Tutorial to Laser Vision Correction Parramatta, Sydney

Understanding options with Vision Correction Eye Surgery Parramatta, Sydney

To understand all of your options, it could take you a very long period of research.

You will be subjected to a barrage of information along the way.

Our practice is a middle-sized clinic which offers friendly personalised attention. You must choose a clinic style that suits you and a surgeon who you can relate to.

The aim of this section is to compress all of your research into one ten minute session with a pithy, factual and frank summary.

Laser Vision Correction Eye Surgery in Parramatta, Sydney

Dr Lim, Dr Thomson and Dr Sumich are well known and respected eye surgeons and will guide you to the best decision at your consultation. We are passionately interested in getting the best results for our patients and we will do all the hard work - but it is important that you understand some of the basic concepts to inform yourself of the various options you might wish to explore.

You will be ready to make an appointment with us after this basic introduction.

What is Lasik surgery?

Go to our LASIK Educational Module for a quick impression of the LASIK technique.

Am I suitable for LASIK Surgery?

You are suitable if you are:

  • 20 years or older
  • A stable refraction for several years
  • Normal and healthy eyes except for the need to wear glasses or contact lenses
  • Myopic (short sighted), Hyperopic (long sighted), Presbyopic (reading glasses) or astigmatic (distorted and "stretched" images)

Understanding Refractive Spectacle Error Terminology:

  • Myopia = short sighted = need negative spectacles = can't see in the distance. Usually from a young age.
  • Hyperopia = long sighted = need positive spectacles = good distance vision when young but worse distance with age.
  • Presbyopia = loss of near vision requiring reading glasses at age 45. Earlier onset if hyperopia present.
  • Astigmatism = abnormally shaped cornea which breaks up the light rays and causes poor vision. Some rays go short and some go long.

The Basics of Laser Vision Correction:

The aim of Excimer Laser treatments is to reshape the front of your cornea to be a better focusing lens - in place of your glasses.

All of the laser treatments mentioned below have this reshaping feature in common.

The major visual aim is for independence from wearing spectacles on a day to day basis. This has special relevance to patients who are totally dependent on their glasses just to get around. Our results show that 98% will end up 6/12 (20/40) or better and of these 98% there will be 90% who end up with 6/6 (20/20) vision or better. Therefore it is largely a very successful operation. Some patients still find that a "fine tuning" pair of weak spectacles is necessary for demanding tasks such as night driving, but they are free of spectacles for everyday activities like walking, working, swimming and going out with friends.

Be realistic and avoid slick or sensational advertising with promises of "supervision" and "bargain prices".

The Technology Behind Vision Correction Eye Surgery:

Every different surgeon providing Laser Vision Correction Eye Surgery has their own laser technology and a good argument as to why they are using this technology.

Most surgeons use Lasers made by: VISX , Ladarvision, Technolas, MEL80 or Wavelight and all are very good technologies.

Don't get too sidetracked with understanding the technology because it changes constantly and not even eye surgeons can agree amongst themselves which technologies are best. The truth is that all of the popular technologies are of excellent quality, with little to choose between them. The rest is all marketing hype.

It is like trying to compare a BMW versus a Mercedes Benz. They are all of very high standard and it comes down to personal choice.

Your time is better spent understanding the surgical choices you are making and appreciating the pros and cons of surgery.

PRK / LASEK / EpiLASEK / ASLA / Bladeless Laser / Nulase

These are all surface laser techniques which use no blade and create no corneal flap. The different names above are a testament to the confusion that marketting can cause.

10 years ago, this was the only laser reshaping available and was applied directly to the surface of the cornea after the skin (epithelium) of the eye was removed. There was no LASIK flap created because the techniques for making flaps were not accurate enough in those early days. This was called PRK. It fell out of favour because the resultant ulceration was uncomfortable and took several days to heal. Visual recovery was slow - taking a week or two as the cornea healed. Also, because the healing response of the eye varies between people, the final results were difficult to estimate.Patients occasionally experienced hazy vision and more chance of scarring and regression (slip-back towards the old spectacle error).

It fell from favour and was largely replaced by LASIK in the late 1990's.

However, with improvements in excimer laser technology, faster computer software and understanding of corneal wound healing, this PRK / Surface method improved greatly and has had a renaissance. It is now used in approximately 10-20% of cases. The results are equal to LASIK but the recovery takes a week longer and most patients still notice a stinging sensation similar to cutting onions, hence the uptake by only 10-20% of patients despite the safety advantages of no flap creation.

If the skin (epithelium) is replaced onto the eye afterwards, it gets called LASEK (note the similarity to the word LASIK). ASLA was developed as a term to replace PRK due to the negative connotations of the original PRK.

LASIK (Laser in situ Keratomileusis)

Laser vision correction eye surgery Parramatta/sydney,

With LASIK, a very thin sliver, called a “flap” is created using a laser called “intralase” - as shown above.

The shave is not completed right across the cornea, thus creating a thin hinge upon which the sliver (flap) can be folded back to expose the 'stroma' of the cornea.

The laser is applied to this exposed stroma and then the flap is closed to restore the normal surface of the eye.

Imagine shaving the curved edge of an apple with a knife and not completing your cut - thus leaving a little apple skin.

This apple skin can act as a hinge, to open an "apple trapdoor". If this was the eye, the laser is then applied to the apple inside with the flap opened and then the trapdoor is closed to complete the apple again. Thus the laser is performed "under the surface" of the apple with its normal appearance restored when the flap is replaced.

This makes LASIK essentially painless and provides a faster visual recovery (2-7 days with LASIK compared with 1-2 weeks with PRK / LASEK ).

It all sounds too good - there must be some disadvantages to LASIK!

The main disadvantage of LASIK is the thin flap itself. Whilst it usually flops straight back into position, there is the rare case of "flap slippage" after the patient has gone home, which can cause a wrinkle in the flap. This is why you are asked to close your eyes after the procedure and rest quietly. You must never rub your eyes in the early post operative period. If the flap does slip, it has to be re-lifted and laid down neatly to flatten it out. Usually this can be done with no detrimental effects to your vision. Other possible complications with the flap include a "free flap" where the shaver doesn't stop in time and there is no hinge created. Therefore the thin sliver is free without a hinge. In the rare occurrence of a "free flap", the surgeon may simply replace the flap gently and may choose not to perform the laser operation. ie. "Live again to fight another day" or else the patient and surgeon might agree that no further surgery should occur and it's back to wearing glasses again with no harm done. Another rare event is an inflammation process which occurs within the thin space between the flap and the stroma. This is called DLK or "Sands of the Sahara" and is usually mild and responsive to steroid eye drops.

Overall, flap complications account for problems in 1-2 % of patients in which their best spectacle corrected vision is reduced by one or two reading lines from the level it was preoperatively.

These concerns are the reason that 10-20% of patients still choose to have PRK / LASEK (no flap technique) instead of LASIK despite the slightly longer recovery time and the slight discomfort with PRK / LASEK.

The other disadvantage of LASIK is that the creation of the flap can weaken the cornea and cause a condition called kerectasia (keratoconus). This usually occurs only in patients who already have an inborn predisposition to this condition. We screen patients thoroughly for this predisposition during the clinical assessment and can nearly always screen out the patients who are at risk. Unfortunately, not every patient who will ultimately develop kerectasia is detectable in the earliest stages and therefore it is a possibility that kerectasia could develop in the years following Lasik surgery and could infact be hastened by having had the surgery. Kerectasia can badly harm the vision and may require a corneal transplant operation to repair the vision if it becomes severe. Again, this is a good reason to have surface treatment instead of Lasik if you are concerned about this theoretical risk.

Vision Correction Eye Surgery Sydney


Laser Vision correction has passed the 10 Million patient mark worldwide.

Results are excellent with over 90% of patients achieving 6/6 vision (= the old 20/20) without the need for spectacles.

98% of patients are sufficiently improved that even without spectacles they are living their every day life such as walking, working, swimming and going out with friends.

The chances of a visually significant problem are 1-2% but the problem is only rarely severe (loss of more than 2 lines of spectacle vision).

The statistical chances are that you will have a great result. However, patients have the right to know of any down-side to help in their decision making. It is similar to taking advice from an accountant - you have to trust him but you should at least understand the basics of his final advice. Therefore it is important to remember that there are never any guarantees in medicine or surgery because the human body is sometimes unpredictable.

We would be most grateful for your feedback on this quick tutorial and whether it was useful to you.

If you wish to for assessment we look forward to answering any questions you have.

Other important information:

The eye may continue to change over the years after the operation. The operation cannot make time stand still! Therefore we always ask you whether your eyes have been stable for the few years prior to the operation.

Reading glasses will still be needed in middle life when the eye loses its ability to focus on near objects. The exception to this is obviously the middle aged patients who are having the laser to treat their near vision reading problems in the first place.

Wavefront = Custom Treatment: The use of a special instrument (aberrometer) to specifically analyse the finest abnormalities of your eye. The instrument gets a "fingerprint" of your finest abnormalities and can fine-tune the laser treatment. Reduces the chances of night glare. Is used in patients with large pupils, large corrections requiring treatment but is "tissue hungry" and requires the laser to shave deeper, thus weakening the cornea more. Used as a standard in some centres but we tend to be selective in our use of this technology, treating only the patients in whom it will make a significant difference to visual outcomes.

Other possible problems after laser surgery:

Dry eye: moreso with LASIK than PRK / LASEK - often improves after 6 months and requires tear supplements. A common post operative problem.

Night glare: especially if large pupils or a large spectacle error is being treated. Can be treated with eye drops. May need night spectacles. Seen less with Wavefront treatments.

Alternatives to Laser Vision Correction:

Clear lensectomy

This procedure is exactly the same as a cataract operation which is used to remove the cloudy lens from older patients. The natural lens is replaced with an ocular implant of a power similar to your spectacles. Therefore your glasses are worn "inside your eye". It is not the first choice operation because the potential for risk to the eye is greater than Laser Vision Correction but can be used in some patients who are outside of the range for Laser.

Conductive Keratoplasty (CK)

A newer technique which involves reshaping the cornea with a heating electrical radio current. Carries little risk of serious eye damage and is simple to perform. Used mainly as a treatment for reading glasses but suffers from some early over correction tendencies and a wearing off of effect over time. May cause some astigmatism in some patients. It is still finding its place in the surgeon's kit bag. Some surgeons swear by it and others are not impressed. Some patients are ecstatic and others are less happy. With mixed reviews like this we are choosing to observe this technology for a little longer before offering it.

If you are looking for eye treatment like Vision Correction Eye Surgery in Parramatta, Sydney; feel free to contact "Hunter Eye".

Hunter Street Lasik Laser Eye Specialists are located in Parramatta. We are an eye clinic specialising in Lasik Laser Eye Surgery, Advanced Cataract surgery, Laser Vision Correction and Lasik eye procedures. Hunter Street Laser Eye Surgery is located in Parramatta Sydney Australia