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Cataract Surgery

A cataract occurs when the natural, crystalline lens inside the eye becomes cloudy, affecting vision. Cataract usually occurs from the age of 60 upwards, although it can occur in younger adults and rarely even in children and babies.

Most cataracts are a result of the natural ageing of the eye.   From age 40 onwards, metabolic changes start occurring in the crystalline lens that cause it to take on water and become less flexible. The first signs of this are difficulty focusing on near objects – called presbyopia. Presbyopia occurs in everyone after a certain age and is corrected with glasses.

Eventually, these lens changes progress to the point where cloudy opacities develop in the lens which at first can cause difficulty with glare and driving at night, but eventually cause blurring and alteration of colour perception. This can only be improved through surgery.

 

Treatment

During cataract surgery, a fine ultrasound probe (less than 2mm in diameter) is inserted through a tiny opening in the cornea, and the cloudy lens is literally sucked out, leaving its’ supporting bag (or lens capsule) behind. A prosthetic lens is then inserted into the lens capsule to restore vision.

Cataract surgery takes 5-10 minutes using local anaesthetic. You can ask for light sedation if required.

The results of cataract surgery

Most people are thrilled with the results from cataract surgery. For most patients, vision improvement is experienced immediately or within the first day. Other patient’s vision will clear within the month, occasionally this may take longer. You will still need glasses to achieve best quality vision including reading.

Sometimes other eye disease, such as diseases of the macula hinder results. These conditions evade detection prior to your surgery due to the cataract obstructing the doctor’s ability to view your retina. Your doctor will perform OCT scans to gauge whether the macula will affect your vision after surgery.

After cataract surgery

After surgery you will have a shield over your eye. Your eye will feel irritated, you may have double vision or a slight discharge (this is treatable with lubrication drops). Your eye shouldn’t ach or throb.

Instructions will be given to you on how to care for your eye and you will be supplied with a month’s duration of drops. The doctor will see you one day after your operation and again over the next month.

Laser surgery may be required over the following months and years after as the membrane behind the lens can become cloudy (read about Posterior Capsule Opacity in our notes.)

Potential complications of cataract surgery

Complications post-surgery are rare. 2% of people require more intensive post operative care and less than 1% need further surgery to fix surgery complications.  Almost no patient ends up worse than before the surgery.  

 

However, without surgery, every eye with cataract will go blind eventually.  It is not a question of IF you need cataract surgery, but WHEN you do.

For the vast majority of patients, the benefits of cataract surgery can be experienced almost immediately and improve both independence and quality of life.

When is the best time to do cataract surgery?

 

The time to do cataract surgery usually depends on the patient. Initially we are waiting for the cataract to actually have an affect on the vision.   We help patients who have real problems with their vision to overcome these problems. 

 

Once Cataracts are starting, it is a question of when to do them, not if they will ever need to be done. They always get worse over time.  The natural history of cataract is blindness over time.   We do cataract surgery to prevent blindness and to improve the vision.  

 

Each individual patient is the best judge of when to have cataract surgery    At the most basic level, if a patient isn’t having a problem with the vision, then they do not need cataract surgery.  “If it ain’t broke, don’t fix it.”

 

Once the vision starts to drop and the cause is due to the cataract, that is when we offer cataract surgery.  Usually the patient sees the optometrist 1st to make sure the vision isn’t corrected with a simple update of glasses.  

 

It’s good advice not to delay cataract surgery. The longer patients delay surgery, the lesser the quality of surgical result, and the higher the complication risk.   With any severity of cataract surgery, the benefits outweigh the risks.   But the longer you wait, The risks increase and the benefits decrease.   

 

The BIG PICTURE of cataract surgery is this…we are doing it to stop you going blind from cataract, which is the natural history over time.  Without surgery, eventually, you have a 100% chance of blindness from your cataract.  With surgery, almost everyone avoids blindness, and gains vision.  

 

As a bonus, we restore your eyesight, reduce your need for glasses, and allow an updated pair of glasses to give you best possible vision.  This is the optical aims of cataract surgery.

 

The two steps to Best vision

Most people have some cataracts in both eyes. Therefore, both eyes need doing for best vision. Usually the two eyes are done fairly close together, often one or two weeks apart. The sooner we get the cataract surgery done, the sooner you are enjoying better vision. The final step is updating the glasses in both eyes. Absolute best vision always comes with an update of glasses.

 

Which Eye first?

Most patients expect that we do the poorer seeing eye first.  However, for almost all patients, there are cataracts in both eyes.  Therefore for most patients we do the dominant eye second. The first eye surgery is less accurate than the second eye, so we use the results of the first eye to optimise the second eye.  This is why we want the dominant eye to be the second eye that we do.  

 

As soon as we do one eye, almost all patients want us to do the second eye straight away. So because of the advantages of doing the dominant eye second, for almost all patients we plan to do the non-dominant eye first. The only exception is when there is no cataract in the non-dominant eye and in those patients we would do the dominant eye first.

 

It is a good idea to work with your optometrist BEFORE you develop cataract, to determine which eye is your dominant eye.  

Re-focussing the eyes with surgery, which intra-ocular lens, and other practical considerations.

 

Let’s be honest.  Most of us would like to NEVER need glasses.  Me too.  

 

However, there are basic truths about focussing of the eye, cataract and lens surgery, and the need for glasses, that all patients need to understand, if they are to be happy with the outcome of eye surgery.

 

Please read these notes carefully.  Please discuss with your optometrist and family, how you would like to see after eye surgery.  

 

Refocussing the eye with surgery

Focusing the eyes with cataract surgery is like focusing a telescope.    A telescope has a gross-focusing knob, and a fine-focusing knob.   Eye surgery resembles the gross-focussing knob, and glasses resemble the fine-focussing knob.   

The absolute best vision comes when you are young, and your eye can automatically refocus itself for all viewing distances, using the internal lens.  It is like an automatic focussing camera.  But once we age, we loose the ability to automatically refocus.  This is called PRESBYOPIA.  Optometrists fix this with PROGRESSIVE glasses.  

 

All eye surgery is good at grossly refocusing the eye. But fine-focusing is still best performed with updated glasses after cataract surgery.

 

No artificial lens in the eye focuses the eye perfectly.  Artificial lenses are different to the natural crystalline lenses you are born with.  

THERE IS NO INTRA-OCULAR LENS THAT IS AS GOOD AS THE PROGRESSIVE GLASSES THE OPTOMETRISTS CAN MAKE.  This is a very important point.  

 

After eye surgery, there is always some residual optical blur, that can be improved with glasses, regardless of what lens design the surgeon uses in the eye.   

 

What this means in practice is this -  most patients can drive a car without glasses and do most activities of daily living, such as working on the computer,  without glasses.   But for fine visual tasks such as knitting, needlework and the like, glasses will give absolute best vision.   

 

With eye surgery, we aim to reduce the need for glasses. But we cannot eliminate the need for glasses for every eye for every visual task for every viewing distance.

Which intra-ocular lens should you chose?

Please consider these facts about eye surgery, and discuss with your surgeon and optometrist.

  1. Lens surgery cannot perfectly refocus the eye.  We cannot perfectly measure, and therefore correct, the focus of the eye.    The artificial lenses used in eye surgery do not change or adjust their focus.    Therefore, after surgery, there is always some optical blurring, at difference viewing distances.

  2. Sometimes the optical blur, called refractive error, is unacceptable, and we need to change the intra-ocular lens for another power.

  3. Best-quality vision is always obtained with an update of glasses.  This applies for all viewing distances.  The focus of the eye drifts and changes over time.   Therefore, over time, most patients end up having glasses for best-quality vision, both for distance, intermediate, and near viewing.

  4. Having said this, most patients can do most visual activities most of the time without glasses.  Most of our patients can legally drive without glasses, and many can read in bright light conditions.  

  5. Most patients achieve best quality vision with single focus intra-ocular lenses.    We usually plan to do the non-dominant eye first.  In this eye, we aim for mild myopia (short-sightedness).  This can help the patient with intermediate and reading vision without glasses.    We then measure the first eye, and use the focusing result of the first eye (the refraction) in planning the second dominant eye, usually targeting clear distance vision.

  6. The focussing that we aim for is not always what we achieve, because of the variability and inaccuracy of cataract surgery, even when performed by the best surgeon, using the best machines.  Eyes are NOT perfectly predictable.  

  7. The modern multifocal glasses, sometimes called “variable” or “progressive lenses”, are the best way to achieve clear vision for all viewing distances.  However some patients cannot tolerate this lens design in their glasses.

  8. Single-focus lenses in the eye allow the best-quality vision, achieved with an updated pair of glasses after surgery.

  9. For patients wanting to minimise the need for glasses after eye surgery, (which is most of us, let’s be honest), there are various types of intra-ocular lenses designed to do this.    There are two basic categories.  Firstly, there are bifocal, or trifocal lenses, sometimes also called multifocal lenses.  Second, there are lenses called "extended-depth-of-single-focus" (EDOF) lenses.  All these lenses reduce the quality of vision, in a way that glasses cannot correct.  They reduce the need for glasses, but at the cost of reducing quality of vision.  This reduction of quality is most apparent in dim light conditions, such as driving at night.  Also to be really technical, they should be called "extended RANGE of focus" - the only true EDOF is a pinhole lens, which we sometimes use in patients with corneal distortion from disease such as keratoconus.  ​​

  10. When we use these multifocal or EDOF lenses, sometimes patients do not achieve the desired vision, and we need to replace them with single-focus lenses.  But we NEVER replace single-focus lenses with multi-focal or EDOF's. Floaters are often more obvious with these lenses, and floater treatment is more likely needed with vitrectomy surgery.

  11. All lenses work better in bright-light conditions.  In dim light, the vision is always reduced.  

  12. All surgical methods that aim to reduce the need for glasses after surgery, such as multifocal intra-ocular lenses, have the disadvantage of reducing best-quality vision

  13. Sometimes we can focus one eye for distance, and the other eye for near.  This is called mono vision.  This works best when patients already have this.  However, it can fail because one eye is always blurry, where ever the patient is looking.  This relies on the brain to ignore the blurry eye.  Some patients have this ability, but some (like me!) do not.  

  14. The best time to try the various refractive outcomes - mono vision, blended vision, multifocal lenses etc - is with contact lenses, BEFORE you develop cataract.  See your optometrist to discuss this.

  15. Many elderly patients have other eye diseases such as macula degeneration, and blepharitis.  In these patients, we always prefer single-focus lenses.

  16. Many patients who do not have other eye disease at the time of surgery, will develop other eye disease later on.  These patients are better off, had the original eye surgeon used single focus lenses.  

  17. In the United States of America, eye surgeons are paid considerably more to do surgery with EDOF’s or multifocal lenses.  So there is a strong international motivation to promote them, which influences the marketing that Australian patients may experience.  

So what lens is best for me?

This is an important conversation that every patient should have with their surgeon.  To assist you, please consider the notes and watch the movie above.  

Ask yourself these questions

1.  Are you a "best quality vision" person OR an "I hate glasses" person?

2.  Are you very physically active?

3. Do you drive at night, or do activities in dim light conditions?

4.  Do you mind wearing glasses when you need them for certain activities?

5. Do you understand that the focus of your eyes will drift and change throughout life, whatever the doctor achieves for you?

Which eye should have surgery first?

We prefer to do the non-dominant eye first. We use the refractive result, or the focusing result, from the first eye to then optimise the focusing for the second dominant eye.   We measure this usually one week after the first surgery.   This gives us the best chance for the clearest distance vision in the dominant eye without glasses.   

What about a "lazy eye"?

 

Some patients have one eye as a “lazy eye”, or weaker eye. We call this “amblyopia”.   

 

We prefer to do the weaker eye first even if it is poorly sighted. There are two reasons for this.    First, we usually improve the lazy eye.   Second, we obtain very useful information from the first eye surgery, that improves and makes safer surgery for the dominant second eye.  

When can I drive?

After cataract or lens-replacement surgery, most patients can resume driving within a day or two, when they feel safe to do so. This requires the vision to be "driving standard" or better (6/12 or better) in the operated eye.  But it also requires the two eyes to be balanced, with no double vision or ghosting.  

 

Imbalance between the two eyes prevents a patient returning to driving.  This often exists after the first eye is done, when patients are waiting for the second eye surgery.   This is one of the reasons why we schedule surgery for the two eyes closely, one or two weeks apart.  When there is significant imbalance, a temporary contact lenses fitted to the second eye by the optometrist, can sometimes help.

 

You must not drive unless you feel completely safe to do so, and you are meeting the legal standards to do so.  

 

Other conditions 

 

Cataract surgery is extremely good at fixing cataract.   Lens replacement surgery is very good at reducing refractive error, or optical blurring.

 

But it doesn’t fix other problems in the eye, which also commonly reduce the vision.  These are some of the very common conditions that also reduce the vision for patients.

 

  1. Dry eye and tear film dysfunction, often affected by blepharitis and rosacea, is extremely common.  Occasionally after cataract surgery, the ocular surface gets worse, and needs additional treatment.  If you notice things getting worse at any stage after eye surgery, contact your surgeon immediately, but do not panic.  Most things are treatable.  

  2. Macular disease will also limit the quality of vision.  This may require other treatments such as macula surgery or intra vitreal injections.   ​

Post-operative restrictions

There are very few restrictions after eye surgery.  Do not rub your eye.  Do not wash the surface of your eye with water.  Use your drops as instructed.

Otherwise it is "life as normal".  You can bend.  You can lift.  Use commonsense to avoid pressure on the eye.  

After the first eye has surgery.  

 

Often on day one post surgery, the patient will notice improved clarity, vision, improve brightness, improved colour perception.  But not always. It always takes a few days for the eye to settle down and for the vision to settle.   

 

The hospital will have given the patient a sheet of post-operative instructions and post-operative drops. On the morning after the surgery we want the patient to remove the eye pad and start the drops.

 

Some patients experience bruising in the skin around the eye or on the surface of the eye from the anaesthetic needle. This bruising usually settles in four weeks.

 

We ask the patient to bring the distance glasses to the day-one appointment, so we can push the lens out of the glasses.  Usually this lens will no longer be correct for the operated eye.   If we cannot push the lens out, then we ask the patient to return to their optometrist one or two days after surgery to push the lens out.    The patient goes without a lens initially while the eye recovers from surgery.   

 

After the first eye is done, some patients will experience imbalance between the two eyes. This applies when the refractive error, or the script in the glasses, exceeds 2 dioptres. The problem is that the image created from each eye is a different size and the brain cannot merge the two images from each eye into one image.

 

This imbalance will prevent a patient from resuming normal activities such as driving.  Occasionally it makes the patient feel unsafe.   You are better off having one eye blurry, than trying to wear out-of-balance glasses.   

 

Changing the glasses cannot correct this imbalance.  The only solution is a temporary contact lens on the eye that has not yet had surgery.    In these patients, we ask you to see the optometrist one or two days after the first eye cataract surgery.

 

We will ask you to return to see us for a check, to measure the result of the first eye surgery, and plan for the second eye surgery. Usually we do this in 1 to 2 weeks.

 

On the first post-operative day, we also make a plan for the second eye, which almost always needs cataract surgery to balance the two eyes and give best overall quality vision.   Usually a plan for both eyes has been made at the first pre-operative appointment. 

 

On the first day, we also remind you to pay attention for serious problems such as infection. At any stage, if the eye becomes increasingly blurry or painful, you must ring and present immediately.   The people who have bad outcomes are the people who get worse, and don’t present immediately.

 

 

After the second eye is done

 

Usually the patient does not experience improved vision as rapidly with the second eye, and this is because the patient is comparing it with a good first eye that has already been fixed with surgery.  

 

Sometimes other eye disease will limit the visual result. Usually we wait several weeks before deciding how much the vision is limited by other disease.

 

We advise patients to return to their community optometrist, usually 4 to 5 weeks after the second cataract surgery is done, to update the glasses, and to continue optometry screening examinations, which are required every year.  

 

After the second eye is done, patients can usually drive without glasses, but they often need to use a temporary pair of reading glasses to get by until they can return to see their optometrist  4 to 5 weeks after the second eye is done.   

 

Patients can usually resume normal activities, such as driving, when they feel safe to do so, when the vision is adequate. 

 

Most recreational activities, such as playing golf, can usually be resumed immediately.

METHODS OF CATARACT SURGERY

There are two ways of doing of cataract surgery.   

 

Manual cataract surgery is a 20 year-old technique but has been continually refined by skilled surgeons.  It is the Gold-standard technique and is very safe.  Our surgeons are very skilled, and have completed over 40 000 manual surgeries.  The surgeon performs all the surgical steps by hand.  Energy from an ultrasound probe breaks up the cataract.  Compared with laser surgery (below), manual surgery is shorter in time, less complicated, results in better vision, and is the preferred method for 95% of eye surgeons.  A probe is inserted into the eye and the cataract is sucked out, leaving the supporting capsular bag and ligaments behind. A new artificial lens is placed into this bag. No stitches are required as the wounds self-seal.

 

Femtosecond laser-assisted cataract surgery (FLACS) was introduced into Australia in 2011.  With his research partners, Dr Peter Davies published some of the first data in the world warning about the dangers of FLACS.  We showed that FLACS was less safe in our patients and we abandoned the technique in 2013. The majority of the world’s eye surgeons do not offer FLACS to their patients, but a small minority of eye doctors still offer this technique.  Extra costs are required to cover the costs of the laser per eye.

 

FLACS uses laser technology that pre-treats the eye with an additional procedure, prior to the surgeon performing the manual surgery. This is discussed on the last page.  Newcastle Eye Hospital abandoned this technology in 2013 because it failed to show any benefit to patients.  In fact, it made our results worse.  We published our results in a leading eye journal Ophthalmology.  Other large studies such as the European Cataract Refractive Study 2015 have found the same result as our study.  Most eye surgeons around the world do not recommend laser cataract surgery.  

 

Newcastle Eye Hospital installed the first Laser Cataract System in the Hunter Valley in August 2012.  

 

FLACS commenced in Australia in April 2011.  After several years, the number and quality of clinical studies is poor, and there is still no study of scientific quality demonstrating benefit from FLACS.  At Newcastle Eye Hospital Research Foundation, Dr Davies partnered with Prof Brendan Vote to produce the world’s largest study comparing laser and manual cataract surgery.  

 

Our studies were published in Ophthalmology Journal in January 2014 and 2016.  Our research has helped doctors to understand how the laser works, and we have questioned the safety and benefits of FLACS.  We have shown that FLACS is NOT better for every doctor or every patient.  We argue that perhaps doctors with higher complications could benefit from FLACS.  But our manual results were shown to be so safe, that there was no benefit from FLACS for us.

 

The laser pre-treats the eye, and adds a second procedure to the process of cataract surgery.

  1. The wounds into the eye are created.

  2. The circular hole in the front of the cataract (capsulorhexis) is created.

  3. The cataract is pre-treated with laser energy.

 

The promoted benefits of laser cataract surgery:

  1. A perfectly round capsulorhexis allows more accurate and stable lens positioning in the eye.  There is no evidence that this improves vision.

  2. Pre-treating the cataract allows less ultrasound energy to be used.  But this energy is replaced by laser energy which is still not well understood.

 

The disadvantages of the laser are:

  1. A ragged cut cataract.  We produced electron microscope images here at Newcastle University in 2013, showing images like Image A (left) below.  The laser does NOT cut the human cataract cleanly or precisely as was first claimed by industry.

  2. Increased patient cost.  FLACS does not meet accepted standards for cost benefit for medical treatment.  FLACS is simply not worth the extra cost.  This finding is published in Ophthalmology Journal.

 

These pictures illustrate the difference between manual hand accuracy and laser precision to tear the capsulorhexis.  At a microscopic level, the laser does not cut the human capsule as neatly as when torn by the human hand.

 

 

The cost of the laser is not covered by either Medicare or your health fund.

 

Therefore, in 2013 we discontinued offering laser cataract surgery to patients.  We have led world opinion in this topic, and currently 92% of Australian eye surgeons do NOT offer laser cataract surgery to their patients.

 

Verion Surgical Guidance System

Newcastle Eye Hospital has the latest technology for astigmatism refraction correction.  This system improves surgeon control for the placement of intra-ocular lenses to reduce astigmatism and reduce refractive (optical error) after cataract surgery.  It is used routinely for all patients.

To learn about cataract surgery at Newcastle Eye Hospital, click the movie below.

For patients having surgery, you can read the detailed notes below written by Dr Peter Davies.  Dr Davies also conducts community education events for patients.  Please contact the rooms on 02 49676677 or email admin@huntereyesurgeons.com, to be included in the next event.  

These instructions are general in nature, and do not replace any advice given to you by your treating eye surgeon.  

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