2007 AMO_San Diego Supplement-2=dl final.qxd

www.eyeworld.org
The News Magazine of the American Society of Cataract and Refractive Surgery
S U P P L E M E N T T O E Y E W O R L D • M AY 2 0 1 0
With the latest advancements in
“
optics, lens design, and biometry
technology, we are continuing to
increase our success with premium
cataract surgery
”
William Trattler, M.D.
Taking cataract and refractive
surgery to the next level
Refractive Cataract
Surgery
Pages 2–7
Ocular Surface
Management
Page 8–9
Laser Vision
Correction
Pages 10–15
contributors
Farrell “Toby” Tyson, M.D.
Elizabeth Davis, M.D.
John Vukich, M.D.
John Wittpenn, M.D.
Steven Dewey, M.D.
Roger Steinert, M.D.
Marguerite McDonald, M.D.
William Trattler, M.D.
Robert Maloney, M.D.
Stephen Lane, M.D.
James Loden, M.D.
Steven Schallhorn, M.D.
Louis Probst, M.D.
David Tanzer, M.D.
COL Scott Barnes, M.D.
Supported by an educational grant from Abbott Medical Optics Inc.
2 ASCRS•ASOA Boston • Show Supplement — Taking cataract and refractive surgery to the next level
Update on next generation one-piece multifocal IOL
Surgeon finds new one-piece has relative pupil independence across
all lighting conditions so patients have improved reading in dim light
by Farrell C. “Toby” Tyson II, M.D.
I
think a one-piece IOL has
numerous advantages, and
now we can add the Tecnis
multifocal optic technology
(Abbott Medical Optics Inc.,
Santa Ana, Calif.) to the list. This
new one-piece lens is easy to use,
injectable through a smaller incision,
and provides patients with relative
pupil independence across all lighting conditions.
Features and benefits
The Tecnis multifocal lens is the first
and only approved wavefrontdesigned optic that rejuvenates vision
by correcting spherical aberration to
essentially zero. It is made of a
hydrophobic acrylic material with
the lowest chromatic aberration and
highest optical throughput, thereby
Good
“
transmission of
light and image
focus
provide patients
with both good
reading vision and
improved contrast
sensitivity in
dimmer lights
”
Farrell C. “Toby” Tyson II, M.D.
transmitting healthy blue light and
reducing the incidence of glistenings
that can reduce contrast sensitivity.
The one-piece lens design contributes to reliable lens centration
and reduction in cell migration.
Traditionally one-piece lenses have a
tendency to move around in the bag.
However, this lens is designed to stay
nicely in place as a result of three fixation points that come into contact
with the lens capsule. The 360-degree
square edge creates an angled barrier
that helps prevent PCO, maintaining
visual quality and reducing the necessity for capsulotomy.
Just like the 3-piece Tecnis
Multifocal, this lens has relative pupil
independence across all lighting conditions as a result of the Tecnis multifocal optic. I think this is one of the
differentiating benefits of the technology versus other single-piece multifocal lenses. The diffractive rings
extend out to the periphery of the
lens optic. As a result, when lighting
conditions change there is not as
much degradation in vision based on
pupil size. In addition, the lens incorporates 0.27 microns of spherical
aberration correction into the optic
that helps increase patient contrast
sensitivity, which is important as just
by being diffractive a little bit of contrast is lost (Figure 1 & 2). Therefore,
good transmission of light and image
focus provide patients with both
good reading vision and improved
contrast sensitivity in dimmer lights.
Figure 1. Dr. Tyson finds the Tecnis lens offers the greatest amount of spherical aberration
correction
Clinical experience
I have had a good experience with
this new lens. My one- and two-year
follow-ups on the acrylic three-piece
platform have been excellent, with
no significant PCO. This is especially
key because with a diffractive multifocal a significant amount of reading
vision could be lost very quickly with
PCO. It is nice to have a lens that is
going to reject PCO as long as possible.
Recently I have been using this
one-piece version of the lens and am
pleased with the results to date. I was
Figure 2. Spherical aberration correction results in improved image quality and contrast
sensitivity especially in dimmer lighting situations
in the clinical trial for the silicone
version and I have three-year data on
that lens. I have been using the
three-piece acrylic since its release
about a year and a half ago and have
had excellent outcomes.
This lens takes surgeons from the
three-piece Tecnis multifocal platform to a one-piece platform. Many
surgeons are more comfortable with a
one-piece design so now they can
have the benefits of the Tecnis multifocal optic on their preferred platform.
Farrell C. Tyson II, M.D., is in practice at Cape
Coral Eye Center, Cape Coral, Fla. He can be
reached at 239-945-1054 or by email at
Farrell.Tyson@capecoraleyecenter.com.
Refractive Cataract Surgery — Show Supplement • ASCRS•ASOA Boston 3
Large-scale comparison of visual outcomes of three presbyopic IOLs
Surgeon finds latest generation diffractive lens
provides excellent range of vision
by Elizabeth A. Davis, M.D.
T
he Tecnis Multifocal IOL
(Abbott Medical Optics
Inc., Santa Ana, Calif.)
provides outstanding performance at all distances
and superior performance at intermediate and near, according to a recent
study of three presbyopic IOLs. The
study compared the visual outcomes
at distance, intermediate, and near
for the Tecnis Multifocal IOL,
Crystalens HD (Bausch & Lomb
Surgical, Aliso Viejo, Calif.), and
ReStor +3 (Alcon, Fort Worth, Texas).
For the presbyopic IOL study, my colleague Guy Kezirian, M.D., and I
conducted an analysis of 3,177 eyes
using the data collected through
DataLink Inc., a repository of IOL
data not collected using a protocol,
but reported by surgeons around the
The Tecnis
“
Multifocal delivers
on intermediate
vision as good as
ReStor +3 but also
provides excellent
near vision
”
”
Elizabeth A. Davis, M.D.
The Tecnis Multifocal demonstrated excellent performance at near and intermediate
world into a registry. The registry is
funded by Bausch & Lomb and
administered by SurgiVision
Consultants Inc.
The study included eyes with no
prior surgery, mean Ks between 41.00
and 46.50, and an axial length range
from 22 to 26.5 mm. Pre-op corneal
astigmatism was ≤ 1.00 D. Analysis
used the last reported post-op exam
in the one- to three-month interval.
The eyes with good refractive outcomes were included in this survey to
permit a comparison of visual
acuities in eyes with similar refractions. Spheroequivalents were limited
to ± 0.50 D and astigmatism to 0.75
D. In the study, 2,641 received the
Crystalens HD, 391 received the
ReStor +3 D, and 145 received the
Tecnis Multifocal.
Results
Overall in the study we saw that all
the lenses provided adequate vision
at all ranges. However, the Tecnis
Multifocal provided excellent vision
at all distances and superior performance at intermediate and near. The
Crystalens HD provided the best
average intermediate vision, while
the ReStor +3 D and the Tecnis
Multifocal had similar average intermediate visual results as recorded in
DataLink.
For UCVA at distance, 91% of the
Tecnis patients saw 20/30 or better,
compared with 90% of the Crystalens
HD patients and 86% of the ReStor
+3 patients. For intermediate vision,
87% of Tecnis patients saw 20/30 or
better, compared with 84% of
Crystalens HD patients and 68% of
ReStor +3 patients. For near vision,
99% of Tecnis patients achieved
20/30, compared with 91% of ReStor
patients and 65% of Crystalens
patients. Further evaluation is necessary, but these results are promising
and confirm my personal clinical
findings.
This study is indicative of real
world results as it evaluated the IOL
data collected from practices
throughout the world for a wide
range of patients. The Tecnis
Multifocal delivers on intermediate
vision as good as ReStor +3 but also
provides excellent near vision. In this
regard, the Tecnis Multifocal provides
patients with a good range of vision
across distance, intermediate, and
near distances.
Elizabeth Davis, M.D., is director of Minnesota
Eye Laser and Surgery Center, Minnesota Eye
Consultants, Bloomington, Minn. She can be
reached at 800-393-8639 or by email at
eadavis@mneye.com.
Are all add powers the same?
by Elizabeth A. Davis, M.D.
M
y clinical experience has shown that the Tecnis Multifocal optic
(Abbott Medical Optics Inc., Santa Ana, Calif.) has excellent functional performance. Outstanding quality of vision can be attributed to several features. The len’s aspheric anterior surface is designed to
correct the average amount of corneal spherical aberration. In addition,
the diffractive design, high ABBE number, and reading add (optical power
+4.0 D) reduce chromatic aberrations.
Some surgeons might wonder why the +4.0 D reading add does not
translate into the same close near focal point that is seen in patients
implanted with the AcrySof IQ ReStor +4.0 multifocal IOL (Alcon, Fort
Worth, Texas). This theoretical difference may be explained in part by the
fact that the diffractive rings are on the posterior surface of the Tecnis
optic and they are on the anterior surface of the ReStor IOL. A difference
between the lenses in the A constant may also play a role.
The Tecnis Multifocal’s diffractive ring design makes vision pupil independent and also allows for good vision in all lighting conditions. The diffractive rings for the Tecnis Multifocal IOL fully extend to the optic periphery, unlike the ReStor multifocal IOL where the reading diffractive zones
are limited to the central 3.6 mm of the optic. As a result, reading vision
may be compromised with the ReStor multifocal IOL when the pupil is
dilated in dim light.
In my personal clinical experience, I have had patients who were
implanted with the ReStor +4.0 and the Tecnis and they have very different near points. Patients with the Tecnis multifocal have never had an
issue with too close of a near point.
4 ASCRS•ASOA Boston • Show Supplement — Taking cataract and refractive surgery to the next level
Next generation accommodative lens technology
Surgeon says dual-optic lenses provide functional visual acuity
over a range of distances, including very natural near vision
by John A. Vukich, M.D.
I
have found that second generation accommodative IOLs provide improved long-term
accommodation leading to
enhanced near vision compared
to some first generation accommodative lenses or multifocals. I think the
second generation dual-optic accommodative lens Synchrony (Abbott
Medical Optics Inc., Santa Ana,
Calif.) compares favorably to diffractive multifocal IOLs currently in the
U.S. market.
Features and functionality
The Synchrony IOL is a single-piece,
dual-optic, silicone lens designed to
mimic the natural lens (Abbott
Medical Optics acquired Visiogen in
2009). The lens has been in the U.S.
as part of Phase III clinical trials for
The natural
“
facility of near
vision seen in
Synchrony patients
is similar to young
emmetropes
”
John A. Vukich, M.D.
more than three years and is now
under review. I was one of the original investigators and have patient
follow-up data of three years or more.
The Synchrony has a 5.5-mm high
plus anterior optic of +32 D, coupled
with a 6.0-mm negatively powered
posterior optic. These two lenses are
separated by a spring-activated mechanism. The haptics separate the lenses at a given distance under constriction of the capsule, and during relaxation of the capsule following accommodative effort, anterior movement
of the positive anterior optic produces increased power for near tasks.
I think the lens is a significant step
forward in terms of the ability to use
standard thin lens optics in order to
change focal length. For example, the
focal distance can be changed by
slightly moving a plus lens relative to
a minus lens a certain distance and
that will provide a change in the
focal point.
Unlike first generation accommodative lenses, the Synchrony fills
the capsular bag and maintains the
relative volume of the previous natural human lenses. As a result, it more
naturally mimics the physiological
state of the relationship between the
ciliary body, the zonules, and the
translated optomechanical movement that occurs during the accommodative response.
The surgical technique for
implanting the Synchrony is standard
cataract surgery with close attention
being paid to the anterior capsulotomy. The capsulotomy must be well
centered and small. It also needs to
be intact because it creates a mechanical system that will be under tension. The lens is then inserted
through a 3.8-mm incision using an
injector system that injects the posterior optic first, followed by the anterior optic. The post-op regimen is also
similar to standard cataract surgery.
than ReStor at 60 cm, 80 cm, 1 M,
and 2 M; it was similar between the
two IOLs at 40 cm and 4 M (Figure
2). No Synchrony patient complained
of severe/very severe halos or glare.
My clinical experience as an
investigator over the last three years
confirms the published results.
Patients achieve excellent recovery of
intermediate and near vision. They
report near vision with few symptoms of glare or halo. The most
important and subtle difference is the
natural ease that patients see up
close. While this may be hard to
quantify, I know it when I see it. This
near vision is different than the near
vision with the previous generation
of accommodative lenses, and the
natural facility of near vision seen in
Synchrony patients is similar to
young emmetropes.
John Vukich, M.D., is an assistant clinical professor at the School of Medicine and Public
Health, University of Wisconsin, Madison. He
can be reached at 608-282-2000 or by email at
javukich@gmail.com.
References
1. Ricardo Alarcón, M.D., Victor Bohorquez,
M.D., Ivan Ossma, M.D., Andrea Galvis, M.D.
2009 American Academy of Ophthalmology
Annual Meeting.
Figure 1. Patients implanted with Synchrony showed better uncorrected vision at all
distances
Results
In a recent study conducted in South
America that compared Synchrony to
the ReStor multifocal (Alcon, Fort
Worth, Texas), Synchrony performed
well in terms of reading speed, contrast sensitivity, and functional visual
acuity over a range of distances1
(Figure 1). For distance visual acuity
at one year, Synchrony was better
Figure 2. Distance corrected visual acuity was better with Synchrony at 60 cm, 80 cm, 1 M,
and 2 M than with ReStor. It was similar between the two IOLs at 40 cm (p = 0.23) and 4 M
(p = 0.52)
Refractive Cataract Surgery — Show Supplement • ASCRS•ASOA Boston 5
Avoiding glistenings
Surgeon finds peace of mind with IOL materials
that haven’t been associated with glistenings
by John R. Wittpenn, M.D.
T
he phenomenon of lens
optic glistenings has
increasingly been reported
in AcrySof hydrophobic
acrylic lenses (Alcon, Fort
Worth, Texas). Published studies have
shown the incidence of this complication to range from 30% to 100%,13 with as many as one quarter showing some detriment to visual acuity.3
It appears to occur when aqueous
seeps into the lens polymer, causing
the acrylic molecules to shift away
from the water vacuoles.
During a five-year period from
2003 to 2008, the AcrySof SA and SN
IOLs were my most frequent choices,
primarily for their ease of insertion.
This made for efficient surgery—no
matter which nurse was scrubbed in
... glistenings
“
have the potential
to negatively
affect visual
quality ...
I decided that
I would rather
implant lenses
that are not
subject to
glistenings
”
John R. Wittpenn, M.D.
to assist me, there were never any
problems loading these lenses.
I noticed some glistenings in the
lens material early on. In some
patients the glistenings continued to
worsen over time and in a few cases
were quite dense. In a recent retrospective chart review of nearly 500
eyes implanted with AcrySof IOLs in
my practice, about half had at least
1+ glistenings. One percent of the
lenses had dense glistenings, rated as
4+.
Two cases in particular heightened my concerns about glistenings
and eventually led me to stop
implanting AcrySof lenses.
The first was a 78-year-old
woman with SA60 lenses in both
eyes. The lens in one of her eyes had
no glistenings while the other had
dense, 4+ glistenings that developed
over several years. The eye with no
glistenings had 20/20 best-corrected
visual acuity, while the eye with glistenings had 20/30 BCVA. The patient
was not complaining and I did not
explant the lens, but I was troubled
by the imbalance between the two
eyes.
The second patient was a man in
his 60s who had an SA60 lens
implanted in the right eye. He had a
prior retinal detachment with bestcorrected acuity of 20/80 in the left
eye. When I first saw this patient, the
“good eye” had a BCVA of 20/20. The
glistenings gradually worsened to 4+
and the visual acuity deteriorated to
20/30 in that eye, with no explanation other than the glistenings. This
patient complained of difficulty with
driving and other night vision tasks,
but I have been reluctant to
exchange the lens because of the
potential for complications and the
reduced acuity in the fellow eye.
In younger patients like this 60year-old man or in those with premium, presbyopia-correcting IOLs, glistenings have the potential to negatively affect visual quality and acuity.
Worse yet, we don’t know how these
lens optics might continue to change
over the next 10 years. For my own
peace of mind, I decided that I would
rather implant lenses that are not
subject to glistenings.
With the introduction of the
Tecnis 1-Piece IOL (Abbott Medical
Optics Inc., Santa Ana, Calif.), I have
not had to choose between efficiency
and material clarity. The Tecnis 1Piece loads very easily in the injector
and unfolds nicely in the eye. It is
made of the same acrylic material as
the Sensar AR40 lenses that I
implanted in the past without any
glistenings, yet it has all the advantages of the latest generation of IOL
design. For all these reasons, the
Tecnis 1-Piece has become my lens of
choice for most cases.
References
1. Gunenc U, Oner FH, Tongal S, Ferliel M.
Effects on visual function of glistening and folding marks in AcrySof intraocular lenses. J
Cataract Refract Surg 2001;27(10):1611-4.
2. Moreno-Montañés J, Alvarez A, RodríguezConde R, Fernández-Hortelano A. Clinical factors
related to the frequency and intensity of glistening in AcrySof intraocular lenses. J Cataract
Refract Surg 2003;29(10):1980-4.
3. Christiansen G, Durcan FJ, Olson RJ,
Christiansen K. Glistening in the AcrySof
intraocular lens: Pilot study. J Cataract Refract
Surg 2001;27(5):728-33.
John R. Wittpenn, M.D., is in private practice
with Ophthalmic Consultants of Long Island.
Contact him at 631-941-3363 or
jrwittpenn@aol.com.
Patient with monofocal acrylic IOL with significant glistenings and reduced quality of vision
Source: William B. Trattler, M.D.
Grade 4+ glistenings in an AcrySof hydrophobic acrylic lens implanted in the left eye of an
elderly patient
Source: John R. Wittpenn, M.D.
6 ASCRS•ASOA Boston • Show Supplement — Taking cataract and refractive surgery to the next level
Pick your pump
Dual-pump system allows surgeon to switch vacuum
pumps on the fly, with just the touch of a button
by Steven Dewey, M.D.
P
eristaltic vacuum pumps
have long been favored by
cataract surgeons because
they reduce the risk of
chamber instability. Preprogrammed peristaltic safety features, such as advanced CASE and
occlusion mode, modulate flow and
vacuum to limit chamber shallowing.
However, the safety of peristaltic
pumps is balanced by their reputation for being a little less efficient
than venturi systems. With a venturi
pump, the vacuum is always “live”
and therefore the potential for chamber shallowing or damage from accidental capsular contact always exists.
The WhiteStar Signature system
(Abbott Medical Optics Inc., Santa
Ana, Calif.) is the first dual-pump system with a single cassette so that I
can switch between the two vacuum
Whether you opt
“
for an all-peristaltic,
all-venturi, or combination approach, it
is a great benefit to
be able to adapt
different modalities
within a single
device to your own
”
surgical technique
Steven Dewey, M.D.
styles on the fly, with
the touch of a single
button.
I was at first quite
skeptical of this concept. I imagined that it
would only be useful
for surgeons with different pump preferences who wanted to
share a single device.
Indeed, it is great for
multi-surgeon locations for this very reason. I continued using
my normal peristaltic
pump settings and
ignored the venturi
capabilities for awhile.
But because it is so
easy to switch from
peristaltic to venturi—
and back again if one
is not comfortable—I
gradually began to try
the venturi pump in more cases.
Today, my preference is to actually use the venturi pump for the
entire procedure in almost all cases. I
particularly like venturi for denser
cataracts because of the lower power
profile. For added safety, I use the
Dewey radius phaco tip
(MicroSurgical Technology, Redmond,
Wash.), which is much less likely to
break the capsule if it does come into
contact with it.
Pump comparison
I recently conducted a prospective
study in 104 eyes undergoing cataract
surgery to compare the effects of venturi and peristaltic vacuum. In all
eyes, a perfect chop, bisecting the
cataract, was required. In the first 52
eyes, I used the venturi vacuum on
the first half of the cataract then
switched to peristaltic for the second
half. In the next 52 eyes, I began
with peristaltic and used venturi for
the second bisected half. These
patients were accumulated over a
four-month period, with the limiting
factor being the elusive “perfect”
chop.
Combining both the first and
second halves, the cataract extractions performed with the venturi
pump required 20% less power compared to those performed with the
peristaltic pump. Extraction with the
venturi vacuum was also accomplished in 14% less time inside the
eye.
This is an interesting validation
that the faster rise time we get with
venturi vacuum allows us to perform
the surgery with just a little more
efficiency. I do not recommend going
faster just for speed’s sake. But if the
performance of the surgery is basically the same, then an improvement in
efficiency that reduces the amount of
energy going into the eye and limits
the time in which a complication can
happen is at least theoretically advantageous. In this study, there were no
complications in either group.
Besides efficiency and personal
preference, there may not be any
strong clinical reason to choose one
vacuum style over the other. Using
the WhiteStar Signature device, particularly with Ellips transversal
phaco, I see exceptionally clear
corneas post-op. Even the densest
cataracts seem to be emulsified with
ease, so I don’t see any significant
difference in clinical outcomes based
on vacuum styles.
Many surgeons opt to use both
vacuum styles within a single case,
often beginning with peristaltic vacuum and switching to venturi for the
cortical cleanup and/or viscoelastic
removal at the end of the case. The
additional shearing force that venturi
can apply at the lumen of the irrigation/aspiration tip evacuates viscoelastic more efficiently, whether it’s
a cohesive, dispersive, or supercohesive OVD.
The intraoperative versatility to
switch back and forth during a case is
the key to maximizing the advantages of each pump and to enhancing
the surgeon’s comfort with an unfamiliar vacuum style. Whether you
opt for an all-peristaltic, all-venturi,
or combination approach, it is a great
benefit to be able to adapt different
modalities within a single device to
your own surgical technique.
Steven Dewey, M.D., is in private practice at
Colorado Springs Health Partners in Colorado
Springs, Colo. Contact him at 719-475-7700 or
deweys@prodigy.net.
Refractive Cataract Surgery — Show Supplement • ASCRS•ASOA Boston 7
Next generation transversal phaco
Surgeon finds latest modifications improve
efficiency and smoothness of transversal phaco
by Roger F. Steinert, M.D.
O
ver the years, cataract surgery has become safer,
with ongoing improvements in power modulation, pulse shaping, and
fluidics. Among the latest advances is
the new Ellips FX Transversal
Ultrasound handpiece, designed for
use with the WhiteStar Signature system (Abbott Medical Optics Inc.,
Santa Ana, Calif.).
Transversal phaco blends the forward-and-back motion of longitudinal ultrasound with a lateral movement. The resulting elliptical cutting
path increases the efficiency of
cataract removal because the tip is
simultaneously cutting in multiple
directions. From a practical standpoint, there are several advantages to
this blended approach. First, because
both the longitudinal and transversal
modes are simultaneously incorporated, I don’t have to switch back and
forth between the two modes.
Additionally, transversal phaco
can be performed with either a
straight or curved phaco tip, while
other forms of lateral phaco require a
bent tip needle to accomplish their
oscillating movement. The curved or
bent tip changes the surgeon’s angle
of approach and can make maintenance of suction more challenging.
With transversal ultrasound, the surgeon can more easily maintain suction
with a bent tip or get the benefits of
the technology with the straight tip
handpiece that many prefer.
I have been using transversal
phaco since it was introduced in 2007.
Since I have found no disadvantages, I
have it enabled for every case. I have
seen advantages in the speed and efficiency of surgery, especially for harder
nuclei, and in the followability of
nuclear material. The elliptical movement also contributes to the overall
stability of the chamber.
Key improvements
I have seen several key improvements
in the new version of Ellips, already
Transversal phaco can be performed with
“
either a straight or curved phaco tip, while
other forms of lateral phaco require a bent
tip needle to accomplish their oscillating
movement
”
in clinical use. The ultrasound repetition rate has been increased by about
50%. The faster cutting frequency
makes nuclear removal even more
efficient. This is important not so
much for the sake of speed, but
because it means I can use less power
and less balanced salt solution, minimizing endothelial cell damage. The
result is a clear cornea in the immediate post-op period and a healthier
corneal endothelium for the long
term.
It also makes the cataract extraction feel very smooth, from the surgeon’s perspective. For the chopping
Although one
“
might not notice
this difference in
softer lenses, the
three-fold increase
in the stroke path
greatly facilitates
removal of more
resistant material in
dense cataracts
”
Roger F. Steinert, M.D.
Ellips FX technology provides a larger stroke path and simultaneous blending of longitudinal
and transversal motion for efficient cutting and faster lens removal
Roger F. Steinert, M.D.
techniques I use, it is ideal for the
phaco tip to move through the nucleus very smoothly and evenly so that
it doesn’t put pressure on the nucleus
or zonules.
With Ellips, I think there is a
noticeable difference in denser (3+)
nuclei, and this is also true of Ellips
FX. Harder nuclei can be chopped
and the fragments emulsified much
more smoothly than with a conventional handpiece. Ellips FX also has a
significantly larger stroke or cutting
path. Although one might not notice
this difference in softer lenses, the
three-fold increase in the stroke path
greatly facilitates removal of more
resistant material in dense cataracts.
In my opinion, where the
WhiteStar Signature system excels is
in marrying ultrasound and fluidics
advancements for better followability,
lower energy, and a more stable anterior chamber. When transversal
phaco is combined with Fusion
Fluidics and the versatility of having
both peristaltic and venturi vacuum
pumps on board, surgeons can maximize post-op outcomes no matter
what sort of case presents itself in the
operating room.
Roger F. Steinert, M.D., is professor of ophthalmology, professor of biomedical engineering,
director of the Gavin Herbert Eye Institute, and
chair of ophthalmology at the University of
California-Irvine (UCI). Contact him at
steinert@uci.edu or 949-824-8089.
8 ASCRS•ASOA Boston • Show Supplement — Taking cataract and refractive surgery to the next level
Dry eye management
Surgeon finds advanced lubricating drops can
improve visual quality and tear film osmolarity
by Marguerite B. McDonald, M.D.
I
have found that high-quality
lubricating drops, on their own
or along with other therapeutic
measures, can improve quality
of life and visual acuity in dry
eye patients. In patients preparing for
refractive or cataract surgery, it is
doubly important to stabilize the tear
film before surgery and before obtaining pre-op measurements.
In my experience, a poor quality
tear film can significantly affect
topography, refraction, keratometry,
and wavefront testing, possibly
reducing the accuracy of pre-op
measurements. In refractive surgery,
there is also a higher incidence of
epithelial defects, diffuse lamellar keratitis, slipped flaps, and enhancement in dry eyes. We have seen that
patients with dry eyes who are poor
candidates for surgery can become
In patients
“
preparing for
refractive or
cataract surgery, it
is doubly important
to stabilize the tear
film before surgery
and before obtaining pre-op
measurements
”
Marguerite B. McDonald, M.D.
good candidates with aggressive treatment and that patients benefit from
topical cyclosporine treatment after
LASIK, whether they had dry eyes to
start with or not.
Comparing the options
There are many artificial tear products available for patients to use but
not all offer the same degree of palliative relief and refractive clarity.
We conducted a double-masked,
prospective study to evaluate the
effects of Blink Tears (Abbott Medical
Optics Inc., Santa Ana, Calif.) and
Systane (Alcon, Fort Worth, Texas)
after LASIK.1 Forty patients (80 eyes)
were randomized to instill Blink Tears
in one eye and Systane in the other
eye. Study visits were at baseline, one
week, and one month. Outcome
measures included higher-order aberrations (HOA), corneal and conjunctival staining, drop preference, and
visual acuity.
We saw a statistically significant
improvement in post-op HOA in the
Blink group compared to the Systane
group. In fact, in the Systane group,
the HOAs actually worsened with use
of the tear (Figure 1). This may be
partly explained by the high viscosity
of the original Systane formulation,
which has a tendency to blur vision.
Both groups had very good visual
outcomes, with all eyes seeing 20/40
or better at one week, but 80% of the
patients using Blink Tears achieved
20/20 or better uncorrected vision,
compared to 72% of the Systane
group.
These findings are supported by
other studies looking at the role of
lubricant drops in tear film osmolarity. Traditional measures of dry eye,
such as Schirmer’s testing, correlate
poorly with dry eye symptoms. Tear
film osmolarity has the potential to
be more predictive of dry eye because
it may be the link between lacrimal
gland pathology and ocular surface
changes. A number of papers have
documented that with a reduction in
aqueous secretions, such as one sees
in dry eye or post-LASIK neurotrophic corneas, other tear constituents
become more concentrated.
With the TearLab Osmolarity
System (TearLab Corporation, San
Diego, Calif.) a score of 300 indicates
marginal dry eye, while 346 or
greater is severe.
Benelli and colleagues randomized 60 subjects with dry eye symptoms to treatment for one month
with Blink Tears or Systane.2 Patients
were seen at baseline and one month
after beginning the drops. Tear osmolarity was measured just before and
five minutes after drop instillation at
both visits. The researchers found significantly better improvement in tear
film osmolarity with Blink (Figure 2).
The Blink group had a corresponding
improvement in best-corrected visual
acuity that was not seen in the other
group.
Conclusions
Post-LASIK dryness presents a challenging test for any lubricating drop,
so the ability to actually improve
the post-surgical aberration profile
with a tear product is impressive
and is supported by the osmolarity
data we see being presented. The
unique viscoadaptive properties of
Blink Tears help to normalize the
tear film, improving signs and
symptoms of dry eye and potentially
improving visual outcomes and
patient satisfaction with ophthalmic
surgery.
Marguerite B. McDonald, M.D., is clinical professor of ophthalmology at NYU Langone
Medical Center, New York, adjunct clinical professor of ophthalmology, Tulane University
Health Sciences Center, New Orleans, La., and in
private practice with Ophthalmic Consultants of
Long Island, Lynbrook, N.Y. Contact her at 516593-7778 or margueritemcdmd@aol.com.
References:
1. McDonald MB. Efficacy of lubricating eyedrops for treatment of dry-eye syndrome and
higher-order aberrations in post-LASIK. Paper
presentation, American Society of Cataract and
Refractive Surgery, Boston, April 2010.
2. Benelli U, Nardi M, Posarelli C, Albert TG.
Tear osmolarity measurement using the TearLab
Osmolarity System in the assessment of dry eye
treatment effectiveness. Cont Lens Anterior Eye
2010;33(2):61-7.
Figure 1. HOA improved after installation of Blink and worsened post-installation of Systane.
The difference between tears is significant
Figure 2. Blink Tears provides a greater improvement in tear film osmolarity than Systane
Ocular Surface Management — Show Supplement • ASCRS•ASOA Boston 9
Optimal ocular surface needed pre-op
For the best results, tear film should be in top shape
prior to lens selection and surgery, surgeon says
by William B. Trattler, M.D.
N
ew research shows that in
order to get the most accurate pre-op testing readings and the best post-op
visual results, ocular surface problems must be identified and
treated first, and then patients should
return for their pre-op testing procedures. Our research on the incidence
of dry eye in patients scheduled for
cataract surgery, the Prospective
Health Assessment of Cataract
Patients’ Ocular Surface (PHACO)
Study, demonstrated that dry eye is
extremely common. Achieving the
best visual outcomes with cataract
surgery requires a careful evaluation
of the ocular surface and initiating
treatment to normalize the ocular
surface. Once dry eye has been treat-
ed and the corneal surface is healthy,
patients may undergo biometry and
keratometry measurements for selecting the intraocular lens.
I know that accounting for even
small factors is necessary to end up
on target. If a patient has dry eye
with a poor tear film, the keratometry readings are likely to be off target,
which can lead to inaccurate IOL
readings and an increased risk of
needing an additional procedure to
end up with a satisfactory visual
result.
Therefore we attempt to identify
patients who need ocular surface
treatment prior to surgery. These
patients can be brought back into the
office after their eyes have been treated. At that time measurements can
be performed, and this will result in
more accurate and precise readings.
Dry eye incidence
The multicenter prospective PHACO
study set out to determine the incidence and severity of dry eye in
patients at least 55 years of age
undergoing cataract surgery. The goal
of the study is to include 10 sites and
200 patients who are scheduled for
surgery and who are not currently
using any types of eye drops. Patients
on glaucoma drops were excluded.
Outcome measures included the
incidence of dry eye as evaluated by
grade on ITF level, tear break up time
(TBUT), ocular surface disease index
(OSDI), corneal staining with fluorescein, conjunctival staining with lissamine, and a patient symptom questionnaire. The interim study results,
presented at the 2010 American
Society of Cataract and Refractive
Surgery meeting, included 71 patients
(142 eyes). The demographics
revealed an even distribution of
males and females, with a mean age
of 71. Twenty-five percent of patients
had a prior diagnosis of dry eye disease.
Results
The average tear break up time in the
subgroup of patients presented at
ASCRS was just under 5 seconds. The
percentage of eyes with a TBUT of
less than 5 seconds was just under
60%. Three quarters of eyes had positive corneal staining, and nearly 50%
of eyes had central corneal staining.
Just over 40% of eyes had a
Schirmer’s score of ≤ 10, and just
under 20% of eyes had a Schirmer’s
score of ≤ 5.
Overall, we found that dry eye
signs are very common in patients
scheduled for cataract surgery (age 55
or older) and that more than 50% of
eyes had very abnormal TBUTs. Just
under 50% of eyes had abnormal
central corneal staining.
Many surgeons do not realize the
number of people who are presenting
with dry eye. Often the primary focus
is the cataract surgery and the discussion of the move on to presbyopic
IOLs and getting ready for surgery.
However, the rationale for identifying
dry eye prior to intraocular surgery is
compelling for several reasons. It will
result in better topography images
and improved biometry (better Ks).
In addition, there is the potential for
reduced risk of infection, less corneal
staining, and a more comfortable
patient who will experience faster
healing.
Therefore, it is imperative for surgeons to take the time to look carefully at the ocular surface to attain
the best readings and improved outcomes for their patients.
William B. Trattler, M.D., is director of the
Cornea Center For Excellence in Eye Care,
Miami, Fla. Contact him at 305-598-2020 or by
email at wtrattler@gmail.com.
Overall, we
“
found that dry eye
signs are very
common in patients
scheduled for
cataract surgery
(age 55 or older)
and that more than
50% of eyes had
very abnormal
TBUTs
”
William B. Trattler, M.D.
Two hundred patients were included in the PHACO Study, which found dry eye is common in pre-surgical patients
10 ASCRS•ASOA Boston • Show Supplement — Taking cataract and refractive surgery to the next level
Fewer enhancements with femtosecond technology
Surgeon says advanced technology and techniques lead to a
reduced incidence of enhancements and flap complications
by Robert K. Maloney, M.D.
A
dopting all-laser LASIK in
my practice reduced my
enhancement and complication rates. Now it is
extraordinarily rare to do
enhancements for patients who have
less than 4 D of myopia and who are
under the age of 40. I attribute that
in part to femtosecond technology.
The adoption of new technologies over time has made a difference
in the quality of my results. My philosophy is to adopt new technologies
that provide improved results. In my
opinion, it is worth the investment
because the best technology allows
the surgeon to get better results.
Femtosecond benefits
The other advantage of femtosecond
technology is reducing the rate of sig-
nificant flap complications in a couple of areas.
Flap slipage: Flap slipage is much
less with femtosecond technology. I
attribute that to the fact that the
beds remain drier and stickier.
More perfect flaps: While suction releases can still happen on the
femtosecond platform, when they
happen they are of much less consequence. When a suction loss occurs
with a mechanical microkeratome, an
irregular flap or free cap results. With
femtosecond technology, the flap is
still nicely attached to the cornea by
residual bridges of tissue, which allow
the surgeon to go back and simply
repeat the femtosecond treatment on
the spot, achieving a superb flap even
in the setting of a suction release.
Flap centration: This has contributed significantly to our improved
results. With the femtosecond laser
we can better center the flaps and
adjust the position of the flap after
applanation of the eye. By better centering the flap, night vision complications can be reduced because a flap
that is perfectly centered on the pupil
ensures that the ablation doesn’t
overlap onto the epithelium, maximizing the regularity of the ablation
and minimizing night vision issues.
Nomogram
We have also made an improvement
to the method of flap centration that
we call the IntraLase (Abbott Medical
Optics Inc., Santa Ana, Calif.)
Centration Nomogram. This nomogram shifts the flap center nasally
and results in improved centration. If
the surgeon docks the IntraLase and
centers the flap on the pupil on the
computer screen, it usually doesn’t
quite end up centered on the pupil.
Instead, it ends up slightly decentered temporally.
To use the centration nomogram,
the IntraLase is docked and then the
surgeon looks at where the pupil is.
Maloney Vision Institute
Intralase Centration Nomogram
OS
Intralase Centration Nomogram
OD
Version 4
6/1/09
6/1/09
technologies that
provide improved
results
”
Robert K. Maloney, M.D.
To Center on the Pupil, if you
move the cursor:
11 or more clicks
10
8
6
4
2
0
2
4
6
8
10
12
14
16
18
20
Robert K. Maloney, M.D., is director of Maloney
Vision Institute, Los Angeles, Calif. He can be
reached at 877-999-3937 or by email at
DrMaloney@maloneyvision.com.
Maloney Vision Institute
Version 4
My philosophy
“
is to adopt new
The surgeon clicks the cursor left or
right to move the center of the ablation pattern onto the center of the
pupil while counting the clicks and
noting which direction the movement is. Then the surgeon looks on
the nomogram for the line that corresponds to the number of clicks (right
or left). The nomogram gives the
number of extra clicks to be done
and the direction. The effect of this is
that surgeons get an even more precisely centered flap, which is better
for night vision.
Surgeons can achieve better
results with state-of-the-art wavefront-guided lasers and femotsecond
technology. If they are still using
conventional lasers and microkeratomes, I think it is time to switch.
Clicks
Clicks
Clicks
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Clicks
Clicks
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21 or more clicks
Right
Right
Right
Right
Right
Right
Left
Left
Left
Left
Left
Left
Left
Left
Left
Left
Left
To Center on the Pupil, if you
move the cursor:
Then Move:
11 or more clicks
recenter the suction ring
11
10
9
8
7
6
5
4
3
2
1
0
1
2
3
4
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Right
Right
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Right
Right
Left
Left
Left
Left
recenter the suction ring
Instructions:
1) Count horizontal and diagonal clicks. Ignore vertical clicks.
2) Round down in-between values (e.g. 3 clicks left reads the row for 2 clicks left)
3) Copyright Robert K. Maloney, 2007-2009. Permission is hereby given to any
surgeon to reproduce this for personal use
Figure 1. Centration nomogram, left and right eye
10
8
6
4
2
0
2
4
6
8
10
12
14
16
18
20
Clicks
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21 or more clicks
Left
Left
Left
Left
Left
Left
Right
Right
Right
Right
Right
Right
Right
Right
Right
Right
Right
Then Move:
recenter the suction ring
11
10
9
8
7
6
5
4
3
2
1
0
1
2
3
4
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Left
Left
Left
Left
Left
Left
Left
Left
Left
Left
Left
Right
Right
Right
Right
recenter the suction ring
Instructions:
1) Count horizontal and diagonal clicks. Ignore vertical clicks.
2) Round down in-between values (e.g. 3 clicks left reads the row for 2 clicks left)
3) Copyright Robert K. Maloney, 2007-2009. Permission is hereby given to any
surgeon to reproduce this for personal use
Laser Vision Correction — Show Supplement • ASCRS•ASOA Boston 11
Revising outcome expectations
Surgeon says wavefront-guided surgery provides excellent visual outcomes now and is the ideal platform for even better results in the future
by Stephen S. Lane, M.D.
I
n the early days of laser vision
correction, we were striving for
the ideal outcome of 20/20
uncorrected visual acuity. But it
didn’t take long to realize that
20/20 didn’t always mean happy.
Poor quality of vision could leave
even a 20/20 patient wildly dissatisfied.
Quality of vision is directly related to higher-order aberrations (HOA).
Modern conventional platforms
induce less HOAs than their predecessors. But a custom procedure that
addresses an individual patient’s actual aberrations is the best way to provide consistently high quality of
vision.
Numerous studies have demonstrated the advantages of custom correction. Steve C. Schallhorn, M.D.,
has shown that wavefront-guided sur-
Custom wave“
front-guided ablation gives us the
ability to offer each
patient an individualized treatment
with the potential
to provide the ideal
correction for his or
her visual system
”
Stephen S. Lane, M.D.
gery with a femtosecond laser flap
produces better visual acuity (88% vs.
68% 20/16 or better) and better contrast acuity than conventional ablation with a mechanical microkeratome.1 In our own clinic, wavefrontguided ablations have produced consistently better results than conventional surgery.
Night-driving simulations provide perhaps the best evidence that
correcting higher-order aberrations is
important. In another study conducted by Dr. Schallhorn, subjects who
underwent LASIK for moderate
myopia with either a custom or conventional ablation were tested on a
night driving simulator pre-op and
six months after surgery.2
Performance loss—or a reduction in
the ability to detect and identify simulated roadside hazards—was significantly worse with conventional treatment. In fact, wavefront-guided
patients actually performed better
after surgery and were able to detect
a hazard 20 feet earlier than pre-op,
while the conventional group’s ability to detect hazards declined significantly (Figure 1).
We are rapidly reaching a point
at which nearly all patients achieve
20/20 or better vision post-op. In the
future, we will focus more attention
on the subtleties of the procedure,
further improving quality of vision,
and reducing the potential for rare
complications like ectasia.
As the sophistication of diagnostic and laser technology increases,
our understanding of the impact of
HOAs and the ideal HOA profile will
grow as well. Custom wavefront-guided ablation gives us the ability to
offer each patient an individualized
treatment with the potential to provide the ideal correction for his or
her visual system.
Steven S. Lane, M.D., is adjunct professor of
ophthalmology, University of Minnesota, and is
in private practice with Associated Eye Care in
Stillwater, Minn. Contact him at 651-275-3000
or sslane@associatedeyecare.com.
References
1. Schallhorn SC. “Evidence that Custom Cornea
Really is Better.” 2006 American Academy of
Ophthalmology/International Society of
Refractive Surgery presentation.
2. Schallhorn SC, Tanzer DJ, Kaupp SE, Malady
SE. Comparison of Night Driving Performance
After Wavefront-Guided and Conventional LASIK
for Moderate Myopia. Ophthalmology 2009;
116(4):702-9.
Figure 1. Wavefront-guided treated patients were able to identify and detect
hazards faster post-op in night driving simulator testing
Source: Steve Schallhorn, M.D.
Evaluating femto features
by James C. Loden, M.D.
S
ince I began performing bladeless LASIK several years ago, I worry a
lot less about potential flap complications, and I am able to offer custom LASIK, rather than PRK, to people with thinner corneas or deep
ablations.
But as femtosecond laser technology expands, it is important to realize
that not all femtosecond lasers are alike. Having used both the IntraLase
iFS (Abbott Medical Optics Inc., Santa Ana, Calif.) and Ziemer (Port,
Switzerland) platforms, I can attest to the fact that there are differences in
terms of cost, convenience, complications, and surgical ease of use. Here
are the five qualities I look for in a femtosecond laser.
Reproducibility. The lack of “surprises” is the major reason to switch
to a femtosecond laser. When you program the flap depth or hinge width,
you should get exactly what you expect.
Low rate of complications. A femtosecond laser must be compatible
with custom, all-laser LASIK and the patient expectations associated with
that. If you have to cancel surgery due to complications more than once or
twice a year, that’s too often.
Customizability. A customizable femtosecond laser gives me the freedom to choose the flap profiles I want for particular types of cases (e.g.,
myopes, hyperopes, narrow fissures) without having to compromise for the
limitations of the technology. The iFS laser allows me to make the vertical
or slightly inverted side cuts (90-degree to 120-degree) I prefer, as well as
the slightly elliptical shape I occasionally use for very narrow fissures.
Simplicity. One should be able to easily place the suction ring on most
eyes. Centration should be straightforward and easy to maintain. IntraLase
lasers use the same type of docking cone and suction ring for every patient,
limiting the need to switch things around depending on the case.
Visibility. Not being able to see the flap as you make it significantly
limits the safety of flap creation. With the IntraLase laser I can watch the
progression of the raster pass and confirm there is adequate meniscus
throughout the procedure. If there is any problem, I can see it in real time,
stop, and re-applanate or abort the procedure as needed.
For all the reasons outlined above, I find the IntraLase iFS best meets
my expectations for smooth, predictable surgery, and a custom, all-laser
experience for the patient.
James C. Loden, M.D., is in private practice at Loden Vision Centers in Nashville, Tenn. Contact
him at 615-859-3937 or lodenmd@lodenvision.com.
12 ASCRS•ASOA Boston • Show Supplement — Taking cataract and refractive surgery to the next level
The future of laser vision correction
Surgeon says advancements in patient selection, wavefront aberrometry, flap-making
technology, and treatment algorithms will continue to improve LASIK outcomes
by Steven C. Schallhorn, M.D.
L
aser vision correction has
come a long way since the
first excimer laser approvals
in 1996. We are now at a
point where it is reasonable
to assume that the majority of
patients can actually achieve better
than 20/20 uncorrected acuity. Yet we
can still look forward to ongoing
refinements at every stage of the
treatment.
Better diagnostic devices. Our
goal is simple: to select patients who
will do well and avoid those with
valid risk factors. In the past, patients
with certain conditions or pre-op
characteristics have often been treated—or denied treatment—based on
the surgeon’s anecdotal experience
with similar patients. A great deal of
work is being done right now to better predict ectasia and other compli-
The next genera“
tion of aberrometers
will have a broader
dynamic range and
will capture hundreds more data
points for higher
resolution and better spot quality
”
Steven C. Schallhorn, M.D.
cations so that we can move away
from anecdote-based decision making.
Advanced aberrometry. The
next generation of aberrometers will
have a broader dynamic range and
will capture hundreds more data
points for higher resolution and better spot quality. The result will be a
more accurate representation of the
true wavefront (Figure 1). We will
also be moving toward aberrometers
that perform multiple measurements
at once, so that wavefront aberrometry, topography, autorefractometry,
pupillometry, and keratometry can all
be captured with a single button
push.
Flap improvements.
Femtosecond lasers have already
improved the consistency, biomechanical stability, and predictability
of flaps, but there is ongoing research
into the tremendous potential of this
technology. The latest femtosecond
lasers, for example, make it possible
to customize the shape and side-cut
angle of the flap (Figure 2). In the
future, surgeons will continue to
learn more about how to leverage
this customizability to improve outcomes.
Better alignment and registration of the treatment. Iris registration has made a huge difference in
the accuracy and precision with
which the excimer laser treatment is
applied to the cornea, but we can
expect further advancements in
lasers’ ability to accurately identify
the limbus. We may also see active,
real-time cyclo-alignment and cycloadjustment that would further reduce
errors.
Refined algorithms. As aberrometry improves, laser algorithms can
be refined to predict and address
higher-order aberrations more directly. Optimized algorithms attempt to
correct for average spherical aberration, but future wavefront algorithms
will be better able to incorporate the
patient’s actual pre-op aberrations
and expected interactions among
those aberrations into the treatment
algorithm. Age, corneal curvature,
and many other parameters may also
be built into the algorithms.
Topography-guided ablations
are exciting because they offer the
potential to treat unusual or highly
aberrated corneas that can’t be
addressed with current technology.
Advanced aberrometry
Figure 1. With much greater resolution, advanced aberrometers will be able to more
precisely map the true wavefront
Flap improvements
Figure 2. Elliptical flaps allow for the creation of a wide hinge without ablating over
the hinge area. They may also protect more corneal nerves, improving corneal sensation, and reducing dry eye symptoms after surgery
Eyes with corneal scars, grossly
decentered ablations, and other
corneal pathologies would benefit
from a topography-guided
approach—and any surgeon with a
few such patients in his or her case
files welcomes therapeutic solutions
for these challenging eyes. But for the
vast majority of normal eyes, we
should continue to treat based on the
wavefront, which measures the total
optical path and corrects for all the
eye’s aberrations, not just the corneal
ones. Topography-guided corrections
rely on manually entered, subjectively derived manifest refractions—a
step backward in the treatment of
eyes that could otherwise benefit
from customized, precise correction
based on objective wavefront data.
While purely topography-guided
ablations will likely be a niche tool
for abnormal eyes, the ability to
influence wavefront-guided ablations
with topographical information has
powerful implications for all eyes.
The advanced aberrometers of the
future will likely be able to import
true topographic data from hundreds
of points on the cornea and integrate
that into the wavefront. This would
allow the laser to compensate for the
cosine effect in a much more sophisticated manner, without giving up
the higher-order corrections we
achieve with wavefront-guided ablations.
With all of the advances outlined
here, the future looks bright for continued improvements in patient satisfaction and refractive surgery outcomes.
Steven C. Schallhorn, M.D., is global medical
director of Optical Express. Contact him at
619-920-9031or scschallhorn@yahoo.com.
Laser Vision Correction — Show Supplement • ASCRS•ASOA Boston 13
Measuring beyond 20/20
LASIK results have improved dramatically and it is time
for post-op measurements to catch up, surgeon says
by Louis E. Probst, M.D.
W
e are at a great point
in the evolution of
laser refractive surgery.
Custom treatments
with iris registration,
correction for centroid shift and
cyclotorsion, fourier-based algorithms, and femtosecond laser flaps
have all improved the consistency
and quality of visual results. Despite
these gains, however, our post-op
acuity testing hasn’t changed all that
much.
The classic approach to post-op
visual acuity testing has been to aim
for what we called “20/happy.” We
recognized that not every patient
could be 20/20—nor did they necessarily need that to be satisfied with
the procedure. Even as outcomes and
patient satisfaction have risen over
the years, I feel that pushing to test
acuity much beyond 20/20 would be
“
Measuring our
success—and our
patients’ success—
promotes the
procedure, drives
business, and
continues to drive
improvements in
outcomes
”
Louis E. Probst, M.D.
counterproductive and might make
patients feel they had somehow
failed our vision test.
Recent data have challenged my
assumptions. Last year, Steve
Schallhorn, M.D., and Jan Venter,
M.D., reported that 71.6% of more
than 32,000 myopic eyes could see
20/16 or better uncorrected after laser
vision correction.1 Schallhorn reported that satisfaction with the procedure continued to increase with each
line of uncorrected acuity.2 David
Tanzer, M.D., also reported excellent
results. In more than 300 eyes treated
with myopic LASIK with a STAR S4 IR
excimer laser (Abbott Medical Optics
Inc., Santa Ana, Calif.) and an
IntraLase femtosecond laser (Abbott
Medical Optics Inc.), nearly 30% were
20/10 and 84% were 20/12.5 one
month after surgery3 (Figure 1).
These results demonstrated to me
that patients were achieving better
outcomes than we thought, even if
we weren’t measuring those outcomes. I decided to start tracking outcomes better than 20/20 in my own
practice, and we are gradually making
that shift throughout TLC.
We now use a more controlled
and standardized backlit LCD monitor that can display ETDRS charts. We
also make sure that eyes are well
lubricated prior to testing.
We still celebrate the achievement of 20/20 before asking the
patient to attempt the smaller lines.
We are currently analyzing data for a
study, but so far, the vast majority of
our patients are indeed seeing better
than 20/20. Telling them so seems to
have a very positive impact on their
satisfaction and on word-of-mouth
referrals.
Other reasons to test beyond
20/20 include the opportunity to
place your practice in the best light
with regard to the competition and
the ability to continue improving
outcomes. Even if your 20/20 rate is
great and your patients are highly
satisfied, you may discover that some
nomogram tweaks or increased preop lubrication could raise your 20/16
or 20/10 rates.
With today’s refractive surgery
technology, refractive surgeons can
produce dramatically better results
than we achieved in the early days of
laser vision correction. We no longer
need to be afraid of testing more
aggressively because we can actually
deliver the results that patients want.
Measuring our success—and our
patients’ success—promotes the procedure, drives business, and continues to drive improvements in outcomes.
Louis E. Probst, M.D., is the medical director of
TLC Laser Eye Centers. Contact him at 608-2496000.
References
moderate myopia with the VISX STAR S4 Laser
in 32,569 eyes. J Refract Surg 2009; 25:S63441.
2. Schallhorn SC. Patient satisfaction with laser
vision correction as performed by a large corporate provider. Paper presentation, Refractive
Subspecialty Day, AAO, Oct. 23, 2009.
3. Tanzer DJ. Bringing LASIK to the next level
with advanced femtosecond technology: A clinical comparison. Paper presentation, ESCRS,
Barcelona, Spain, Sept. 15, 2009.
1. Schallhorn SC, Venter JA. One-month outcomes of wavefront-guided LASIK for low to
Figure 1. In a study by David Tanzer, M.D., 322 eyes with pre-op refractive error ranging from
–0.34 D to –8.62 D underwent LASIK with the STAR S4 IR excimer laser and the IntraLase FS60
or iFS femtosecond laser. At 1 month, nearly 30% were 20/10 and 84% were 20/12.5 or better
Getting to the best refraction
by Steven C. Schallhorn, M.D.
C
omparing the wavefront refraction to the manifest refraction is a critical step in designing a custom laser vision treatment. This comparison is best facilitated by performing the wavefront exam first and
then using it to guide the manifest refraction.
Even when carefully done, the wavefront and manifest refractions can
be different from one another. This is because they are fundamentally different measures. The manifest refraction is a measure of the sphere, cylinder, and axis needed for a patient to achieve the best possible subjective
vision through trial and error.
A wavefront refraction, by contrast, is a completely objective, automated measurement of a patient’s sphere, cylinder, and axis errors extracted
from the overall ocular aberrations. There can be a coupling effect between
lower- and higher-order aberrations that cannot be duplicated with a
phoropter that corrects only for lower-order aberrations.
I have found that with modern aberrometers like the WaveScan (Abbott
Medical Optics Inc., Santa Ana, Calif.), the cylinder value and axis in normal, untreated eyes are very accurate and therefore, I have never needed to
adjust the wavefront cylinder. When the manifest cylinder doesn’t match
the wavefront, the patient will typically see better when presented with the
aberrometry-derived cylinder correction.
From a clinic flow perspective, it is also more efficient to obtain the
wavefront refraction first. With modern aberrometers, wavefront refractions
are highly accurate and can reduce the time spent performing the manifest
refraction significantly. Starting out closer to your goal can also limit the
need for repeated exams.
Steven C. Schallhorn, M.D., is global medical director of Optical Express. Contact him at 619920-9031or scschallhorn@yahoo.com.
14 ASCRS•ASOA Boston • Show Supplement — Taking cataract and refractive surgery to the next level
Comparing wavefront-guided and wavefront-optimized LVC
Surgeon finds outcomes, including excellent visual
quality and faster results, make the difference
by COL. Scott D. Barnes, M.D.
S
ome Army centers are using
wavefront-guided technology while others favor the
wavefront-optimized platform. With the availability
of two excellent platforms, I needed
to decide which was the best for our
soldiers at Fort Bragg. Recent evaluations comparing the outcomes of
wavefront-guided and wavefrontoptimized LVC in Army personnel
have shown that while both technologies produced good results at
about six to nine months, the wavefront-guided LVC eyes experienced a
significantly faster recovery than
wavefront-optimized LVC eyes.
When I set out to evaluate the
LVC platforms I critically analyzed
objective clinical studies that were
presented to the FDA as well as cor-
Our military
“
data evaluation
confirmed the WFG
laser used for
surface ablation
procedures showed
improved results in
a shorter period of
time
porate laser center data (TLC), maintained a healthy suspicion, and then
evaluated the platforms based on the
results obtained at some of our larger
Army refractive centers. Finally, I had
to be willing to change my “opinion”
based on facts if necessary. I evaluated the wavefront-optimized (WFO)
Allegretto (Alcon, Fort Worth, Texas),
which has a treatment based on
sphere, cylinder, and axis, without
specifically addressing multiple higher-order aberrations, and the wavefront-guided (WFG) STAR S4 laser
(Abbott Medical Optics Inc., Santa
Ana, Calif.), which is designed to
reduce or eliminate all HOA and has
a wavefront treatment basis.
The results of LASIK clinical trials
showed that on myopic treatments as
well as hyperopic treatments the best
outcomes were seen with the WFG
platform. In the corporate industry,
we looked at the TLC data to see
what results they have achieved with
regard to quality of vision. The TLC
LASIK data demonstrated more
patients achieved 20/16 by three
months post-op with the WFG platform. In fact, with myopia less than
or equal to –4 D, twice as many
patients achieved 20/16 or better
with the WFG platform compared to
those with the WFO platform.
Our military data evaluation confirmed the WFG laser used for surface
ablation procedures showed
improved results in a shorter period
of time. At one month and three
months a significant difference in the
number of patients who had 20/15
and 20/20 UCVA outcomes was
noted. At one month, 47% of WFG
eyes reached 20/15 and 92% reached
20/20, compared to 25% and 72% of
WFO eyes, respectively. At three
months, 76% of WFG eyes reached
20/15 and 100% were at 20/20, compared to 55% and 91% of WFO eyes.
Finally, at six months, the results
became closer yet still pointed toward
better outcomes with the WFG platform (Figure 1).
The data from some Army centers
using the WFO system suggested that
even though they eventually did
well, a number of patients were taking longer to recover, especially with
cylinder correction. We hadn’t experienced this delay in our WFG platform at Fort Bragg and because of
these excellent early results, we
decided to continue using the WFG
platform to treat our soldiers.
One benefit noted in the WFO
platform was that it was slightly
faster (3 sec/per D versus 4–7 sec/per
D depending on the amount of cylin-
der) than the WFG platform.
However, this increased speed did not
translate into a clinically relevant
increase in patient volume, as the 15
second savings per eye meant we
could only treat 1.5 more eyes per
day using the WFO platform.
A longer, more in-depth study is
warranted to confirm these findings.
However, when we evaluated the retrospective military data from several
centers, it demonstrated that at one
month patients were ahead with
WFG, and at three months the gap
was narrowing somewhat. Yet, it was
not until six months that the results
were similar.
In summary, through critical
evaluation we noted that the clinical
trials and the TLC LASIK studies indicated the WFG LVC produced a similar or better outcome than the WFO
procedure and in some cases, at an
earlier post-op time. When we analyzed our own data, the results
showed that WFG therapy showed
excellent results with a faster recovery time than the WFO platform with
the same type of procedure. As a
result we have continued with WFG
therapy in our soldiers at Fort Bragg.
COL Scott D. Barnes, M.D., is chief of refractive surgery, U.S. Army at Ft. Bragg, N.C. He
can be reached at scott.d.barnes@us.army.mil.
Military PRK — WFG vs. WFO
”
COL. Scott D. Barnes, M.D.
Figure 1. The results showed that wavefront-guided correction provided excellent results with a faster recovery time than conventional and
wavefront-optimized corrections
Laser Vision Correction — Show Supplement • ASCRS•ASOA Boston 15
Majority of military personnel have WFG LVC
Evidence-based medicine is used to
develop Navy standards for LVC
by David J. Tanzer, M.D., CAPT, MC (FS), USN
I
think premium LASIK with a
femtosecond laser represents the
best refractive surgical procedure performed today. The military clinical results are outstanding with 100% of patients
reaching 20/20, 97% reaching 20/16,
and 72% reaching 20/12 uncorrected
visual acuity (UCVA) at two weeks,
according to preliminary results from
the LASIK Naval Aviators Study
(Figure 1).
In terms of functional vision, no
induced aberrations are evident and
improvement in low contrast visual
acuity is clear. No complaints have
been voiced by aviators, and 100% of
our aviators have returned to flight
status, as expected, two weeks after
myopic LASIK and four weeks after
hyperopic or mixed astigmatic LASIK.
Satisfaction is incredibly high in all
Satisfaction is
“
incredibly high in
all service members, with 100% of
aviators saying
they would recommend LASIK to
fellow aviators
”
David J. Tanzer, M.D.
service members, with 100% of aviators saying they would recommend
LASIK to fellow aviators.
I have found that U.S. warfighter
LVC has been overwhelmingly successful in the military in all types of
jobs and has shown tremendous
operational benefits.
Military refractive surgery
Within the Department of Defense a
total of 25 warfighter refractive surgery centers (Army: 12, Navy: 7, Air
Force: 6) completed more than
312,000 refractive surgery procedures
over the past 10 years. LVC has been
allowed for all aspects of military
service, including aviation, special
operations, and support personnel. It
is also approved for NASA astronauts.
All surgery is done on a voluntary
basis.
Only one Department of Defense
medical disability retirement has
been recorded (one medical board in
156,000 patients treated yields an
impressive incidence rate of
0.000007%). This one medical board
was a result of quality of vision complaints, despite the individual having
20/20 UCVA. It has been proven
through the military’s vast experience
that LVC is extremely safe and very
effective for our warfighters.
Evidence-based medicine has driven
refractive surgery standards and policies in the U.S. military.
Figure 1. One hundred percent of patients reached 20/20, 97% reached 20/16, and 72%
reached 20/12 uncorrected visual acuity (UCVA) at two weeks, according to preliminary
results from the LASIK Naval Aviators Study
Data
The LASIK in U.S. Naval Aviators
Study is ongoing. To date, more than
200 aviators, including over 50 pilots
in actual control of aircraft, are in the
study, which is being conducted at
the Naval Medical Center San Diego,
the primary treatment facility, and at
the Naval Medical Center
Portsmouth. Both wavefront-guided
and wavefront-optimized lasers are
used; however, more than 90% of
cases have been wavefront-guided,
and all of the aviators have their
LASIK flaps created with a femtosecond keratome.
Treatment has ranged from +3.4
D to –7.6 D MRSE. For UCVA, 100%
of former myopes are 20/20 uncorrected by two weeks, and at four
weeks, 97% are 20/16 or better, 86%
are 20/12 or better, and 26% are
20/10 or better (Figure 1). In terms of
efficacy, 95% of the myopic aviators
Figure 2. A significant gain is seen in low contrast visual acuity following LVC
are as good or better uncorrected at
four weeks compared to what they
were pre-op best corrected. I have
found the procedure results in exquisite refractive stability. At one week,
our average post-op refractive error is
plano sphere and that fluctuates by
approximately 0.05 D out to three
months. A significant gain is seen in
low contrast visual acuity following
LVC (Figure 2). Patients have no significant complaints of post-op glare,
haze, halo, or sharpness of vision
compared to pre-op habitual corrections (vision with glasses).
High satisfaction
Patient satisfaction is outstanding at
three months post-op. Using a ques-
tionnaire, aviators are surveyed on
their overall satisfaction at three
months post-op. Ninety-eight percent
indicated they felt their vision was
better than they expected, and 80%
felt it was much better. Ninety-eight
percent also indicated that they felt
LASIK helped their effectiveness as a
naval aviator, and 85% felt it was
very helpful. Further, 99% indicated
they would definitely recommend
LASIK treatment to a fellow navy aviator.
David J. Tanzer, M.D., CAPT, MC (FS), USN, is
the program director of the Navy Refractive
Surgery Center, department of ophthalmology,
Naval Medical Center San Diego. He can be
reached at David.Tanzer@med.navy.mil.
This supplement was produced by EyeWorld under an educational grant from Abbott Medical Optics Inc.
Copyright 2010 ASCRS Ophthalmic Corporation. All rights reserved. The views expressed here do not necessarily reflect
those of the editor, editorial board, or the publisher, and in no way imply endorsement by EyeWorld or ASCRS.