Surgeons know toavoid touchingthe capsule witha phaco needleduring pha-

coemulsification, but even ifthey follow that rule capsu-lar damage can still occur.New research identifies oneway to reduce such compli-cations.

The expanded utiliza-tion of torsional ultrasoundenergy by phacoemulsifica-tion system applicationssuch as the OZil IntelligentPhaco (IP, Alcon, Fort

Worth, Texas) may help re-duce overall complications,especially failures of theposterior capsule, accordingto a study by RichardMackool, M.D., the MackoolEye Institute, Astoria, N.Y.,and Robert Osher, M.D.,Cincinnati Eye Institute,Ohio.

This study of the im-pacts of phaco energy onthe posterior capsule indi-cated that phacoemulsifica-tion systems that use largeramounts of longitudinal ul-trasound power may in-

crease the risk of rupture.The study compared thelikelihood of posterior cap-sule tears in porcine eyemodels where either longitu-dinal or torsional energywas utilized. In 36 crys-talline lens removal trialssplit between 17 torsionalcases and 19 longitudinalcases, the posterior capsulewas aspirated to occlusionand then linear ultrasoundwas applied until a posteriorchamber tear occurred.

The study found thatlongitudinal ultrasound tip

motion consistently tore theposterior capsule at lowerultrasound power than tor-sional ultrasound tip motion.

The findings could havesafety implications for manysurgeons who blend longitu-dinal and torsional ultra-sound for cataracts in orderto prevent clogging that canslow phacoemulsification. Inaddition to concerns thatsuch regular use of longitu-dinal ultrasound energy maybe excessive in soft cataractcases, the research indi-cates that its use should be

“ The expanded utilization of torsional ultrasound energy applications such as the OZil Intelligent Phacomay help reduce overallcomplications”Richard Mackool, M.D.

Surgeon says posterior capsule protection among OZil IP advantages

S u p p l e m e n t t o E y e W o r l d • S e p t e m b e r 2 0 1 0

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

www.eyeworld.org

Clinical applicationsfor torsional phacoSupported by an unrestricted educationalgrant from Alcon Inc.

continued on page 2

minimized for safety rea-sons.

Among the newestphaco applications to incor-porate that concept is theOZil IP, which applies longi-tudinal energy only when anocclusion is imminent.

“OZil IP improves cut-ting efficiency by its ability tocontinuously remove nu-clear material without thedevelopment of either inter-mittent obstruction or theuse of excessive longitudi-nal tip vibration that cancause chattering of particlesand endanger the endothe-lium,” Dr. Mackool said. “Theabsence of chatteringcauses particles to remainnear the tip and reduces thepossibility that they may bepropelled into the peripheryof the anterior chamberwhere they may be se-

questered in OVD, the filtra-tion angle, etc.”

Dr. Mackool noted thatthe reduced use of longitu-dinal energy by the OZil IPapplication also allows con-tinuous followability of lensmaterial because repulsionof nuclear material does notoccur.

Another protective ben-efit of OZil IP’s approach tothe use of ultrasound en-ergy includes better protec-tion of the cornealendothelium during pha-coemulsification.

“Because of the ab-sence of chattering and thefollowability of lens material,reduced amounts of BSSPLUS (balanced salt solu-tion, Alcon) are required forthe procedure,” said Dr.Mackool. “These factors actin concert to protect thecorneal endothelium during

the procedure, thereby re-ducing endothelial cell loss.”

Dr. Mackool has foundfurther corneal endotheliumprotection is provided bycombining the OZil IP appli-cation with sodium chon-droitin sulfate and sodiumhyaluronate (VISCOAT,Alcon).

“Even with flow ratesgreater than 30 cc perminute, VISCOAT remainsin the corneal dome,whereas OVDs that do notcontain chondroitin sulfatedo not,” Dr. Mackool said. “Inmy opinion, the combinationof VISCOAT and IP are thetwo most important aspectsof the phacoemulsificationprocedure that positively im-pact preservation of the en-dothelium.”

The performance bene-fits that come with the OZil

IP’s reduced use of longitu-dinal power have not comeat the price of more work forthe surgeon. In fact, Dr.Mackool has found that thenew application has re-duced the length of hisphaco procedures.

Additionally, Dr. Mackoolhas found no learning curvewith the new application,which lends itself well to hispreferred soft shell tech-nique and his aspiration ofthe viscoelastic from thesurface of the nucleus be-fore beginning phacoemulsi-fication.

“This should be doneregardless of the pha-coemulsification system thatis employed,” Dr. Mackoolsaid.

Contact informationMackool: 718-728-3400, mackooleye@aol.com

2 Clinical applications for torsional phaco

continued from page 1

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The twin goals ofreduced surgerytime and reducedenergy used inphacoemulsifica-

tion procedures got a boostwith the combination of theOZil torsional handpiece(Alcon, Fort Worth, Texas)and the Intelligent Phaco(IP) software for the INFINITI Vision System(Alcon).

Those improvementswere found in a comparisonof OZil system cataract pro-cedures performed bothwith and without the OZil IP.The study originated fromthe impression of BradleyBlack, M.D., assistant clini-cal professor, department of

ophthalmology and visualsciences, University ofLouisville, that the OZil IPwas reducing both the re-quired time and energywhen he began using thesystem in September 2009.

Dr. Black’s study com-pared time and energy usedin dense nuclei cases byboth the established OZilsystem and the newer OZilIP, and it confirmed thenewer technology reducedboth the time in the eye andenergy usage. The study ofthe same two OZil systemsused by the same surgeonfound OZil IP’s dense nucleicases used an average of27% less energy. The cumu-lative dissipated energy

(CDE) was 19.98 units onaverage in OZil system pa-tients but dropped to an av-erage of 14.62 units in OZilwith IP patients. “It waspretty dramatic,” Dr. Blacksaid.

“I was looking forward toOZil with IP when it came toremoving the quadrantsafter chopping or dividing areally dense cataract, and Iwas not disappointed,” Dr.Black said. “It was a nightand day difference in deal-ing with those types ofcataracts.”

The improvements intime and energy usagestemmed from the designapproach of OZil IP thatsought to maximize cutting

efficiency, improve the flu-idics’ dynamics, and keepnuclear material on the tip.The result was less turbu-lence in the anterior cham-ber and better protection forthe endothelium.

The impact of the OZilIP was also seen in post-opvisits, where patients ap-peared to have even clearercorneas than they did withthe OZil system.

“We had clear corneasbefore but any time youmake even a minor improve-ment, when you look at alarge number of patients—particularly patients whomight have a compromisedendothelium to start with,such as Fuchs’ endothelial

Surgeon finds less time and energy used in OZil IP patients

“ OZil IP allows me toutilize longitudinal energy without the negative side effects”Bradley Black, M.D.

continued on page 4

4 Clinical applications for torsional phaco

dystrophy—you will seeeven less corneal edema,corneal thickening, andcorneal striae,” Dr. Blacksaid.

The new system alsoappears to have addressedone of the concerns somesurgeons have raised withthe OZil system: occasionalflow interruption. AlthoughDr. Black never experiencedthe problem, some sur-geons who use static aspi-ration and vacuum settingswith OZil have seen the tipocclude and clog slightly,particularly in dense nucleicases. Occlusion raises therisk of increased heat en-ergy and prevents the flowof material through the tip,and stagnation can result inthe anterior chamber.

To prevent such inter-ruptions in flow and dimin-ished followability, the OZilIP uses short bursts of lon-gitudinal energy when avacuum threshold has beenmet. This feature minimizes

the repulsion of the frag-ments at the phaco tip andminimizes heat buildup,which can come from ahigher level of thermal en-ergy produced by longitudi-nal energy, compared totorsional energy.

“OZil IP allows me toutilize longitudinal energywithout the negative side ef-fects,” Dr. Black said.

“For me it has reallymade a difference in thedense cataracts in helping toremove the quadrants andpieces of nuclear material.The followability has beenimproved over OZil alone.”

The impact of the de-sign changes provided byOZil IP may include a reduc-tion in the need for a secondsurgical instrument in theeye. Some surgeons havetold Dr. Black that they needto use a guide instrument tokeep fragments of densenuclei from falling off theside of the phaco tip. Thisimprovement is especially

important if surgeons use aone-hand technique, suchas the pre-chop approachutilized by Dr. Black.

“Some surgeons tell methat they hardly even usethe second instrument nowthat they have the OZil andthe IP upgrade becausethey hardly need the secondinstrument, and if they areusing the second instrumentit is to hold the posteriorcapsule back when they areremoving the final fragmentsof the nucleus.”

Dr. Black urges sur-geons to entirely eliminatethe second instrument,which can leave the cham-ber more stable because itremoves a second port ofegress for fluid.

Additionally, Dr. Blacksaid new surgeons can getgood results from the OZilIP system if they start outwith very moderate settings.He suggested using 95% ofocclusion, short bursts of 7to 8 milliseconds, and per-

centage of phaco power at.8. As surgeons take ondenser cataracts, theyshould lower their systems’thresholds to allow for morelongitudinal energy that pre-vents occlusion.

Then, as surgeons be-come more experiencedwith OZil IP they can identifythe settings that work bestfor them.

“After I got used to IPand started playing aroundwith the parameters I wasable to become opportunis-tic and maximize the set-tings of the IP to reduce thephaco energy and allow theshort bursts of longitudinalenergy to work for me andnot just prevent occlusion,”Dr. Black said. “I played withthe settings until I came upwith those that maximizedefficiency, especially in themore dense nuclei.”

Contact informationBlack: 812-284-0660, drbradblack@aol.com

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Anew phacoemul-sification systemsoftware up-grade was foundto reduce occlu-

sion time in cataract casesthrough improved followabil-ity, which could lower theoverall risk of wound burnsand reduce BSS-related en-dothelial edema, accordingto Robert J. Cionni, M.D.,medical director, the Eye In-stitute of Utah, Salt LakeCity.

Dr. Cionni examined theability of one of the latesttorsional phaco system up-grades—OZil IP (Alcon, FortWorth, Texas)—to decrease

repulsion and improve fol-lowability.

To quantify any im-provements in repulsion andfollowability provided by thenew technology, Dr. Cionnitracked the average time inocclusion while in footswitchposition 3, the length of theaverage longest occlusiveevent, cumulative dissipatedenergy (CDE), and BSS irri-gating solution (Alcon) useamong two groups of 61cataract patients treated ei-ther with or without the newsoftware enabled.

In each area examined,Dr. Cionni’s research identi-fied improvements for pa-

tients treated with the soft-ware upgrade. For instance,the mean CDE droppedfrom 11.02 in patientstreated without the upgradeto 9.97 in patients operatedon with the new software.

Average occlusion timelikewise dropped from 0.99seconds among non-up-graded phaco system pa-tients to 0.48 seconds inOZil IP-treated eyes. Theaverage longest occlusiveevent was shorter in eyestreated with OZil IP, drop-ping from 0.42 seconds to0.23 seconds.

Dr. Cionni creditedthese improvements to the

approach of OZil IP, whichgenerally relies on torsionalenergy and adds longitudi-nal energy only whenneeded. The upgrade en-gages longitudinal energywhenever maximum presetvacuum is approached,which repositions the nu-clear fragments for torsionalemulsification.

“The addition of longitu-dinal power when neededhelps to prevent the lumenfrom becoming sluggishfrom lenticular debris andtherefore maintains a con-tinuous flow of materialthrough the tip,” Dr. Cionnisaid. “The result of OZil IP is

Surgeon finds reduction in occlusiontime could lower edema risks

5

“ The result of OZil IPis less volatility, lessBSS used, and lesschance for a full occlusive event”Robert Cionni, M.D.

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6 Clinical applications for torsional phaco

less volatility, less BSSused, and less chance for afull occlusive event.”

His research also con-firmed that OZil IP requiredless BSS use. Dr. Cionni’sstudy noted an average of35.08 cc of BSS irrigatingsolution was used in eyestreated with the non-up-graded phaco system, whileBSS use was only an aver-age of 27.48 cc in patientstreated with OZil IP.

The reduced amount ofBSS use stemmed from theoverall reduction in theamount of time the surgeonhas to spend in the eye, ac-cording to Dr. Cionni. Thepotential benefit of reducingthese values was a loweramount of corneal edemafound at one day post-op.

“My initial impressionswere that adding IP im-proved followability about asmuch as torsional improved

continued from page 5

followability over longitudi-nal,” Dr. Cionni said.

Such improvements infollowability also reduce theassociated “chatter,” whichcan avoid problems with nu-clear chips becoming “hungup” in a dispersive OVD.

“The less chatter, theless chips fly away from thetip, and the less likely thatchips will become trappedin OVD,” Dr. Cionni said.

Another advantage ofOZil IP that Dr. Cionni hasindentified while using theupgrade at 95% maximumvacuum is a reduced needto manually reposition thenuclear segments with asecond instrument.

“There’s no need tomodify your technique atall,” he said.

Contact informationCionni: 801-266-2283,rcionni@theeyeinstitute.com

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Protecting endothelial cells inmature cataract cases

Surgeons havelong known thatultrasound en-ergy used inphacoemulsifica-

tion can endanger the en-dothelium. But that dangeris especially serious incases of mature or hardcataracts because of thegreater energy required tobreak these nuclei apart.

However, the energydilemma posed by such ad-vanced cataract cases maynot be as imposing as itonce was.

New research byJames A. Davison, M.D.,

Wolfe Eye Clinic, Marshall-town, Iowa, using the latestOZil handpiece (Alcon, FortWorth, Texas) upgrade,known as Intelligent Phaco(IP), indicates that maturecataracts may be removedwithout damage to the en-dothelium.

Dr. Davison comparedendothelial cell results for18 mature cataract pa-tients—based on LOCS IIIgradings—eight of whomwere treated with longitudi-nal ultrasound energy and10 with OZil IP’s torsionalenergy interjected with lon-gitudinal energy. An analysis

of the pre-op and three-month post-op endothelialcell count changes usingthe central cornea 50 cellcounting method found amean 4.4% (±4.4%) en-dothelial cell density lossamong the longitudinal en-ergy patients and a mean2.79% (±3.9%) cell densitygain among the OZil IP-treated mature cataract pa-tients.

The findings surprisedDr. Davison, who acknowl-edged that the study issomewhat limited by its size,because previous studieshad found endothelial cell

loss of up to 25% after pha-coemulsification in such ad-vanced cataract cases.

He credited the OZil IP’simproved protection of theendothelium to its primaryreliance on torsional energy,while largely limiting the de-ployment of longitudinal en-ergy to occlusions at the tip.This limited use of longitudi-nal energy aims to harnessthe greater power of longitu-dinal ultrasound without itsnegative side effects, whichinclude the repulsion of nu-clear fragments at the tip.

“With the IP you areable to control the nucleus a

“With the IP you are able to control thenucleus a lot more soyou don’t have chatterup against the endothelium”James Davison, M.D.

continued on page 8

lot more so you don’t havechatter up against the en-dothelium,” Dr. Davison said.

The limited use of longi-tudinal energy also aims toavoid the damaging effectsof heat buildup. Previous re-search indicates that almosttwice as much thermal en-ergy is produced with longi-tudinal ultrasoundcompared to torsionalphaco.

It was the combinationof those design characteris-tics and Dr. Davison’s pre-ferred surgical approach,the horizontally oriented di-vide and conquer technique,that he credits with the im-proved corneal endotheliumoutcome.

“I always knew that thetechnique I use is a verygentle technique on thecorneal endothelium,” Dr.Davison said. “The bottomline is you can have goodresults if you use this tech-

nique with hard cataracts,and the only way it can bebetter is if you use the IPbecause it helps shave thenucleus.”

The findings may bearparticular significance incases with pre-existingcorneal complications, suchas corneal endothelial dys-trophy. The findings shouldalso caution surgeonsagainst combined cataractand corneal procedureswhere the endothelial celldensity post-phaco is lessthan certain.

“The moral of that storyis that you should always dothe cataract surgery firstand then see how thecornea looks afterward,” Dr.Davison said.

Contact informationDavison: 800-542-7956,jdavison@wolfeclinic.com

This supplement was produced by EyeWorld under an educational grant from Alcon.

Copyright 2010 ASCRS Ophthalmic Corporation. All rights reserved. The views expressed here do not necessarily reflect those of the editor, editorialboard, or the publisher, and in no way imply endorsement by EyeWorld or ASCRS.

8 Clinical applications for torsional phaco

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