ABOUT
LASIK is the most commonly performed refractive surgery procedure. You may hear people calling it “LASIX,” but the name is actually short for ” laser-ain situ keratomileusis.” The surgeon folds the flap back out of the way, and then removes some corneal tissue underneath using an excimer laser. The excimer laser uses a cool ultraviolet light beam to precisely remove (“ablate”) very tiny bits of tissue from the cornea to reshape it. When the cornea is reshaped in the right way, it works better to focus light into the eye and onto the retina, providing clearer vision than before. The flap is then laid back in place, covering the area where the corneal tissue was removed. Both nearsighted and farsighted people can benefit from the LASIK procedure. With nearsighted people, the goal is to flatten the too-steep cornea; with farsighted people, a steeper cornea is desired.
While this is not widely recognized by consumers, excimer lasers also can correct astigmatism by smoothing an irregular cornea into a more normal shape. In order to decide whether you’re a good candidate for LASIK, your eye doctor will examine your eyes to determine their health, what kind of vision correction you need, and how much laser ablation is required. Also, a corneal topographer is usually used; this device photographs your eye and creates a kind of “map” of your cornea. With new wavefront technology associated with custom LASIK, you also are likely to undergo a wavefront analysis that sends light waves through the eye to provide an even more precise map of aberrations affecting your vision.
Monovision
Monovision addresses the problem of presbyopia that most people start to encounter at the age of 40-45 when they begin to need reading glasses or bifocals for close vision. With monovision, the dominant eye (the eye you would use to focus a camera) is focused for distance vision, and the non- dominant eye is focused for near to intermediate vision. This can be done with contact lenses, refractive surgery or intraocular lenses.
Monovision certainly isn’t appropriate for everyone. However, when paired with the right person, it can be a great fit. Monovision is a blend of near and distance vision, and is ideal for people with an active lifestyle. However, there is a caveat to consider: since it is a compromise, most people’s vision isn’t perfectly crisp up close or far away. Instead, it offers the best of both worlds. Most people who opt for monovision go through a brief period of adaptation as the brain “learns” to see with the eye best suited for the task. If you’re considering refractive surgery as a permanent form of monovision, it might be best to consider a “test drive” with contact lenses before making a decision. Often times patients are unsure whether they would prefer to have their eyes surgically corrected so they have to work in tandem (thus monovision) or just have both eyes corrected to see equally. There are costs and benefits with both; it really depends on your doctor’s assessment of your eyes and your personal habits.
WHAT IS LASIK?
What is LASIK Laser Vision Correction? Laser vision correction is a surgical procedure that uses cool pulses of UV light to re-shape the cornea (the clear part of the eye) by removing thin layers of tissue to correct nearsightedness, farsightedness, and certain types of astigmatism. The goal of LASIK / PRK is to reduce or eliminate the need for glasses and contacts.
Because the surface cells, or epithelium, of the eye heal and grow quickly, LASIK surgery is generally painless and doesn’t require much recovery time. However, it is important to remember, that it is a surgical procedure and there are risks involved. There are multiple factors that determine whether LASIK / PRK is the right solution for you including age, general eye health, shape of the eye, degree and type of vision problem, etc.
Dr. Tinoosh takes great care in your vision to provide you the most accurate care and best results to correct your vision. Dr. Tinoosh will perform a comprehensive and thorough eye examination, evaluate your medical history, and perform diagnostic investigations to evaluate your candidacy.
- In general, the procedure takes less than 10 minutes in Dr. Tinoosh’s hands.
- LASIK (Laser-Assisted in Situ Keratomileusis) – a very thin, hinged corneal flap is created. The laser removes tissue and re-shapes cornea, and the flap is replaced as a natural ‘bandage’. Vision is generally clear within hours and the procedure is relatively pain-free.
- PRK (photorefractive keratectomy), also called LASEK or Epi-LASIK – this is the original laser correction surgery, in which the top surface (epithelium) is removed, a laser removes tissue and re-shapes the cornea, and a protective ‘bandage’ contact lens is used to protect the eye while the epithelium heals – usually in about 72 hours.
- There are many factors that determine which procedure is best, but PRK is generally used when the cornea is too thin or irregular to create the flap used in LASIK. Some studies show that results are more stable with PRK, although recovery time is longer and slightly more uncomfortable.
LASIK & PRK Correction
What Can LASIK and PRK Correct?
Myopia (Nearsightedness)Vision is clear up close, but is blurred far away. Patients who are nearsighted may find a negative number in the sphere column of their prescription.
Hyperopia (Farsightedness)
Vision is better far away than close, however both are blurry. Patients who are farsighted will find a positive number in the sphere column of their prescription.
Astigmatism
Vision is distorted and blurred in general, both up close and far away. Information regarding astigmatism is found in the cylinder column of your prescription. Many people with myopia or hyperopia have some degree of astigmatism.
Presbyopia
Presbyopia is the natural hardening of the lens that occurs as we age, resulting in blurred near vision. This usually starts at about age 40 and tends to stabilize by about age 60. The standard LASIK and PRK procedures do not correct Presbyopia. However, a “blended” or “monovision” procedure – a process by which one eye is corrected for distance vision and the other eye is corrected to for intermediate and near vision – is an excellent option for presbyopia. Not everyone is an ideal candidate for Blended or Monovision, so it is important to simulate this type of vision with patients before undergoing the procedure. There are also a variety of lens implants available that can also help correct myopia for patients over the age of 50. They provide binocular clear distance and near vision in each eye individually (see Cataract lens implants for more information).
Monovision
Can be achieved by LASIK or PRK. The dominant (preferred) eye is focused far away, while the non-dominant eye is focused at the reading or computer distance. It is designed to make vision functional, the majority of the time. Most patients can easily adapt to monovision either immediately or within a few weeks. Patients may need to wear glasses to neutralize monovision with some activities like night driving.
WaveLight® EX500Excimer Laser
The WaveLight® EX500 Excimer Laser system combines a number of innovations in refractive technology to produce fast, effective and reliable procedures.1–4 Its proven, state-of-the-art technology results in excellent Wavefront Optimized® and Wavefront-Guided laser vision correction.
The WaveLight EX500 Excimer Laser is capable of pinpointing and correcting a number of corneal/visual abnormalities. With this state-of-the-art optometric restoration technology, the ability to minimize or eradicate corneal irregularities has taken a giant step forward. Patients suffering from ocular myopia or hyperopia can now benefit from these minimally invasive FDA approved procedures, which can virtually eliminate the need for prescription eye glasses or contact lenses.
With the EX500 Excimer Laser, Wavefront® Optimization is one of the major components capable of ascertaining a detailed map of the cornea prior to surgery, thus allowing eye specialists to detect where the problem areas are and be able to recommend suitable courses of treatment.
Whether being nearsighted or farsighted, the type of precision involved with wavefront optimized lasers is unparalleled when compared to other devices; this comprehensive layout includes concise scanning capabilities and uniform surface ablation functions. When it comes to most any LASIK procedure, accuracy is the key element when dealing with laser-related treatments.
Being able to detect spherical aberrations, wave front optimized technology also employs the use of light-waves to gauge and measure exact prescriptions for each eye individually. Often times these aberrations are not correctible via contact lenses or eyeglasses; using the EX500 with wave front optimization can also minimize the risk of aberrational recurrence in the affected areas, or prevent aberrations from forming in the future.
This is also a vitally important step concerning protocol with preoperative planning for prospective patients. With a detailed layout of each corneal abnormality in question, monitoring eye movement during the LASIK procedure can give ophthalmologists and other eye specialists a more concentrated area of focus on the treatment zones, which can vastly improve overall outcomes. Empirical evidence suggests that procedures performed via the EX500 and wavefront optimization have been able to produce favorable results.
It’s also important to note that the EX500 Excimer Laser treatment method is not only the most accurate, but also the quickest way to restore normal vision. Because of the fact that measurement points are extremely crucial, the WaveLight® EX500 is capable of ascertaining exact parameters, thus allowing for a smoother workflow and seamless transitions. Adaptability and focus issues, especially in dimly lit areas, can also be improved dramatically.
In addition, the above-mentioned combined applications are effective in treating myopic astigmatism with higher success rates. As a precaution, potential candidates need to be screened for any of the above procedures; those who are afflicted with degenerative eye conditions may not be eligible, as each projected course of treatment will be assessed on a case-by-case basis.
LASIK Technology
Perfect Pulse Technology™ Perfect Pulse Technology™ represents a new approach to laser vision correction. It accounts for much of the speed, precision, and safety of the ALLEGRETTO WAVE® laser and offers improvements that are revolutionary in the field. Smart energy control measures and adjusts energy levels in the laser pulse from creation to delivery. High-speed eye tracking charts the eye’s movement 200 times per second. As a result, every laser pulse is completely controlled, allowing for the most accurate level of correction possible.
You can have peace of mind that the amount of energy in the laser has been calibrated to exactly the right level. After the beam has been created, it passes through three checkpoints on its way to your eye. At each of these points, the energy level is checked and adjusted if necessary, ensuring that the beam is perfectly attuned at its destination. The ALLEGRETTO WAVE® laser is essentially a precise, controlled beam of energy. The laser employs a proprietary overlapping method to ensure accurate laser placement, and is one of the ways that ALLEGRETTO WAVE® is able to achieve a rounder, more natural corneal surface than many other lasers used for vision correction.
The ALLEGRETTO WAVE® expands the boundaries of candidacy for LASIK. However, there are certain people who are less than ideal candidates for LASIK and ALLEGRETTO WAVE® treatment. Wavelight Allegretto Excimer Laser System Allegretto Wave
The ALLEGRETTO WAVE™ is capable of producing some of the largest available optical zones. The optical zone refers to the portion of the cornea that has been corrected by the laser. A larger optical zone is especially important for night vision and for patients with very large pupils. If a patient’s pupil is larger than the optical zone, they may experience poor peripheral vision, poor night vision, and a higher than normal incidence of “halos” and glare. In the past, this has been one of the biggest drawbacks to conventional laser correction surgery. Wavefront Optimized™ technology built into the ALLEGRETTO WAVE® addresses this limitation.
At night and in dark conditions, the pupil becomes larger to permit the maximum amount of light to enter the eye. Laser eye correction needs to take this fact into account. If the optical zone is smaller than the size of the pupil at its largest, there is a good chance that the patient will experience poor night vision or problems with glare and halos around bright objects such as oncoming headlights. ALLEGRETTO WAVE® is able to produce a larger optical zone, virtually eliminating glare and night vision problems associated with older generation lasers.
One of the most innovative features of the ALLEGRETTO WAVE® is the way it uses Wavefront Optimized™ technology to automatically compensate for the curvature of the cornea. In earlier laser correction systems, the “optical zone,” or area of correction, was centered on the front of the cornea; the result was a flattened circular area that ended with an abrupt edge, causing unwanted side effects like poor night vision, glare, and halos. The ALLEGRETTO WAVE® changes all that. The ALLEGRETTO WAVE® sends extra pulses to the peripheral corneal area in order to compensate for the angle of the laser beam.
In this manner, the aspherical shape of the cornea is preserved to a degree that older lasers simply could not achieve. This compensation, combined with the incredibly small, 1mm size of the laser, produces a smooth, effective optical zone that results in what can only be described as seeing like never before.
Imagine a glass ball. If you took a flashlight and aimed it directly at the top of the ball, the light would form a circular shape on the surface of the ball. If you now aimed the flashlight towards the side of the ball, the light would form an elliptical shape and not seem as bright anymore. This is because the same amount of light is suddenly distributed over a larger area, and some of the light is reflected away due to the angled surface of the glass ball.
You are encouraged to speak with your doctor to find the best vision correction alternative if:
- You are under 18. In this case, your growth phase has not been fully completed, meaning that your eyes can still change. In that case, LASIK is not a good option.
- You are pregnant or nursing. Pregnancy causes changes to your hormonal system. This can also cause your vision to change. It is therefore better to wait until your child is born and you have finished nursing.
- You have keratoconus, a corneal irregularity.
- You have glaucoma or high blood pressure.
- You have inflammation of the eye (uveitis, blepharitis or iritis)
- Your eyes have been infected by herpes simplex.
- You have suffered previous severe injuries on the eye.
- You have large corneal scars or infections.
- You are taking certain medications.
- You suffer from other diseases of the eye such as AMD, diabetic retinopathy, cataract, or others.
If you have any of the following, careful attention must be made
– Very large pupils
– Thin corneas
– Dry eye
– Unstable refractive errors- During the consultation with your doctor, please be sure to mention all medications you are taking and any medical conditions you have that might affect the success of laser correction. A great source for information about LASIK and questions to ask your physician is the FDA website and the website of the American Society of Cataract and Refractive Surgery.
Ziemer LASIK
FEMTO LDV Z6 means ultimate femto technology for corneal surgery. It is a real breakthrough in femtosecond laser technology. Innovative improvements, from the laser source to the architecture, enables surgeons to perform perfect lamellar and penetrating keratoplasties, intracorneal rings and pockets, Z-LASIK and Z-LASIK Z as well as clear coroneal incisions and arcuate incisions. LASIK procedures have been helping millions of patients improve their visual acuity for decades thru various refractive methods; designed to correct astigmatism (distorted and/or blurred vision), myopia (nearsightedness), hyperopia (farsightedness), and presbyopia (degenerative focal ability), the need to wear eyeglasses and/or contact lenses has been dramatically reduced. Though a select number of LASIK treatments have been deemed highly effective in minimizing or eradicating the above-mentioned eye conditions, the cutting tools of the trade have been replaced by two different bladeless options: Z-LASIK, and Z-LASIK Crystal plus. Z-LASIK is a two-tiered process that involves the use of a femtosecond laser, which is capable of creating a thin layered corneal flap in a timely fashion.
The flap itself is then carefully peeled back and prepped for the second phase, which requires a specialized laser to treat the affected corneal tissue. While this may seem like a time-consuming endeavor, it only takes but a few seconds to make the necessary repairs. The flap is placed back onto the corneal area and will adhere to it naturally.
The Z-LASIK Crystal plus procedure possesses the latest femto laser technology available, and is up 100 times faster than any other method on the market today. Created by Ziemer, the FEMTO LDV Crystal Line has already gained a reputation for being the most precise and minimally invasive practice to date. In many cases, correctable vision is restored immediately following the procedure, as to where some patients will regain their visual acuity within a 24-hour period. The bladeless technology used allows for quicker healing periods and mitigating complications as well.
While both of these visual correction methods are predominantly proficient, it’s also important to know the potential risks involved. Fortunately, enough, most of the side-effects from Z-LASIK and Z-LASIK Crystal plus are temporary and should subside within a few days to a few weeks, yet extreme cases can last from three to six months. Some of the reported symptoms include dry eyes, seeing halos, experiencing glare and light sensitivity, hazy vision, reduced sharpness in vision, and difficulty seeing in dimly lit areas or while driving at night. If one or more of these issues fail to be resolved within the allotted time frames, follow-up appointments should be able to determine what courses of action need to be taken.
A very small percentage of LASIK patients will experience extended side-effects, which may depend upon other pre-existing factors prior to either of these procedures; in other words, LASIK treatment is not for everyone. Those who have pre-existing eye conditions such as macular degeneration or retinopathy may not benefit from LASIK, as well as those whose corneas are too thin, or having large pupils can also pose a number of risks. Even though these LASIK treatments are outpatient procedures usually lasting less than an hour, it’s important to comply with post-op instructions to ensure the best possible outcomes.
Zeimer FEMTO LDV Z8 Laser
The Femto LDV Z8 (Ziemer Ophthalmic Systems AG, Port, Switzerland) is a high-frequency femtosecond laser system for corneal surgery, corneal refractive surgery, and cataract surgery. Unique among cataract laser systems, the Z8 applies the concept of overlapping low-energy near-infrared (1030 nm) femtosecond laser pulses in the nano-Joule range. This concept was originally developed by Ziemer Ophthalmic Systems for corneal surgery but was later adapted for cataract surgery applications such as lens fragmentation, capsulotomy, clear corneal incisions, and arcuate incisions. In order to shorten surgery time because small spots with large numerical aperture are used, the laser system runs in the MHz range applying up to 1 billion pulses per surgery. Conventional femtosecond lasers with small numerical apertures that run in the kHz range, leads to a larger spot with a higher pulse energy and more gas creation.
Each pulse creates a cavitation bubble approximately a few microns wide, which gently separates tissue. The handpiece is the size of a compact camera and integrates all required electronics, optics, and actuators to perform visualization and resection in the anterior chamber of the eye. Visual resolution is possible down to 5 microns and is performed with a combination of a color camera and spectral-domain optical coherence tomography (OCT) operated at 840 nm
The FEMTO LDV Z8 uses a high focusing power microscope lens integrated in the handpiece to achieve focusing to a small spot size (<2 μm), which enables cuts to be made with nJ pulse energy. Low pulse energy with high-frequency applications is very precise and allows a spot diameter of less than 2 μm . Conventional femtosecond lasers with a small numerical aperture and pulse energies in the µJ range has spot diameters greater than 5 μm and spot separation greater than the spot diameter (typically 10–20 μm), which can lead to tissue bridges.
Given this unique combination of technical parameters, FLACS is able to create a more precise and circular capsulorhexis that could improve phacoemulsification and IOL centration, so a more precise refractive outcome after surgery could be expected
Expectations After Surgery
Immediately after the surgery the PRK procedure, you will sit with your eyes closed for about thirty minutes. Your doctor (the ophthalmologist/surgeon) will examine your eye. You should expect blurry vision and possibly some pain or discomfort, but medication will be given. The feeling has often been described as “increased sensitivity”. Do not rub your eyes for the duration of your recovery for the next several months.What to Expect After LASIK Surgery?
Your procedure will take less than 10 minutes for both eyes and will be minimally uncomfortable. As soon as you sit up right after surgery, you will be able to see distances that you could not see before. However, your vision will be “foggy” for the rest of the day. You may experience discomfort in your eyes for about 4-6 hours. Closing your eyes, combined with regularly applying lubricating drops to the eyes is the best remedy for discomfort.
When you wake up in the morning, your eyes will feel normal with no or little discomfort and your vision will be clearer. It will continue to improve over time. It is common for patients to see halos and starbursts around lights when they are driving at night. This generally disappears in a few weeks.As with any kind of eye surgery, it’s important that you follow your doctor’s instructions to the letter. Get proper rest, use all prescribed medications as directed and call your doctor immediately if you suspect a problem.
Immediately after PRK, the doctor will have you rest for a bit, then you can go home (someone else must drive). At home, you should relax for at least a few hours.
You may be able to go to work the next day, but many doctors advise a couple of days of rest instead. They also recommend no strenuous exercise for up to a week, since this can traumatize the eye and affect healing. Avoid rubbing your eye (your doctor will tell you how long). Your surgeon or general eye doctor will examine your eye the day after surgery and several times thereafter to make sure the epithelium is healing properly. You probably will wear a special “bandage” contact lens, use antibiotic drops for a few days and apply anti-inflammatory drops for several weeks. Your surgeon also will prescribe medication to reduce eye discomfort that you are likely to experience the first few days after PRK surgery.
PRK and LASIK outcomes typically are similar. Most people achieve 20/20 or better vision with PRK (also true of LASIK). Some may achieve only 20/40 or not quite as good. In fact, 20/40 is fairly good vision — considered good enough for driving in most states. Some patients still may need eyeglasses or contact lenses following laser vision correction, though their prescription level will be much lower than before.
Postoperative PRK and LASIK complications can include infection and/or night glare (starbursts or halos that are most noticeable when you’re viewing lights at night, such as while you’re driving). Even if you see 20/20 or better on an eye chart after laser eye surgery, you still may need reading glasses once you hit your 40s. This is because the eye’s lens becomes less flexible with age (a condition called presbyopia), reducing your near vision.
Bladeless LASIK
In bladeless or all-laser LASIK for corrective eye surgery, lasers have replaced mechanical cutting tools (microkeratome) associated with conventional LASIK. Instead, bladeless LASIK uses two different kinds of lasers:
Femtosecond laser: This laser directs laser energy precisely to create a thin, hinged flap, which then is lifted temporarily from the eye’s surface or cornea.
- Excimer laser: Energy from this type of laser is applied to the newly exposed eye surface, where tissue is removed in a precise pattern to alter the cornea’s shape.
How Bladeless LASIK Works
The LASIK surgeon uses computer software to guide the femtosecond laser beam, which applies a series of tiny bubbles within the central layer of the cornea. The resulting corneal flap is created at a precise depth and diameter pre-determined by the surgeon. As occurs with a mechanical microkeratome, a small section of tissue at one edge of the flap is left uncut, forming a hinge that allows the surgeon to fold back the flap so the cornea can be accessed and reshaped for vision correction.
How Bladeless LASIK Compares With Blade Flap LASIK
With bladeless LASIK, people with thin corneas who once were deemed unsuitable for LASIK may now be candidates. Most people have corneas that are between 500 and 600 microns thick. To maintain corneal stability and avoid serious LASIK complications such as ectasia, surgeons want to leave as much corneal thickness under the flap as possible. So, generally speaking, the thinner the corneal flap the better, because this leaves a greater amount of corneal tissue under the flap for treatment.Most microkeratomes previously cut flaps that generally ranged in thickness from 140 to 180 microns. Femtosecond lasers, on the other hand, can create flaps as thin as 100 microns. So at one time, bladeless LASIK had a distinct advantage over microkeratomes in terms of the ability to make thinner flaps. This meant that people with thinner-than-average corneas who may not have been good candidates for conventional LASIK could safely have all-laser LASIK performed on their eyes.
You may be able to go to work the next day, but many doctors advise a couple of days of rest instead. They also recommend no strenuous exercise for up to a week, since this can traumatize the eye and affect healing. Avoid rubbing your eye (your doctor will tell you how long). Your surgeon or general eye doctor will examine your eye the day after surgery and several times thereafter to make sure the epithelium is healing properly. You probably will wear a special “bandage” contact lens, use antibiotic drops for a few days and apply anti-inflammatory drops for several weeks. Your surgeon also will prescribe medication to reduce eye discomfort that you are likely to experience the first few days after PRK surgery.
PRK and LASIK outcomes typically are similar. Most people achieve 20/20 or better vision with PRK (also true of LASIK). Some may achieve only 20/40 or not quite as good. In fact, 20/40 is fairly good vision — considered good enough for driving in most states. Some patients still may need eyeglasses or contact lenses following laser vision correction, though their prescription level will be much lower than before.
Postoperative PRK and LASIK complications can include infection and/or night glare (starbursts or halos that are most noticeable when you’re viewing lights at night, such as while you’re driving). Even if you see 20/20 or better on an eye chart after laser eye surgery, you still may need reading glasses once you hit your 40s. This is because the eye’s lens becomes less flexible with age (a condition called presbyopia), reducing your near vision.
What to Expect Before Surgery
Who is a Candidate for LASIK Eye Surgery?
Your doctor will probably ask you to follow a few simple directions leading up to your LASIK eye surgery, including:
- If you currently wear contact lenses, you will likely be asked not to wear them for two to four weeks prior to your procedure. Contact lenses can change the shape of your corneas, so you’ll want to keep them out long enough for your corneas to assume their natural shape.
- Keep your eyes free of debris. Your doctor may ask you to avoid using creams, make-up, or perfumes at least a day in advance of the procedure.
- Your doctor may recommend that you wash the area surrounding your eyes with a mild cleanser (such as baby shampoo) for a few days prior to the procedure.