The Importance Of Laser Technology
All laser vision correction systems use a laser beam to reshape the cornea and correct vision problems. But that's where the similarities end. The laser technology on which different vision correction systems are based varies considerably. You should choose the system best suited to correct your individual vision problems, and you want the system that delivers the most accurate vision possible.
Advances in Laser Technology
Since refractive surgery was first performed, there have been great strides in technology. Early refractive surgery was called Radial Keratotomy (RK), and the cornea was reshaped with a scalpel. Now, with the introduction of LASIK, a computer-controlled excimer laser is the reshaping device of choice.
In the early days of refractive surgery, only nearsightedness
Accordingly, the result of your laser eye surgery depends on your choice of laser technology, along with your doctor's skill and experience.
Choose the Right Laser Technology for You
Not every laser system is indicated, or approved by the FDA, to treat every type of vision problem. When choosing your doctor, ask which technologies are used. Most importantly, you should confirm with your doctor that the laser system used in your procedure can correct your specific eye problems.
While the laser technology used in a vision correction system is an important factor when choosing a procedure, it's not the only factor. In addition, there are many other considerations to take into account when making your decision about laser eye surgery.
Glossary Entries
cornea: The clear front surface of the eye. Refractive surgeries like PRK, LASIK, LASEK and RK reshape this surface to correct vision problems.
refractive surgery: Any surgical procedure performed to change the eye`s refractive error.
Radial Keratotomy: Commonly referred to as RK, this refractive surgical procedure flattens the central cornea with a series of spoke-like incisions.
excimer laser: A type of laser used in laser vision correction that removes tissue from the cornea.
FDA: An acronym for the Food and Drug Administration, a federal agency within the U.S. Department of Health and Human Services responsible for determining the validity and safety of any drug, cosmetic, or medical device.
Glossary
Confused on LASIK jargon? Click on terms in bold to pull up the glossary tab.
Myopia:
a. Approval of the premarket approval application is for the WaveLight® ALLEGRETTO WAVE® / ALLEGRETTO WAVE® Eye-Q Excimer Laser System to perform LASIK treatments in patients 18 years of age or older for the reduction or elimination of myopic refractive errors up to -12.0 diopters (D) of sphere with and without astigmatic refractive errors up to -6.0 D; and in patients with documented evidence of a stable manifest refraction defined as less than or equal to 0.50 D of preoperative spherical equivalent shift over one year prior to surgery.
b. LASIK is an elective procedure with the alternatives including but not limited to eyeglasses, contact lenses, photorefractive keratectomy (PRK), and other refractive surgeries.
c. Approval of the application is based on clinical trials in the United States with 901 eyes treated, of which 813 of 866 eligible eyes were followed for 12 months. Accountability at 3 months was 93.8%, at 6 months was 91.9%, and at 12 months was 93.9%.
d. The studies found that of the 844 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at the 3-month stability time point, 98.0% were corrected to 20/40 or better, and 84.4% were corrected to 20/20 or better without spectacles or contact lenses.
e. The clinical trials showed that the following subjective patient adverse events were reported as “moderate to severe” at a level at least 1% higher than baseline of the subjects at 3 months posttreatment: visual fluctuations (12.8% at baseline versus 28.6% at 3 months).
f. Long-term risks of LASIK for myopia with and without astigmatism beyond 12 months have not been studied.
g. Note that the complete name for this ophthalmic laser is “WaveLight® ALLEGRETTO WAVE® / ALLEGRETTO WAVE® Eye-Q Excimer Laser System for laser assisted in-situ keratomileusis (LASIK) treatments of myopic refractive errors up to -12.0 diopters (D) of sphere with and without astigmatic refractive errors up to -6.0 D at the spectacle plane.”
Hyperopia:
a. Approval of the premarket approval application is for the WaveLight® ALLEGRETTO WAVE® / ALLEGRETTO WAVE® Eye-Q Excimer Laser System to perform LASIK treatments in patients 18 years of age or older for the reduction or elimination of hyperopic refractive errors up to +6.0 diopters (D) of sphere with and without astigmatic refractive errors up to 5.0 D at the spectacle plane, with a maximum manifest refraction spherical equivalent (MRSE) of +6.0 D; and in patients with documented evidence of a stable manifest refraction defined as less than or equal to 0.50 D of preoperative spherical equivalent shift over one year prior to surgery, exclusive of changes due to unmasking latent hyperopia.
b. LASIK is an elective procedure with the alternatives including but not limited to eyeglasses, contact lenses, photorefractive keratectomy (PRK), and other refractive surgeries.
c. Approval of the application is based on clinical trials in the United States with 290 eyes treated, of which 100 of 290 eligible eyes were followed for 12 months. Accountability at 3 months was 95.2%, at 6 months was 93.9%, and at 12 months was 69.9%.
d. The studies found that of the 212 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at the 6-month stability time point, 95.3% were corrected to 20/40 or better, and 67.5% were corrected to 20/20 or better without spectacles or contact lenses.
e. The study showed that the following subjective patient adverse events were reported as “much worse” by at least 1% of the subjects (in order of increasing frequency) at 6 months post final treatment: glare from bright lights (3.0%); night driving glare (4.2%) light sensitivity (4.9%); visual fluctuations (6.1%); and halos (6.4%).
f. Long term risks of LASIK for hyperopia with and without astigmatism beyond 12 months have not been studied.
g. Note that the complete name for this ophthalmic laser is “WaveLight® ALLEGRETTO WAVE® / ALLEGRETTO WAVE® Eye-Q Excimer Laser System for laser assisted in-situ keratomileusis (LASIK) treatments of hyperopic refractive errors up to +6.0 diopters (D) of sphere with and without astigmatic refractive errors up to 5.0 D with a maximum manifest refraction spherical equivalent (MRSE) of +6.0 D.”
Mixed Astigmatism:
a. Approval of the premarket approval application is for the WaveLight® ALLEGRETTO WAVE® / ALLEGRETTO WAVE® Eye-Q Excimer Laser System to perform LASIK treatments in patients 21 years of age or older for the reduction or elimination of naturally occurring mixed astigmatism of up to 6.00 D at the spectacle plane; and in patients with documentation of a stable manifest refraction defined as less than or equal to 0.50 D of preoperative spherical equivalent shift over one year prior to surgery.
b. LASIK is an elective procedure with the alternatives including but not limited to eyeglasses, contact lenses, photorefractive keratectomy (PRK), and other refractive surgeries.
c. Approval of the application is based on clinical trials in the United States with 162 eyes treated, of which 111 were eligible to be followed at 6 months. Accountability at 1 month was 99.4%, at 3 months was 96.0%, and at 6 months was 100.0%.
d. The studies found that of the 142 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at the 3-month stability time point, 95.8% achieved acuity of 20/40 or better, and 67.6% achieved acuity of 20/20 or better without spectacles or contact lenses.
e. The clinical trials showed that the following subjective patient adverse events were reported as “moderate to severe” at a level at least 1% higher than baseline of the subjects at 3 months post-treatment: sensitivity to light (43.3% at baseline versus 52.9% at 3 months); visual fluctuations (32.1% at baseline versus 43.0% at 3 months); and halos (37.0% at baseline versus 42.3% at 3 months).
f. Long term risks of LASIK for mixed astigmatism beyond 6 months have not been studied.
g. The safety and effectiveness of LASIK surgery has ONLY been established with an optical zone of 6.0 - 7.0 mm and an ablation zone of 9.0 mm.
h. Note that the complete name for this ophthalmic laser is “WaveLight® ALLEGRETTO WAVE® / ALLEGRETTO WAVE® Eye-Q Excimer Laser System for laser assisted in-situ keratomileusis (LASIK) treatments of naturally occurring mixed astigmatism of up to 6.00 D at the spectacle plane.”
Wavefront-Guided Treatment of Myopia:
a. Approval of the premarket approval application is for the WaveLight® ALLEGRETTO WAVE® / ALLEGRETTO WAVE® Eye-Q Excimer Laser System used in conjunction with the WaveLight® ALLEGRO Analyzer® device. The device uses a 6.5 mm optical zone, a 9.0 mm ablation/treatment zone, and is indicated for wavefront-guided (WFG) laser assisted in-situ keratomileusis (LASIK): 1) for the reduction or elimination of up to -7.00 diopters (D) of spherical equivalent myopia or myopia with astigmatism, with up to -7.00 D of spherical component and up to 3.00 D of astigmatic component at the spectacle plane; 2) in patients who are 18 years of age or older; and 3) in patients with documentation of a stable manifest refraction defined as ≤0.50 D of preoperative spherical equivalent shift over one year prior to surgery.
b. LASIK is an elective procedure with the alternatives including but not limited to eyeglasses, contact lenses, photorefractive keratectomy (PRK), traditional LASIK and other refractive surgeries.
c. Approval of the application is based on a randomized clinical trial in the United States with 374 eyes treated; 188 with wavefront-guided LASIK (Study Cohort) and 186 with Wavefront Optimized® LASIK (Control Cohort). 178 of the Study Cohort and 180 of the Control Cohort were eligible to be followed at 6 months. In the Study Cohort, accountability at 1 month was 96.8%, at 3 months was 96.8%, and at 6 months was 93.3%. In the Control Cohort, accountability at 1 month was 94.6%, at 3 months was 94.6%, and at 6 months was 92.2%.
d. The studies found that of the 180 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at the 6-month stability time point in the Study Cohort, 99.4% were corrected to 20/40 or better, and 93.4% were corrected to 20/20 or better without spectacles or contact lenses. In the Control Cohort, of the 176 eyes eligible for the uncorrected visual acuity (UCVA) analysis of effectiveness at the 6-month stability time point, 99.4% were corrected to 20/40 or better, and 92.8% were corrected to 20/20 or better without spectacles or contact lenses.
e. The clinical trials showed that the following subjective patient adverse events were reported as “moderate to severe” at a level at least 1% higher than baseline of the subjects at 3 months post-treatment in the Study Cohort, light sensitivity (37.2% at baseline versus 47.8% at 3 months) and visual fluctuations (13.8% at baseline versus 20.0% at 3 months). In the Control Cohort, halos (36.6% at baseline versus 45.4% at 3 months) and visual fluctuations (18.3% at baseline versus 21.9% at 3 months).
f. Long term risks of wavefront-guided LASIK for myopia with and without astigmatism beyond 6 months have not been studied.
g. Note that the complete name for this ophthalmic laser is “WaveLight® ALLEGRETTO WAVE® / ALLEGRETTO WAVE® Eye-Q Excimer Laser System used in conjunction with the WaveLight® ALLEGRO Analyzer® device. The device uses a 6.5 mm optical zone, a 9.0 mm ablation/treatment zone, and is indicated for wavefront-guided (WFG) laser-assisted in-situ keratomileusis (LASIK): 1) for the reduction or elimination of up to -7.00 diopters (D) of spherical equivalent myopia or myopia with astigmatism, with up to -7.00 D of spherical component and up to 3.00 D of astigmatic component at the spectacle plane; 2) in patients who are 18 years of age or older; and 3) in patients with documentation of a stable manifest refraction defined as ≤0.50 D of preoperative spherical equivalent shift over one year prior to surgery.”