Manufacturers and their collaborators (including but not limited to clinics, refractive surgeons, and
agents) withheld and distorted safety and effectiveness data (Section A) submitted to the Food and Drug
Administration (FDA) so that LASIK devices would appear to have:
Starting during my tenure, FDA decision–making on LASIK devices was dominated by LASIK
surgeons working hand–in–glove with LASIK manufacturers. Data recently brought to light exposes
this partnership for what it was: a classic example of the fox guarding the henhouse, wherein the
primary arbiters of safety and effectiveness of LASIK devices were the device manufacturers and its
collaborators. Surgeons used LASIK devices in violation of required manufacturing quality controls
(21 CFR 820), patient protections (including but not limited to 21 CFR 50; 54; 56; and 812), and
reports of adverse events (including but not limited to 21 CFR 803; 812; and 820) when they
manufactured and distributed LASIK devices in interstate commerce within the United State as:
As a consequence the FDA was deprived of knowledge of the full extent of LASIK injuries prior to and
during FDA reviews of documents submitted in support of the safety and effectiveness of LASIK devices
under 21 CFR 812 and 21 CFR 814. In addition, LASIK manufacturers and their collaborators withheld
safety and effectiveness information from their investigational device exemption (IDE) reports to the
FDA. In addition, they hid LASIK injuries from FDA within the context of out–of–court settlement of
innumerable lawsuits. Clinic–sponsored IDE studies cherry–picked, withheld, and hid data from FDA that
clearly showed LASIK with excessive adverse event rates (greater than 1%). These activities were an
industry–wide effort, organized wholly or in part by the manufacturers and their collaborators in order to
circumvent FDA law and regulation. I will submit CONFIDENTIAL information on these matters
separately to FDA’s Office of Criminal Investigation.
Published scientific data shows LASIK devices induce an average adverse event rate of about 22% that
persists beyond six months to five or more years. Moreover, the published data (Section B) shows that
LASIK devices transform healthy corneas into sick corneas that:
A. PMA Applicants Withheld and Distorted Safety Data In Submissions to FDA
Figure 1 is a LASIK industry graph falsely showing that dry eyes, night vision, glare, and halos do not
occur six months after LASIK. FDA reproduces the manufacturer’s graph on its website without
attribution or identification of the evidence upon which it is based . Visitors to the LASIK
manufacturer’s website are sent to FDA’s LASIK website to view the graph as if it was FDA’s.
Manufacturers knew (and know) that these adverse events occur with a frequency much higher than 1% at
6 months post–LASIK.
Figure 1 is an example of untruthful and inaccurate information submitted to the FDA by manufacturers
and their collaborators in support of premarket applications (PMA) for LASIK devices (P970005,
P990010, P970053, P970043, P900016, P980008, P930016, P020050, P030008, P930008, P060004).
These manufacturers and their collaborators have been engaged in, and still are engaged in, a pattern of
falsifying, misrepresenting, manipulating, and withholding safety and effectiveness data from FDA to
make their LASIK devices appear safer than they are.
1. Falsified and Misrepresented Data in Submissions to FDA
LASIK manufacturers and their collaborators made and are making false statements to FDA when they
report and label their devices with an adverse event rate of less than 1%. Figures 2–7 show that the
manufacturers knew (know) that the adverse event rates are much higher than 5% and persist for at least
12 months. The vertical axis on each of these figures is percent post–LASIK vision changes compared to
pre–operative values. The horizontal axis on each figure is the follow–up (FU) month post–LASIK at
which data was collected. These data are taken from manufacturers documents submitted to FDA and
identified in Table 1 [cit7].
The data shown in Figure 2–7 clearly show substantial adverse effects beyond six months post–LASIK.
The following section shows that manufacturers and their collaborators pressured FDA to not count these
adverse effects in the “adverse event rate”.
2. Manufacturers Pressured FDA to Not Count Certain Adverse Events.
FDA originally counted glare, halos, dry eye, night driving difficulties, and similar problems after
excimer laser refractive surgery as adverse events, e.g. page 16 of the Patient Information Brochure
for P970053c says “…adverse events beyond the first few months: night vision difficulty (48.1% at
six months)…glare (34.4% at 6 months)…” LASIK manufacturers and their collaborators
successfully pressured FDA to classify these problems as mere “symptoms” so that manufacturers
could claim that the adverse event rate is less than one percent. FDA required an adverse event rate
of less than one percent of eyes . In 2009 FDA publicly acknowledged that “…halos, glare, night
vision problems, and dry eye from LASIK should be reported to FDA..,” , in other words that these
problems are “reportable events” and thus adverse unless proven unrelated to LASIK. The result is
that the true adverse event for LASIK devices is much higher than 1% [cit8].
In addition to falsifying and misrepresenting these adverse events the manufacturers and their
collaborators withheld significant adverse event data from FDA.
3. Manufacturers Withheld Safety Data
Table 1 shows that LASIK manufacturers withheld an average of about 30% of the follow–up data on
adverse events, including but not limited to dry eyes, night vision problems, glare, and halos (see Table
1A in the Appendix for sources of the data). Manufacturers asserted that the missing data was not
submitted because vision outcomes were so good that subjects would not come back for post–operative
visits . They repeatedly made this claim in meetings with FDA.
Table 1 – Percent Adverse Events Data Withheld by Manufacturers
Manufacturer | Follow-Up (months) | % Data Withheld |
Kremer LASIK | 12 | 79.9 |
Kremer LASIK | 12 | 39.7 |
VISX LASIK | 3 | 62.1 |
Nidek EC–5000 | 12 | 41.5 |
LADARVision | 6 | 57.9 |
VISX Star S2, S3 | 6 | 29.4 |
LaserSight | 6 | 88.2 |
LaserSight | 6 | 73 |
VISX | 6 | 4.3 |
LADARVision 4000 | 6 | 68.1 |
VISX Star S4 | 6 | 22.3 |
Allegretto Wave | 3 | 7.6 |
Allegretto Wave | 6 | 10.3 |
LADARVision 4000 | 3 | 29.9 |
VISX Star S4 | 6 | 1.1 |
VISX WaveScan | 6 | 7 |
VISX Star S4 | 6 | 41.8 |
Allegretto Wave | 6 | 12.3 |
LADARVision 4000 | 6 | 20.2 |
LADARVision 4000 & 600 | 6 | 0 |
Allegretto Wave | 3 | 4.2 |
Allegretto Wave | 3 | 6.4 |
MEL–80 | 6 | 2.2 |
Nidek EC–5000 | 12 | 5.2 |
VISX Star Wave | 12 | 9.4 |
Sum = 724 |
N = 25 |
Mean = 29.7 |
Manufacturers and their collaborators withheld more than 10% of the adverse event data from 13 of the
25 studies, more than 20% from 12 studies, and more than 40% from seven studies. In addition, they
withheld information from FDA about LASIK injuries that resulted in lawsuits and out–of–court
settlement that occurred during investigational studies and during FDA review of the PMAs.
Manufacturers and their collaborators did not report these adverse events to FDA during my tenure at
FDA .
The “true” adverse event rate is more than 1% at 6 months post–LASIK (Figures 2–7) [cit9]. For example, the
manufacturers reported to FDA that dry eyes occur at ~21% (Figure 7, Table 3A), night vision problems
at ~11% (Figure 6, Table 3A), glare at ~12% (Figure 6, Table 3A), and halos at ~14% (Figure 7).
However, the published literature shows that these four adverse event rates are approximately 22%, 16%,
20%, and 19% respectively (Table 2). Thus the “true” adverse event rate six months or more post–LASIK
is at least 20 times the FDA approvable rate of 1%.
Table 2. Adverse Event (AE) Rates at >6 Months After LASIK
Adverse Event |
Published Adverse Event Rates |
Adverse Event Rate (%)
Reported by Manufacturers
to FDA |
Reported % |
Mean % |
Dry Eyes |
46.0 |
~22 |
~20.6 |
9.0 |
35.3 |
12.5 |
20.8 |
27.0 |
4.0 5 years post LASIK |
Night Vision
Problems |
>6.19 |
~16 |
~10.9 |
5.15 |
10.3 |
7.1 |
4.7 |
29.5 |
29.0 |
11.7 |
33.8 |
24.0 5 years post LASIK |
Glare |
12.0 |
~20 |
~11.6 |
16.3 |
27.2 |
24.5 5 years post LASIK |
Hallos |
24.7 |
~19 |
~14.1 |
30.0 |
3.0 5 years post LASIK |
LASIK manufacturers and their collaborators emphasized “patient satisfaction” to divert FDA attention
from continuing LASIK-patient complaints about glare, halos, dry eye and night driving problems.
Reports by refractive surgeons that most patients are satisfied with LASIK even as they report dry eyes
and night vision impairment are suspect. Perhaps patients did not have these adverse events when they
were asked if they were satisfied. Or, perhaps it was because post-LASIK complications surfaced months
or years after LASIK surgery. Or the patient may report high satisfaction because of a need to justify to
have LASIK in the first place.
LASIK manufacturers continue to falsely label their LASIK devices as having an adverse event rate of
≤1% (see manufacturers’ patient brochures ). To this moment they and their collaborators have been
successfully engaged in a pattern of falsifying, misrepresenting, manipulating, and withholding safety and
effectiveness data from FDA to make their LASIK devices appear safer than they are.
4. Manufacturers Distorted Effectiveness of LASIK Device
Table 3 shows manufacturers knew that about 43% of LASIK patients’ visual acuity could be improved
by wearing spectacles 6–12 months after surgery. The manufacturers and their collaborators distorted this
evidence.
Initially, one of the FDA effectiveness measures used in the approval of excimer laser refractive surgery
was the percent of post–LASIK patients that would not need spectacles or contact lenses (e.g.,
P930016S10 Patient Brochure). However, the manufacturers and their collaborators successfully lobbied
FDA to eliminate labeling that would indicate the number of patients who might need corrective lenses
post–LASIK, instead using percent uncorrected visual acuity less than or equal to 20/40. Candidates for
LASIK are not informed that they have only about a 57% chance of getting rid of their spectacles or
contact lenses but instead are told that there is a 95% chance that they will see better than 20/40. The
manufacturers own data (Table 3) also showed that about 43% of patients’ vision could be improved with
spectacles at 6 – 12 months after surgery.
Published evidence confirms a persistent double–digit adverse event rate for LASIK, and there has been
no significant trend for improvement in night vision problems and dry eyes with changes in laser
technology. The evidence from the PMAs show that the LASIK adverse event rate is at least twenty
times the 1% rate acceptable to FDA and probably would be much worse if the manufacturers and their
agents had not withheld and distorted the safety data. It is highly unlikely, if not impossible, that the
FDA would have approved PMAs with a 20% adverse event rate and an effectiveness rate of 57%. Now
let us turn to scientific evidence showing that LASIK devices transform healthy corneas into unhealthy
ones (Section B).
Initially, one of the FDA effectiveness measures used in the approval of excimer laser refractive surgery
was the percent of post–LASIK patients that would not need spectacles or contact lenses (e.g.,
P930016S10 Patient Brochure). However, the manufacturers and their collaborators successfully lobbied
FDA to eliminate labeling that would indicate the number of patients who might need corrective lenses
post–LASIK, instead using percent uncorrected visual acuity less than or equal to 20/40. Candidates for
LASIK are not informed that they have only about a 57% chance of getting rid of their spectacles or
contact lenses but instead are told that there is a 95% chance that they will see better than 20/40. The
manufacturers own data (Table 3) also showed that about 43% of patients’ vision could be improved with
spectacles at 6 – 12 months after surgery.
Published evidence confirms a persistent double–digit adverse event rate for LASIK, and there has been
no significant trend for improvement in night vision problems and dry eyes with changes in laser
technology. The evidence from the PMAs show that the LASIK adverse event rate is at least twenty
times the 1% rate acceptable to FDA and probably would be much worse if the manufacturers and their
agents had not withheld and distorted the safety data. It is highly unlikely, if not impossible, that the
FDA would have approved PMAs with a 20% adverse event rate and an effectiveness rate of 57%. Now
let us turn to scientific evidence showing that LASIK devices transform healthy corneas into unhealthy
ones (Section B).
B. LASIK Creates Sick Corneas From Normal Ones
Published scientific reports demonstrate that LASIK devices make normal corneas sick: the corneal
interface never heals completely; is permanently weakened and vulnerable to thinning and bulging
(keratectasia), which may require hard contact lenses and corneal transplant. After LASIK a drier often
painful and distorted corneal surface compromises night driving.
1. LASIK flap never completely heals
LASIK patients have permanently weak and sick corneas. It is shown that all post–mortem LASIK
corneas examined have “permanent pathological changes” . Since the LASIK flap never heals
completely it is at a lifetime risk of dislocation. This fragile flap is vulnerable to traumatic eye injury
and infection for the remainder of the patient’s life, and numerous reports of dislodged and amputated
flaps exist in the literature, even after minor trauma . Diffuse inflammation under the flap (called
diffuse lamellar keratitis) is reported to occur as late as 12 years postoperatively . The average incidence
of this surgically induced and sight–threatening inflammation is as high with the newer technology of
femtosecond laser flap maker as it is with the older mechanical microkeratome .
2. LASIK permanently weakens the cornea
The post–LASIK cornea has a mechanical strength of only ~2% of normal cornea: “Corneal stromal
LASIK wounds were found to heal weaker than normal because these structures were not regenerated
during the healing response. Moreover, the central and paracentral stromal LASIK wounds were found to
heal by producing a hypocellular primitive stromal scar that is very weak in tensile strength, averaging
2.4% of normal, and displays no evidence of remodeling over time in specimens out to 6.5 years after
surgery.”
3. LASIK severs corneal nerves, causing neuropathic dry eyes
The nerves destroyed by LASIK devices are needed for tear production. These nerves never fully
recover, often leading to permanent dry eye disease . Post–LASIK dry eye is a neuropathic
epitheliopathy, a medical device induced epidemic. Dry eye is the most common complication of
LASIK surgery , . Figure 8 shows how LASIK causes neuropathic dry eye .
Patients are not adequately informed of the seriousness and chronic nature of post–LASIK dry eye
disease. Moderate chronic dry eye produces a pain level comparable to moderate angina to those who
experience it . Six months after LASIK patients with dry eyes (48%) experience soreness of the eye to
the touch (6.7%), sharp pains (8.0%), and eyelid sticking to the eyeball (5.6%) .
LASIK induces dry eye in 46% of cases performed with mechanical microkeratomes and 9% with the
femtosecond laser flap–maker; no subjects had dry eye symptoms preoperatively . Corneal nerves
severed and ablated by LASIK never return to their pre–surgical densities and patterns . The LASIKinduced
incidence of dry eyes at six months is reported at 12.5% in eyes with nasal hinges and 35.3% in
eyes with superior–hinges .
Dry eyes can occur due to contact lens wear but this dry eye is not due to neuropathy. Moreover,
removing the contact lenses and treatment with eye drops, are likely to restore the cornea surface to
normality. In contrast, LASIK severs corneal nerves in otherwise healthy eyes causing corneal dryness
that is essentially permanent since these nerves never completely regenerate.
4. LASIK Devices Induce Progressive Pathology in the Cornea
LASIK devices do more damage than cutting corneal nerves; they also cause progressive loss of
important corneal cells called keratocytes. LASIK devices change the biomechanical, anatomical, and
molecular dynamics of the eye . The cornea is deformed with a rapid rise and fall of intraocular
pressure; the flap is cut and brushed back onto a hinge. Then the laser craters the stroma and the flap
floated to cover the void.
One of the most striking long–term pathological changes in the post–LASIK cornea is the 5–year
progressive decline in the density of corneal stromal keratocytes . Figure 9 shows this decline and
Table 4 shows the annual rate of keratocyte loss. Keratocyte density declines in LASIK–induced
thinning and bulging of the cornea (keratectasia) but NOT in keratoconic corneas . The density of
keratocytes is probably related to corneal stiffness , however, it not yet known if it is linked to
keratectasia or some other disease process.
5. LASIK Causes Keratectasia, a Sight-Threatening Disorder
The post–LASIK cornea may become thin and bulge weeks, months, or years later to become the
potentially blinding condition of keratectasia Table 5 summarizes some of the reports of
keratectasia The absence of keratectasia findings in LASIK is likely due to the failure of long–term
follow up an interpretation that is consistent with the failure to report adverse events and to followup
on patients for an extended period of time. Patients may also choose to see a surgeon or eye care
practitioner other than the one who performed LASIK and caused the problem they are experiencing.
In a personal communication Dr. Edward Boshnick says that he has at least 75 patients with LASIKinduced
keratectasia strongly suggesting a much higher percentage of LASIK–induced bulging of
the cornea than is reported by refractive surgery businesses (user facilities) in the professional
journals they control. A worst–case approach would be to select 0.9% as the keratectasia rate. It
seems likely that there is a large degree of under reporting of keratectasia so that it is likely that
keratectasia rate is at least 0.66%
Table 5 — Incidence of LASIK Induced Corneal Bulging
Binder PS. Analysis of ectasia after laser in situkeratomileusis: Risk factors
Table 1. Reported incidence of post-LASIK ectasia. |
Source |
Number |
(%) |
Reinstein3,* | 6/5212 | (0.12) |
Pallakaris4 | 19/2873 | (0.66) |
Rad5 | — | (0.2) |
Condon6 | 3/140 | (0.8) |
Current† | 3/9283 | (0.01) |
Kansky‡ | — | (0.9) |
Sergey ‡ | 13/23990 | (0.05) |
Oliviera ‡ | 6/2500 | (0.24) |
Stulting§ | R1:5000 | — |
ESCRS registry of ectasia cases (9/2006) | 72 | — |
*Projection |
†Myopic errors |
‡Data presented at the XXIV Congress of the European Society of Cataract & Refractive Surgeons, London, England, September 2006 |
§Data presented at the annual meeting of the American Academy of Ophthalmology, Las Vegas, Nevada, USA, November 2006; projection based on literature reports |
6. LASIK Induces Corneal Distortions
In the attempt to correct defocus (sphere) and astigmatism (cylinder) LASIK devices induce distortions
that degrade vision. LASIK devices make corneas more pancake–like , often de–centered, warped,
chaotic, and rough with stromal microfolds .
Several issues must be resolved in order to prevent double–digit rate of the adverse effects of blur, haloes,
glare and night vision losses , . These unresolved safety issues include, but are not limited to, laser
beam characteristics, alignment issues, corneal tissue thickness, spatial ablation efficiency, large
variability in flap thickness, tissue biomechanics and healing response on the alteration of the intended
surface structure prescribed for a given treatment .
Dr. Leo Maguire forewarned of the public health threat of LASIK in an editorial published in the March,
1994 edition of American Journal of Ophthalmology:
“I hope the reader will now understand how a patient may have clinically acceptable 20/20 visual
acuity in the daytime and still suffer from clinically dangerous visual aberration at night if that
patient’s visual system must cope with an altered refractive error, increased glare, poorer contrast
discrimination, and preferentially degraded peripheral vision. People die at night in motor vehicle
accidents four times as frequently as they do during the day, and these figures are adjusted for miles
driven. Night driving presents a hazardous visual experience to adults without aberrations. When
we discuss aberration at night we are considering a possible morbid effect of refractive surgery.”
In a normal eye LASIK can only increase corneal aberrations. LASIK–induced aberrations are significant
in magnitude, adverse consequences, and frequency. Even the newer wavefront–guided LASIK, that is,
LASIK guided by aberration measurements of the client’s healthy cornea, increases higher order
aberrations with commensurate losses in contrast sensitivity in myopic eyes greater than or equal to –6D .
LASIK increases both corneal and total aberrations with changes in the anterior and posterior corneal
surfaces contributing to the rise in higher order aberrations , . LASIK may correct distortions such as
defocus but it induces other distortions. Figure 10 shows the LASIK–induced increase in higher order
aberrations.
According to published studies, higher order distortions induced by LASIK are significantly correlated
with loss of quality of vision, such as loss of contrast sensitivity, and increases in halos and night
vision problems , . In addition, LASIK–induced higher order aberrations are more troublesome in
binocular than in monocular viewing . Moreover, binocular vision worsens during post–LASIK recovery
because the interocular differences in higher order aberrations increases as each cornea re–models itself to
the specific pattern of injuries introduced into each eye.
Some LASIK manufacturers and allied clinics report waveguided–LASIK devices do not increase higher
order aberrations or cause fewer halos and night vision problems than conventional LASIK
devices. , , Still others report waveguided–LASIK does increase higher order aberrations or increase
aberrations more for one LASIK device than another . Other studies report no significant improvement
of waveguide–LASIK compared to conventional LASIK. .
7. Persistent post–LASIK Loss of Contrast Sensitivity in Dim Light
There is considerable evidence that LASIK induces corneal aberrations that are linked to losses in
contrast sensitivity and critical losses of vision . Most of the decrease in post–LASIK contrast sensitivity
found can be explained and computed directly from the physical measurement of the wave aberration .
LASIK increases higher order aberrations and decreases contrast sensitivity at 6 and 12 months. There
are no data after 12 months but it can be assumed from the high percentage of contrast sensitivity loss and
night vision disturbances that have been reported remain as long as the cornea is unstable, which appears
to be many years.
LASIK manufacturers and their collaborators successfully lobbied FDA to use a 6 mm pupil diameter for
measuring safety and effectiveness instead of a larger one. Also, they successfully lobbied FDA not to
require LASIK manufacturers to measure contrast sensitivity in dim light before and after LASIK .
Since the induction of visual aberrations are directly related to pupil size, this practice effectively “clip
off” aberrations outside the 6 mm central zone and ignore the aberrations that patients see in dim light
through a large pupil. The consequences of these decisions are seen below.
Table 6 shows contrast sensitivity losses for the VISX LASIK device. At 6 months LASIK reduces low
contrast visual acuity one to two diopters for 20.2% of the subjects while 2.2% of patients lose more than
2 diopters. Also, predictably contrast sensitivity losses in dim light are worse (9.1%) than losses in bright
light (3.8%). Contrast sensitivity in dim light with a glare source is worse (16.4%) than in dim light
without glare (14.2%) which in turn is worse than in bright light without glare (6.3%). These losses in
contrast sensitivity persist 12 months after LASIK.
LASIK induces dim light contrast sensitivity losses by light scatter (haze) at high spatial frequencies and
by defocus (optical aberrations) at medium and high spatial frequencies . Also, LASIK causes loss of
sensitivity in the midperipheral visual field correlated with refractive error, flap thickness, and optical
zone diameter .
8. LASIK is Unstable and Regresses
Multiple studies have determined that the effects of LASIK are unstable and regress. Seven years after
LASIK fifty–five percent are unhappy with their vision and the number of eyes that lost 2 or more lines of
visual acuity has doubled . Another study found similar results at 8 years with only 39% of highly
myopic [cit21] eyes with a visual acuity of 20/20 uncorrected, along with a significant increase in higher
order aberrations, and decrease in contrast sensitivity; deterioration in vision occurred even after
wavefront–guided LASIK . Similar vision deterioration over time has been found after corneal surgery
with other LASIK devices , .
9. LASIK Creates the Need for Additional Eye Care
A catalogue of the additional medical care that LASIK patients require is beyond the scope of this
petition. However, this care is considerable, costly, and often accompanied by additional risk. LASIK
patients often need treatment for LASIK–induced adverse events including but not limited to dry eyes,
night vision impairment, diffuse lamellar keratitis, and keratectasia. Two additional problems are
particularly thorny.
a. LASIK Increases Risk of Undiagnosed Glaucoma
Having LASIK increases the lifetime risk of undiagnosed glaucoma because the post–LASIK cornea
produces falsely low intraocular pressure (IOP) readings. IOP measurements are performed during
routine eye exams to screen for glaucoma. Therefore, vision–threatening glaucoma may go undiagnosed
and untreated in patients who have had LASIK surgery . Glaucoma is a leading cause of blindness.
b. LASIK Increases risk of Poor Outcome Following Cataract Surgery
Also, because LASIK devices change corneal shape, the risk of a poor outcome from cataract surgery is
increased . Most people who have LASIK will require cataract surgery later in life and the surgeon’s
measurements of post–LASIK corneas to calculate the appropriate intraocular lens (IOL) power will likely
be inaccurate.
10. Newer LASIK Devices Cause the Same Permanent Corneal Damage as Older Models.
Newer technologies have not resolved problems inherent in the LASIK procedure, such as induction of
aberrations that impair night vision and nerve damage that causes post–LASIK dry eye . In fact, studies
show that wavefront–guided and wavefront–optimized LASIK actually increase, not decrease, higher
order aberrations, reducing visual quality in previously untreated eyes . This study demonstrates that
wavefront guided LASIK induces a 1.9 fold increase in total aberrations at 6 months, a 5–fold increase in
vertical distortions and a large increase in spherical aberrations . A review of the literature on
wavefront–guided LASIK concludes that evidence does not support claims that wavefront out performs
conventional LASIK . Femtosecond laser flap creation does not reduce the incidence of most
complications . Furthermore, femtosecond–created laser flaps are more difficult to lift than flaps created
with a blade, which may result in a higher incidence of torn flaps. The femtosecond laser keratome
currently requires longer suction on the eye than blade microkeratomes to create the LASIK flap. The
incidence of suction ring–induced posterior vitreous detachment with blade microkeratomes is high at
13% overall, and 24% for patients with high myopia in one study . A search of peer–reviewed literature
reveals problems associated with the femtosecond laser such as slipped flaps, interface inflammation, flap
folds, infectious keratitis, corneal stromal inflammation, delayed wound healing, macular hemorrhage,
and gas bubbles in the anterior chamber after surgery .
Citations
[cit7] | The source documents for these data are identified in Table 1A, Appendix. |
[cit8] | I will submit CONFIDENTIAL information on these matters to FDA’s Office of Criminal Investigation. |
[cit21] | Highly myopic defined as equal to or greater than –6 D. Table 36 – S25b |
Footnotes