How LASIK Works

LASIK addresses common vision problems by using lasers to reshape the curve of the cornea and solve ‘Refractive Error’.

What Is ‘Refractive Error’?

In normal vision, the cornea refracts or bends light so it focuses properly on the retina. Nearsightedness, Farsightedness, and Astigmatism are the result of irregularities of the shape of the cornea, or errors in the cornea’s refractive power, resulting in blurred or distorted images being received by the retina. This is termed ‘refractive error’ and can vary from person to person.


3 Steps from “Refractive Error” to 20/20 Vision

1. The first step of a LASIK procedure is the creation of the corneal flap which is a thin segment of the outer layer of the cornea. In the early days of LASIK, an instrument called a microkeratome, a hand-held spinning razor blade, was used to create the corneal flap. With all-laser LASIK this step is performed with a special laser to create a thinner and more precise flap that enables faster healing and a more comfortable patient experience.

2. Next, a different laser called an excimer laser, is used to re-shape the underlying corneal tissue to correct any irregularities. This step in Custom LASIK is based on an individuals’ 3D map taken of the eye so the most precise corrections are possible.

3. Finally, the flap is folded back into place where it bonds quickly. Healing is rapid with all-laser LASIK and most people can return to work the next day.

The actual LASIK procedure takes just minutes per eye. You can expect to feel no pain at all and perhaps just a sensation of pressure. Inserting or removing contact lenses – or just rubbing tired eyes from wearing glasses can produce more discomfort than an all-laser LASIK procedure.

 


Key Questions About The Technology Behind The 3 Steps

·         What Is All-Laser or Blade-Free LASIK?

All-laser LASIK is the most advanced evolution for the flap-creation step. In the ‘blade-free’ or ‘all-laser’ technique, a laser forms a series of bubbles in the corneal tissue to create the flap- rather than using a blade. The advantages with this advanced technique are: more accuracy and stability and greater patient comfort.

·         Which Technology Solves Night Vision Problems?

Many of us suffer from night vision problems with or without refractive surgery. In the earliest days of laser vision correction, some patients reported halos and ‘star bursts’ after their procedures, especially when driving at night. Patients with large pupils were susceptible to this complication.

Today’s advanced lasers such as the VisX Star S4 have dealt authoritatively with night vision issues. In fact, many patients report improved night vision after the LASIK procedure.

·         How long does LASIK last?

The refractive errors corrected by LASIK stay corrected for the rest of your life. Since the cornea is living tissue there can be minor fluctuations and occasionally the need for enhancements as the cornea adapts following the procedure. These are a normal part of the post-operative process.

After the post-operative processes are complete, you can expect your vision to improve and stabilize, with many LASIK patients reporting excellent vision that gets even better over time.

As your eyes age, another component causes further vision trouble for the over-40 crowd, requiring the need for reading glasses.

This element is the eye’s lens, which gradually loses flexibility and results in a condition called presbyopia, or the need for reading glasses. Blended Vision LASIK can help this condition significantly.

By the time you are in your 60s or 70s you may be experiencing another age-related vision problem; cataracts, which LASIK doesn’t address. However, depending on the age at which you have your procedure, you can expect decades of excellent vision free of the effects of refractive error.

For important safety information regarding these lasers, please click here.

IMPORTANT SAFETY INFORMATION

IntraLase

Indications for Use

The IntraLase FS and iFS Lasers are 21 CFR 1040 class IIIb ophthalmic surgical lasers with the following indications for use:

  • In patients undergoing surgery or other treatment requiring initial lamellar resection of the cornea
  • In patients undergoing surgery or other treatment requiring initial lamellar resection of the cornea to create tunnels for placement of corneal ring segments
  • In lamellar keratoplasty and corneal harvesting
  • In keratomileusis in situ for the correction of myopia
  • In the creation of a corneal flap in patients undergoing LASIK surgery or other treatment requiring initial lamellar resection of the cornea
  • In the creation of a lamellar cut/resection of the cornea for lamellar keratoplasty and for the creation of a penetrating cut/incision for penetrating keratoplasty.

The IntraLase FS and iFS Laser delivery systems are used in conjunction with a sterile disposable IntraLase Patient Interface, consisting of pre-sterilized suction ring assemblies and pre-sterilized applanation lenses, intended for single-use.

The IntraLase FS and iFS Lasers should only be operated by, or under the direct supervision of a trained physician with certification in laser safety and in the use of the IntraLase FS Laser.

Flap Contraindications

Lamellar resection for the creation of a corneal flap using the IntraLase FS or iFS Lasers is contraindicated if any of the following conditions exist. Potential contraindications are not limited to those included in this list:

  • Corneal edema
  • Corneal lesions
  • Hypotony
  • Glaucoma
  • Existing corneal implant
  • Keratoconus

IntraLase Enabled Keratoplasty (IEK) Contraindications

Contraindications to use of the IntraLase FS or iFS Lasers for the indications described for the IEK procedure include:

  • Any corneal opacity adequately dense to obscure visualization of the iris;
  • Descemetocoele with impending corneal rupture;
  • Previous corneal incisions that might provide a potential space into which the gas produced by the procedure can escape; and
  • Corneal thickness requirements that are beyond the range of the system.

The following conditions should also be considered when using the IntraLase FS or iFS Lasers for IEK:

  • Severe corneal thinning
  • Subjects with pre-existing glaucoma
  • A history of steroid responsive rise in intraocular pressure
  • Preoperative intraocular pressure greater than 21 mmHg in the operative eye
  • Subjects with more than 1200 µm corneal thickness at the 9 mm peripheral zone
  • Active intraocular inflammation
  • Active ocular infection

Warnings

FS and iFS Lasers

  • The performance of surgical or laser alignment procedures, operation of controls or any other adjustments other than those specified herein may result in hazardous conditions for both patients and personnel.
  • While the risk of fire is extremely low, the IntraLase FS or iFS Laser should not be operated in the presence of flammable anesthetics, volatile substances, or oxygen flow lines.
  • Only certified accessories that conform to National and International standards (i.e., IEC 60950-1, IEC 60601-1 or similar) should be connected to the input/output ports on the FS Laser.
  • High voltage electrical circuits are accessible if the console panels are removed. Only trained AMO service representatives should attempt to open the console panels. Serious injury or death may occur as a result of exposure to electrical circuits in the unit interior.
  • Do not use cell phones, pagers, or radio frequency devices of any kind in the same room as the IntraLase FS or iFS Laser.
  • If an articulating chair is used in conjunction with the FS or iFS Laser system, take proper precautions to avoid any unintended movement of the chair toward the laser system. Refer to the specific operating instructions provided by the manufacturer of the articulating chair.
  • To ensure the proper operation of the Z-Verifier safety features, use the joystick to applanate and to activate the green eye contact LED. Do not lift and place the objective on the eye in lieu of using the joystick.
  • The suction ring assembly must be disengaged from the patient’s cornea before using the Home button.
  • Check all treatment parameters for accuracy.
  • Only trained AMO service representatives should perform unpacking, installation, and servicing of the IntraLase FS or iFS Lasers. Covers must not be removed by anyone other than AMO service representatives. Accidental contact with the high voltage electrical circuits in the interior of the IntraLase FS or iFS Laser consoles may result in serious injury or death.
  • Ocular exposure to collimated beams contained in the console interior can produce retinal damage.
  • The UPS (Uninterruptable Power Supply) is designed for exclusive use with the FS or iFS Laser system. Do not connect any other electrical device to the UPS system.
  • Check all parameters for accuracy before proceeding to the next phase.
  • Patient procedures performed with an improperly operating IntraLase FS or iFS Laser may produce poor or otherwise unacceptable resections, or may result in complications.
  • Use of this laser system allows laser surgical incisions to be created up to 1200 µm deep. Additionally, resection patterns can be freely adjusted to create various geometric shapes. It is advised that the user check all treatment parameters, and then verify the pattern outline in the graphical display, before proceeding to the next phase.
  • Setting the posterior depth too deep during could result in injury to other intraocular structures.
  • Operation of this system, with the keratoplasty application, requires that the user provide a calibrated corneal thickness measurement device.
  • Caution must be taken to remove suction prior to removing applanation to avoid injury to intraocular structures.

Patient Interface

  • The Patient Interface disposables should not be reused or re-sterilized.
  • Used IntraLase Patient Interface assemblies should be treated as medical waste. Use and disposal of the IntraLase Patient Interface is detailed in the IntraLase Patient Interface Directions for Use (DFU).
  • The applanation lens becomes etched by the laser during the side-cut procedure and MUST NOT be re-used. Laser light will not effectively permeate an etched lens, and the precision of the laser will be altered.
  • To preserve sterility, open the disposable tray while wearing sterile, powder free surgical gloves and complete the following steps.
  • Do not attempt to use a damaged Patient Interface.
  • If the suction ring assembly clip fails to disengage, or if it prematurely disengages, do not attempt use.

Flap Complications

Possible complications resulting from Lasik surgery include (potential complications are not limited to those included in this list):

  • Corneal edema
  • Corneal pain
  • Epithelial ingrowth
  • Epithelial defect
  • Infection
  • Flap de-centration
  • Incomplete flap creation
  • Flap tearing or incomplete lift-off
  • Free cap
  • Photophobia
  • Corneal inflammation, such as diffuse lamellar keratitis (DLK), corneal infiltrates, and iritis
  • Thin or thick flaps
  • Flap striae

The following sporadically reported visual symptoms may occur following LASIK flap creation with the IntraLase FS or iFS Laser.

Transient Light Sensitivity Syndrome (TLSS)

Transient Light Sensitivity Syndrome is characterized by symptoms of mild to severe light sensitivity which manifests between two and six weeks postoperatively. Patients experience no decrease in uncorrected or best spectacle-corrected visual acuity. The incidence of this sensitivity is observed in approximately 1% of patients who undergo flap creation with the IntraLase FS laser. Patients respond to the use of hourly topical steroids such as Pred Forte, and most report improvement within one week of treatment.

Peripheral Light Spectrum (PLS)

Peripheral Light Spectrum (PLS) is a temporary phenomenon whereby patients report the perception of a spoke-like spectrum of light in the periphery of their vision. PLS has no clinical examination findings and no effect on visual acuity; however the potential diffractive effects may be bothersome to some patients. Reported in only 0.03% of cases, the onset of symptoms occurs during the immediate postoperative period, and typically resolves within three months but may be slightly persistent in rare cases. The visual impact of PLS is clinically inconsequential for the vast majority of patients.

US Federal law restricts this device to sale, distribution, and use by or on the order of a physician or other licensed eye care practitioner.

VISX S4 IR

VISX Wavefront-Guided LASIK for Correction of Myopic Astigmatism, Hyperopic Astigmatism and Mixed Astigmatism (CustomVue LASIK Laser Treatment)

Statements regarding the potential benefits of wavefront-guided LASIK (CustomVue) are based upon the results of clinical trials. These results are indicative of not only the CustomVue treatment but also the care of the clinical physicians, the control of the surgical environment by those physicians, the clinical trials’ treatment parameters and the clinical trials’ patient inclusion and exclusion criteria. Although many clinical trial patients after the CustomVue Procedure saw 20/20 or better and/or had or reported having better vision during the day and at night, compared to their vision with glasses or contact lenses before the procedure, your results may vary. You can find information about the clinical trials below and in the CustomVue Patient Information Booklet. Only an eye care professional trained in laser vision correction can determine whether you are a suitable candidate for the CustomVue Procedure. As with any surgical procedure, there are risks associated with the CustomVue treatment. Before deciding whether to have the CustomVue Procedure, you should ask your doctor for and carefully review the CustomVue Patient Information Booklet. It is important to discuss the risks associated with the procedure and any questions you may have about the procedure with your doctor.

WAVEFRONT-GUIDED LASIK INDICATIONS AND INTENDED USES (LOW TO MODERATE MYOPIC ASTIGMATISM):

The VISX STAR S4 Excimer Laser System and WaveScan WaveFront System is approved to perform wavefront-guided laser assisted in-situ keratomileusis (LASIK) treatments for the reduction or elimination of low to moderate myopic astigmatism up to -6.00 D MRSE, with cylinder between 0.00 and -3.00 D in patients 21 years of age or older; and in patients with documented evidence of a change in manifest refraction of no more than 0.50 D (in both cylinder and sphere components) for at least one year prior to the date of preoperative examination. Note that the complete name for this ophthalmic laser is “STAR S4 ActiveTrak Excimer Laser System for wavefront-guided laser assisted in-situ keratomileusis (LASIK) treatments of myopic astigmatism up to -6.00 D MRSE, with cylinder between 0.00 and -3.00 D.” An acceptable alternate version of this official name is “wavefront-guided LASIK for correction of myopic astigmatism.”
Wavefront-guided LASIK is an elective procedure with the alternatives including but not limited to eyeglasses, contact lenses, photorefractive keratectomy (PRK), conventional LASIK, and other refractive surgeries. Approval of the application is based on a clinical trial of 351 eyes (189 primary and 162 secondary). Of all eyes treated, 318 were evaluated for effectiveness with 98.8% accountability at 3 months, 277 eyes with 96.9% accountability at 6 months, 102 eyes with 95.3% accountability at 9 months, and 86 eyes with 95.6% accountability at 12 months. The studies found that of the 277 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at 6 months, 100% were corrected to 20/40 or better, and 95.8% were corrected to 20/20 or better in 71 spherical myopia eyes; and 99.5% were corrected to 20/40 or better, and 93.2% were corrected to 20/20 or better in 206 astigmatic myopia eyes.
The study showed that at the 3 month stability time point: there was a loss of ?2 lines of best corrected vision that can be obtained with spectacles in 1 of 239 astigmatic myopia eyes and there was no loss of ?2 lines of best corrected vision in 79 spherical myopia eyes; there was 1 of 239 astigmatic myopia eyes with best spectacle corrected visual acuity (BSCVA) worse than 20/25 and none in 79 spherical myopia eyes with BSCVA worse than 20/25. During the course of study, no eye lost >2 lines of BSCVA and no eye had a BSCVA worse than 20/40.

WAVEFRONT-GUIDED LASIK INDICATIONS AND INTENDED USES (HIGH MYOPIC ASTIGMATISM):

The VISX STAR S4 IR Excimer Laser System with VSS and WaveScan WaveFront System are approved to perform wavefront-guided laser assisted in-situ keratomileusis (LASIK) treatments for the reduction or elimination of high myopic astigmatism from -6.00 D to -11.00 D MRSE, with cylinder between 0.00 and -3.00 D in patients 21 years of age or older; and in patients with documented evidence of a change in manifest refraction of no more than 1.00 D (in both cylinder and sphere components) for at least one year prior to the date of preoperative examination. Note that the complete name for this ophthalmic laser is “STAR S4 IR Excimer Laser System for wavefront-guided laser assisted in-situ keratomileusis (LASIK) treatments of myopic astigmatism from -6.00 to -11.00 D MRSE, with cylinder between 0.00 and -3.00 D.” An acceptable alternate version of this official name is “wavefront-guided LASIK for correction of high myopia with or without astigmatism.”
Wavefront-guided LASIK for correction of high myopic astigmatism is an elective procedure with the alternatives including but not limited to eyeglasses, contact lenses, photorefractive keratectomy (PRK), conventional LASIK, and other refractive surgeries. Approval of the application is based on a clinical trial of 184 eyes. Of all eyes treated, 180 were evaluated for effectiveness with 97.8% accountability at 3 months, 178 eyes with 96.7% accountability at 6 months, 170 eyes with 96.5% accountability at 9 months, and 107 eyes with 93.9% accountability at 12 months. The studies found that of the 178 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at 6 months, 98.3% were corrected to 20/40 or better, 97.2% were corrected to 20/32 or better, and 84.3% were corrected to 20/20 or better without spectacles or contact lenses. The study showed that of 83 spherical and 101 astigmatic eyes, no eyes lost 2 or more lines of best corrected vision that can be obtained with spectacles (BSCVA) and none of the eyes had BSCVA worse than 20/40.

WAVEFRONT-GUIDED LASIK INDICATIONS AND INTENDED USES (HYPEROPIC ASTIGMATISM):

The VISX STAR S4 Excimer Laser System and WaveScan WaveFront System are approved to perform wavefront-guided laser assisted in-situ keratomileusis (LASIK) treatments for the reduction or elimination of hyperopic astigmatism up to +3.00 D MRSE, with cylinder between 0.00 and +2.00 D in patients 21 years of age or older; and in patients with documented evidence of a change in manifest refraction of no more than 1.0 D (in both cylinder and sphere components) for at least one year prior to the date of preoperative examination. Note that the complete name for this ophthalmic laser is “STAR S4 ActiveTrak Excimer Laser System for wavefront-guided laser assisted in-situ keratomileusis (LASIK) treatments of hyperopic astigmatism up to +3.00 D MRSE, with cylinder between 0.00 and +2.00 D.” An acceptable alternate version of this official name is “wavefront-guided LASIK for correction of hyperopic astigmatism.”
Wavefront-guided LASIK for hyperopic astigmatism is an elective procedure with the alternatives including but not limited to eyeglasses, contact lenses, photorefractive keratectomy (PRK), conventional LASIK, and other refractive surgeries. Approval of the application was based on a clinical trial of 144 eyes (74 primary and 70 secondary). Of all eyes treated, 134 were evaluated for effectiveness with 98.5% accountability at 3 months, 131 eyes with 97.0% accountability at 6 months, 118 eyes with 90.8% accountability at 9 months, and 27 eyes with 87.1% accountability at 12 months. The studies found that of the 131 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at 6 months, 97.3% were corrected to 20/40 or better, and 66.2% were corrected to 20/20 or better in 74 spherical hyperopia eyes; and 93.0% were corrected to 20/40 or better, and 56.1% were corrected to 20/20 or better in 57 astigmatic hyperopia eyes.
The study showed that at the 6 month stability time point: there was no loss of ?2 lines of best corrected vision that can be obtained with spectacles in 1 of 239 astigmatic myopia eyes and there was no loss of ?2 lines of best corrected vision that can be obtained with spectacles in either 63 astigmatic hyperopia eyes or 74 spherical hyperopia eyes; none of the 63 astigmatic hyperopia or 74 spherical hyperopia eyes had best spectacle corrected visual acuity (BSCVA) worse than 20/25. During the course of the study, one in 63 eyes with astigmatic hyperopia lost >2 lines of BSCVA at 1 month, no eyes with spherical hyperopia lost >2 lines of BSCVA, and no eye had a BSCVA worse than 20/40.

WAVEFRONT-GUIDED INDICATIONS AND INTENDED USES (MIXED ASTIGMATISM):

The VISX STAR S4 IR Excimer Laser System with VSS and WaveScan WaveFront System are approved to perform wavefront-guided laser assisted in-situ keratomileusis (LASIK) treatments for the reduction or elimination of naturally occurring mixed astigmatism when the magnitude of cylinder (from 1.0 to 5.0 D) is greater than the magnitude of sphere and the cylinder and sphere have opposite signs; and in patients 21 years of age or older with documented evidence of a change in manifest refraction of no more than 0.50 D (in both cylinder and sphere components) for at least one year prior to the date of preoperative examination. Note that the complete name for this ophthalmic laser is “STAR S4 IR Excimer Laser System” for wavefront-guided laser assisted in-situ keratomileusis (LASIK) treatments of naturally occurring mixed astigmatism when the magnitude of cylinder (from 1.0 to 5.0 D) is greater than the magnitude of sphere and the cylinder and sphere have opposite signs. An acceptable alternate version of this official name is “wavefront-guided LASIK for correction of mixed astigmatism.”
Wavefront-guided LASIK for mixed astigmatism is an elective procedure with the alternatives including but not limited to eyeglasses, contact lenses, photorefractive keratectomy (PRK), conventional LASIK, and other refractive surgeries. Approval of the application is based on a clinical trial of 86 eyes. Of all eyes treated, 86 were evaluated for effectiveness with 100.0% accountability at 3 months, 80 eyes with 95.2% accountability at 6 months, 69 eyes with 86.3% accountability at 9 months, and 63 eyes with 94.0% accountability at 12 months. The studies found that of the 86 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at 3 months, 95.3% were corrected to 20/40 or better, 91.9% were corrected to 20/32 or better, and 61.6% were corrected to 20/20 or better without spectacles or contact lenses.
The study showed that of 86 astigmatic eyes, one eye temporarily lost 2 lines of best corrected vision that can be obtained with spectacles at 1 month and at 6 months, and none of the eyes had best spectacle corrected visual acuity (BSCVA) worse than 20/40.

CONTRAINDICATIONS:

Wavefront-guided LASIK is contraindicated in patients with collagen vascular, autoimmune or immunodeficiency disease, signs of keratoconus or abnormal corneal topography, patients taking isotretinoin (Accutane®*) or amiodarone hydrochloride (Cordarone®†) or are pregnant or nursing.

WARNINGS:

Wavefront-guided LASIK is not recommended in patients who have diabetes, a history of Herpes simplex or Herpes zoster keratitis, significant dry eye that is unresponsive to treatment, or severe allergies. For the treatment of low to moderate myopic astigmatism, lower uncorrected visual acuity may be anticipated in the treatment of higher degrees of myopia with and without astigmatism (?5.0 D MRSE).

PRECAUTIONS:

Long-term risks of wavefront-guided LASIK beyond 12 months have not been studied. The safety and effectiveness of wavefront-guided LASIK surgery has ONLY been established with an optical zone of 6 mm and an ablation zone of 8 mm for myopic treatments, and an ablation zone of 9 mm for hyperopic and mixed astigmatism treatments. The safety and effectiveness of STAR S4 Excimer Laser System have NOT been established for wavefront-guided surgery in patients with low to moderate myopic astigmatism: whose WaveScan wavefront diameter is less than 6 mm; for treatments greater than -6 diopters of MRSE or with greater than 3 diopters of astigmatism and for retreatment with CustomVue LASIK. The safety and effectiveness of STAR S4 Excimer Laser System have NOT been established for wavefront-guided surgery in patients with high myopic astigmatism: whose WaveScan wavefront diameter is less than 5 mm; for treatments greater than -11 diopters of MRSE or with greater than 3 diopters of astigmatism. The safety and effectiveness of STAR S4 Excimer Laser System have NOT been established for wavefront-guided surgery in patients with hyperopic astigmatism: whose WaveScan wavefront diameter is less than 5 mm; for treatments greater than +3 diopters of MRSE or with greater than 2 diopters of astigmatism and for retreatment with CustomVue LASIK. The safety and effectiveness of the STAR S4 IR Excimer Laser System have NOT been established for wavefront-guided surgery in patients with mixed astigmatism: whose WaveScan wavefront diameter is less than 5.00 mm; for treatments greater than 5.00 D or less than 1.00 D of astigmatism and for retreatment with CustomVue LASIK.
Although the WaveScan WaveFront System measures the refractive error and wavefront aberrations of the human eyes, including myopia, hyperopia, astigmatism, coma, spherical aberration, trefoil, and other higher order aberrations through sixth order, in the clinical studies for low to moderate myopic astigmatism, hyperopic astigmatism and mixed astigmatism, the average higher order aberration did not decrease after CustomVue treatment. In the clinical studies for high myopic astigmatism, the average higher order aberration increased after CustomVue treatment.
It is possible, after wavefront-guided LASIK treatment, that patients will find it more difficult than usual to see in conditions such as very dim light, rain, snow, fog, or glare from bright lights at night. Visual performance possibly could be worsened by large pupil sizes or decentered pupils. Pupil size should be evaluated under mesopic illumination conditions.

ADVERSE EVENTS AND COMPLICATIONS (LOW TO MODERATE MYOPIC ASTIGMATISM):

The clinical trial showed that the following adverse events or complications occurred in at least 1% of the 351 eyes at any interval up to 6 months post-treatment: inflammation of the cornea under the flap (1.4%); double or ghost images (1.4%); and scratch on the surface of the eye (1.4%).
The following subjective symptoms frequency rated “often or always” were increased in the effectiveness cohort at 6 months post-treatment on 258 eyes compared with pre-treatment on 332 eyes: dryness (9% vs. 6%); fluctuation of vision (3% vs. 2%); glare (4% vs. 2%) and halos (7% vs. 5%).

ADVERSE EVENTS AND COMPLICATIONS (HIGH MYOPIC ASTIGMATISM):

The clinical trial showed that the following adverse events or complications occurred in at least 1% of the 184 eyes at one or more postoperative examinations up to 6 months post-treatment: cells growing under the flap (1.1%); scratch on the surface of the eye at 1 month or later (2.2%); swelling of the corneal between 1 week and 1 month postoperatively (2.7%) and double vision (or “ghost images”) in the operative eye (6.0%).
The following subjective symptoms were reported as present “often or always” by a higher percentage of subjects 6 months after treatment than before treatment: dryness (10.8% vs. 9.3%); halos (21.6% vs. 15.4%); and ghosting or shadowing of images (2.8% vs. 1.1%).

ADVERSE EVENTS AND COMPLICATIONS (HYPEROPIC ASTIGMATISM):

The clinical trial showed that the following adverse events or complications occurred in at least 1% of the 144 eyes at any interval up to 6 months post-treatment: cells growing under the flap (2.1%); feeling of something in the eye (1.4%); double or ghost images (11.3%); and scratch on the surface of the eye (2.1%).
The following subjective symptoms rated “often or always” were increased in frequency in the effectiveness cohort at 6 months post-treatment on 131 eyes compared with pretreatment on 136 eyes: dryness (17% vs. 6%); blurry vision (10% vs. 7%); fluctuation of vision (14% vs. 6%); halos (10% vs. 5%); double or ghost images (7% vs.3%).

ADVERSE EVENTS AND COMPLICATIONS (MIXED ASTIGMATISM):

The clinical trials showed that the following adverse events or complications occurred in at least 1% of the 86 eyes at one or more postoperative examinations up to 3 months post-treatment: miscreated flap (1.2%); cells growing under the flap (4.7%); and double vision (or “ghost images”) in the operative eye (8.1%).
The following subjective symptoms were reported as present “often or always” by a higher percentage of subjects 3 months after treatment than before treatment: dryness (22% vs. 6%); halos (20% vs. 13%).

*Accutane® is a registered trademark of Hoffmann-La Roche Inc.
†Cordarone® is a registered trademark of Sanofi-Synthelabo, Inc.