Cataracts can appear at any time beyond the age of 40, although they are more common after the age of 65 to 70. Fifty per cent of people will have cataracts by the age of 80, rising to 70% by 85.

The effect of cataracts on your vision is progressive blurring. Imagine you are looking through a dirty pair of glasses or, if the cataracts are advanced, a piece of ground glass.

Cataracts are the most common cause of reversible blindness in the world today. According to the World Health Organization (WHO), cataracts cause one-third of all cases of blindness across the globe, affecting just over 65 million people. Furthermore, cataracts cause moderate to severe sight loss in over 52 million people, of whom 99% live in developing countries.

Cataract surgery is one of if not the most common surgical procedure in the world. The high level of safety and effectiveness has led to considerable demand for cataract surgery.

In the UK alone, there are an estimated 400,000 cataract procedures performed each year. In the United States, 3.8 million cataract surgeries were carried out in 2017.

Cataracts have long since been regarded as a condition primarily correlated with age. Longer life expectancy and a shift towards an older average age will lead to increased incidences of cataracts. Because cataracts can lead to blindness, surgery is considered essential.

Jeffrey Wong, Analyst Director at iData Research, says, “In addition to a general increase in the overall patient base due to an ageing population, there is also an ongoing demographic shift that will further augment this effect.”

Once delayed for as long as possible and primarily reserved for elderly patients, cataract surgery is increasingly performed on patients who have yet to reach retirement age. This is supported by several factors, including a growing awareness for cataract surgery, improved patient education, and enhanced surgical safety and results, which are a byproduct of advancements in techniques, instrumentation, and implants.

Drugs and medications

Please bring a list of all your current medications to your preoperative consultation. Some drugs can affect what happens during your cataract surgery procedure, so we must know about these ahead of time.

In particular, we will want to know if you are taking drugs to prevent blood clotting.

Most medications can be taken as usual on the day of your surgery. If your procedure is taking place in the morning, you may wish to delay taking any diuretic (water) tablets until the procedure is complete. This will save you from wanting to go to the bathroom during the treatment!

Contact lenses

If you wear contact lenses, please stop wearing them for one week prior to your consultation appointment. This allows your cornea to relax back into its natural shape and ensures that we have extremely accurate and correct readings of the shape of your eyes.

We will use this information to calculate the correct power of the intraocular lens (IOL) implant that needs to be placed inside your eye.

If you wear hard (rigid) contact lenses, we may need you to leave them out for a more extended period and repeat some measurements after four weeks. There is no need to leave them out for more than one week for your first visit unless you wish to do everything in one session; if that is the case, please leave out your hard contact lenses for four weeks before the appointment.

Driving

During your preoperative assessment, we will use some drops to dilate the pupil of each eye. We can then obtain a complete view of your lens and the extent of the cataract present. We can also see your retina to check that this vital light-sensitive layer is intact and healthy.

The dilating eye drops can blur your vision, so we advise that you do not drive to your appointment. Either have someone else drive you or make alternative travel arrangements instead of your car.

At present, there are no medications or drops that can halt or reverse the changes of cataract. Fortunately, we have a surgical technique to remove the cataract and safely restore vision.

The one effective treatment for cataracts is the surgical removal of the problematic cloudy lens through a microscopic keyhole incision and replacing it with a clear artificial intraocular lens (IOL) implant. Today, around 400,000 cataract procedures are performed each year in the UK; the US carries out nearly four million cataract operations annually.

The modern era of cataract surgery began in 1949 when Sir Harold Ridley implanted the first synthetic lens implant at St. Thomas’s hospital in London.

The development of ultrasound phacoemulsification, introduced by Charles Kelman and Anton Banko in 1967 as a way to dissolve the body of the lens and the design of modern intraocular lenses, led to a revolution in safety and effectiveness in cataract surgery.

There are many types of IOLs in modern use. The choice is determined by the visual needs and age of the patients, the health of the eye and the health system of the country, e.g. public health service or private sector:

• Monofocal IOLs
• Premium monofocal IOLs
• Toric IOLs
• Extended Depth-of-Focus IOLs (EDOF)
• Multifocal IOLs (including the commonly used trifocals)
• Accommodative IOLs (more rarely used)
• Phakic IOLs
• Piggyback IOLs

Many important factors will affect which intraocular lenses are the right choice for you. Common questions you should ask yourself are:

• Are you suffering from short-sightedness or long-sightedness?
• Do you have significant astigmatism? (the second number on your prescription)
• Are you happy to continue to wear glasses or contact lenses, either part or full time, after your cataract operation?
• Would you like not to require the use of glasses or contacts after the cataract procedure?
• How important is clear vision at night or in low light to your lifestyle? Do you often drive in the dark?
• Overall, how well do you adapt to new situations and acquiring new skills?
• During your day-to-day life, including your occupation, what activities or tasks do you often participate in?
• What are your hobbies? How often do you participate in these hobbies?
• What do you find to be the most inconvenient or aggravating aspect of wearing glasses or contact lenses?

Modern intraocular lenses have developed tremendously over the past 20 years. However, there is no one-size-fits-all lens that will work for everyone in all situations. The best lens for you does depend on the health of your eyes, your glasses prescription, your lifestyle as well as the extent that you wish to be free from glasses or contact lenses.

Your surgeon will help you decide on the right lens after an in-depth discussion and examination. Once you understand what to expect from each IOL, the choice is usually straightforward.

The modern era of cataract surgery began in 1949 when Harold Ridley implanted the first synthetic lens implant at St. Thomas’s hospital in London.

Sir Nicholas Harold Lloyd Ridley (born on 10 July 1906 and died age 94 on 25 May 2001) was an English ophthalmologist who invented and pioneered the intraocular lens (IOL) implant and introduced IOL surgery for patients suffering from cataracts.

IOLs have been greatly refined over the following decades with tremendous improvements in lens design, IOL materials used and manufacturing process. Modern IOLs are extremely safe and effective, with a range of designs that can also correct astigmatism and the need for reading and computer glasses.

Cataract surgery is performed with one of three anaesthetic options. The choice will depend on the patient’s age and various health conditions. Please discuss with your surgeon if you have a preference.

Local anaesthetic

Most cataract operations are carried out using a local anaesthetic (LA), using only drops to numb the eye effectively. This is also referred to as topical anaesthesia. For some patients who find they have a desire to squeeze their eyelids, a small injection of a local anaesthetic around the eye will reduce both eye and eyelid movement. This is known as sub-Tenon’s local anaesthesia, or sub-Tenon’s for short.

With a local anaesthetic, the patient benefits because there are no restrictions before or afterwards. The patient can eat and drink prior to coming to the hospital or operating centre. There will be no pain during the cataract operation, and patients find it a comfortable procedure. They can leave the centre less than 60 minutes after the surgery.
Sedation

Of course, they will be patients who feel some level of anxiety. Sedation can be a very useful option here, taken as a tablet about one hour before the procedure. Your surgeon can discuss this option at your consultation.

Intravenous sedation and general anaesthesia

If a greater level of sedation is required, the sedative can be given as an injection. Alternatively, some patients will require a general anaesthetic and be asleep during the cataract procedure.

The downsides of general anaesthesia (GA) are the need to not eat or drink for at least six hours beforehand and the risks of having a full GA, including having a severe reaction or, extremely rarely, loss of life. Because of this, having cataract surgery under LA is the preferred choice for most patients.

You should avoid driving yourself to the surgical centre for your procedure. Indeed, you will not drive yourself home! It is better to have a relative or friend travel with you or someone who can drop you off and collect you when you are ready to return home.

The operation involves removing the natural lens through a tiny 2.2mm incision. Once the natural lens has been removed, a new replacement lens called the ‘intraocular lens’ is gently inserted through the same small incision and set into its permanent position.

Cataract surgery involves creating a tiny keyhole incision approximately 2mm long at the edge of the cornea. All this is once the eye has been fully anaesthetised, so you won’t be able to feel very much, perhaps light touch or gentle pressure. Some patients might find microscope light initially very bright but the eye will get used to it very quickly.

A special instrument is passed through this opening to dissolve the natural lens and gently vacuum it away. This leaves behind a clear empty bag called the capsule. A flexible artificial replacement lens, the so-called intraocular lens (IOL), is folded up and gently inserted through the same 2mm opening. Once inside the capsule, the lens unfolds and is held firmly in place within the clear bag.

The keyhole opening seals without the need for stitches. Therefore, there is no need to return to have sutures removed, unlike older forms of cataract surgery.

You may have one or both eyes operated on during the visit. You will be able to leave less than 60 minutes after completion of the treatment.

Local anaesthetic eye drops are the most frequent choice, which will eliminate pain from the eye. Drops may be used together with a mild sedative if required. Some patients may experience a gentle feeling of pressure during the procedure or a feeling of water touching the eye.

As long as the lighting is not too bright, it is OK to start with watching TV or reading immediately. However, because the eye has been very fully dilated during the operation to remove your cataract, it can take 1-2 days for the pupil to shrink down again to its normal diameter. You may have had both eyes treated on the same day, so both can remain dilated.

It is not unusual to notice altered lighting, dazzle, glare or other effects soon after the procedure, but these symptoms should quickly subside.

Many patients will be aware that their vision is noticeably better directly following the procedure to remove the cataract. After all, the opacity that was blocking light has now been removed. The next day after treatment, many patients will have vision that reaches the legal standard to drive a car. We recommend that you wait until your follow-up appointment to confirm that you are safe to drive.

Of course, you should not drive until you are confident that you are safe to do so – you should be able to read a number plate (made after 1st September 2001) from a distance of 20 metres away.

The quality of your vision will steadily improve during the next four weeks. Some patients will need glasses or find they prefer their vision with some correction; you can obtain a new pair once the vision is stable.

Cataract surgery has become straightforward, safe and cost-effective due to advances in the operation technique and instruments used.

Cataract extraction has become the most frequently performed surgical procedure in the world.
In Europe in 2017, almost five million cataract surgeries were performed, and around 400,000 cataract extraction operations take place each year in the UK.

In the U.S., approximately 3,800,000 cataract surgeries are performed annually. The number of procedures is steadily rising along with an ageing population – by the year 2050, the number of people in the U.S. with cataract is expected to double from just under 25 million to around 50 million.

Even with the safest procedure, when millions of operations are being performed, complications are expected to occur. Statistically, even one in a million events will be seen from time to time.

The risks vary and relate to whether an individual case is complicated or straightforward. If there are pre-existing eye problems or adverse anatomical factors, these will make the procedure more difficult. A large Canadian study showed that two-thirds of surgeries were simple, and one third were complex. Amongst the complex cases, patients with a small pupil (difficulty accessing the lens behind the iris) or intraoperative floppy-iris syndrome (an unstable iris) were the most common.

In this study, around 1 in 50-60 (1.7% – 2.0%) patients had some event during the procedure classed as a complication, but most of these are managed effectively at the time of surgery.

These include a break in the back surface of the lens capsule or escape of vitreous gel. Patients can typically still expect a good visual result.

More serious complications can occur, including infection and retinal detachment.

Infection inside the eye (endophthalmitis) after cataract surgery is fortunately rare and occurs in less than 1 in 3,000-5,000 cases. Vision following endophthalmitis can be poor. Between 60% and 80% of postoperative infections inside the eye is caused by bacteria found on the eyelid margin and within the tear film.

The use of an antibiotic (cefuroxime, or potentially moxifloxacin) that is injected into the front part of the eye at the end of cataract surgery (intracameral antibiotics) has helped markedly reduce the incidence of infection and is now a standard addition to the surgery in many places.

A landmark European study found that not using cefuroxime at the end of the procedure was associated with a five-fold increase in the risk for postoperative endophthalmitis.

Retinal detachment is a rare but possible complication following cataract surgery. It is more common in short-sighted eyes and eyes with preoperative evidence of weakening in the peripheral retina (lattice degeneration).

A large research study published in 2020 showed that the 10-year incidence of retinal detachment after cataract surgery was between 0.36% and 2.9%, with an average figure of 0.7%. The incidence decreases over time to 0.1-0.2% annually (1 in 500-1,000 patients per year) but remains above that of the general population. You should discuss your individual risks with your eye surgeon before the procedure.

The most common reasons why patients return to the clinic after surgery:

1. Vision fluctuation due to dry eye
2. Having a residual prescription, usually astigmatism (if the aim was a refractive correction)
3. Cystoid macular oedema (, CMO, swelling in the posterior retina)
4. Posterior capsular opacification (PCO, a naturally occurring healing process that occurs in around 20% of cases and treatable with YAG laser capsulotomy)

Other complications can include loss of cells from the back of the cornea, leading to swelling and reduced vision (decompensation), implant instability, refractive surprise where there is still a significant prescription needed postoperatively, and glaucoma.

If you total these cases, they combine to less than one-half percent. In most of these situations, vision can be improved with further surgery, a change in medications, or additional time. It is fortunately rare for patients to end up worse than the vision they had before surgery.

Multiple research studies indicate that the clinical outcomes of femtosecond laser-assisted cataract surgery (FLACS, laser-assisted cataract surgery) are not different or superior to conventional phacoemulsification cataract surgery.

Adding a laser to the procedure has not met initial hopes or led to improved vision results, although it does make the treatment considerably more expensive. Laser cataract surgery is not cost-effective when compared with conventional phacoemulsification surgery.

Following an evidence-based approach, we do not recommend choosing laser-assisted cataract surgery over established phacoemulsification cataract surgery.

Prior to your surgery, you will receive a pre-admission form to complete which asks you questions about any current medication you are taking, your medical history and general health. You will then receive a courtesy call from a member of the surgical team to go through this and answer any questions you may have.

Upon arriving at London Cataract Centre, you will be welcomed at reception by one of the team.
Once you are booked in, an ophthalmic nurse will carry out routine investigations, including a lateral flow test for COVID-19, checking your temperature, blood pressure and O2 (oxygen) saturation.

The nurse will explain what will happen during and after the operation and answer any further questions you may have. The aftercare instructions and postoperative drops will then be explained to you.

Once the pre-operative checks have been completed, the nurse will instil eye drops that dilate your pupil in preparation for the cataract procedure. In the privacy of a consultation room, you will have another chance to discuss the operation with your consultant surgeon.

You will be asked to re-consent, stating that you have been provided with, and understand, all the information given relating to the operation (including the risks and benefits of the surgery) and that you agree to the proposed treatment.

You will then be taken to the operating theatre in your own clothes (with the addition of surgical shoe covers and a hair net). It is important to wear something comfortable.

Following the admission process, you will be taken to the theatre, where you will be asked to sit on a special reclining operating chair. The team will then perform their routine surgical safety checks, confirming a few specific details. Please be patient as some questions will be repeated from before, all to ensure your safety and the best possible outcome.

Once the team has signed off the necessary checklist, the chair will be reclined into the correct position for surgery, and we will ensure you are comfortable prior to treatment.

The area around your eye will then be washed and cleansed, and a sterile cover (drape) will be placed over your eye and face to create a clean, germ-free environment. The cover will be lifted off your mouth so you can breathe and talk easily.

The operation is painless and lasts just 10-15 minutes per eye in most cases. The technology used is called phaco-emulsification and employs ultrasound energy to liquefy the lens, which can then be aspirated away. A new lens is then inserted utilising an injection system and is unfolded and positioned within the eye. We typically do not use stitches during surgery, which allows for a faster recovery and means no sutures have to be later removed.

You will see little of what is happening during surgery, but we will explain what we are doing as the operation goes along should you wish to know. The theatre staff will make sure you are comfortable and will help you relax. Someone will be there to hold your hand if you wish.

Initially, you will see a bright light which is the illumination from the microscope, but you will gradually get used to it. Some patients describe it as a light show or like looking into a kaleidoscope. Right at the start, there may be some vision, but this quickly gets very blurry. Vague shapes and movements may be seen.

After the operation, you will be taken to the recovery room where you can rest and will be offered refreshments.

Overall, you will need to allow 2-3 hours for your hospital stay so that we can run through your treatment and aftercare with you. You will need someone to collect you, or we can arrange transport. You may leave the hospital when you feel ready.

After the anaesthetic wears off, about one to two hours following the operation, the eye may water and feel a little gritty. This is nothing to worry about, and your standard headache tablets should settle any discomfort. By the next day, the eye will feel much better.

An increasing number of surgeons and centres treat both eyes at the same visit, and it appears to be safe to do so. Covid-19 has likely increased this trend. Patients overall certainly prefer to have both eyes treated on the same day. Same-day surgery saves additional trips and avoids the period of imbalance between the eyes while waiting for the second eye to be done, and allows both eyes to recover together, minimising downtime after the surgery.

When both eyes are operated on the same day, each eye is treated fully separately. When the second eye receives surgery, different batches of products, e.g. saline, drops, instruments, are used – similar to what would happen if the eyes were operated on several weeks apart. If there was an issue with one batch of products from the manufacturer (extremely rare), the other eye would not be affected.

Hence, we can avoid cross-contamination between the eyes and avoid increasing the risk of infection passing from one eye to the other.

The chance of infection in one eye (endophthalmitis) with modern cataract surgical technique and use of antibiotics is around 1 in 3,000-5,000 cases. The chance of having an infection in both eyes would be in the order of 1 in 400,000 cases.

At London Cataract Centre, we routinely performed cataract treatment to both eyes on the same day. We can discuss this option when you visit for your consultation.

The short answer is “No”.

A cataract is when your clear, natural lens has become misty or opaque, most commonly with ageing. Once this natural lens of the eye is removed, it cannot regrow, and a cataract cannot reform. The artificial lens implant which replaces your eye’s natural lens is a permanent replacement, providing clear vision after the procedure.

Most types of cataract affect both eyes, even if one eye develops a cataract before the other. Unless caused by a purely local effect, e.g. trauma to one eye, you can expect the other eye to get a cataract at some point.

However, there is a condition known as posterior capsular opacification (PCO), sometimes called secondary cataract or after-cataract, where the same type of vision loss symptoms can return following cataract surgery. This can occur months or years later and, not unreasonably, people sometimes worry that their cataract has ’grown back’.

The human lens is wrapped in a thin, transparent membrane called the capsular bag or lens capsule. At the time of cataract surgery, a large hole is made in the part of the capsule in front of the lens. This allows the surgeon to gain access to the hazy, clouded lens (cataract); the cataract can then be split into smaller parts and dissolved using ultrasound (phacoemulsification), removed from the capsular bag and replaced with a new, clear intraocular lens (IOL).

The rear part of the lens capsule (the portion behind the lens) is left intact by design during the cataract removal procedure. The IOL is inserted through the opening in the front part of the capsule, and the IOL is implanted directly inside the bag, in front of the intact posterior bag.

There are always some microscopic lens cells left behind after removing a cataract because it is impossible to eliminate every single cell. Over time, these cells will make a natural healing response which may be enough to make the remaining rear capsule misty.

This mistiness is called posterior capsular opacification (PCO) and happens in around 20% of cases after cataract surgery, anytime from several months up to years later.

PCO is not a complication of cataract surgery, rather a normal and anticipated healing response. About one in five patients will get PCO.

A painless outpatient laser treatment called YAG capsulotomy makes an opening in the rear capsule, restoring clear vision.

If you notice that your vision has become worse some months or years following cataract surgery, PCO is a likely cause, and you might need YAG treatment. A YAG laser session is only required once in each eye after cataract surgery.

Many patients never require YAG because the healing response is insufficient to scar the posterior capsule.

No – the intraocular lens implant (IOL) is designed to last for your lifetime. The IOL is made from a range of high-tech materials that cause no reaction from the body. There are no moving parts, so the lens can’t wear out. They are designed to last a lifetime.

In 1949, the first intraocular lens (IOL) implanted after cataract extraction surgery was performed by Sir Harold Ridley, at St Thomas’ Hospital in London. By the 1970s, IOL insertion following cataract surgery was beginning to be a standard procedure. The material used for the first IOLs was polymethyl methacrylate (PMMA), a rigid plastic material. As the implant wasn’t flexible, the corneal incision had to be at least as big as the IOL. This large incision was its most significant disadvantage, needing suturing and often led to astigmatism after surgery.

The current materials used for IOL optics are composed of two main types—acrylic and silicone.

Acrylic materials can be rigid (PMMA) but are more typically foldable and made of hydrophobic acrylic materials (e.g. AcrySof from Alcon Laboratories) and hydrophilic acrylics (e.g. Centerflex, Akreos). These materials are inert, meaning they do not induce a biological response to a foreign body material.

Yes – these are typically used for up to four weeks after the procedure. Full instructions on how and when to use the drops will be given to you on the day of your cataract surgery.

You can restart gentle low-impact exercise a few days after your cataract surgery. If you wish to participate in more high impact activities, such as running, we advise that they should be avoided for at least two weeks. You should not go swimming for one month in order to prevent the risk of infection. We advise our patients to avoid doing any heavy gardening for a week or so.

Yes, you can, but keep it to light objects only. Don’t lift heavy weights or any weight that would lead you to hold your breath.

Cataract surgery does more than just replace the clouded lens with a new, transparent implant. It is also a refractive procedure, meaning it attempts to correct any pre-existing long- or short-sightedness at the same time.

Exact measurements are taken of the anatomy of your eyes preoperatively. Calculations are performed to work out the best IOL implant power that will leave you with clear distance vision after surgery. Premium lenses are also available privately that will improve the optics of the eye and correct for any pre-existing astigmatism. Advanced multifocal designs can also allow you to read without glasses after surgery.

In summary, cataract surgery can help eliminate or reduce your dependence on glasses as well as getting rid of your cataract.

Following your cataract surgery, your vision will initially be somewhat blurry, and you may be asked to wear a protective eye patch. You should notice that your sight begins to return a few hours after the procedure, and your vision will typically improve quickly over the next 1-2 weeks, reaching its optimum level by 4-6 weeks.

By the following day after cataract treatment, many patients will have vision that is at the legal standard to drive a car. However, we recommend that you should wait until your next follow-up visit to confirm that you are safe to drive. You should feel confident to drive and be able to read a number plate (made after 1st September 2001) from a distance of 20 metres away.

Cataracts do not spread from one eye to the other, and they are not caused by infection (which often does spread to the other eye, e.g. with conjunctivitis). However, most causes of cataracts, including ageing, tend to affect both eyes at roughly the same time. You may find that cataract initially only affects one eye, but in time the other eye will likely develop a cataract too.

Trauma is one cause where a patient may have a cataract in one eye only if the injury was localised to one side of the face.

Typically no, as 98% of cataract surgery is performed as a day-case procedure. The procedure itself takes around 15 minutes, and patients can usually go home less than 60 minutes later. We advise that you bring someone with you, such as a friend or family member.

If you work in a clean environment, for example, in an office, you can expect to return to work in a few days. However, if you work in a dirty or dusty environment, you will need to be more careful to avoid the risk of infection and wait longer before you can safely return.

After you have had cataract surgery, you could fly as a passenger the following day. You will, however, need to think about eye care in your destination – is there a place locally that could assist if you need advice or attention during the early postoperative period?

If you are a pilot, you must be cleared by the Civil Aviation Authority (CAA) as fit to fly before you do. You can click here for more information on the CAA regulations for pilots and cataract surgery.