CATARACT TECHNOLOGY AND TECHNIQUES
| CATARACT SURGERY: WHAT’S NEW ?—Douglas D. Koch, MD, Professor of Ophthalmology and the Allen, Mosbacher,
and Law Chair of Ophthalmology, Baylor College of Medicine, Houston, TX
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| Elements of phacoemulsification technology: power delivery—traditional ultrasonic methods; alternative methods;
fluidics—plunging of intraocular pressure (IOP) at occlusion break forces ceiling on vacuum and flow rates
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| Fluidics (WhiteStar ICE technology for Sovereign phacoemulsification system [AMO]; CASE laboratory
study results): reacts as fast as 26 msecs to reverse pump; can reduce surge as much as 56%; instead of IOP
dropping, pump activates to diminish surge
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| Power delivery: 1) refinements of standard ultrasonic device; 2) modified ultrasonic device; 3) other power modalities;
Whitestar ICE pulse—“punch” at beginning of each pulse enhances cavitation emulsification and makes device more
efficient
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| New methodologies: AquaLase—used for grade 1 to 2 nuclei; ceramic tip less likely to rupture capsule, but overall
benefit not well defined; speed comparison—NeoSoniX handpiece (oscillation of phaco tip 100 Hz); longitudinal
(40,000 Hz); torsional (Ozil [Alcon]; 32,000 Hz)
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| Advantages of torsional phacoemulsification: cooler and more efficient; removes material by shearing rather than
by hammering; material stays on tip (reduces chatter); less tip movement in wound, less friction, and less heat generated
than with longitudinal phacoemulsification
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| Yellow intraocular lenses (IOLs): AcrySof Natural IOL; Hoya lens; advantages?—protection against macular degeneration
(no clear evidence); improved contrast sensitivity by elimination of blue light (no clear data);
disadvantages?—reduced night vision (no clear evidence; overall illumination of retina reduced 18%, compared to
standard IOL); based on standard color-vision testing, yellow IOLs do not alter color vision
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| Toric IOLs: Staar toric lens—plate haptic lens; tends to rotate (reoperation rates as high as 10%); SA60TT (Alcon)—
approved by Food and Drug Administration (FDA), but not released by Alcon; corrects 1.0, 1.5, or 2.0 D at spectacle
plane; in FDA study, stability excellent; little, if any, rotation of AcrySof platform
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| Dysphotopsia and edge design: round edges—monofocal SI-40 IOL (AMO) associated with acceptable rate of
posterior capsule opacification; square edges—starting with AcrySof MA60BM (Alcon) lens; had highly reflective
surface; then Alcon milled surface (less reflective); some patients complain of negative dysphotopsia (negative image);
OptiEdge design (AMO)—rounded at top and slightly square edge at bottom; posterior capsule opacification less
likely, compared to lenses with conventional straight edge; speaker has removed 2 lenses because of positive dysphotopsia
(in both cases, edge not covered by capsulorrhexis); with Alcon lens, increase in posterior capsule opacification
starting 2 and 3 yr postoperatively; if patient presents with dysphotopsia and etiology unclear, do not perform routine
neodymium-yttrium aluminum garnet (Nd:YAG) posterior capsulotomy (correcting edge problem far less complex)
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| Capsular tension rings (CTRs): standard and modified; when to use—to support capsule when patients have 4 or 5
clock-hours of zonular loss; controversy whether CTRs indicated in all eyes with pseudoexfoliation; on one hand, stripping
zonules during insertion may predispose bag to dislocation; on other hand, zonular support better; also, can provide
mechanism for suturing lens into sclera if whole bag dislocates (standard treatment for dislocated bags); when not to
use—zonules diffusely weak or placement of IOL in bag otherwise undesirable; ring not helpful if support not adequate
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| Modified CTR: if focal loss of zonules >4 or 5 clock-hours, consider modified CTR developed by Cionni; small loop
sutured into ciliary sulcus to support capsular bag; downside—reports of 10-0 proline suture breaking; ring eyelet not in
contact with vascular tissue (floats in anterior chamber); whether 9-0 proline or Gor-Tex suture preferable not well defined
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| IOLs and implants for iris defects: option for patients who are aniridic or have traumatic zonule injury; lenses can
be sutured to provide artificial pupil; aesthetics not always ideal, but better than having vision obliterated by halos; tinted
contact lenses can work well; used at selected centers (educate patients); opaque segments can be used in focal iris defects
that cannot be repaired by suture
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| Intraoperative floppy iris syndrome (IFIS): tamsulosin (Flomax) specific for α1A -adrenergic receptors; paralytic
condition (innervation of iris lost); muscle atrophic (if nerve stimulated with external medication, no iris response);
signs—pupil flaccid and floppy; with pupil constriction, iris prolapse and paracentesis; management—no role for discontinuing
Flomax; do not stretch pupils; use low-flow settings and smaller bottle to avoid overinfusion; consider 1/1000
bisulfite-free epinephrine mixed 1/3 with balanced salt solution (BSS) as injection to give tone to iris; techniques—to keep
Healon 5 in eye, maintain vacuum <250 mm Hg and aspiration flow rate ≤20 mL/min
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| INTELLIGENT IMPLANTS —Mark Packer, MD, Clinical Assistant Professor of Ophthalmology, Casey Eye Institute,
Oregon Health and Science University, Eugene
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| Targeting emmetropia: applanation A-scan no longer adequate; immersion A-scan and partial coherence interferometry
equally good at measuring axial length; start with IOL Master; if in doubt or if axial length cannot be measured due to
density of media, immersion used (faster than applanation; does not require repeat A-scan)
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| IOL calculation: Holladay IOL Consultant II software most accurate readily available formula; printout shows frequency
distribution, charts progress of surgery, and calculates mean absolute error; especially useful when dealing with
multifocal presbyopia-correcting IOLs (eg, 3-piece AcrySof ReStor IOL); results outstanding
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| Spectacle independence: in FDA study, using 3-piece ReStor, 81% of patients never wore glasses (with single-piece
Acrysof ReStor, 76%); ReZoom multifocal IOL (AMO) has shown good results in data from Europe; rate of near-vision
spectacle independence ≈70% (however, multifocal IOLs related to halos at night)
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| Quality of vision with Array multifocal IOL (AMO; study): comparison of SI-40 monofocal IOL (AMO) to
Array refractive multifocal IOL; only statistically significant difference involved halos (multifocal lens produces halos);
other measures (eg, glare, satisfaction, trouble with vision) same
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| Visual disturbances at 6 mo postoperatively (FDA): halos associated with Acrysof ReStor IOL (single-piece
toric IOL; moderate 23%; severe 7%); ≈30% of patients notice halos and find them troublesome; halos may disappear (or
patients adapt to technology) over time
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| Normalization of contrast sensitivity: comparison of SI-40 with Array lens (monofocal vs multifocal); by 6 mo, contrast
sensitivity of eyes same (although baseline considerably lower with multifocal); neuroadaptation process not clearly
understood
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| Combined visual acuities (FDA): similar to ReZoom IOL data (≈73% of patients 20/25 or better at near vision); results
different for monofocal IOL
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| New vision through distance correction: comparison of Crystalens accommodating IOL vs monofocal IOL; 30%
of eyes J3 or better with standard monofocal IOL distance-corrected near vision, but clearly higher with Crystalens group
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| Crystalens: postoperative uncorrected distance vision less predictable than multifocal technology; study—83 patients
undergoing refractive lens exchange (all undercorrected hyperopes); group +2 D before and after surgery not happy (enhancement
procedure likely)
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| Comparison of 3 technologies (ReStor SA 60 D3 and MA 60 D3; ReZoom NXG 1; Crystalens AT 45)
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 | Difference in add power at spectacle plane: ReStor diffractive optic has greatest add power (patients need to hold material
closer than with ReZoom; 2.5 D accommodation); Crystalens may be 1.0 D (some patients spectacle-independent,
20/20, J1, and have 2.5 D accommodation)
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| Pupil size: smaller the pupil, better the near vision with ReStor (larger the pupil, the better the near vision with ReZoom);
with ReZoom, speaker has had patients who had to turn down light to read (near zone does not start until pupil gets to
≈3 mm); on other hand, ReStor patients need brighter light to read; no pupil size dependence with Crystalens (monofocal
IOL that produces increased depth of focus)
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| Visual disturbances: multifocal IOLs have halos; for halo-averse patient who wants spectacle independence, Crystalens best
choice
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| Incision size: Crystalens can be placed through 2.8-mm incision; single-piece ReStor IOL can go through 2.2-mm incision
with Royale injector
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| Fixation: if capsule damaged during surgery, accommodative IOL probably will not function properly and cannot be implanted;
(same true for single-piece Acrysof IOL); must use 3-piece Acrysof IOL or ReZoom IOL if problem with bag
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| Posterior capsule opacification (PCO): single-piece Acrysof ReStor (SA)—haptic/optic junction is Achilles heel; lack of
square edge associated with creeping epithelial cell proliferation (Nd:YAG procedure likely in 3-5 yr); ReZoom—
lower Nd:YAG rate because of square edge; Crystalens—square-edge design on new SE version will lower incidence
of Nd:YAG capsulotomy (in FDA study, rate ≈10% over 5 yr)
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| Tecnis multifocal IOL (AMO): presbyopia-correcting IOL; not yet available in US; FDA data not yet available
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| Reading acuity and speed (study by Hütz): comparison of Array SA 40 N, Technis ZM 001, and AcrySof ReStor
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| Reading acuity: uncorrected, best distance correction, and best near correction; bright light—Array does less well than
diffractive modalities (Tecnis multifocal and ReStor); Array “catches up” when eye given best near correction; Array
patient with 2.5 D add can read as well as patient with diffractive lens; dim light—Array lens pupil size-dependent;
like ReZoom, near part of Array lens not in focus until pupil size 3 mm; diffractive lenses do less well; ReZoom
slightly better (even better than ReStor with near correction; refractive technology requires larger pupil size)
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| Reading speed (distance-corrected near vision): 180 words per minute (wpm) down to low of ≈60 wpm (patients read out
loud for examiner); bright light—Tecnis multifocal at head of group; dim light—ReStor scores lower because of
apodization; pupil larger and weight of lens adjusts to distance; in dim light, with larger pupil, more light through refractive
peripheral portion of lens; because of apodization, near vision falls off; at same time, Array does better because
of pupil size dependence; Tecnis multifocal independent of pupil size (same in bright and dim light due to
diffractive grading across entire 6-mm surface)
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| Synchrony dual-optic accommodating IOL (Visiogen): next on horizon; preloaded injector; 2 lenses inserted
into capsular bag; FDA-monitored study began in 2005 (220 lenses implanted); design—front optic moves 32 D, and
variably powered minus optic adjusts for patient’s refractive error (result emmetropia); theoretical 3.3 D accommodation;
clinical data (American Society of Cataract and Refractive Surgery [ASCRS] 2005)—distance-corrected near vision
20/40 or better 96% at 6 mo; at 3 mo, most recent patients 93%; large device can be inserted through 3.8-mm incision
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| NuLens: another new technology on horizon; not placed in capsular bag; natural lens removed, capsular bag compressed,
and device placed in sulcus; with ciliary body movement, trampoline effect of capsule moves plunger and changes surface
curvature of lens to produce large theoretic accommodation (up to 50 D)
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| IMPLANTABLE CONTACT LENS —John A. Vukich, MD, Clinical Assistant Professor of Ophthalmology, University of
Wisconsin School of Medicine, Madison
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| Phakic IOLs (overview): for many, good option; may provide ability to see well without glasses; laser-assisted in situ
keratomileusis (LASIK) not best choice for everyone (problem of thin cornea [eg, 490 µ cornea with -6 D] and dry eye);
Artisan/Verisyse phakic IOL—marketed in United States as Verisyse (outside US, Artisan); iris-fixated or iris-claw
lens; polymethylmethacrylate (PMMA); Implantable Collamer Lens (ICL)—≈25% of implants; other implants—
phakic refractive lens (PRL); NuVita lens; most not in US trials
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| Concerns: long-term complications with phakic IOLs; ICL and Artisan lens (>15 clinical trial sites each); persistent cell and
flare issue for some AC lenses (rate 1.3%); posterior chamber (PC) lenses do not have same propensity; some potential for
trauma or damage to crystalline lens; some lenses have come loose or needed to be removed for variety of reasons; Artisan
lenses—3.8% of lenses removed due to trauma (haptic came loose); chronic inflammation (1.3%); lenticular changes;
ICL—2.2% of lenses removed for reasons of wrong sizing or power; risk for cataract—common denominator for all
phakic IOLs
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| Lenticular postoperative lens opacities (clinical trial): at 3 yr, 4.5% of Artisan lenses developed lenticular opacities
(3.6% of ICLs); eyes undergoing cataract surgery (Artisan lenses, 1.3%; ICL, 0.9%)
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| Sizing remains challenge for PC ICL: white-to-white distance still used (imperfect correlation to sulcus-to-sulcus
distance); lens does not sit in sulcus (30% of footplates sit on zonules); difficult to identify recess of sulcus accurately on
ultrasonography (dependent on operator and angle; gross variations meridian-to-meridian); adequate clearance—
related to vault; huge range of what is acceptable (shock absorber for imprecision in sizing)
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| Toric ICL: next generation addresses astigmatic correction (could be available this year); data—186 eyes (119 patients);
mean -9.25 D; refractive cylinder just <2 D; correction 20/20 or better, 84%; 20/25 or better, 95%; consistent at
every level; preoperative best-spectacle corrected acuity 20/20 or better, 85%; uncorrected acuity of 20/20 or better, 84%;
<1-point spread for 20/25 or better; patients extremely happy; corneal coma and higher-order aberrations—induced
aspherical aberration about one third that associated with ICL and LASIK
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Educational Objectives
| The goal of this program is to educate the listener about recent advances in cataract surgery and intraocular lens (IOL) design.
After hearing and assimilating this program, the clinician will be better able to:
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| 1. Describe recent advances in power delivery for phacoemulsification.
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| 2. Identify innovations in fluidics as a component of phacoemulsification technology.
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| 3. Compare advantages and disadvantages of selected IOLs.
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| 4. Describe indications and contraindications for capsular tension rings.
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| 5. Describe indications for and challenges of implantable contact lenses.
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Discussed on This Program
Tamsulosin HCl [Flomax]
Suggested Reading
Chang DF, Campbell JR: Intraoperative floppy iris syndrom.associated with tamsulosin. J Cataract Refract Surg
31:664, 2005; Hoffman RS et al: Retained IOL fragment and corneal decompensation after pseudophakic IOL exchange.
J Cataract Refract Surg 30:1362, 2004; Hoffman RS et al: Stabilization of flat anterior chamber after trabeculectomy
with Healon 5. J Cataract Refract Surg 28:712, 2002; Lane SS et al: A prospective multicenter clinical trial
to evaluate the safety and effectiveness of the implantable miniature telescope. Am J Ophthalmol 137:993, 2004; Leaming
DV: Practice styles and preferences of ASCRS members—2003 survey. J Cataract Refract Surg 30:892, 2004;
Montes-Mico R, Alio JL: Distance and near contrast sensitivity function after multifocal intraocular lens implantation.
J Cataract Refract Surg 29:703, 2003; Packer M et al: Refractive lens exchange with the array multifocal intraocular
lens. J Cataract Refract Surg 28:421, 2002; Sanders DR et al: Incidence of lens opacities and clinically significant
cataracts with the implantable contact lens: comparison of two lens designs. J Refract Surg 18:673, 2002; Sanders DR
et al: U.S. Food and Drug Administration clinical trial of the Implantable Contact Lens for moderate to high myopia. Ophthalmology
110:255, 2003; Sanders DR, Vukich JA: Comparison of implantable contact lens and laser assisted in situ
keratomileusis for moderate to high myopia. Cornea 22:324, 2003; Sen HN et al: Quality ov vision after AMO Array
multifocal intraocular lens implantation. J Cataract Refract Surg 30:2483, 2004.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue, the following
relationships have been disclosed. Dr. Koch: Alcon (research support; honorarium recipient), Othera Pharmaceutical (board
member), AMO (Speakers’ Bureau; consultant), AccuFocus (consultant); Dr. Packer: Eyeonics, Starr Surgical, Alcon,
AMO, AVS, Visiogen, Zeiss, B&L, Visioncare (Speakers’ Bureau or consultant); Dr. Vukich: Starr Surgical and Zeiss
(Speakers’ Bureau).
Dr. Koch was recorded at the Washington Academy of Eye Physicians and Surgeons 2006 Annual Meeting, presented
March 30-31, 2006, in Seattle, WA; Drs. Packer and Vukich were recorded at the Cataract and Refractive Surgery
Congress, presented February 24-25, 2006, in Miami, FL, by the Bascom Palmer Eye Institute. The Audio-Digest
Foundation thanks Drs. Koch, Packer, and Vukich, and the sponsors for their cooperation in the production of this
program.
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