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GP NEWS AND INFORMATION FROM BAUSCH & LOMB VOLUME 16 • MAY 2005

AS THE global marketplace expands, companies understand that conforming tointernational standards is necessary to improve their competitiveness in the

world. Standards that once only defined product specifications are now expanding tofocus on product performance. Ideally, GP material standards should allow eye careprofessionals to easily compare materials currently on the market and choose thosemost suited for their patient’s vision needs. However, due to the variability inmeasuring these standard parameters, published product specifications can often bemisleading. In addition, standards may not always reflect real life performance. Inthis article, we will explore two common standard parameters for GP materials,oxygen permeability and wetting angle. These standard parameters are often difficultto compare when published by different companies due to the large number ofvariables that can affect each measurement. In addition, while standard test methods

AMONG the reasons practitioners give for not fitting GP lenses is that there are too many variables and the diagnostic fitting process is too time-

consuming. And indeed that may be the case if a diagnostic lens does not fit andone or more additional lenses must be tried in order to determine the best fit.

What if the practitioner was free to do the diagnostic fitting at his/herconvenience? What if the GP lens diagnostic fitting process did not involve tryingvarious lenses on eyes for evaluation before placing a lens order? What if thepatient need not even be present to perform a diagnostic GP lens fitting? What ifthe best fitting lens could be determined quickly and that order sent electronicallyto the laboratory? And what if the patient lens received by the practitioner wouldfit each patient witha degree of accuracythat met orexceeded 90%?

Hard to believe?It’s true and it’salmost here. VirtualGP lens fitting usingtopography and acomputer softwarefitting program willallow practitionersto fit a given eye

Virtual Fitting of GP Lenses: A New Frontierby Alex Cannella, RN, FCLSA

continued on page 2

continued on page 6

Figure 1a. Virtual lens fitting using simulated fluorescein patternand on-eye evaluation.

IN THIS ISSUE…Virtual Fitting of GP Lenses: A New Frontier . . . . . . . . . page 1

Linking Standards with Product Performance . . . . . page 1

Focal Points™: The Power of Computing . . . . . . . . . . page 4

Legends of Contact LensesHonored . . . . . . . . . . . . . . page 5

LEAN: In Pursuit of the Perfect Process . . . . . . . . page 10

International Congress in Slovakia . . . . . . . . . . . . page 11

Around & About . . . . . . . page 12

Did you know that Bausch & Lombrecently introduced its FDA-approvedVision Shaping Treatment™ (VST)system in the U.S.?Vision Shaping Treatment is an“umbrella” concept for ortho-kfitting using a variety of methodsand a series of tested and provenovernight orthokeratology designs.VST will be distributed in the U.S.only through a select group ofAuthorized Boston Manufacturers,currently BE Retainer, Contex OKE-System, DreamLens, and EuclidEmerald. FDA-required CertificationSeminars are being held in majorU.S. cities. Certification is alsoavailable online at:http://www.bausch.com/vst

DID YOU KNOW?

Linking Standards with Product Performanceby Marianne Yarmey, Manager, New Business Technologies, Bausch & Lomb Wilmington

2

INTERNATIONAL OFFICES:Europe: Mr. Marcel Kopitoe:mail [email protected]

Italy and Balkans: Mr. Guido Crespie:mail [email protected]

Russia, CIS & Baltic States: Mr. Marcel Kopitoe:mail [email protected]

Australia/New Zealand/Singapore/Malaysia: Mr. Charles Di Natalee:mail [email protected]

Chinas: PRC/Taiwan/HK: Mr. Jackson Leunge:mail [email protected]

Japan and South Korea: Mr. Tatsuo Haratae:mail [email protected]

For Latin America: Mr. David Cardente

David BlandDirector of North American Salese:mail [email protected]

George AndrewsProduct Manager, Boston Materials & Solutions e:mail [email protected]

Milt KallasRegional Managere:mail [email protected]

Dennis McClureRegional Managere:mail [email protected]

NORTH AMERICAN OFFICES:Jonathan JacobsonDirector of Global GP Businesse:mail [email protected]

David CardenteLatin America Regional Manager/Int’l Customer Support Managere:mail [email protected]

Alex CannellaGlobal Professional Services Managere:mail [email protected]

Elizabeth Shannon MorinExecutive Administrative Assistante:mail [email protected]

Christina EnglundSenior Graphic Designere:mail [email protected]

FOR NEWSLETTER INFORMATION CONTACT:Bausch & Lomb, Incorporated100 Research Drive, Wilmington, MA 01887 USAphone 1-978-658-6111 / e:mail [email protected]

The Boston Update Newsletter publishes articles and studies contributed by practitioners from around the world. The points of view presented should not necessarily be construed as those ofBausch & Lomb, Inc. ®/™ denote trademarks of Bausch & Lomb, Inc.. © Bausch & Lomb, Inc. All rights reserved. Trademarks proprietary to other corporations used with permission.

Andrew WhiteRegional Managere:mail [email protected]

John HibbsRegional Managere:mail [email protected]

Sonia TumminelliSales Promotions Managere:mail [email protected]

Amy KellyGP Lab Sales Representativee:mail [email protected]

continued from page 1

with the appropriate lens design,manipulate the fit using simulatedfluorescein patterns, evaluate the lenson-eye in a variety of views, and ordera lens that will fit each patient with ahigh degree of accuracy (Figure 1a,page 1; Figures 1b, 1c, this page).

New, sophisticated GP lens fittingsoftware programs are about to beintroduced that will enable thepractitioner to fit GP lenses of all types

easily and accuratelyfor each patient. Theinvestment on thepractitioner’s part isthe cost of a cornealtopographer, aninexpensive GPdesign/fitting softwareprogram, and thedesire to take theircontact lens practicestrongly into thefuture.

One such program iscalled Focal Points

Professional. Focal Points was inventedby Renato Liffredo, an engineer andcomputer software designer fromMilan, Italy. Mr. Liffredo’s idea was todevelop ways to accelerate technologygains for GP lens design, manufacture,and fitting through computer softwareprograms.

At this moment, the majority ofFocal Points users worldwide are

manufacturing laboratories that haveembraced this technology to create,license, and manufacture a multitudeof sophisticated GP lens designs. Butadvanced manufacturing is of littlevalue if the fitting process is still miredin the past. The next phase is for thistechnology to extend to the fitter.

Here is how a system such as thisis envisioned to work:1. Using software such as Focal Points,

specific patient topography data isimported into the program.

2. Based on the type of lens beingfitted (toric, keratoconus, ortho-k,etc.), a GP design is chosen.

3. The software program applies thechosen design to the patient’stopography. With future versions,the practitioner can allow thesoftware program to automaticallyselect and apply the proper design

Figure 2a. Central tear layer thickness= 20 µm with 50 µm edge lift beforedesign change

Figure 2b. Same cornea and designafter change to 9µm central tearthickness with 60-µm edge lift

Figure 3. Lens parameter record

Figure 1b. Simulated on-eye lens fit evaluation.

Figure 1c. Simulated fluoresceinpattern, rotated viewing angle.

Boston Update, North American Edition Volume 16, May 2005

fitting process even more. Focal PointsProfessional will soon introduce a newin-office fitting software programcalled “Quick Fit.” This program isexpected to be a very affordablepackage for practitioner offices.

So, the path is clear. The use oftopography coupled with softwarefitting programs will become thediagnostic fitting for the future…

the very near future. True specialty and customGP lens fitting is at hand.Laboratories have andcontinue to make theinvestments necessary tofacilitate this nextadvancement. What remainsis for each practitioner tonow determine the directionand outlook for their owncontact lens practices overthe next 5 or 10 years, andask themselves where theywant to be and then askwhere they are going tobe.

stored in the patient record for futurereference (Figure 3).

The magic continues as the patientlens data is transferred electronicallyto the lab where the manufacturingside of Focal Points takes over. Herethe patient lens data is bar-coded and printed out so that all the lensinformation can be quickly andaccurately scanned into the lathe

manufacturing program(Figure 4). The obviousadvantage of this system is that fewer errors will bemade using this approachcompared to manuallyreceiving, transcribing, andentering lens parameters, as the human element isremoved or limited.

The real magic occurswhen the practitionerreceives the lens, places it on the patient’s eye forevaluation, and finds thatthe actual lens fit mirrors thefitting image seen during thevirtual fitting process with a

high degree of accuracy (Figures 5aand 5b).

It is easy to see that this processnot only streamlines choosing theinitial lens, but it also shortens theentire fitting process. Table 1 shows acomparison between actual diagnosticlens fitting and the virtual process.

Further refinements to this fittingsoftware continue to be made with theintent of streamlining the virtual

3Boston Update, North American Edition Volume 16, May 2005

3

Figure 5a. Simulated spherical adaptiveGP fluorescein pattern on topography

Figure 5b. Actual spherical adaptive GPfluorescein pattern on topography

for a specific topography. Nothingreally “magic” happens yet, right?

Based upon the design, the fit cannow be manipulated according to therules associated with that design. Forexample, if the design is a fixedparameter system such as Boston®

Envision®, the design can be alteredaccording to the range of base curvesand diameters available for Envision.

The real value of Focal Points willbe the ability to apply and manipulatecompletely adaptive GP lens designs.These designs can be changed not byaltering curve radii and widths, but byspecifying the clearance between theback surface of the lens and the frontsurface of the cornea at any pointalong the back lens surface. The tearlayer thickness can be analyzed andchanged until a desired lens-corneafitting relationship, asevidenced by simulatedfluorescein pattern, isachieved (Figures 2a and 2b).

The “magic” begins whenthe best-fit design is chosen.Quickly, the fitter will cometo the realization that duringthis process, no reference wasrequired to keratometryreadings. It is also realizedthat no curvature calculationsor choices were necessaryduring the process. The best-fit GP lens design parametersare automatically calculatedand recorded at the sametime the virtual GP lens wasbeing fitted and refined. Allthis information is then

Figure 4

Diagnostic Fitting Virtual Fitting

Visit One: • Obtain patient data (K’s/Rx)• Calculate initial trial lens

parameters• Place lens on eye and allow to

settle• If fit is acceptable, order lens

from lab• If fit not acceptable, trial fit

again and order• Lab ships lens same/next day• Patient required to be in office

Visit Two: • Schedule patient visit for

trial/dispensing• Patient education/dispense• If unacceptable, reorder

Visit One: • Obtain patient data

(Topography/Rx)• Import topography and

choose appropriate initial lensfrom menu or choose Auto-Fit

• Evaluate simulated fluoresceinpattern

• Adjust virtual lens design todetermine best fit lens andelectronically send order to lab

• Lab ships lens same/next day• Patient not required to be in

office

Visit Two: • Schedule patient visit for

trial/dispensing • Evaluate lens on-eye• Patient education/dispense

Table 1

THE gas permeable lens industry,like virtually all contemporary

industries, has adopted computer-driven processes to improveproductivity and quality. In mostlabs, computers have long beeninvolved in a broad range ofactivities, from order taking toaccounting. More recently, theyhave been brought into themanufacturing process. Whileprogress in this area has beensignificant, there is growingawareness that much more ispossible.

The efficiency, precision andreproducibility that moderncomputer numeric control (CNC)lathes deliver can be exceptional, butentering design data and makingchanges can be a very timeconsuming, cumbersome, and oftenexpensive process. These limitationsand inefficiencies confront all of theparticipants involved in the lensfitting process from the lens designer,to the manufacturing lab, to the fitter,as well as the processes and peoplewho support them. To answer thisneed, Renato Liffredo of AdvanceMedical (Milan) developed FocalPoints. This work earned Mr. Liffredothe prestigious EFCLIN TechnologyAward in 2002.

The Focal Points system is acollection of linked software programsthat help the GP lens manufacturerintegrate and fully exploit modernlathing technologies to efficientlyprovide gas permeable lens designs foroptimal comfort and exactingreproducible quality. Additionally, alink between the practitioner and the

manufacturer can be formed with theuse of Focal Points Professional.

Focal Points Professional gives thefitter the ability to auto-fit trulycustom lenses using a variety ofcommonly available cornealtopographers. By combining thepowerful design tools of Focal PointsDesigner with the ease and simplicityof auto-fitting, Focal PointsProfessional vastly simplifies theprocess of fitting even complex lensessuch as torics, without diagnosticlenses.

Developed in association withmanufacturers and fitters, the newFocal Points Professional is highlyintuitive and designed with the fitterin mind. Most designs can be fit bysimply selecting a patient from thedatabase, loading a topographic map,and entering refraction data. By usingthe QuickFit feature, the rest of thelens parameters will be calculated andan interactive simulated fluoresceinpattern will be displayed.Characteristics of the cornealtopography of the patient’s eye willdetermine which lens is initiallyselected and fit.

Of course, experienced fitters willhave an array of customization toolsto choose from if they wish to usethem. However, they are not necessaryto get an excellent fit the first time.Analysis of the lens form, of the tearlayer, and of the power profile are all

possible, offering fitters theability to better predict theperformance of lenses beforethey are manufactured anddispensed.

The simplicity of the fittingprocess will encouragepractitioners uncomfortablewith GP fitting to build theirsuccess rate and theirconfidence in GP fitting.Experienced GP fitters willenjoy the customizationoptions and also will beencouraged to virtually fit abroader array of lenses fasterand easier than they might

otherwise have considered if each fitrequired a trial lens or a custom lenspurchase.

On the laboratory side, orderprocessing is simplified with the use ofFocal Points Practitioner in somepractical ways. First, orders coming infrom fitters don’t need to be re-enteredinto the system. When a new order isreceived, it automatically appears inthe manufacturing queue, flagged forreview. Laboratory personnel thenreview the order for pricing and foraccuracy and, when satisfied that it isready for production, accept the orderand release it to production. At nopoint in the process does the lab needto enter data or calculate lensparameters; the order arrived from thefitter ready to go.

The communication between thelab and the fitter is two way. Whilenew orders are coming into the lab,the lab is automatically sending pricelist updates, new lens designs, and


Focal PointsThe Power of Computing in GP Lens Design and Manufacturingby Kurtis Brown, Consultant, Bausch & Lomb Wilmington

Barcoded

job orders

ensure

error-free data entry at

the lathe.

Renato Liffredo (left) receiving the 2002 EFCLINTechnology Award from Shimon Behar, EFCLIN president.

Trial-free

fitting may

be possible

with

advanced simulated

fluorescein displays.

other messages back to the practitioner. Whena new lens design is available, it willautomatically appear as an option inProfessional. Price lists and discounts are alsomaintained behind the scenes.

Focal Points will also handle invoicing,sales reports, inventory, and raw materialmanagement, as well as shipping and caselabeling.

Increasingly, practitioners are investing incorneal topographers and, more importantly,are getting in the habit of using them as partof their standard exam. By giving them thetools that they need to broaden the value ofthis technology, Focal Points Professional willgreatly aid in the growth of the GP segment.By simplifying the fitting process andimproving the initial success rate, Focal PointsProfessional will add greatly to the perceivedvalue of GP lenses to the practices of bothexperienced and novice fitters.

Four pioneers and major contributors to the field of contact lensdesign, materials, education, and research were honored at the31st Annual Bronstein Contact Lens Seminar held recently inScottsdale, Arizona.

The 2005 recipients of the Bronstein Memorial Awards areDrs. Donald Korb, Perry Rosenthal, Leonard Seidner, and NewtonWesley.

Dr. Edward Bennett, Executive Director of the Gas PermeableLens Institute (GPLI), the educational branch of the CLMA, wasMaster of Ceremonies and made the presentations to the threerecipients who attended the event. Dr. Newton Wesley was unableto attend, but provided an audio message of thanks to his friendsand colleagues for the award.

Dr. Wesley was honored (along with former student andbusiness partner George Jessen) for the development, education,and public awareness created in the US for contact lenses as theresult of their work with the Plastic Contact Lens Company ofChicago, Illinois.

Dr. Donald Korb was cited for his research and clinicalcontributions in the field of contact lens design and clinicalphysiology, particularly for the introduction of the”Korb-Fit”philosophy that was incorporated into the Polycon lens GPdesign.

Dr. Perry Rosenthal was honored for his role in thedevelopment and leadership, as a founder of Polymer Technology,in introducing the Boston® GP lens materials and solutions. Dr.Rosenthal was also honored for his ongoing work as founder andpresident of the Boston Foundation for Sight, a nonprofitfoundation that provides Dr. Rosenthal’s unique vision restoringlens designs to people afflicted with debilitating corneal disorders.

Dr. Leonard Seidner was honored for his work with NormanGaylord to introduce the first FDA-approved GP lens in the U.S.in 1979, with the introduction of the Polycon GP lens and thelow-eccentricity aspheric presbyopic GPs, such as the Lifestyle GPmultifocal lens.


Left to right: Perry Rosenthal, Leonard Seidner, and Donald Korb (Notpictured: Newton Wesley). Photo courtesy of John Rinehart OD.

TOPOGRAPHERS CURRENTLYSUPPORTED BY FOCAL POINTS

C.S.O. S.R.L., Italy

EyeMap EH-290, Alcon, USA

Humphrey Refractor/Keratographer, CarlZeiss Meditech, Inc., Germany

Keratron Optikon 200

Keratron Scout

Magellan Mapper, NIDEK, Japan

OPD-Scan Refractive Power/CornealAnalyzer, NIDEK, Japan

E-300, Medmont Pty., Australia

CT-100, Shin-Nippon Commerce, Inc.,Japan

TMS-4, Tomey Corp., Japan

The optical

performance of the

lens can be

controlled with a

variety of tools.

Legends of Contact LensesHonored


for operating oxygen permeability canbe indicative of on-eye lens oxygenpermeability, standard contact anglebench test methods have not shownhigh correlation to on-eye lenswettability.

DK MEASUREMENTSIn 1996, ISO established the

international standard for measuringoxygen permeability (Dk) of contactlens materials (ISO/DIS 9913-1Determination of Oxygen Permeabilityand Transmissibility by the FATTMethod). This method, developed byDr. Irving Fatt Ph.D. at the Universityof California, Berkeley, USA, measuresthe oxygen permeability of GP lensesunder wet conditions and simulatesthe Dk performance of a lens on thecornea. During the test, a lens isplaced on an oxygen probe with theother side of the lens exposed to anoxygen saturated, buffered salinesolution. As the probe measures theconcentration of oxygen, it depletesthe oxygen on the probe side of thelens causing an oxygen differentialacross the lens (Figure 2). Oxygen willthen diffuse from a region of highoxygen concentration through thelens toward the probe side where theoxygen concentration is low. This rateof oxygen flow or Dk can then becalculated through a series ofequations. Similarly when a lens isworn on the eye, the cornea depletesthe oxygen on one side of the lenscausing oxygen to diffuse through thelens towards the cornea to replenishthis oxygen. The ability of a lensmaterial to allow oxygen to passthrough it is very important to cornealhealth, closely linking this ISO/Fatt Dkmeasurement with actual on-eye

performance.

In 1998, the Contact LensManufacturers Association (CLMA)became increasingly concerned thatinaccurate permeability measurementswere still being reported bymanufacturers. They commissionedthe EyePhysiology &OcularProstheticsLaboratory at theUniversity ofAlabamaBirmingham toderive the Dkvalues of contactlens materialsmarketed in theU.S. by the ISO9913-1 method.As new GPmaterialscontinue to enterthe market, the CLMA recommendsthat manufacturers submit the newmaterial to this laboratory forconfirmation of the Dk.

In a recent study using thestandard ISO/Fatt Dk method, wemeasured the permeability of some ofour own materials and newer materialsfrom other companies that have

recently entered the market. We foundsome discrepancies between the Dkvalues that are currently reported inthe manufacturers’ literature and thosethat we measured (Table 1). To verifythe accuracy of our results, standardswere obtained from the PermeabilityReference Material Repository(custodian Dr. William J. Benjamin,University of Alabama, Birmingham,Alabama). Measurements carried outby our lab and official repositoryvalues are presented in Table 2,showing close agreement. From thesefindings, we would suggest that ourresults are closer to the real Dk valueof these materials than Dk valuescurrently reported in the literature.This difference in Dk values leads us tothe conclusion and recommendationthat Dk measurements should be

confirmed for all new materials by animpartial recognized laboratory, suchas that of the repository lab at heSchool of Optometry, University ofAlabama at Birmingham, throughblind submission of the material froman independent source.

CONTACT ANGLEMEASUREMENTS

Contact angle is a measure ofthe ability of a liquid to wet a solidsurface producing a uniform,continuous film. The standard testmethod for measuring the contactangle of contact lens materials isdefined in ANSI Z80.20-1998,Section 8.11. Two techniques aredescribed in this standard, thesessile drop method and thecaptive bubble method. The sessiledrop method measures the angle of

continued from page 1

Figure 1. Dr. Irving Fatt PhD, 1920–1996

PARAGON HDS 41 39.4 – 43.1 58*

BOSTON EQUALENS® II 85 76.5 – 93.5 85*

OPTIMUM EXTREME 96 86.2 – 107.9 123.8*

VISTA OPTICS HiRI 9 8.1 – 9.8 50†

ONSI-56 33 30.4 – 34.9 56*

Material Average Dk* 95% Confidence Limits* Published Values

TABLE 1. OXYGEN PERMEABILITY MEASURED USING ISO/FATT METHOD

* x 10-11 (cm3 O2) (cm) / [(sec)(cm2)(mmHg)]† No units given

Figure 2. Rehder Polarographic Oxygen Permeability Unit

contact between a liquid and solidwhen a drop of standard salinesolution is placed on a flat polymersurface in air. The captive bubblemethod measures the angle of contactbetween a gas bubble and a polymersurface when a bubble of air floats upagainst the underside of a flat polymersurface in standard saline solution(Figure 3). The CLMA hasadopted this method astheir standard fordetermining wetting angleson GP materials. Due to thewide number of variablesthat can influence wettingangle measurements, theANSI standard clearlydefines the samplepreparation, sampleconditioning, experimentalapparatus, andenvironmental conditionsunder which these testsmust be run. In a recentstudy, we measured thewetting angle of some ourown materials and materialsfrom other manufacturers by thecaptive bubble method. All materialswere cleaned with Boston LaboratoryLens Cleanser and rinsed with distilledwater. Boston GP materials were then

several GP materials of differentmanufacturers. A more dynamicmethod of measuring contactangle is the Wilhelmy platemethod where wetting angles are not measured directly, but are calculated from forcemeasurements as a function of immersion depth of the lens material in saline solution(Figure 3).

It is our opinion that, due to the dynamic nature of theWilhelmy plate method, two contactangles, an advancing and a recedingangle, for a single lens material can be easily measured. The differencebetween these two angles is called thecontact angle hysteresis. Both anglesare needed to completely describe thewetting properties dynamically.

We investigated the dynamicadvancing and receding contact angles of these same GPmaterials using a Cahn DynamicContact Angle (DCA) AnalyzerDC315. The motor speed was set to 100 microns/sec. Theimmersion depth for all samples was 6 mm. Sampleswere cleaned and conditionedprior to the contact anglemeasurements. Allmeasurements were done in PBS (phosphate bufferedsaline solution). The results ofthis study are shown in Graphs1 and 2. Only small differenceswere observed in contact angle

measurements when comparing thevarious GP materials. The biggestdifference in contact anglemeasurements was observed whencomparing care solutions. The samples

soaked in Boston AdvanceConditioning Solutiondemonstrated loweradvancing contact anglesand hysteresis values thanthe Optimum care solutionsand the PBS.

A word of caution mustbe raised when attemptingto use these contact angleresults to predict actual on-eye wetting characteristic ofa GP lens. Although we feelthat the DCA method is amore accurate way of

cleaned with Boston Advance Cleaner,rinsed with water, and soaked inBoston Advance Comfort FormulaConditioning solution for 7 days.Contamac Optimum GP materialswere cleaned in Optimum by LobobCleaning/Disinfecting/Storage Solutionand then soaked in this solution for 7days. All materials were rinsed with

distilled water before making captivebubble measurements in phosphatebuffered saline solution (PBS). Table 3shows the contact angle values anddifferent methods published for


Figure 3

FLUOROPERM 30 25.8 24.6 – 27.2 26.0

BOSTON® EQUALENS I 47.0 43.1 – 57.1 51.2

MENICON EX 57.3 52.2 – 63.5 62.4

Material Dk* 95% Confidence Limits* Repository Value*†

TABLE 2. OXYGEN PERMEABILITIES OF REFERENCE MATERIALS MEASURED BYISO/FATT METHOD

* x 10-11 (cm3 O2) (cm) / [(sec)(cm2)(mmHg)]† Repository values were complied from the measurements at four different laboratories. Individual labs values werewithin 8.8% of the above repository values.

METHODS OF DETERMINING CONTACT ANGLES

Sessile Drop

advancing receding

Captive Bubble Wilhelmy Plate

BOSTON® EQUALENS II 30°

BOSTON® EO 49°

BOSTON® XO 49°

PARAGON HDS 14.7° (receding angle)

PARAGON HDS 100 42° (receding angle)

OPTIMUM COMFORT 6° 60°

OPTIMUM EXTREME 6° 66°

MENICON Z 24° (after soaking)

VISTA OPTICS HiRI <25°

Material Contact Angle

TABLE 3. CONTACT ANGLE RESULTS FOR GPMATERIALS USING VARIOUS TECHNIQUES

Captive Bubble, ISO/ANSI Receding angle Not specified

8

measuring contact angle, none ofthese techniques provide results thatcorrelate well with on-eye wetting ofGP lenses. For example, although mostGP contact lens materials have a lowerwetting angle than PMMA, mostclinicians would agree that PMMA hasprobably the best on-eye wettingproperties for a rigid contact lensmaterial. This is due to the fact that adrop of conditioning solution appliedto a lens is quickly replaced by tearfluid upon insertion of the lens in theeye. Tear fluid contains proteins andlipids that greatly affect the wettingcharacteristic of a lens. Tearcomponents can vary significantlyfrom person to person and therefore,it is difficult to develop a laboratorystandard that accurately predicts on-eye wetting performance.

CONCLUSIONSIdeally, the eye care

professional should be able tocompare and choose the mostappropriate GP material whenfitting a patient with contactlenses using the data from thematerial properties reported bythe manufacturer. For example,oxygen permeability is a keyindicator in determining productperformance for particularapplications such as ExtendedWear and Overnight Ortho-K/corneal reshaping. However,due to the variability, it is oftendifficult to compare published Dkvalues. The need remains for thepermeability measurements of allGP materials to be tested by thesame impartial recognizedlaboratory so that this parametercan be compared on an equalbasis.

On-eye wetting characteristicsof a GP material are also veryimportant to the eye careprofessional in choosing a GPmaterial. Unfortunately, althoughthe captive bubble method fordetermining contact angle hasbecome the industry standard, itis not indicative of real lifeperformance. Other methods formeasuring contact angle, perhapsmore accurate than captivebubble, also do not reliablypredict on-eye wetting. The needstill exists for a standard testmethod that directly correlatesmaterial surface properties withon-eye wetting performance.

References

W. J. Benjamin, A. Ho, L.C. Winterton,K. Nakada, Optometry and VisionScience, 1997, 74 (Suppl): 95

W.J. Benjamin, Q.A. Cappelli, Optometryand Vision Science, 2002, 79 (1)R.H. Dettre, R.E. Johnson, J. Phys.Chem., 1965, 69, 1507

J. Zhang, R. Herskowitz, Contact LensSpectrum, October 1992S. Tonge, L. Jones, S. Goodball, B.Tighe, Current Eye Research, 2001, 23(1), 51


Figure 4. Cahn Dynamic Contact Angle AnalyzerDC315

Graph 1. Advancing and receding contact angles measured for various GP materials soaked indifferent care solutions. All samples were first cleaned with Boston Laboratory Lens Cleanser andrinsed with water. The samples were then cleaned using the appropriate cleaner and were placedin separate vials to soak in the appropriate conditioning solution for seven days. Just prior totesting each wafer was removed from solution and rinsed by dipping it 10 times into 15 ml ofPBS. All dynamic contact angle measurements were made in PBS.

* Samples were cleaned with Boston® Laboratory Lens Cleanser, rinsed with distilled water, and thensoaked for 7 days in Phosphate Buffered Saline.

** Samples were cleaned with Boston Laboratory Lens Cleanser, rinsed with distilled water, cleaned withBoston ADVANCE Cleaner, rinsed with distilled water, soaked in Boston Advance® Comfort FormulaConditioning Solution for 7 days.

*** Samples were cleaned with Boston Laboratory Lens Cleanser, rinsed with water, cleaned withOptimum by Lobob Cleaning/Disinfecting/Storage Solution (C/D/S), rinsed with water, soaked inOptimum C/D/S for 7 days, rinsed with distilled water, placed in Optimum by LobobWetting/Rewetting Drop and in-the–eye lubricant for 20 minutes.


Spotlight on Jim LunkleyEditor’s note: Jim Lunkley is Boston’sTechnical Field Representative, based inFountain Hills, Arizona, who travelsaround the globe to assist and advisecustomers.

Would you tell our readers briefly about yourbackground, education, job experience, and positionsheld?

After graduating from college in the early 1970s, mywife and I moved to Phoenix. I worked for a motorcyclerental business for a few months and then purchasedthe business. This business happened to be located inthe same building as Guaranteed Contact Lens, thedevelopers of the Polycon GP material. By the late1970s, I was out of the motorcycle business and wascontacted by Syntex Ophthalmics, the company thatpurchased Polycon from Guaranteed Contact Lens, andasked if I would consider working for them. Starting in1978, I worked for Syntex as a Process Engineer andProduction Manager until 1989 when I moved to mypresent position.

How do you see the GP industry evolving from atechnical perspective over the next 5 to 10 years?

I think the GP industry will become an industry ofspecialty products. This will mean that it will becomeincreasingly important for GP manufacturers toimplement equipment and processes that canaccurately and consistently produce and evaluate themore complicated designs.

Tell us little about your family, your hobbies, andwhat you like to do in your free time.

My wife and I met in high school and got marriedwhen we were in college. We have been happilymarried for 36 years. In my spare time I like to get onmy motorcycle and ride. I also like to do somewoodworking and landscape oil painting.

What part of your job gives you the most personalsatisfaction?

I find it very satisfying to meet and work with ourcustomers on a one-to-one basis. I especially enjoyhelping them solve problems and improve theirmanufacturing systems.

What do you find most challenging about your work?

The amount of travel I do can sometimes bechallenging. Working with people new to the industryis also quite challenging because there are many termsand processes unique to this industry. This can alsolead to some of the most rewarding experiences.

* Samples were cleaned with Boston®

Laboratory Lens Cleanser, rinsed withdistilled water, and then soaked for 7days in Phosphate Buffered Saline.

** Samples were cleaned with BostonLaboratory Lens Cleanser, rinsed withdistilled water, cleaned with BostonADVANCE Cleaner, rinsed with distilledwater, soaked in Boston Advance®

Comfort Formula ConditioningSolution for 7 days.

*** Samples were cleaned with BostonLaboratory Lens Cleanser, rinsed withwater, cleaned with Optimum byLobob Cleaning/Disinfecting/StorageSolution (C/D/S), rinsed with water,soaked in Optimum C/D/S for 7 days,rinsed with distilled water, placed inOptimum by Lobob Wetting/RewettingDrop and in-the–eye lubricant for 20minutes.

Graph 2. Contact angle hysteresis was obtained by subtracting the receding contact anglefrom the advancing contact angle for each GP material. Lower hysteresis values correlatewith better wetting properties under the conditions of the study.

10

IS THE perfect manufacturing processone that results in the lowest

operating cost, produces zero defects,results in perfect on-time delivery, orsome combination of theseattributes? At our Wilmington,Massachusetts production facilitywhere we produce Boston®

buttons, we define the perfectmanufacturing process as one thatconsists entirely of value-addedoperations producing the rightproduct, the right way, at theright time.

“Value-added” is defined asthose activities that, in the eyes of thefinal customer, make a product orservice more valuable. For example,precision grinding of a GP button to a12.7 mm diameter is a value-addedoperation. Conversely, non value-adding activities do not make theproduct or service more valuable andare considered wasteful. For example,transferring parts from one containerto another as they move through themanufacturing operations may seemto be a necessary activity, but isconsidered wasteful based on ourdefinition of value in the eyes of thecustomer.

Our goal is tocontinually improve allaspects of our processes byfocusing on the methodicalelimination of successivelayers of wasteful, non-valued-added activities. Toguide us in this endeavor,we have recently embraceda manufacturingphilosophy commonlyreferred to as LEANManufacturing.

LEAN Manufacturing isdefined as “a manufacturingphilosophy that shortensthe time-line between thecustomer order and theshipment by eliminatingwaste.”

This system is basedupon the revolutionaryproduction systempioneered by the Toyota

Motor Corporation. While LEANmanufacturing has becomeincreasingly popular in recent years, itis still highly underutilized in manyindustries.

We believe that LEANmanufacturing provides the tools andmethods that will allow us to movecloser to achieving that perfectmanufacturing process. So, whatexactly is LEAN manufacturing?

Introducing a new philosophy toan existing manufacturing system isoften easier said than done. The key tosuccessfully introducing such a changein philosophy is that every employeewithin the organization must betrained to recognize what thosewasteful, non-value-added activitiesare. Experience shows that when anorganization realizes that an activity

being performed is wasteful,employees will intuitively look forways to eliminate or improve theactivity.

The LEAN philosophy hasidentified seven categories ofwasteful activities. Upon adoptingthis program, every employee in ourfacility received training andawareness of these seven “deadly”wastes and is always on the lookoutfor activities that fall into one ofthese categories.1. Overproduction: producing toomuch or too soon, resulting in poorflow of information or goods andexcessive inventories.

2. Defects: frequent errors inpaperwork, product qualityproblems, or poor deliveryperformance.

3. Inventory: excessive storage anddelay of information or products,resulting in excessive cost and poorcustomer service.

4. Over-processing: going about workprocesses using the wrong set oftools, procedures, or systems, oftenwhen a simpler approach may bemore effective.

5. Transportation: excessivemovement of people,information, or goods,resulting in wasted time,effort, and cost.6. Waiting: long periods ofinactivity for people,information, or goods,resulting in poor flow andlong lead times.7. Motion: excess motionto locate tools, obtainparts, or retrieveinformation, resulting inpoor workplaceorganization, frequentlylost items, and delays.

It’s important to noticethat these “wastes” applynot only to themanufacture of product,but also to the flow ofinformation. Purchasingcomponents, processingorders/invoices, and other


LEAN Manufacturing is defined as

“a manufacturing philosophy that

shortens the time-line between the

customer order and the shipment

by eliminating waste.”

LEAN: In Pursuit of the Perfect Processby Ken Harty, Operations Manager, Bausch & Lomb Wilmington

11

logistical/administrative activities arejust as prone to wasteful, non-value-added activities as are manufacturingoperations.

Do these “deadly wastes” exist inyour operation? Would you besurprised to learn that close to 95% ofall activities in most industries, areconsidered to be non-value-added,and thus are wasteful? It is thisseemingly vast amount of wastefulactivity that represents the significantopportunity for improvement.

In the 18 months since thisphilosophy has been implemented inour operation, we have seensignificant improvement in manyfacets of our business. For instance,we have…• Reduced our lead-time to

manufacture product by 45%, • Reduced our inventories by 20%,• Increased our product yields by

4%, while maintaining same-daycommitment-to-order shipment.

In addition, there have beennumerous improvements to workplaceorganization, streamlinedadministrative processing, and spaceutilization.

We believe LEAN provides themost comprehensive manufacturingphilosophy that any organization canemploy to further improve everyaspect of their operation. In futurearticles, I will present and discusssome of the specific tools LEANemploys and describe how we’ve putthem to use. I will also present howthese principles might be applied tothe lab manufacturing processes.

Please contact us if you seekfurther information as to how wehave successfully integrated LEANinto our organization. Ken Harty maybe reached at +1-978-694-1229 or byemail at: [email protected].


First International Contact LensCongress Held in SlovakiaBy Marcel Kopito, Regional Business Manager, Europe and Middle East

Left to right: Sibylle Scholtz, Angela de Rossi, Katarina Eckert

THE first-ever contact lens congress to be held in the Slovakian capital ofBratislava occurred on April 2, 2005. The congress was organized by Angela de

Rossi Jelsova, a well-known contact lens practitioner in Bratislava. Distinguishedpresenters spoke on a variety of topics:

• Mr. Wolfgang Cagnolati, President of the German Optometry Association,gave an overview of optometry in Europe and the world.

• Prof. Theo Gumpelmayr, President of the Austrian Optometry Association,described the academic program for optometrists in Austria.

• Prof. Anton Gerinic of the University Eye Clinic of Bratislava spoke on thetopic “Contact Lenses and Children.”

• Dr. Torsten Bendrat, Consultant to the Slovakian government on Europeaneconomic issues, described how technology can be transformed intoeconomic opportunities in new European markets.

• Mr. Ulrich Maxam, of Deutsch Optiker Zeitung, presented the challengesfor the optometry and optician professions in competition with theinternet, large chains, and hypermarkets.

• Christian Krüsi from Galifa Contact Lenses in Switzerland discussed thewide range of opportunities in contact lens fitting, employing modernaspheric, toric and multifocal lens designs.

Before proceeding with the election of the Board of Directors of the new Prof. Wichterle Contact Lens Association, Sibylle Scholtz from AMO Germanyrecounted an exciting history of Prof. Otto Wichterle, his work, his independentpolitical voice, and his dedication to the development of the first HEMA soft lensmaterial, which eventually became the Bausch & Lomb Sof-Lens in the U.S. in1971.

Elected to the Board of Directors were: President Angela de Rossi and Board Members Katarina Eckert, Engineer/Optician, and Sibylle Scholtz,Biologist/Chemist (See photo). The evening celebration featured a concert byvarious orchestras and choirs from Bratislava in the Mirror Hall of the PrimatialPalace. This historical hall was witness to the signing of the peace treaty ofBratislava between Napoleon and the Federated countries in 1805 after the battleof Austerlitz.

EVENTS CALENDARMAY1–5 ARVO*

Ft. Lauderdale, FL, USA

6–9 MIDO**Milan, Italy

JUNE3–5 BCLA*

Brighton, UK

22–26 AOA (AmericanOptometric Assn.)Dallas, TX, USA

24–26 ECLSO*London, UK

JULY28–31 GOS, 3rd Annual**

Chicago, IL, USA

AUGUST14–17 Int’l Vision Expo West

Las Vegas, NV, USA

21–23 China Int’l Optics Fair**Beijing, China (PRC)

* Indicates Boston attendance** Indicates Boston exhibit

Bausch & Lomb, Incorporated

100 Research Drive

Wilmington, MA 01887 USA

RPL0204 Printed in USA. All rights reserved.

Above, left to right: Sra.Daniela Garese (Montevideo,Uruguay), Sami El Hage OD(Houston, TX) and PennyAsbell, MD (Long Island, NY)attending the Pan AmericanAcademy of Ophthalmologyin Santiago, Chile in March.Drs. Asbell and El Hage wereamong the featured speakerson orthokeratology from theU.S.

Above, at left: Marcel Kopito, with DmitryMirsaiafov of Doctorlens Moscow, presentsinformation on Boston products and activities atthe Moscow Optical Trade Show.

Left: Jim Lunkley(Bausch & Lomb)with GP labmanufacturingpersonnel atWenzhou MedicalCollege, China PRC,to initiate Boston GPlens production intheir new laboratoryfacility.

Right: Dr. Li Yuan Yuan(standing) and Jonathan

Jacobson meet fordiscussion during Shanghai

Optical Fair in April.

Right, standing in center:Kurtis Brown and Jim Lunkley(Bausch & Lomb) visit Dr.Tom Tao (second from left)and sales and productionteam at Autek Lab in Hefei,China PRC, to assist inmaximizing GP lensproduction techniques.

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