, M.D. is in private practicein Madrid, Spain.Figure 1: Intermediate vision improvements were 60% with J3 or better in bright light for

the mix-and-match patients versus 20% with the bilateral group, and 60% versus 30% withJ5 in dim light, respectively.

“ In my experi-ence, healthyeyes have noproblem integrat-ing the visualinput from twodifferent IOLs intheir eyes.”

Angel López Castro, M.D.

6 Las Vegas Show Supplement — Presbyopia Solutions

Whether you aim for omnifocal vision or monovision, early datashow presbyopes benefit from wavefront-guided correction

Wavefront-Guided Treatments for Presbyopes:U.S. Clinical Trials Update

by Colman R. Kraff, M.D.

Iwould like to report on theresults of two studies thatwould expand our abilities toprovide wavefront-guidedtreatments that allow presby-

opic patients to increase their levelof spectacle independence. Wetake different approaches, depend-ing on whether the treatment ishyperopic or myopic.

Myopic presbyopes: Custom monovisionFor the myopic presbyope whowants to be less dependent on glass-es, monovision with AdvancedCustomVue (Advanced MedicalOptics, AMO, Santa Ana, Calif.)LASIK or PRK is the best option.However, at this point, physicianscan only make a ±0.75-D adjustmentto the WaveScan refraction, whichdoesn't induce enough monovisionto provide the near vision most ofour patients are looking for. We endup treating the distance eye with acustom correction, but having to use

a conventional treatment for thenear eye.

I have been participating in aprospective multicenter Food andDrug Administration (FDA) clinicaltrial to treat myopic patients withcustom wavefront-guided treatmentswith a monovision target. In thisstudy, the distant dominant eye wastargeted for emmetropia and thenear eye was under-corrected by upto -2.0D.

All study patients undergo acontact lens monovision trial ifthey haven't previously worn lensesfor monovision. This has beenquite helpful in screening formonovision tolerance and indemonstrating to the patient whatmonovision is like.

In all, 296 eyes of 160 patientswere treated. Patients range from 40to 65 years old; the mean age is 50.Pre-operative MRSE in the dominanteyes, which were targeted for dis-tance, was -3.82 D, while the non-dominant eyes were -4.15 D, onaverage.

The results have been excellent.At six months, 87% of patientsachieved uncorrected binocular dis-tance acuity of 20/20 or better andmore than two-thirds were 20/16 orbetter (Figure 1). Nearly 90% haduncorrected binocular near acuity of20/20 or better and close to halfwere 20/16 or better (Figure 2). Theintermediate vision results were simi-larly good.

We don't see the losses in qualityof vision that patients typically expe-rience with monovision. The per-centage of people who said theynever or rarely experience glare orhalos around lights actually roseslightly after surgery. Only about10% of patients experienced anydecrease in contrast sensitivity underdistance dim-lighting conditions.There was no significant change inhigher-order aberrations from pre- topost-operative.

Satisfaction was very high.Ninety-seven percent of subjects saidthey would elect to have AdvancedCustomVue LASIK monovision again.The remaining 3% said they weren'tsure. And nearly all (95%) had areduction in the need for spectaclessix months after the procedure.

Hyperopic presbyopes: Custom aspheric ablationWavefront-guided multifocal oraspheric ablations for hyperopicpresbyopes have been under inves-

tigation for several years in Canada,but in the United States, we are justconcluding a smaller investigation-al study.

The multifocal AdvancedCustomVue ablation changes thecurvature of the eye to allow for nearvision in the center of the corneaand distance vision in the periphery.The optics are balanced and opti-mized throughout the entire rangeof vision to provide a longer depthof focus and a wider depth of field.The result: Patients can see well at alldistances, including near, far, andintermediate, under a variety oflighting conditions.

Both of these studies are amongthe first to incorporate IrisRegistration (IR) technology, whichI believe is critical to success intreating presbyopes. As clinical tri-als progress, and both custommonovision and custom aspherictreatments become more widelyavailable, it will be very importantfor U.S. surgeons to feel comfort-able with iris registration.

Colman R. Kraff, M.D. is in private practice,Kraff Eye Institute, Chicago, and is a clinicalinstructor, Northwestern University MedicalSchool, Evanston, Ill.

Figure 1: At six months, 87% of patients achieved uncorrected binocular distance acuity of20/20 or better and more than two-thirds were 20/16 or better.

Figure 2: Nearly 90% had uncorrected binocular near acuity of 20/20 or better, and close tohalf were 20/16 or better.

“ Ninety-sevenpercent of sub-jects said theywould elect tohave AdvancedCustomVue LASIKmonovisionagain.”

Colman R. Kraff, M.D.

Presbyopia Solutions — Las Vegas Show Supplement 7

Latest data show that aberration profile changes are predictable andpatients maintain normal contrast sensitivity following treatment

Hyperopic Presbyopic Experience in Canada

by W. Bruce Jackson, M.D.

In Canada, we've been treatinghyperopic presbyopes withmultifocal AdvancedCustomVue (Advanced MedicalOptics, AMO, Santa Ana,

Calif.) ablations for several yearsnow. We have treated 93 eyes of 56patients at three centers, with 12-month follow-up now available onmany of these eyes.

Hyperopic presbyopic ablationsare unique. They differ from a stan-dard hyperopic correction in that asubtle ablation shape change ismade to the patient's wavefrontmap, using variable spot-scanningtechnology. This makes the corneaaspheric, with a near zone in thecenter that blends into distancevision in the periphery.

In addition to expanding thepatient's range of vision with a cur-vature change, we also are address-ing higher-order aberrations with awavefront-guided ablation. Thetreatment is further customized totake the patient's pupil size intoaccount. If the pupil is relativelylarge, for example, the surgeon canincrease the central near zone. Wehave found that aiming to have thereading pupil fully within the cen-tral near treatment area is optimal.

The ResultsThe visual acuity results, which wehave reported many times, are verygood. Uncorrected distance visioncorresponds to what one would

expect from non-aspheric wave-front hyperopic treatments, even inbright light when the pupil con-tracts. At 12 months, 100% of sub-jects achieve uncorrected vision ofboth 20/25 or better for distanceand J3 or better for near. Eighty-fivepercent are seeing at least 20/25and J1 simultaneously, and satisfac-tion rates are high.

We recently began looking atwhat happens to higher-order aber-rations and contrast sensitivity. Wefound that while contrast sensitivi-ty (CS) does drop from pre-opera-tive values, it improves steadilyduring the post-operative period. At12 months, CS is still a little belowpre-operative levels, but it is wellwithin the normal values for a pop-ulation of 50- to 75-year-olds(Figure 1).

This is reflected in the highrates of satisfaction with nightvision. There was some concernearly in the trial that night-drivingvision might be adversely affectedby the treatment. However, patientsurveys have consistently indicatedthat patients are happier driving atnight without their glasses aftersurgery than they were with theirglasses pre-operatively.

We also compared pre- andpost-operative wavefront data.Earlier iterations of presbyopic abla-tion, in which the treatment waspurposely off-center, tended toinduce a lot of coma and otherhigher-order aberrations. In ourapproach, however, coma increasesonly slightly following surgery andremains stable over time (Figure 2).As one would expect, the creationof an aspheric, more prolate corneaalso shifts the spherical aberration(SA) from positive to negative. SAthen remains stable over 12months of follow-up.

For the young hyperopic pres-byope with a healthy lens, anaspheric ablation is an excellentprocedure for reducing spectacleindependence without intraocularsurgery.

W. Bruce. Jackson, M.D. is professor of oph-thalmology and director, University of OttawaEye Institute, Ontario, Canada.

“ For theyoung hyperopicpresbyope with ahealthy lens, anaspheric ablationis an excellentprocedure forreducing spectacle independencewithout intraocular surgery.”

W. Bruce Jackson M.D.

Figure 1. Dim contrast at 12 mos, CS is well within population norms for the 50- to 75-yearolds.

Figure 2. Advancements in aspheric treatment design are resulting in a reduction in theamount of induced coma.

8 Las Vegas Show Supplement — Laser Vision Correction

Advanced CustomVue with Iris Registration is critical for these challenging cases

Understanding the Importance of AblationRegistration When Correcting Mixed Astigmatism

by Mounir A. Khalifa, M.D.

Wavefront-guided LASIKwith iris registration isthe safest, most effi-cient, most predictablemethod for treating

mixed astigmatism. At our practice,our clinical experience has shownthat the accurate registration—either axial with the adjustment ofthe pupil centroid shift or torsionalwith the iris pattern torsional align-ment—is the crucial factor in accu-rately treating mixed astigmatismwith the customized bitoric abla-tion.

However, Iris Registration (IR)in a mixed astigmatism case can bea challenge. For axial registration,the larger the difference betweenscotopic pupils and photopicpupils, the greater the chance forpupil centroid shift. For torsionalregistration, the change from erectto supine position leads to excyclo-torsion 2.2 degrees or more (up to10 to 15 degrees). However, studiesin the literature have shown that inbitoric ablation, centration and tor-sional alignment are crucial.

Our ExperienceIn our study, we evaluated wave-front-guided ablation (customizedbitoric) with or without iris regis-tration in treating mixed astigma-tism.

The study included three groups.Group A was a retrospective study of20 eyes of mixed astigmatism withconventional ablation (manualmarking). This group included fourmales and six females with a meanage of 22.7 years. Mean pre-operativesphere was +1.67+1.32 D, and meanpre-operative cylinder was -2.79+2.24D.

Figure 1: At three months post-operative, 100% of the wavefront-guided plus iris registrationpatients were 20/30 or better compared to 80% of the wavefront and 75% of the conventionalLVC patients. This difference is statistically significant.

“ … we havefound that preciseregistration is anintegral factor inaccurately treatingthe challengingcases of mixedastigmatism …”

Mounir A. Khalifa, M.D.

Iris registration (IR) is critical for prior laser vision cor-rection cases. Because the wavefront pattern is typi-cally more complex, it is much more important tocompensate for pupil centroid shift as well as cyclo-torsion. The Fourier wavefront analysis of the VISX

platform adds to the fidelity of the data. These factors aremagnified when attempting to ablate complex patternsonto the corneal surface.

Complicated cases include ones in which higher-order aberrations are very high and the cylinder compo-nent of the treatment is very high or irregular. For exam-ple, a post-operative PRK patient complained of night-vision problems, glare, and mild diplopia despite having

20/18 uncorrected visual acuity on high-contrast EarlyTreatment Diabetic Retinopathy Study testing. His HOARMS was 0.66, the majority of which was coma. His PSFaccurately described his complaints, so we decided toenhance with Advanced CustomVue (Advanced MedicalOptics, Santa Ana, Calif.) PRK, which incorporates the IRtechnology.

He is six months post-operative; his vision is 20/16on high contrast ETDRS chart, his HOA is now 0.39, andhis complaints are resolving. Previously, without the IRtechnology, I would not have offered this patient anenhancement.

The Role of IR in Laser Vision Correction Enhancementsby Maj. Charles Reilly, M.D.

Group B was a retrospectivestudy of 20 eyes of mixed astigma-tism with wavefront-guided abla-tion without IR (manual marking).This group included three malesand seven females with a meanage of 23.8 years. Mean pre-opera-tive sphere was +1.27+0.6 D, andMean pre-operative cylinder was -3.35+1.48 D.

Group C was a prospectivestudy of 20 eyes of mixed astigma-tism with wavefront-guided abla-tion with IR. Four males and sevenfemales with a mean age of 25.4years were included in this group.Mean pre-operative sphere was+1.0+1.69 D, and mean pre-opera-tive cylinder was -2.5+5.6 D.

A wavescan aberrometer withFourier analysis was used to meas-

ure low-order and high-order aber-rations pre- and post-operativelyand to design the CustomVue(Advanced Medical Optics, AMO,Santa Ana, Calif.) wavefront-guidedablation for groups B and C.Manual marking was done at theslitlamp in groups A and B, and irisregistration was used in group C.

ResultsFor uncorrected visual acuity atthree months, 90% of the wave-front-guided plus IR patients were20/20 or better, while 70% of thewavefront-guided only and 65% ofthe conventional laser vision cor-rection (LVC) patients were 20/20or better. One hundred percent ofthe wavefront-guided plus IRpatients were 20/30 or better, while

Laser Vision Correction — Las Vegas Show Supplement 9

Figure 2: At three months post-operative, 80% of the patients treated with advancedCustomVue with IR were within 0.5D of intended correction versus 60% of the conventionaland 65% CustomVue without IR cohorts.

The Importance of Iris Registration in Presbyopia Correctionby W. Bruce Jackson, M.D.

I ris registration (IR) with Advanced CustomVue (Advanced MedicalOptics, AMO, Santa Ana, Calif.) offers several advantages intreating hyperopic presbyopes with aspheric ablations.

First, as with any other treatment, IR ensures that the wavefrontpattern ablated at the time of surgery corresponds precisely to thepre-operative wavefront map. This is accomplished partly by com-pensating for any cyclotorsion that occurs between measurementand treatment.

However, it is the second component of IR—pupil centroidcompensation—that is absolutely critical for aspheric ablations. Toachieve optimal results, the change in curvature that provides thenear vision enhancement must be delivered over the entrance pupil,corresponding exactly to the center of the wavefront map. The cen-ter of the pupil can shift considerably as the pupil changes sizeunder different lighting conditions, but IR identifies and compen-sates for any such shift.

Our study of aspheric ablations actually provides a good modelfor examining the role of IR because this technology was introducedabout halfway through enrollment. Of the 96 eyes treated, 50 hadIR. The group with IR ended up a little closer to emmetropia thanthose without IR (Figure 1) and had slightly better near acuity(Figure 2).

We prefer to use IR on every CustomVue case. Our capturerates are now well above 95%. Thanks to software modifications,almost all eyes can be captured, although pale, featureless iridesremain the most challenging. Surgeon and technician experienceand technique play a role in ease of capture as well.

As aspheric ablations for hyperopic presbyopes become morewidely available, proficiency with IR will be a critical factor in success with these treatments.

80% of the wavefront only and75% of the conventional LVCpatients were 20/30 or better(Figure 1).

At three months post-opera-tive, many cases gained one ormore lines in their best-corrected

visual acuity (BCVA) in the iris reg-istration group. Predictability withthe wavefront plus iris registrationwas excellent. For both sphere andcylinder, 100% of patients wereless than ±1 D of intended correc-tion (Figure 2).

Scotopic contrast sensitivitysignificantly improved in the irisregistration group. This might bebecause we found that wavefront-guided ablation with iris registra-tion precisely corrected the chal-lenging refractive error without sig-nificant induction of high-orderaberrations.

Coma, trefoil, and secondaryastigmatism showed significantincrease in the conventional andwavefront groups, while there wasno significant change in the wave-front plus IR group.

Trefoil and secondary astigma-tism showed the most significantimprovement with IR indicatingmore accurate axis alignment ofthe bitoric customized ablation.When we imagine the nature ofthe bitoric ablation with myopicpattern in one axis and hyperopicpattern in the other, one can findthe crucial importance of accuratealignment of the ablation patternon the cornea either axially orradially. The effect of misalignmentis augmented by the nature of thebitoric ablation. Therefore, wehave found that precise registra-tion is an integral factor in accu-rately treating the challengingcases of mixed astigmatism withthe customized bitoric ablation.

Mounir A. Khalifa, M.D. is in practice at HorusVision Correction Center, Alexandria, Egypt.

Figure 1: The 50 patients that had IR were closer to emmetropia compared to the eyes that werenot treated with IR.

10 Las Vegas Show Supplement — Laser Vision Correction

A small series demonstrates the value of Advanced CustomVuecorrections when patients are symptomatic after refractive surgery

Wavefront-Guided Laser Vision Correction is theAnswer for Basic and Complex Retreatments

by Baha Toygar, M.D.

We have treated thou-sands of patients withvarious laser systems.As with any laser sys-tem, when patients

have some residual refractive errorand are not satisfied with the cor-rection, we have typically been ableto turn them into satisfied patientswith a simple enhancement.

There are some patients, how-ever, who present more complexcases. They complain of symptomssuch as ghosting, double vision, ornight-vision problems, despiteapparently good visual acuity. To behonest, my colleagues and I havesometimes written these patientsoff as having psychological prob-lems because their subjective com-plaints didn't correlate with ourobjective testing.

The Advanced CustomVue(Advanced Medical Optics, AMO,Santa Ana, Calif.) system has com-pletely changed my attitude towardthese "troublesome" patients. Infive cases over two months, wehave performed custom re-treat-ments for patients I would other-wise have been extremely reluctantto re-treat—with superb results.

WaveScan imaging, first of all,provided diagnostic confirmationof a real problem. In every one ofthese five cases, the patients hadunusually high higher-order aberra-tions (HOAs), particularly coma.Moreover, we were chastened todiscover that the point-spread func-tion (PSF) generated by theWaveScan looked, in each case,very distorted and often validatedwhat the patient described seeingwhen looking at a point source oflight.

Once we realized the patientsweren't making up their com-plaints, it has been very reassuring(for both patient and surgeon) tobe able to cut a PreVue lens to get asense of whether second treatmentwill resolve the patients’ com-plaints. In a normal treatment, Inever use a PreVue lens, but it canbe very valuable in complex, post-surgical cases, especially when weare concerned about the liabilityinvolved in taking on a dissatisfiedpatient referred in from elsewhere.

With the Advanced CustomVuesystem, we have been able to cor-

rect address the night-vision orquality-of-vision complaints in asingle procedure. Thus far, we havenot experienced any problems withwavefront capture or IrisRegistration (IR) in post-surgicalcases. In fact, I believe IR is animportant factor in successfullyperforming these re-treatments.

Case example 1 A 30-year-old female was treated atour hospital. Her pre-operativerefraction was +4.25 -0.50 x 125OD and +4.75 OS. She had normaltopography and was deemed agood candidate for hyperopicLASIK. Flap creation and a standardWavelight Allegretto treatment inearly 2005 were uneventful. Post-operative topographies were nor-mal and the treatments appearedto be well centered.

However, the patient com-plained of double vision, halos andglare, and severe night-vision prob-lems. At the nine-month post-oper-ative visit, her best-corrected visualacuity (BCVA) was 20/25 in theright eye but only 20/50 in the left.The refraction was -0.75 - 1.50 x165 OD and -0.75 D OS. My col-leagues and I could not decidewhether to attempt an enhance-ment.

When we got the CustomVuesystem and heard that patients likethis had been successfully treated,we decided to give it a try. TheWaveScan showed high coma andtrefoil in both eyes and the PSFslooked exactly like what she haddescribed seeing at night. We testedthe attempted correction withPreVue lenses, and the patientliked the improvement, so we treat-ed her with CustomVue in May2006. Post-operatively, her com-plaints were resolved; she was see-ing 20/28 uncorrected and was veryhappy.

Although we await longer-termfollow-up data for this and ourother four CustomVue re-treatmentpatients, we are quite confidentthat they remain satisfied becauseour phones are quiet. Thesepatients had been calling almostdaily, and now we have to callthem to remind them to come infor the follow-up examination.Based on these preliminary out-comes and an equally positiveexperience treating normal virgineyes, we feel confident performingwavefront-guided laser vision cor-rection on all patients that presentfor correction to our practice.

Baha Toygard, M.D. is in practice at the DunyaEye Hospital, Istanbul, Turkey.

Figure 1: Utilizing the point spread function image from the wavescan can confirm what apatient sees when they look at a point source at light.

“ With the Advanced CustomVue system, we havebeen able to correct any residual refractiveerror and alsoaddress the night-vision orquality-of-visioncomplaints in a single procedure.”

Baha Toygar, M.D.

Laser Vision Correction — Las Vegas Show Supplement 11

Technology and technique advancements allow surgeons to confidentlyre-treat a wider array of enhancement patients than ever before

Surface and Lamellar Wavefront-Driven Enhancements

by Maj. Charles Reilly, M.D.

Wavefront-guided lasertechnology, with itsaccuracy and preci-sion, is a crucial ele-ment when dealing

with patients who require anenhancement after laser vision cor-rection (LVC). Patients in need ofan enhancement are a special sub-set of the LVC population. In orderto optimize the chance for a suc-cessful enhancement, it is impor-tant to examine clinical factors thatmay have played a role in therefractive outcome before anotherlaser procedure is performed.

Clinical factors such as treatingany ocular surface disease or under-lying systemic condition need to beaddressed. In addition, the patientmay be taking systemic medica-tions that might have contributedto the unsatisfactory refractive out-come. During the physical exami-nation, surgeons should carefullyevaluate if the patient is developinga cataract or if there is some otherreason the refractive shift mighthave occurred.

WFG EnhancementIn our experience with the AirForce, patients usually only have asmall amount of refractive errorthat needs to be addressed.However, with very low amounts ofrefractive error, the astigmatismportion often contributes to a greatamount of the overall refractiveerror. Therefore, it becomes crucialto correct that astigmatic portion asprecisely as possible. Ocular align-ment is a key factor.

The best method to do this iswith a wavefront-guided enhance-ment. The true value of a wave-front-guided enhancement, in addi-tion to producing a more accuratepicture of the entire optical system,is the ability to lay down that treat-ment and compensate for anycyclotorsion that is created whenthe patient transitions from anupright position to a supine posi-tion.

Our current enhancement rateis less than 1%, but because we arethe referral center for the Air ForceRefractive Surgery Program, wehave had the opportunity to treatsome complex cases. We havefound excellent results with bothlamellar and surface enhancementsusing wavefront-guided technology.As expected with all enhancements,the uncorrected visual acuities aremarkedly improved after enhance-ment; we averaged more than 2.5lines of improvement in uncorrect-ed visual acuity in the EarlyTreatment Diabetic RetinopathyStudy (ETDRS) high contrast acuity.

We also follow low contrastvisual acuity and are pleased todemonstrate good response to ourenhancements with no statisticallysignificant worsening of low con-trast vision in our lamellarenhancements and an improve-ment in low contrast sensitivity inour surface enhancements. In addi-tion, we are able to capture wave-front data in some of our enhance-ments, which demonstrates adecrease in HOA RMS at sixmonths follow-up in our surface re-treatments with only a small statis-tically non-significant increase inHOA RMS in the lamellar re-treat-ments (Figures 1 and 2).

Surface vs. LamellarThere is controversy within therefractive surgery communityregarding whether the creation andmaintenance of a lamellar flap dur-ing wavefront-guided enhance-

Figure 1: Uncorrected visual acuity improved dramatically for patients treated with eitherLASIK or PRK wavefront-guided ablation.

Figure 2: Post-operative, the PRK wavefront-guided enhancement group experienced animprovement in low-contrast sensitivity over pre-enhancement.

“ We have found excellentresults with bothlamellar and surface enhance-ments usingwavefront-guidedtechnology.”

Maj. Charles Reilly, M.D.

ments contribute to higher-orderaberrations.

It is worthwhile to consider per-forming a surface enhancementinstead of a lamellar one. Specifically,with a surface enhancement, there isless concern regarding ectasia,epithelial ingrowth, and residualstromal bed issues.

Our experience has shown thatwith surface enhancement there isa superior result in overall qualityof vision as well as not inducingadditional higher-order aberrations.We have found that with surfaceenhancements it can take as longas six to nine months for finalvisual acuity to stabilize as opposedto a LASIK enhancement, in which

patients usually stabilize by monththree.

Despite the longer visual acuitystabilization time, wavefront-guid-ed laser enhancement using a sur-face approach is a worthwhile con-sideration to maximize patients'visual outcomes.

Maj. Charles Reilly, M.D. is chief of cornea andrefractive surgery, Wilford Hall Medical Center,Lackland Air Force Base, San Antonio, andchief consultant for refractive surgery to theAir Force Surgeon General.

12 Las Vegas Show Supplement — Refractive Cataract Surgery

Tecnis aspheric offers best chance for improvedcontrast acuity for broadest range of patients

Understanding the Clinical Differences Between Aspheric IOLs

by Y. Ralph Chu, M.D.

There are now three asphericIOLs in the marketplace,each claiming to reduce orminimally induce sphericalaberration (SA) inside the

optical system of the eye. As weknow, corneal spherical aberrationincreases with age, a problem typi-cally compounded by the implanta-tion of a standard IOL that alsoincreases SA.

Aspheric lenses were designedto reduce this effect and therebyprovide cataract patients with bet-ter night vision and contrast acuity.However, each of the three lenseshas a slightly different theoreticalgoal.

The Tecnis Z-9000 (AdvancedMedical Optics, AMO, Santa Ana,Calif.) lens was designed to fullycompensate for the positive SA ofthe average cornea. In fact, themulticenter, prospective, random-ized Food and Drug Administration(FDA) clinical trial for this lens

demonstrated that total SA wasreduced to nearly zero in a humanstudy population.

The AcrySof SN60WF IQ wasdesigned to partially compensatefor the average cornea's positive SA.I am not aware of any largeprospective trial showing that itactually reduces SA to a given pointin a patient population, but eyemodels predict the average eye stillwould have about 0.1 µm of SA.

The SofPort AO lens attemptsto not induce any positive sphericalaberration, or to be SA-neutral.Because this goal is intrinsic to thelens, it has no relationship to theaverage or actual SA in the eye andmay be less dependent on perfectplacement of the IOL.

Study GroupsWe set out to see how all theseclaims pan out in a typical cataractpatient population. In a multicen-ter study, we took all comers fromthe general population and ran-domized them to one of these threeaspheric IOLs, without regard topre-operative SA.

We intend to enroll about 90patients (30 in each IOL group) andfollow them for six months. Thusfar, 22 patients have reached thethree-month visit.

Pre-operative best-correctedvisual acuity (BCVA) and corneal SAwere similar across all three groups.Interestingly, each group's averagepost-operative BCVA was betterthan 20/20, reinforcing our anec-dotal clinical finding that patientswith aspheric lenses do achieveslightly better acuity.

We measured SA pre-operatively(when possible) and post-operative-ly. The mean total SA increased inthe SofPort AO eyes, decreased con-siderably (but not down to zero) inthe AcrySof IQ eyes, and wentdown to zero in the Tecnis eyes(Figure 1).

Thus far, our study supports theexpectation that the Tecnis lens willachieve zero SA (or very near zero) inthe majority of eyes. StevenSchallhorn (M.D., director, refractivesurgery, Naval Medical Center, SanDiego) and others have shown thatreducing higher-order aberrations,especially SA, to as close to zero aspossible is important in achievingoptimal visual outcomes.

All three of these lenses provideexcellent Snellen acuity. However,we know that Snellen acuity doesn'tdescribe every aspect of a patient'sperceptive vision. With aspheric

IOLs, we are hoping for subtleimprovements in the quality ofvision, especially in low-light, low-contrast situations.

To determine whether this wasachieved, we measured contrastsensitivity, a sort of stress test forthe eye. Overall, contrast sensitivitywas slightly higher with the Tecnislens compared to the other twoIOLs, particularly at greater spatialfrequencies (Figure 2).

The Future Enrollment and follow-up areongoing, and we hope to soon beable to report more on how thesethree aspheric lenses perform in atypical patient population.

Certainly, the drive towardimproved functional vision orimproved quality of vision in bothcataract and refractive surgery willcontinue. Spherical aberration isonly the first higher-order aberra-

tion to be addressed with wave-front-designed IOLs. As we learnmore about how to measure aberra-tions and quantify their effect on apatient's perception, I expect thetrend toward improving quality ofvision for cataract patients to accel-erate and IOLs to become more cus-tomizable.

For now, aspheric IOLs are animportant advance. Although ourdata are preliminary, they indicatethat the Tecnis IOL is the most like-ly of the aspheric lenses to bringpatients' total spherical aberrationback into balance at zero SA.

Y. Ralph Chu, M.D. is founder and medicaldirector, Chu Vision Institute, Edina, Minn., andadjunct assistant professor of ophthalmology,University of Minnesota.

“ Overall, con-trast sensitivitywas slightly higher with theTecnis lens compared to theother two IOLs,particularly atgreater spatialfrequencies.”

Y. Ralph Chu, M.D.

Figure 1: Mathematical models demonstrate that zero optical aberrations will yield the best retinal image.

Figure 2: Patients implanted with the aspheric Tecnis lens demon-strated slightly higher contrast sensitivity compared to the SoftPortAO and AcrySof IQ patients.

Refractive Cataract Surgery — Las Vegas Show Supplement 13

Achieving the best visual system possible means striving for zerohigher-order aberrations, including zero spherical aberration

Less Is More

by Capt. Steven C. Schallhorn, M.D.

As our abilities in cornealand lenticular refractivesurgery advance, one ofthe issues we continue towrestle with is identifying

the optimal aberration profile. Inother words, what goal should westrive for in order to optimizepatients' visual quality?

An In-Depth Look Mathematical models demonstratethat zero optical aberrations (i.e.,none) will yield the best retinalimage. The ideal optical system alsowould have no lower- or higher-order aberration (HOAs).Increasing aberrations lead togreater visual distortion (Figure 1).

It's important to appreciate thatthere can be a coupling effect onvision between lower- and higher-order aberrations. I use this analo-gy: Lower-order aberrations are tohigher-order aberrations as sphereis to cylinder. A low myope mayhave better uncorrected vision ifcombined with plus cylinder, so apatient with a refraction of -1.00+2.00 D (spherical equivalent (SE)of zero) likely will have betteruncorrected vision than if hisrefraction was simply -1.00 Dsphere, even though the cylinderadds aberrations.

In the same fashion, a patientwith 1.00 D of myopia may havebetter vision if combined with aspecific amount of spherical aberra-tion (SA). The SA may cause othervisual symptoms, but it can couplewith the myopia to provide betterhigh-contrast vision.

At the Naval Medical Center,San Diego, we've also studied laserrefractive surgery outcomes exten-sively in an attempt to tease outthe optimal aberration profile. Inone study, we looked at 300 eyes of150 consecutive subjects whounderwent conventional LASIK.Pre-operatively, the average SE was -3.80 D.

We found correlations betweenhigher-order aberrations and sub-jective and objective quality-of-vision measures while looking atthe eyes with worse uncorrectedvisual acuity (n=150). For example,in a plot of halo complaints versusthe amount of spherical aberration(all 6.0-mm pupil analysis), despiteconsiderable scatter, there is a posi-tive correlation (Figure 2).

More spherical aberration corre-lates to more symptoms. Subjectswith more HOA also have worsebest-corrected visual acuity (BCVA)and worse low-contrast acuity. Inthese refractive surgery patients, allour analyses point to the conclu-sion that lower levels of HOA arerelated to better quality of vision.

Pilot StudyWe compared a large sample of 140pilots to a typical refractive surgeryclinic population of 300 patientswith healthy eyes. Whether you lookat high-contrast (photopic) visualacuity, 5% contrast (photopic) acu-ity, or 25% contrast (mesopic) acuity,the distribution is similar. Across theboard, the pilots have better visionthan the clinic patients. The realquestion is whether they have some

particular aberration profile that wewould want to duplicate using laseror lenticular surgery.

WaveScan imaging shows thatthe pilots' eyes are not completelyaberration free. We found no correla-tion between their higher-order aber-rations and high-contrast visual acu-ity (all with 6.0-mm pupil analysis).However, there is a positive correla-tion between their HOA and low-contrast acuity under photopic ormesopic conditions. Lower amountsof HOA are related to better qualityof vision even in this group of pilotswith super-normal vision.

On average, the pilots had 0.08microns of SA. Is this the ideal SA?Should we target this amount? Theanswer is no. The reason: We alsofound a positive correlation betweenspherical aberration and mesopiccontrast acuity. The correlation holdsif we look at absolute SA, withoutletting the positive and negative SAcancel each other out.

In dim light, less spherical aber-ration is related to better contrastacuity in these pilots. Again, thistells me that the ideal SA, even inpilots with super-normal vision, iszero. In other words, zero sphericalaberration should be our surgical tar-get.

In conclusion, every analysisthat we have done—refractive sur-gery patients, pilots with super-nor-mal vision, and opticalmodeling—all point to the sameconclusion: Less aberration is better.

Capt. Steven C. Schallhorn, M.D. is director ofrefractive surgery, Naval Medical Center, SanDiego.

Figure 1: Mathematical models demonstrate that zero optical aberrations will yield the bestretinal image.

Figure 2: Despite considerable scatter, there is a positive correlation between halo com-plaint and spherical aberration—more spherical aberration correlates to more symptoms.

“ … all ouranalyses point tothe conclusionthat lower levelsof HOA are relatedto better qualityof vision.”

Capt. Steven C. Schallhorn, M.D.

14 Las Vegas Show Supplement — Refractive Cataract Surgery

Blue light is important for mesopic and scotopic vision and critical for entraining biological clocks to environmental day-night rhythms

Blue Light’s Important Role in Good Health

by Martin A. Mainster, Ph.D., M.D., FRCOphth.

S cientists have speculatedfor decades that lightexposure may play a rolein age-related maculardegeneration (AMD). This

relationship is intriguing, but nineof the 11 large epidemiologicalinvestigations that studied itfound no correlation betweenAMD and environmental lightexposure. Additionally, a growingbody of scientific evidence nowdemonstrates that effective envi-ronmental blue-light exposure isvital for optimal systemic andmental health.

AMD and retinal phototoxicityRecognition that early polymethyl-methacrylate IOLs transmittedpotentially harmful ultraviolet (UV)radiation to the retina1,2 led to theinclusion of UV-blocking chro-mophores in most IOLs.3 Sub-sequent suggestion that IOLs alsoblock violet light3 was followed by

introduction of the first visible light-blocking IOLs in the early 1990s.

Acute exposures to brilliantlight sources cause photic retin-opathy (retinal phototoxicity).Hazardousness of acute UV-blueretinal phototoxicity increases withdecreasing wavelength. Thus, UVradiation (100-400 nm) is moreharmful than violet light (400-440 nm), which is more harmfulthan blue light (440-500 nm). UVradiation is responsible for 67% of acute UV-blue phototoxicity, butviolet light accounts for 18% andblue light for only 14% of poten-tial pseudophakic UV-blue photo-toxicity.4,5

Visual benefits of blue light Figure 1 shows that blue light ismuch more important for dimlight (mesopic and scotopic) thanbright light (photopic) vision. Infact, it provides 35% of scotopicand 7% of photopic aphakic sensi-tivity.4 In comparison, violet light,which is more hazardous, accountsfor only 10% of scotopic and 1%of photopic sensitivity.4 It’s obvi-ously a better strategy to reduceviolet light than blue light.

Rod photoreceptors providedim light vision. Driving, mobility,and peripheral vision problems areall associated with rod-mediated,not cone-mediated, dark adapta-tion parameters. When you get upin the middle of night and light-ing is too dim for you to see thecolor of objects, you are using rod-mediated vision.4,5

Unfortunately, older adultslose much of their dim light visionbecause of natural yellowing oftheir crystalline lens and age-relat-ed decreases in pupillary diameterand rod photoreceptor popula-tions. Scotopic sensitivity decreas-es and dark adaptation slows withaging. Impaired dark adaptationincreases the risk of falling inolder adults. Falling increases therisk of debilitating injuries, costlylong-term hospitalization, andeven death.4,5

Health benefits of blue lightAge-related pupillary miosis andnatural crystalline lens aging limitthe blue light needed by retinalganglion photoreceptors, con-tributing to circadian dysfunctionand its many consequences.Circadian dysfunction is present inaging and disorders such as coro-nary artery disease, hypertension,

diabetes, Alzheimer’s disease, asth-ma, and most forms of cancer.Health care risks are correlatedwith both the degree and durationof circadian disruption. Numerousclinical studies have shown therisks of disturbed circadian pho-toentrainment and the benefits ofoptimal rhythmicity.4

Blindness has widespread physi-ological effects. Overall life ex-pectancy is decreased. Even mildvisual impairment doubles mortalityrisks. Cataract itself is associated withpoorer survival. Fortunately, lighttherapy and cataract surgerycan help. In particular, cataract sur-gery has been shown to decreaseinsomnia, sleepiness, and depression.Thus, improved blue-light depend-ent retinal ganglion photoreceptionis an important consideration incataract surgery, extending its bene-fits beyond better vision to improvedsystemic and mental health andincreased longevity.

Weighing the trade-offsBlue-blocking IOLs provide 20% lessUV-blue phototoxicity protectionthan a 53-year-old crystalline lens.Most AMD occurs in phakic adultsover 60 years of age, so 53-year-oldcrystalline lenses don’t preventAMD. If light is a significant risk fac-tor in AMD, then blue-blocking IOLswon’t prevent it.4 Blue-blocking IOLsalso provide 14% to 21% less sco-topic sensitivity and 27% to 38% lessmelatonin suppression than conven-tional UV-blocking IOLs.4

Older patients want better night-time vision, less insomnia, and bet-ter health. Cataract surgery is a once-in-a-lifetime chance for patients toovercome natural aging and achievebetter circadian rhythmicity andvision in dim light. Ophthal-mologists improve visual photore-ception with cataract surgery.Improving blue light–dependent,non-visual retinal photoreceptionextends the benefits of cataract sur-gery far beyond mere conscious,image-based vision.

Martin A. Mainster, Ph.D., M.D., FRCOphth. isthe Luther Fry Endowed Professor of Ophthal-mology, University of Kansas School ofMedicine, Kansas City, KS. Dr. Mainsterserves as a consultant for Advanced MedicalOptics (Santa Ana, Calif.), IRIDEX (MountainView, Calif.), and Ocular Instruments(Bellevue, Wash.).

References1. Mainster MA. Spectral transmittance of

intraocular lenses and retinal damage fromintense light sources. Am J Ophthalmol1978;85:167-70.

2. Mainster MA. Solar retinitis, photic macu-lopathy and the pseudophakic eye. J AmIntraocul Implant Soc 1978;4:84-6.

3. Mainster MA. The spectra, classification,and rationale of ultraviolet-protectiveintraocular lenses. Am J Ophthalmol1986;102:727-32.

4. Mainster MA. Violet and blue light blockingintraocular lenses: photoprotection versusphotoreception. Br J Ophthalmol2006;90:784-92.

5. Mainster MA. Intraocular lenses shouldblock UV radiation and violet but not bluelight. Arch Ophthalmol 2005;123:550-5.

Figure 1: Blue light is important for scotopic and mesopic vision mediated by retinal rodphotoreceptors. It is vital for melatonin suppression mediated by blue-light sensitive retinalganglion photoreceptors.

“ ... improvedblue-light retinalganglion photo-reception is an important consideration in cataract surgery ...”

Martin A. Mainster, Ph.D., M.D.,FRCOphth.

Refractive Cataract Surgery — Las Vegas Show Supplement 15

The right technology and surgical techniques will ensure your patientsare seeing great on postop day one and referring their friends

Creating the Optimal Surgical Environment forSuccess with Premium IOL Implantation

Farrell "Toby" Tyson II, M.D., F.A.C.S.

My goal has always beento perform the bestcataract surgery I possi-bly can. With multifo-cal IOL implantation,

patient expectations are higher, andthe surgeon's margin of error islower. These lenses are less forgiv-ing of small power miscalculationsor even minor corneal edema orposterior capsular opacification. Inshort, premium IOLs demand high-precision surgery to give thepatient the fastest recovery and thebest possible chance of spectacleindependence.

The right tools simplifycataract surgery The most important factor inchoosing both phaco technologyand in refining one's phaco tech-nique is to use as little phaco ener-gy as possible. This reducesendothelial loss, improves corneal

clarity, and speeds up postoperativevisual recovery.

I use the Sovereign WhiteStarsystem (Advanced Medical Optics,AMO, Santa Ana, Calif.). Coldphaco with this system reducesphaco energy by about 60%. NewICE (Increased Control &Efficiency) technology furtherreduces ultrasound energy by usinga brief "punch" in the first millisec-ond of the pulse to accelerate cavi-tation (Figure 1). For a fast surgeon,this may not make a huge differ-ence, but it can really reduce effec-tive phaco time (EPT) for someonewho is in the eye longer.

WhiteStar has very good flu-idics, so I don't get any chamberbouncing or "trampolining" of theback of the capsular bag when I amperforming in-the-bag phacoemul-sification. And, while all the newerphaco systems significantly reducethe chance of a corneal burn,WhiteStar almost eliminates thepossibility.

Surgeons who are implantingmultifocal IOLs should be perform-ing small-incision surgery withclear corneal incisions. Clearly, weare moving toward even smallerwounds through bimanual microin-cision surgery. As IOL manufactur-ers catch up and start making lens-es that can fit through smaller inci-sions, we'll see a rapid migration tobimanual surgery, but even now itis valuable for ease of placing theincision on the axis of astigmatismand again, reducing phaco energy.

In a study I recently conducted,245 consecutive eyes were random-ized to either bimanual WhiteStarphaco or standard coaxialWhiteStar phaco. All variable phacosettings were the same in bothgroups. With a 3+ nuclei, thereduction in EPT with bimanualsurgery was 38.2%. With 2+ nuclei,there was a 51.5% reduction in EPT(Figure 2).

The choice of an ocular vis-coelastic device (OVD), while oftenconsidered a minor detail, is actual-ly a critical part of cataract surgery.I use Healon5, a high molecularweight, high-viscosity, viscoadap-tive OVD, on almost all my cataractsurgeries.

I think some have avoidedHealon5 for fear that OVD removalwill slow down their surgery day.My average procedure time is onlyabout five minutes. When I con-verted to Healon5, I actually found

that it made me a faster surgeonbecause every case is the same. Thecapsulorhexis, cataract removal andlens insertion are all smooth andpredictable. This viscoelastic willhold a floppy iris in place or allowyou to enlarge the iris withoutusing retractors in a small pupilcase. It doesn't ooze out of the eye;in fact, if I have a wound that is alittle bit leaky, I will put a dab ofHealon5 behind it to act as a spack-le. I'm not stressed out or sloweddown by mistakes or the need foradditional instruments in toughercases.

Adding up the advantagesI think the combination ofWhiteStar cold phaco and Healon5is healthier for the endothelium,which may result in more years of

better vision. We can't predict thatwith certainty, but it makes senseto me that preserving endothelialcells may give patients better con-trast sensitivity in the long term.

In the short term, the biggestdifference of new technologycataract surgery has been notice-ably clearer corneas on day onepost-operative. I now expect all mycataract patients to be 20/30 or bet-ter the day after surgery unlessthere is some retinal or corneal dis-ease. When your patients can seethis well, they become your biggestfans and word-of-mouth referralsincrease significantly.

Farrell “Toby” Tyson II, M.D. is in private prac-tice in Cape Coral, Fla.

Figure 1: In a study comparing WhiteStar with vs. without ICE in 59 eyes, Dr. Kasaby foundenergy consumption was reduced by over 50%.

Figure 2: Effective Phaco Time is significantly reduced with bimanual surgery.

“ When I con-verted to Healon5, I actually foundthat it made me afaster surgeonbecause everycase is thesame.”

Farrell "Toby" Tyson, M.D.,F.A.C.S.

Educational Symposia

Las Vegas 2006

These activities have been approved for AMA PRATM credit.

Please join us in Las Vegas for CMESymposia during the AAO Annual Meeting

Sunday, November 12, 2006Wynn Las Vegas

The Next Generation of Wavefront-Guided AblationsSupported by an unrestricted educational grant from Advanced Medical Optics – AMO

Registration: 6:00 – 6:30 AMProgram: 6:30 – 8:00 AM

Program Chair: Capt. Steven C. Schallhorn, MD

Faculty: Michael C. Knorz, MDColman R. Kraff, MDJeffery J. Machat, MD Edward E. Manche, MD Louis E. Probst, MDMajor Charles Reilly, MDKerry D. Solomon, MDJulian D. Stevens, FRCSJohn A. Vukich, MD

Preliminary Program:• Redefining Custom Correction• Wavefront-Guided Enhancements• Techniques and Technologies for Laser Vision

Correction of Presbyopia

Monday, November 13, 2006The Venetian

Redefining Lenticular RefractiveOutcomes: Pseudophakic RefractiveManagement, Lens Selection, andPatient ExpectationsSupported by an unrestricted educational grant from Advanced Medical Optics – AMO

Registration: 7:00 – 7:30 AMProgram: 7:30 – 9:00 AM

Program Chair: Steven J. Dell, MDRichard L. Lindstorm, MD

Faculty: Angel López Castro, MD Michael C. Knorz, MDShareef Mahdavi, BAMartin A. Mainster, PhD, MDH.L. “Rick” Milne, MDLouis D. Nichamin, MDTerrence P. O’Brien, MDCapt. Steven C. Schallhorn, MDFarrell C. Tyson III, MD

Preliminary Program:• Keys to Communicating With the Lenticular

Refractive Patient• Matching the Presbyopia Procedure With Patient

Needs and Expectations• Pursuing Refractive Success in the

Pseudophakic Patient• Keynote Lecture