Cataract surgery introduction
Cataract surgery (cataract extraction) has been revolutionised by new multifocal lens implants (IOL). So is it time for you to have your cataracts removed and a premium IOL implanted?
Cataract surgery is very effective in restoring vision. As a result, most patients undergoing the procedure return to having very good sight. Surgeons perform approximately 400,000 cataract extractions each year across the UK.
When symptoms of cataract begin to appear, you may be able to help your vision for a period by using new (stronger or even weaker) glasses, magnifying glasses for certain tasks, better lighting or other aids to improve vision.
Table of Contents
- 1 Cataract surgery introduction
- 2 Download the Complete Patients Guide to Cataract Surgery eBook
- 3 Cataract surgery video animation
- 4 How common is UK cataract surgery?
- 5 Cataract surgery statistics
- 6 Cataract surgery overview
- 7 Cataract surgery evaluation
- 8 Before the surgery day
- 9 On the day of your cataract surgery
- 10 Cataract surgery technique
- 11 Cataract surgery step 1
- 12 Cataract surgery step 2
- 13 Cataract surgery step 3
- 14 Lens types and performance
- 15 Cataract surgery healing and complications
- 16 YAG laser capsulotomy
- 17 The future of cataract surgery
The time for surgery is when cataracts have advanced sufficiently to impair your eyesight and negatively affect your daily life.
Cataracts and ageing
Poor vision is not an inevitable part of getting older. Cataracts are the most common cause of reversible vision loss in the UK. Cataract surgery is a simple procedure to regain vision; hence surgery is usually a walk-in, walk-out day-case procedure using only a local anaesthetic.
Ageing is by far the most frequent cause of the development of cataracts. Basically, if you live long enough, then you will get cataracts, and it can be considered a completely normal part of getting older.
Half of all people will have cataracts by age 80, rising to 70% by 85, according to the North London Eye Study.
Fortunately, a specialist can remove a cataract with a relatively quick day-case procedure, without the need for a general anaesthetic. For instance, in the UK, 98% of all cataract procedures are carried out without the need to stay overnight in a hospital.
There has been a revolution in the modern artificial lens design to correct the need for reading glasses and so patients have a more comprehensive selection than ever before when selecting an artificial lens.
The word cataract comes from the Latin cataracta meaning ‘waterfall or floodgate’ and refers to the white appearance of the pupil in advanced cataracts.
The developing world
It is rare to see such advanced ‘mature’ cataracts in the developed world, but they are not uncommon in developing countries.
According to the World Health Organization (WHO), cataracts are responsible for a third of cases of blindness, worldwide, affecting roughly 65 million people.
Cataracts also lead to moderate or even severe vision loss in a further 52 million people, 99% of whom reside in the developing world.
Download the Complete Patients Guide to Cataract Surgery eBook
The Complete Patient’s Guide to Cataract Surgery (Updated 2020 Edition) contains everything you need to know about your cataracts and cataract surgery treatment.
Click on the link below to get your FREE copy of the 2020 Edition of the guide in PDF format.
Click the book image. Your PDF will download automatically. Check your Downloads folder.
Cataract surgery video animation
The following cataract surgery video courtesy of the American Academy of Ophthalmology describes how phacoemulsification is used to remove the cataract (cloudy lens) and replace it with an intraocular lens (IOL).
The eye is typically anaesthetised using drops, without the need for an injection. The stage of removing the front part of the lens capsule is omitted in this animation.
Cataract extraction with intraocular lens implant for age-related cataract is the most frequent surgery in the NHS.
There were 337,000 cataract operations in England in 2011/12, and the NHS carries out 98 percent as day cases. In 2019, there were an estimated 400,000 cataract extractions.
The % of people who have cataracts based on age is:
- 16% of people aged 65 to 69 years
- 24% of people aged 70 to 74 years
- 42% of people aged 75 to 79 years
- 59% of people aged 80 to 84 years
- 71% of people aged 85+
Cataract surgery statistics
The average age for those undergoing a cataract operation on the first eye was 77 years, with 95% of cataract operations coming from a waiting list. The average waiting time was 65 days.
- Cataracts are the leading cause of world blindness
- Cataract surgery is the most common NHS operation
- 330,000 cataract procedures per year in England
- Average patient age at first eye cataract surgery is 77
- More women have cataract surgery than men – 60% are female
- 41% have surgery on both eyes, with 16 weeks between operations
Over the last decade, there has been a significant increase in the number of cataract operations performed by the NHS in England. For example, there are now almost 100,000 more cataract operations than a decade ago, an increase of 39% over this period.
Data source: The Royal College of Ophthalmologists’ National Ophthalmology Database Study of Cataract Surgery: Report 1, Visual Outcomes and Complications. Eye (Lond). 2015 Apr;29(4):552-60
Click here to book a cataract surgery consultation with our friendly team. We can advise you on the right procedure.
Cataract surgery overview
In most cases, your surgeon will carry out the procedure under local anaesthetic using eye drops (where you’re conscious, but the eye is numbed) and you can usually go home the same day. The procedure is relatively quick and the specialist will complete the operation in around 15 minutes.
Almost everyone who has cataract surgery experiences an improvement in their vision, although it can take a few days or weeks for your sight to settle. Hence, you should be able to return to most of your normal activities within about two weeks.
If you have your surgery on the NHS, you will receive a basic, monofocal lens implant (IOL). After the operation, your plastic lens is set up for a certain level of vision, so you may need to wear glasses to see objects that are either far away or close.
If you wore glasses previously, your prescription will probably change. However, your optician must wait until your vision has settled before they can give you a new prescription.
Most cataract surgery patients are members of the baby boomer generation who were born between 1946 and 1964. Such ‘boomers’ usually have a greater need than ever before to achieve a level of vision after treatment that will enable them to remain physically active and independent as they grow older.
Private cataract surgery
If you have surgery privately, you will have the option to upgrade to premium multifocal lens implants. The manufacturer designs these advanced lenses to give clear intermediate (computer range) and close (reading) vision, as well as good distance sight. (You can jump to the section further down this page on Lens Implant Choices for Cataract Surgery for more information.)
In a private setting, the consultant will usually treat the eyes one week apart, perhaps even the same day. In contrast, surgery for cataracts on the NHS or other universal healthcare settings, the delay can be considerably longer.
For surgeons performing cataract procedures, the aim is to provide patients with an IOL lens implant that will give good distance sight. At the same time, it must address their rapidly changing needs and preferences for clear intermediate and near vision. An additional challenge is that, with patient’s increasing lifespan, decisions made at the time of cataract extraction have long-term consequences, with many patients living several decades after cataract removal.
Click here to book a cataract surgery consultation with our friendly team. We can advise you on the right procedure.
Cataract surgery evaluation
All patients will have had a preoperative examination by a specialist eye doctor to diagnose and confirm the presence of a cataract. Diagnosis of cataracts often happens at your optometrist during a routine appointment or after you have attended noticing a drop in visual acuity. You will usually have one or more of the following assessments:
- How much your vision is affected in normal lighting and when exposed to glare
- The pressure inside your eyes (intraocular pressure, IOP)
- Dilation of your pupil to better see the whole of the lens
- Examination of your retina and vitreous gel to assess any weak spots that could increase the risk of complications
- Diagnosis of the cataract type: nuclear sclerosis, cortical or posterior subcapsular
- Assessment of the macular health – damage to the retina will not be improved by removing a cataract
- Biometry: very accurate measurement of the anatomy of the eye to allow calculation of the correct power IOL implant
You will also have a pre-operative consultation with your surgeon so he or she can learn more about your eye and medical history, plus a conversation about your expectations of cataract surgery, e.g. how good will your vision be. You may want to think of various questions and concerns to discuss at the consultation. Some useful questions you may wish to ask your specialist eye doctor include:
- How long will it take for me to recover from the operation?
- How good will my vision be after cataract surgery?
- What are my options for the intraocular lens (IOL) implant to be used on my eyes?
- Will I still need to use glasses after surgery?
- Will I be able to read without glasses after cataract surgery?
- If you already have one or more general health or eye health conditions, could these increase my chance of complications or reduce how good my vision is after the operation?
- What about the drugs or medicines I am already taking?
- Will my insurance pay for cataract surgery?
- What is the price of my cataract surgery? Is this an all-inclusive cost?
- Do special premium lenses cost extra?
- What kind of aftercare can I expect after my cataract operation?
Once you feel ready to go ahead with cataract surgery, a patient liaison advisor will discuss how things will proceed. You will receive an information pack about the surgical centre where your procedure will be performed including directions, how to prepare for the surgery and what to do about your current tablets, medications and eye drops if applicable.
Before the surgery day
Here are some suggestions to consider before the day of your cataract operation:
- Allow at least one day for recovery with no work or other activities planned
- Arrange for transportation to and from the surgical centre or hospital. Do not drive!
- Don’t drink alcohol in the 24 hours leading up to your procedure
- You can only eat breakfast if your specialist has explicitly said so. If you are unsure, then don’t eat breakfast
- Make sure you know if you have to skip any of your regular tablets on the morning of the operation
- Use no makeup. You should have showered and washed your hair before coming to the centre.
- If you normally would take medicines or tablets during the time you will be at the facility, make sure to bring those with you. For your safety, you must ask your doctor when you can take them
On the day of your cataract surgery
Cataract surgery is almost always carried out as a day case; it is rare to need to stay in hospital overnight. Indeed, 98% of cases are performed on an outpatient basis. When you arrive on the day of your operation, the theatre or centre staff will greet you at reception and help book you in. They will guide you throughout the entire process.
Your specialist eye doctor may have a dedicated surgical centre for these procedures, such as London Cataract Centre. Alternatively, some consultants will use an operating theatre at a local private or NHS/state hospital. Outpatient surgical centres have been shown to have fewer complications than hospitals, though this may reflect the case selection.
Although you will not be asleep during your cataract surgery, you may be asked to rest in a hospital-type bed or, more commonly, a reclining chair. You will be given a mild sedative by mouth and/or IV before your operation to help you relax and remain comfortable during the procedure.
In cataract surgery today, the preferred method to remove the cloudy cataract lens inside your eye will be with a high-frequency ultrasound device. This is known as phacoemulsification; the energy will break up the lens into tiny fragments that are then easily removed using gentle suction.
Once all the pieces of the misty or opaque lens have been removed, the surgeon will insert an implant, the intraocular lens (IOL). The type of lens will have been discussed before your operation; you may have opted for a premium lens that will restore reading vision as well as distance sight.
For most patients, no stitches are needed due to the fact that the incisions are very small. Cataract surgery usually takes less than 20 minutes to complete for one eye. Your total stay may be from one to three hours. You may also have both eyes treated at the same visit.
Cataract surgery technique
The first step after anaesthetising the eye is to remove the cloudy cataract lens from behind the iris. Tiny keyhole entrance points are made at the edge of the cornea to allow access to inside the front part of the eye, either surgically using a miniature diamond blade or with a femtosecond laser.
The lens is contained within a clear fibrous bag known as the capsule, which will remain even after the lens contents have been removed from within it. In order to access the lens material, a small round opening approximately 5-6 mm in diameter must be made in the top of the bag, called a capsulotomy. The capsulotomy can be performed using a special instrument by a skilled surgeon, or with a femtosecond laser.
An advanced ultrasound-based device called a phacoemulsification tip is inserted through the keyhole opening at the edge of the cornea, and through the capsulotomy. The ultrasound tip dissolves the lens fibres and simultaneously sucks them up the central tube within the tip.
The cataract surgeon continues aspirating the lens material from all parts of the bag. It is important to ensure no lens cortex remains as this can lead to inflammation of the eye after surgery.
Click here to book a cataract surgery consultation with our friendly team. We can advise you on the right procedure.
Once all the lens material has been removed, the clear opened capsular bag will remain in place, still suspended from the encircling doughnut-shaped ciliary muscle by fine fibres. This empty bag will be the new home for an artificial plastic intraocular lens implant (IOL).
Modern implants are flexible, allowing them to be folded and inserted via a lens injector, through a very small keyhole opening in the eye. In contrast, older lens implants were rigid and required a much longer incision, which would have required several stitches to close the opening in the eye.
Keyhole cataract surgery
The benefit of keyhole cataract surgery is much more rapid healing, less induced astigmatism post-operatively (so better vision) and, because keyhole ports are self-sealing, no need for any sutures.
There are a variety of lens types that can be implanted. The choice of IOL used depends on whether surgery takes place in the National Health Service (UK NHS), where only standard monofocal lenses are available, or in a private setting where the patient can opt for advanced premium lenses.
Once the specialist eye doctor injects the lens into the capsular bag, they then manipulate and rotate the IOL so that it sits in the correct position. This will ensure the best possible vision after cataract surgery is complete. This stage is also very important for premium and toric lenses, where the position and angle of the lens are vital.
The specialist injects antibiotics into the fluid in front of the iris, which is highly effective at protecting against bacterial infection after surgery.
Surgery usually takes 10-15 minutes per eye. There is no need for sutures as the keyhole entrance ports are self-sealing, removing the need to have stitches taken out at a subsequent post-operative clinic visit.
Until recent years the only choice patients had was a standard single focus intraocular lens (IOL), known as a monofocal design. This is the lens type still used in universal health care plans, such as the NHS.
Standard monofocal lenses do not restore reading vision, i.e. they do not restore reading and distance vision in each eye. For that, you will need premium lenses.
The youthful, natural human lens is much more advanced, allowing us to see in at almost any distance, from far away up to only a few centimetres from the eye (when we are young).
This flexible ‘zoom’ function declines with age, a condition is known as presbyopia and we need reading glasses by mid-life.
However, new optical IOL designs have created presbyopia-correcting intraocular lenses, which have revolutionised refractive cataract surgery. These implants can restore intermediate range (e.g. computer screen) as well as up-close reading, such as a newspaper or phone.
Lens types and performance
such as bifocal and trifocal implants (MIOLs).
Extended Depth Of Focus IOLS
that include high-definition optics.
that attempt to recreate the ‘zoom’ function of the young human lens (AIOLs)
Most people who have cataract surgery would like to be less dependent on glasses after treatment. Presbyopia-correcting IOLs offer this advantage, including decreasing the need for computer glasses and reading glasses but will increase the costs of surgery.
All designs include some optical compromises and a period of adaptation will be needed.
Advantages and risks
The most common complications are indistinct vision (at distance or close, or both), reduced contrast making objects appear less defined, and glare & halos around streetlights and car lights in dim-light conditions. In many cases, these issues become less problematic with time without treatment.
In other cases, a follow-up procedure, e.g. LASIK or PRK may be needed to improve vision and decrease symptoms. In a small number of cases, your surgeon may remove the presbyopia-correcting IOL and replace it with a different lens type.
Be sure to thoroughly discuss the advantages and risks associated with presbyopia-correcting IOLs with your cataract surgeon at your preoperative exam and consultation.
During cataract surgery, your surgeon replaces the cloudy lens with a clear synthetic intraocular lens implant (IOL).
Standard monofocal IOLs only correct vision at one distance, typically to give good far vision, e.g. for driving, TV, etc. Patients still need glasses for reading and computer use. We use these IOLs with monovision, with one eye for distance vision and the other eye for reading.
Premium intraocular lenses are now available that are multifocal (MIOLs) and which can improve vision at more than once distance. The image shows a trifocal design to give better vision at far, intermediate and close ranges.
There are many different types of IOL. Your cataract surgeon can help you decide if you are a good candidate for multifocal IOLs at your preoperative exam and consultation.
Cataract surgery healing and complications
The most common occurrence after cataract surgery is posterior capsule opacification (PCO). PCO happens in about 10-20% of patients, where the back (posterior) part of the capsule can become cloudy some months or even years later, resulting in PCO and blurred vision.
Posterior capsule opacification is not a complication but rather a normal part of the healing process. After the cataract is removed, the capsular bag that held it remains in place. Some microscopic cells also remain behind, and these can proliferate and transform into scar tissue, as happens in normal wound healing.
Fortunately, a YAG laser can treat PCO safely and effectively. Your doctor will perform the procedure (YAG laser capsulotomy) in the out-patient clinic.
True cataract surgery complications are also possible, and include:
- IOL lens implant dislocation
- Eye inflammation
- Retinal detachment
- Light sensitivity
- Infection (endophthalmitis)
- Ptosis (droopy eyelid)
- Photopsia (perceived flashes of light or dark patches)
- Macular oedema (swelling of the central retina)
- Ocular hypertension (elevated eye pressure)
All of these complications are rare but can lead to significant visual loss, and so close follow-up is required after surgery. Your consultant will successfully treat most complications either medically or with additional surgery. If you have preexisting macular degeneration, optic nerve damage or floaters, these will not be made better by cataract surgery. Your ophthalmologist will discuss specific potential complications of the procedure that are unique to your eyes before you sign a consent form.
The most common event after cataract removal is posterior capsule opacification (PCO). This is not a complication, rather a normal part of wound healing. PCO is readily treatable using a YAG laser.
During cataract surgery, your doctor will remove the cloudy natural lens of your eye (the cataract) and replace it with an intraocular lens (IOL). The thin clear membrane bag that surrounds the human lens (known as the lens capsule) is mainly left intact during the operation, and the surgeon will implant the IOL inside it.
However, in about 10-20% of patients, the back (posterior) part of the capsule can become cloudy some months or even years later, resulting in PCO and blurred vision.
Fortunately, a YAG laser can treat PCO safely and effectively. The doctor can perform the procedure (YAG laser capsulotomy) in the out-patient clinic. With your chin on the chin rest, he or she directs a laser beam at the clouded capsule behind the implant lens, and the laser vaporises the tissue, restoring clear vision. The procedure is painless and takes only a few minutes.
You can click here to learn more about YAG capsulotomy.
Following YAG capsulotomy, you may resume normal activities immediately. You may experience some floaters afterwards which typically resolve within a few weeks.
The future of cataract surgery
During the last 35 years, lifespan has gone up by 12 years in the West and by more than 25 years in many developing countries. As the likelihood of developing cataract increases with age (with at least 70% of people aged 85+ affected), the medical community faces the problem of too few ophthalmic surgeons.
In 2015, around 9000, American surgeons carried out 3.6 million cataract procedures. The UK has just 1,300 consultant ophthalmologist positions, with over 90 percent of eye departments estimating that they require between one and five extra consultants over the next two years.
The UK Royal College of Ophthalmologists continues to lobby for additional training jobs, but the current government position is to freeze the number of training posts for the next ten years.
Technological advancements will continue, with new IOL designs in the pipeline and refinements in how we use lasers during the procedure.
Clinical trials of new gel-filled lenses are underway, though the holy grail of a true “accommodating” artificial lens that can change its power (as can the natural lens) is still likely some way off.
The procedure is now almost unrecognisably more advanced than when, on 29 November 1949, Sir Harold Ridley successfully implanted the first intraocular artificial lens at St. Thomas’ Hospital in London.
There is no sign of the pace of new developments slowing; rather, it appears to be accelerating. We look forward to what the future will hold.
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