Laser eye surgery

See as nature intended with the very latest laser eye surgery at Auckland Eye.

Millions of people worldwide have experienced the freedom provided by laser eye surgery which is one of the safest eye procedures available. There are different types of laser eye surgery, the most common one being Intralase LASIK, and for those people with thinner corneas, PRK is an alternative procedure. The advantage of laser eye surgery at Auckland Eye is no matter what the recommended procedure, it is 100% customised for you. This means you can be assured of the best possible visual outcome from the most up-to-date technology available today.

You only have one pair of eyes and we know laser eye surgery is a big decision. Auckland Eye is not only the first clinic in New Zealand to perform LASIK, we are also the only accredited LASIK centre nationwide, so your choice is simple.

How does laser eye surgery work?

All types of laser eye surgery work by re-shaping the front surface of the eye, the cornea. For laser candidates, laser eye surgery will in most cases remove almost all of the eye's distance focusing error and most people will have no need to wear glasses or contact lenses for clear distance vision. 95% of typical patients achieve 20/40 (6/12) or better vision.

The laser removes small amounts of tissue from the cornea in an extremely precise manner, to sculpt a new surface that enables your eye to form a clear image on the retina, much like a camera that has been perfectly focused.

The entire procedure is painless and very fast - less than 15 minutes, during which use of the laser beam lasts between 30 - 90 seconds per eye.

Whilst there are many confusing terms to describe laser eye surgery, there are only two ways that this is done:

1. Surface treatment - also known as PRK, custom surface, ASA or LASEK

• All describe a similar process, where the very top layer of the front surface of the eye (cornea) is removed and the laser reshapes the exposed layer immediately below. The top layer then grows back over the newly shaped surface.

2. LASIK - also known as Lamellar surgery

• This technique has the advantage of not disturbing the very top layer of the cornea. Instead, a flap is created and lifted away to expose the layer immediately below, which is reshaped by the laser. The flap is then replaced on top of the reshaped surface.

What is "custom" or "personalised" LASIK?

Traditionally non custom laser, LASIK or PRK, fires many hundreds of small spots which overlap by different amounts to create a new surface to replicate the focusing pattern of the glasses or contact lenses. This system is called plantoscan.

At Auckland Eye we have the advantage of providing traditional LASIK, and where best suited, 'custom' or our 'personalised' LASIK known as 'wavefront guided' or 'zyoptix'. Using this procedure laser spot positions are not determined by the glasses/contact lenses alone. Instead measurements are made of the whole focusing system by a machine called an aberrometer. Where appropriate, this personalised system has advantages. Our surgeons who are experienced with these methods will recommend the best type of treatment for you.

What is PRK (Photo-refractive keratectomy)?

During PRK, no corneal flap is made making it suitable for people with thin corneas

• Low to moderate myopia
• A thin cornea
• Low astigmatism
• Previous laser eye/refractive surgery

Some disadvantages of surface treatment are:

• Moderate discomfort for 2-4 days
• Relatively slow vision recovery, usually 2-4 weeks
• More variable visual outcomes due to skin healing variability
• Necessity for drops for 2-3 months

What is LASIK (Laser assisted in-situ keratomileusis)?

The more recently developed LASIK creates a flap, which is lifted to allow reshaping of the cornea just below the surface. Once the flap has been created the laser then uses a cool ultraviolet light to remove the corneal tissue by breaking the molecular bonds within the cells allowing exceptional accuracy and with no significant damage to surrounding tissue. LASIK has become the most commonly used method of laser eye surgery. It offers two principal advantages over PRK; it can treat a much wider range of refractive errors and postoperative recovery time is significantly faster. For the right candidate, LASIK provides a new perspective in vision correction.

Step 1 Flap is created and folded away from the central cornea	Step 2 Excimer laser reshapes the cornea
Step 3 Cornea flap is replaced	Step 4 LASIK surgery is complete

Step 1:
The corneal flap is created exposing the inner layers of the cornea. This takes about 30 seconds.

Step 2:
The excimer laser is used to reshape the cornea. This takes between 30-90 seconds and is totally painless. For nearsightedness reshaping takes place in the central area to flatten the cornea, for farsightedness reshaping takes place on the edges to enhance its curve and with astigmatism reshaping target various locations to improve uniformity of the cornea's shape.

Step 3:
The corneal flap is replaced over the reshaped cornea so that there is little or no postoperative discomfort. Within three minutes the flap is securely attached and the procedure is over. There is no need for stitches as the flap bonds so quickly.

Step 4:
Refractive surgery is complete.

LASIK has advantages over other procedures:

• A relative lack of discomfort afterwards
• Improved healing - good vision is usually achieved almost immediately or at least by the very next day
• Eyedrops are usually discontinued after one week.

Some disadvantages of LASIK treatment are:

• Flap complications during surgery can mean deferring the surgery to another date whilst the cornea heals
• Not everyone can have LASIK as it is dependent on the thickness of the cornea.

More about personalised LASIK

At Auckland Eye as part of our 'personalised approach to patient care' we offer, and use, the latest wavefront (custom) technology to deliver an individualised treatment plan for each patient. Wavefront technology offers a new level of diagnosis and treatment for people with nearsightedness, farsightedness and astigmatism.

The benefits are provided via three key components of the Wavefront system:

• The WavePrint map - reveals the way your entire optical system works, rather than just the corneal surface, allowing for a more precise and more detailed analysis of your vision
• Variable spot scanning - allows for a larger treatment area, offering greater flexibility in developing a more personalised laser vision correction, especially with large pupil sizes, which can reduce quality of vision in low lighting
• The 3D active trak - follows the tiny motions of your eye, repositioning the laser to ensure accuracy.

Our WavePrint system offers an individual treatment plan for each patient designed especially for you - hence the term 'custom'. It is the fingerprint of your eye, as no two are the same.

Benefits of Wavefront treatment:

1. More likely to achieve clearer vision (20/20 or better)
2. Reduces likelihood of glare and halos at night
3. Ability to offer treatment to patients with larger pupils and thinner corneas
4. Removes less tissue thereby reducing the risk of complications.

IntraLase ^® LASIK

Auckland Eye is pleased to introduce IntraLase LASIK technology as part of the life-changing experience of laser vision correction. The IntraLase Method™ delivers enhanced comfort, safety and visual outcomes for patients.

As of Oct. 14, 2005 half-million blade-free (IntraLase) LASIK vision correction procedures had been performed.

How LASIK with the IntraLase method™ works

The IntraLase laser is used to create the corneal flap, the important first step of the LASIK procedure. The second step involves reshaping the cornea with an excimer laser. Historically, the first step was performed using a blade (microkeratome). While this has proven to be a very safe and successful procedure, the majority of complications have been associated with use of the microkeratome. Creating the flap with IntraLase eliminates these associated risks.

With the IntraLase method, tiny pulses of laser light pass harmlessly through the outer surface of the cornea, forming a uniform layer of microscopic bubbles just under the surface. Your doctor determines the exact dimensions of the bubble layer and this is all computer controlled for maximum precision. The doctor is then able to gently separate the layers, creating the flap. The cornea is then reshaped with the excimer laser. When the LASIK is complete, the flap 'locks' back into place due to its precise shape and your eye heals very quickly.

Benefits of IntraLase ^® LASIK:

• Provides a 100% blade-free LASIK procedure
• More patients achieved vision 20/20 or better ¹
• Better quality of vision overall, particularly in low light such as at dusk or at night ²
• Customised corneal flap based on what's best for the patient's eyes

When only the best will do, choose IntraLase ^® LASIK at Auckland Eye

Auckland Eye is the only laser eye centre in New Zealand with quality accreditation, providing the highest standards of patient care. IntraLase is part of our commitment to placing your care and outcomes first and foremost.

References
[1] Tanzer DJ, Schallhorn SC, Brown MC, et al. Data on file, IntraLase Corp. 2005
[2] Durrie D. Data on file, IntraLase Corp. 2005

How does the eye function?

Emmetropia (20/20 vision, perfect vision)

This is how a perfect eye "works". The light comes in through the cornea which focuses the light rays through the lens inside the eye and then onto the retina. The retina acts like the film in a camera and is responsible for the picture you see. The light hits the "macula", a special area of the retina that is "built" to see fine detail (i.e. 20/20 vision). If the light hits the macula in perfect focus, you will see 20/20 or better on the doctor's chart.

The way light is focused by the eye is a major factor in determining the quality of vision. Three factors are important:

1. The curvature of the cornea
2. The power of the lens
3. The length of the eye.

When these three elements are correctly balanced, light focuses on the retina giving clear vision. When not balanced correctly, as is the case for millions of people, a refractive (focusing) error occurs resulting in blurry vision for distance and/or near.

What is 20/20 vision?

This is an arbitrary state of vision that is deemed as excellent or normal vision. In New Zealand we call this vision 6/6, vision being measured at a distance of six metres rather than 20 feet as in the United States. Vision is expressed as a fraction, and the closer the numbers the better the vision, i.e. 6/6 and 20/20 are equal to 1. Any different fraction represents better than or worse than normal excellent vision, for example, vision representing a fraction of less than 0.5, or 20/40, or 6/12, is deemed unsatisfactory for legal driving.

What are the eye problems that laser surgery can fix?

Myopia (nearsightedness)

Myopia affects one in four New Zealanders. Myopia occurs when the eye is larger than the "perfect eye." Light rays are focused in front of the retina instead of directly on the retina (see picture). Distance vision is more blurred than near. Laser eye surgery can usually correct or significantly reduce myopia by flattening or removing tissue from the centre of the cornea.

Hyperopia (farsightedness)

Hyperopia results from eyes that are smaller than the "perfect eye," causing light rays to fall past the retina (see picture). Near vision is sometimes more blurred than distance. Farsightedness is a distance vision problem and should not be confused with Presbyopia, which is the need for reading glasses after about 40 years of age (see below). Laser surgery can significantly improve hyperopia through the removal of tissue around the centre of the cornea. Frequently farsightedness may be undiagnosed when younger because the eye's focusing system can overcome the problem. However, later in life the eye's focusing system loses its ability to overcome the error, and vision becomes blurry, first for near, then later for distance.

Astigmatism

Astigmatism is caused by a difference in the curvatures of the cornea (or lens). While a perfect eye is round like a soccer ball, an eye with astigmatism is shaped more like a rugby ball. Light rays are focused at more than one point on the retina. This results
in the retina's inability to clearly focus the image. Astigmatism is an additional cause of blurring which may occur on its own, or with near or farsightedness.

Presbyopia

A normal part of the aging process is a gradual weakening of the eye's near-focusing ability. This is caused by changes in the lens and the muscles which move it. Presbyopia makes reading and other close visual work increasingly difficult with the consequent need for reading glasses or bifocals. This occurs in all individuals, meaning that when the distance vision is fully corrected in both eyes everyone will require glasses for near vision by around the age of 45-50. There are some ways to overcome this:

• Being near-sighted: People with near-sightedness will almost always have clear vision at a point close to them without the need for glasses. As they get older, they just take their glasses off for near and wear them for distance. Some people find this a satisfactory solution to presbyopia
• Monovision: This is where one eye is shortsighted, and the other has no distance focusing error. Some people have this state naturally, but it can be attained with contact lenses, and with laser surgery in suitable candidates. Ideally patients will try the contact lens correction as a "trial" before proceeding with laser surgery. Typically this will require a period of "adaptation" which usually lasts 2-6 weeks.

Solutions for eye focusing problems

• Glasses are a proven safe method of accurately correcting vision, although they have some disadvantages
• Contact lenses provide more normal vision, but with a small risk of complications such as infection. If you simply want to avoid glasses, and have not tried contact lenses recently, then you could see your optometrist to arrange a trial of contact lenses in the latest designs and materials
• Laser eye surgery now offers a relatively safe and effective method of vision correction for people over the age of 20 who have a stable focusing error.

Reasons for choosing laser surgery

• The inability to tolerate contact lenses
• The desire to have more normal vision without dependence on glasses especially in emergency situations
• An occupation requiring good unaided vision e.g. (pilot/aircrew/police)
• Glasses/contact lenses don't match your new image
• Glasses/contact lenses interfere with your working/sporting/family life
• To save money - over the years the cost of lenses, solutions and glasses amounts to thousands of dollars
• To avoid the negative consequences of long term contact lens wear.

Am I suitable for laser surgery?

Certain general health or eye health conditions may make PRK or LASIK inadvisable:

• Under the age of 20, where the eyes may not yet have stabilised
• Pregnancy or breast feeding
• Connective tissue disorders such as rheumatoid arthritis that may increase the risk of complications after surgery
• Systemic medications likely to affect wound healing such as corticosteroids or antimetabolites
• Keratoconus or other active corneal disease.

Auckland Eye offers a no obligation, free laser assessment.
To make an appointment, or if you have any questions about laser surgery, please call us free on 0800 NEW EYES (0800 63 93 93) or contact one of our friendly specialist team.