As you get older, you will find that your eyesight isn’t as good as it once was. While there are a number of eye conditions associated with ageing, cataract is one of the most common. Cataracts affect thousands of Australians every year and cataract surgery is one of the most common surgical procedures worldwide.
Simply put, a cataract is a clouding of the eye’s lens. The lens is located just behind the iris (the coloured part of the eye). It is approximately the size of a Smartie®, and is responsible for focusing the incoming light onto the retina, which is the ‘camera film’ at the back of the eye.
As the lens becomes cloudy, it obscures the incoming light from reaching the retina. Cataract therefore reduces our quality of vision. Cataract formation is accelerated by UV light, diabetes, short-sightedness, eye trauma, iritis, certain eye surgeries, certain medications and certain medical conditions.
What does a Cataract Surgeon suggest if you have cataracts?
If you’ve been told that you have cataracts then you should see an eye surgeon (ophthalmologist). They will be able to assess your cataract severity, screen your eyes for other diseases, and discuss your treatment options with you.
Surgery is the only treatment for cataracts. Although eyedrops have been investigated as a potential future treatment of cataract, this research is in its infancy and is unlikely to ever be viable.
When is the “right time” to have cataract surgery?
The decision to have cataract surgery is based on your cataract severity and your symptoms. There is no set “cutoff” of when cataract surgery is appropriate, and a cataract does not suddenly become “ripe” for surgery. Some patients will choose to have their cataract treated sooner, and others will choose to wait.
The timing of cataract surgery is a joint decision made between you and your eye surgeon.
Factors to consider when deciding if cataract surgery is right for you, include:
Your cataract symptoms. However, because cataracts develop slowly, it can be difficult for an individual to appreciate how their vision has deteriorated. Your ophthalmologist will be able to advise you how much improvement you can expect from cataract surgery.
Your cataract severity. Patients with advanced cataract have more to gain than patients with mild cataract.
Your visual needs. Patients who do demanding visual activities, such as night driving or prolonged reading, may be motivated to have their cataract treated sooner. Patients who do not do demanding visual activities may be happier to wait.
Your surgical risks and willingness to undergo medical procedures.
Your age and health. Many patients choose to have their cataracts treated while they are still in good health.
The financial investment required to have cataract surgery.
Cataract surgery performed by a cataract surgeon involves removing the cloudy cataract and replacing it with a new, high-definition lens implant. This implant lasts for life and it resets your vision to help you see clearly. If a new lens were not implanted, then vision would be severely defocused and the patient would require thick glasses.
I perform cataract surgery as a walk-in, walk-out procedure in a day surgery. The surgery takes approximately 20 minutes and is performed under twilight sedation. One eye is treated at a time with the two eyes typically scheduled 3-7 days apart.
Standard cataract surgery with a single-vision lens. Excellent distance vision but reading glasses are required for objects within arm’s length.
Refractive cataract surgery with a customized depth-of-focus or multifocal lens. Both distance and near objects are in focus.
Achieving optimal vision from cataract surgery
Optimal vision from cataract surgery requires precise eye measurements, rigorous surgical planning, and the calculation of a customised lens implant tailored to the unique optics of your eyes. This is the art of cataract surgery.
During cataract surgery, your cloudy lens (cataract) is replaced with a high-definition artificial lensimplant. This artificial intraocular lens (IOL) lasts for life and it refocuses your vision to help you see clearly. It is custom-selected for your eye to give you the best vision possible.
Before scheduling cataract surgery the dimensions and curvature of your eye must be precisely measured. This is done using a laser scanner (optical biometry) and a high definition camera (corneal topography). The measurements are used to calculate exactly what power of lens the eye requires. If the measurements are inaccurate then the lens selection will be inaccurate and your post-operative vision will be blurry.
I regularly discuss the nuances of cataract surgery on my podcast. I constantly seek to improve my patient results through attention to detail, auditing my outcomes and the use of technology.
STEP 1. Consultation
The purpose of your consultation with a cataract surgeon is for you to understand your eye health and the treatment options available to improve it.
I use advanced diagnostic technology to show my patients the problems affecting their vision. My focus is on cataract surgery education, so that patients have all the information required to make the decision that’s best for them.
My team and I understand that eyecare can be daunting. We want you to feel at ease and we strive to deliver care that is warm, welcoming, and personal.
STEP 2. Choosing the best artificial lens implant for you
This is probably the most important step for you. The lens implant that you and your surgeon choose will make a significant difference to your vision: it will be a part of you, probably forever. You must decide how you want your vision to be after surgery.
During cataract surgery, an artificial lens is implanted to re-focus your vision. Modern lenses are made from flexible acrylic plastic and they come in many different designs, sizes and brands. No artificial lens is perfect, and each design has its advantages and limitations. Once your lens is implanted it is challenging (but not impossible) to change it. Therefore, it is important that your surgeon selects the lens that is best for you. Although I have implanted nearly every lens design available, I now use only a relatively small selection of the highest quality products.
With improvements in technology, lenses are available that have demonstrated improved vision for patients. These lenses are called multifocal lenses, extended depth of field lenses and presbyopia-correcting lenses. They work by different mechanisms and each design has its unique considerations.
Every eye is unique and is suited to certain lens implants only. In addition, my patients all live different lifestyles and have different visual needs. This is why selecting the most appropriate lens is a complex process and must be customised for each person. If a suboptimal lens is implanted then your vision won’t be as good as it could have been. Cataract surgery is a once-in-a-lifetime opportunity to reset how you see.
My focus is on both quantity of vision (how many letters you can read in the distance and up close without glasses), and quality of vision.
Single vision lens
Outstanding distance vision but glasses are usually required for most things inside arm’s length (this usually includes the computer, the mobile phone, and reading). Every eye is suitable for single vision lenses.
Extended depth of focus lenses
Excellent vision for everyday activities. Glasses are usually only required for reading very small print, reading in dim lighting, or reading printed text for prolonged periods (i.e. reading a book).
Distance and reading vision can be achieved without glasses. However, quality of vision is reduced and most patients are left with seeing halos around lights. Only a minority of eyes are well suited to trifocal lenses.
One eye for distance, on eye for reading
This is called monovision, or blended vision. It can be well tolerated in certain circumstances. Some compromises of monovision include:
Awareness of imbalanced vision.
Adaptation time. Some patients adapt to monovision within hours, whereas others can take 6-12 months. Vision can feel strange while adaptation is occurring.
Reduced depth perception.
Discomfort wearing glasses (if glasses are required).
Blurred vision when quickly looking towards the side of the reading eye. This might occur when checking your blind spot while driving. Most patients quickly adapt to this problem by learning to turn their head more.
Small aperture lenses
These lenses function like a pinhole. They are usually reserved for patients with severe corneal disease.
STEP 3. Getting the eyes ready for cataract surgery
The surface of your eye needs to be as smooth and healthy as possible. All pre-existing dry eye needs to be treated. This improves your recovery following cataract surgery, and most importantly, it improves the quality of eye measurements obtained by laser scanners. I am very proactive about treating dry eye before cataract surgery, as this improves my patients’ vision, comfort, and speed of recovery.
STEP 4. Eye Measurements
The dimensions and curvature of your eye must be precisely measured. This is done using a laser scanner (optical biometry) and a high definition camera (corneal topographer). The power of the lens implant your eye requires is calculated using these measurements.
STEP 5. Calculation of Lens Power
To determine the best lens power for each of your eyes, your eye surgeon will enter your eye measurements into lens calculator software. Historically, this has been a very basic process. Nowadays, there are wide range of lens calculators available. I use my own custom-built computer program to integrate the most advanced “4th generation” lens calculators. This increases the likelihood of my patients having the best possible outcome.
Obtaining perfect measurements and selecting the best possible lens for each eye is fundamental to premium cataract surgery with a specialist cataract surgeon. This is one of my key areas of interest and I have published research papers on this process.
STEP 6. Surgery
Cataract surgery is performed in a day surgery as a walk-in, walk-out procedure. You are positioned on a bed and your eye is completely numbed with anaesthetic drops. Intravenous sedation is given by an anaesthetist. The vast majority of my patients have absolutely no recollection of their surgery!
I use a variety of different cataract surgery techniques to optimise the result. Usually, I will make two tiny, keyhole incisions: the largest is only 2.2mm wide. The incisions are so small that they seal with a watertight closure, without the need for stitches.
The new artificial lens implant is rolled up and injected through the incision. It opens up inside the eye to rest inside your natural lens capsule. I then rotate the lens implant, so that it aligns precisely with the optics of the eye. To do this, I use an image guidance system projected inside the eyepieces of my surgical microscope.
The entire procedure takes approximately 15 minutes.
Optimal surgical technique is highly ritualised to minimise the risk of complications, and to produce highly consistent results.
I will check on you after the surgery before you go home.
All surgical procedures carry risk. Before proceeding with any invasive procedure, you should consider seeking a second opinion from an appropriately qualified health practitioner.
STEP 7. Post-operative Eyedrops
Medicated eye drops are used for four weeks to help the eye to heal. Several brief check-ups are performed in clinic during this time. If glasses are required, these can be updated four to six weeks after cataract surgery.
What sets us apart for cataract surgery?
What sets ophthalmologists apart is the planning phase of eye surgery. This is what distinguishes average results from sensational results. At Sight Specialists, we push the very limits of what is possible for cataract surgery. Rather than measure your eye with one device, we use six. These measurements are combined to create a precise, digital model of your eye. Rather than use standard, default software to plan your surgery, we use our own, custom-built software, which took years to develop. The result is a surgical plan that is as perfect as modern technology permits. Welcome to the future of cataract surgery. Your eyesight is one of the most important things you have. Don’t compromise.
The morning after surgery vision will be blurry, although many patients are pleasantly surprised! Your eyes will be light sensitive, as your retina won’t be used to seeing the full colour spectrum so intensely. Although the brightness settles quickly, you may choose to wear sunglasses for a while.
Another after-effect is that the eye feels gritty. This is due to the strong antiseptic solutions required during the operation, and the tiny incision, which is in the outer corner of the eye. This irritation improves over a week, and post-operative eyedrops help to soothe it.
Over the next few weeks vision keeps progressively improving, but it fluctuates. This is due to dry eye, which always gets worse for a while. I provide you with instructions on how to manage this.
What you shouldn’t do after cataract surgery
I tell my patients that they can basically do everything that they normally would, with a few important exceptions:
No driving for 24 hours.
No eye make-up for 5 days.
No eye rubbing for 2 weeks.
No swimming or strenuous exercise for 2 weeks.
What you can do after cataract surgery
You can read, watch television, bend over and go about normal household activities.
Shower and wash your face. (Close the affected eye in the shower for one week).
Wear makeup on your face (but no eye makeup for five days).
All medical procedures carry risk and these risks will be discussed with you as part of your informed consent.
Fortunately, with the latest technology and surgical technique, serious complications from cataract surgery are rare. However, complications can always occur no matter how much care, judgement and skill are employed.
I am fortunate to have specific training and expertise in repairing the complications of cataract surgery. Correcting patients who are dissatisfied with previous cataract surgery forms a large part of my work.
The main risks of cataract surgery are:
Haemorrhage. Bleeding varies from mild bruising on the surface of the eye (common), to severe vision threatening haemorrhage (very rare).
Vision worse than pre-op vision (rare) or permanent loss of sight in the operated eye (very rare).
Cystoid macular oedema. Retinal swelling that reduces the clarity of vision. This ranges from mild (approximately 5%, resolves quickly), to severe macular oedema (very rare).
Eye discomfort. This ranges from mild dry eye (very common), to strong pain requiring medications (rare).
Unexpected defocus post-op. Occasionally, the eye heals after surgery with a different focus to what was anticipated. If required, focus error can usually be treated with another operation.
Imperfect vision requiring a second operation. There are many reasons why a patient may require a second operation in order to achieve their best possible vision.
Even though cataract is a simple problem to understand, cataracts cause a myriad of different eye symptoms. This is because cataract doesn’t just make the lens cloudy: the cataract will also change the colour of the lens, as well as the way it focuses light.
Here are some of the common symptoms of cataract. If you experience these, you should see an eye specialist.
Reduced clarity of vision.
All forms of cataract absorb and scramble incoming light. This causes the image on the retina to be dimmed and blurred.
Patients with cataract may notice that their vision is not as sharp as it used to be, even with updated glasses. Some patients can still read the vision chart, but cataract causes a softness to the vision. Each letter will no longer be as crisp and defined.
A cataract is like a dirty chandelier. Rather than focusing the image onto the retina, the cataract scatters the light inside the eye. This is why patients with cataract often report that the headlights of on-coming cars seem more dazzling, and they see halos and streaks around the headlights.
Changing prescription of glasses
The lens of the eye is living tissue, and a cataract is constantly changing. As the cataract develops, the focus of the eye also changes. This necessitates updating your glasses prescription more frequently.
Reduced vibrancy of colours.
As a cataract develops, colours become dull and slightly yellowed. You may not even notice that this is happening: altered colour perception is rarely perceived before cataract surgery. Afterwards, however, most patients notice that colours are much more vivid.
Blurred distance vision but improved reading vision
Sometimes, cataract may cause your reading vision to improve, while your distance vision gets worse. This occurs because as the cataract becomes more opaque, it also develops increased focusing power. This process of progressive near-sightedness caused by cataract is called “index myopia”.
Double vision even with one eye covered
Due to cataract acting like a chandelier inside the eye, you may find that one of your eyes sees “double”. The second image is a ghosted, displaced copy of the true image. Sometimes, this can appear as “fringing” on one side of the object. This second image remains even if one eye is closed, which differentiates it from double vision (diplopia), caused by a problem in the brain.
Increasing eye pressure
If your eyes are small, anatomically speaking, a cataract can interfere with the normal circulation of fluid within the eye. The cataract can physically obstruct fluid drainage, resulting in the eye pressure increasing. This is called “angle closure”.
Difficulty seeing in dim lighting.
Cataract absorbs light entering the eye, particularly blue and violet colours. But blue and violet colours are most important for our night vision, because in the evening, the colour spectrum we see shifts towards blue. This phenomenon is called the Purkinje Shift.
Cataracts themselves are yellow in colour, and the yellow blocks blue light. As a result, if you have cataract, it is likely that you see poorly at night. Shadows will appear as undifferentiated darkness. You may not be able to see bumps in the pavement, for example. You may also need brighter lights to read comfortably.
No noticeable symptoms whatsoever!
If you’ve been told that you have cataract, but haven't noticed any of the above symptoms, then don’t worry. That is perfectly normal too.
Many patients with cataract aren't aware that the quality of their vision has declined. This is because cataracts develop very slowly, which can make it hard for people to recognise the change.
However, when cataract surgery is performed, these patients are often the most impressed, as they are typically surprised by just how much more vibrant the colours are, how much clearer their vision is, and how they can now see fine detail that they didn't even know that they were missing.
Cataracts are classified into different subtypes according to their appearance, as well as the location of the clouding within the lens.
The three most common forms of cataracts are the following, although there are many other forms of cataract as well.
Nuclear sclerosis cataract
Posterior subcapsular cataract
Each form of cataract has slightly different symptoms, because of the differences in the density and location of the lens opacity. Most patients have a combination of multiple types of cataract.
Nuclear sclerosis cataract
Nuclear sclerosis cataracts appear as a yellow discolouration of the lens. This yellowing is not visible to the naked eye, but can be seen with a special microscope.
The yellow discolouration is caused by accumulation of urochrome within the lens. Urochrome is a yellow pigment (the same one that colours your urine).
Nuclear sclerosis cataracts are predominately caused by UV light exposure, which causes free radical damage to the lens. As a result, the delicate proteins of the lens clump together. The lens is naturally transparent, but loses this transparency when this happens.
If you have nuclear sclerosis cataracts, you might notice blurred vision, halos around lights, dullness of colours, and that you are unable to see clearly in dim lighting.
These cataracts are spoke-like opacities (or spokes of darkness) radiating from the periphery, or edge, of the lens towards the centre of the lens. We don’t really know what causes them.
It could be that they are a result of constant, lifelong stretching of the lens that occurs every time we attempt to focus our eyesight from the distance to near. This process is called “accommodation”. It involves a muscle inside the eye, called the ciliary body, pulling on our lens. This changes the shape of the lens, to bring what we are looking at into focus.
The constant stretching and relaxation of the lens shape stresses protein fibres within the lens. This trauma causes clefts (splits) of water to form within the lens, and the degeneration of lens proteins. Eventually, spoke-like calcifications of the lens occur.
If you have cortical cataracts, you will notice blurred vision, as well as seeing halos and streaks around lights.
Posterior subcapsular cataracts
Posterior subcapsular cataracts appear like a plaque on the back surface of the lens. These cataracts develop rapidly, and can profoundly reduce vision. It is not uncommon for a patient with posterior subcapsular cataract to lose all functional vision in the affected eye within just six months.
Posterior subcapsular cataract is caused by cells inside the lens suddenly growing in a disorganized fashion. These cells migrate to the back surface of the lens, where they are known as ‘Bladder cells’ or ‘Wedl cells’. Instead of growing as translucent, thin strands, these cells grow as dense, round clumps. This gives the appearance of an opaque plaque on the back surface of the lens.
How are cataracts diagnosed?
Diagnosing cataract is relatively simple.
Cataracts are usually diagnosed by optometrists when they are checking your glasses, or by general practitioners when filling out driving license forms. The diagnosis is based upon your symptoms (outlined above), examination of your eye, and diagnostic testing.
The most common symptoms, as noted above, are blurred vision, glare when driving at night, frequent changes in your glasses prescription, and difficulty seeing clearly in the dark.
When an ophthalmologist or optometrist examines your eyes, a special kind of microscope, called a slit lamp biomicroscope, is used. The eye specialist can then assess the severity of your cataract, and where the clouding is located within the lens. Cataracts look yellow, and often have opaque specks and streaks.
In addition, several diagnostic tests can measure the severity of your cataract. These can help you and your eye surgeon decide when surgery is necessary.
One of these tests is the measurement of light scatter. This is done by directing lasers through the cataract, and measuring how the cataract blocks and scrambles the laser beam. The devices that perform this assessment are called “wavefront analyses”. Examples include the iTrace device, the OPD 3, the Topcon KR-1W, and the HD Analyzer.
In my opinion, the iTrace is the best device for assessing cataract. This is the device that I use in my clinic. The iTrace projects 256 laser beams through the cataract. It measures the absorption and deviation of each laser beam. The device reveals how the cataract is degrading vision, and it reconstructs a simulation of what the patient is currently seeing.
The density of a cataract can be measured which indicates how “opaque” a cataract is. To get this measurement, either a Pentacam, or an optical coherence tomography (OCT) device is used. I find these tend to be less reliable than wavefront analysis as cataract density doesn’t correlate well with cataract symptoms.
What to expect following cataract surgery with Dr Nick Andrew - Cataract Surgeon
Most patients find that cataract surgery is painless and that it results in a tremendous improvement in their vision – and their enjoyment of life.
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