Due to modern methods of cataract extraction, a cataract does not need to be ripe before it is removed. Hence, cataract can be removed at any stage even when it is very mild. The most important question to ask is whether the cataract is causing any visual symptoms. If these visual symptoms are affecting a patient’s quality of life and restricting their activities of daily living, cataract surgery should be considered. There is certainly no age limit for cataract surgery and the procedure can be done at any age, from babies to people well over 100 years of age.
Before embarking on cataract surgery, patients will need to sign a consent form to say that they agree to have the surgery. The consent form shows there has been a discussion about the benefits, risks and alternatives to cataract surgery. This should be seen as a healthy part of patients giving informed consent to medical treatment. Consent is a process that can begin before the patient has even seen the eye surgeon – if they have had the chance to read material about cataract surgery such as this article. During a consultation with the doctor, the benefits, risks and alternatives of surgery will be discussed after which the doctor and the patient sign a consent form to confirm agreement. It is good practise for the patient to receive a copy of the consent form in either paper or electronic format. It is also good practise for the consent to be confirmed on the day of surgery to ensure that all questions have been answered.
Biometry is a crucial process that is done as preoperative assessment before cataract surgery. Cataract surgery involves inserting an intraocular lens into the eye to give patients the best possible vision. In order to predict the correct power of this lens to be used, it is essential to take good measurements of the eyes.
During biometry, measurements are taken of the power of the cornea as well as the internal measurements of the eye including the overall length of the eye. In the past these measurements had to be taken separately but new modern biometers can do it very quickly and efficiently. The best devices on the market are the IOL Master and the Lenstar. These machines are able to use various intraocular lens calculation to give the best prediction of the intraocular lens power to use.
To get the most accurate results, it is important that the cornea is in it’s normal resting shape. For this reason, patients who wear contact lenses should take these out for a certain time before the biometry test is done. For soft contact lenses, these should be removed for one week before the biometry test. For rigid gas permeable contact lenses, these should be removed for one month before biometry is done. After the biometry is done, there is no objection to patients wearing contact lenses before the cataract operation.
If biometry reveals that a patient’s cornea has astigmatism more than one diopter, they usually benefit from having corneal topography to determine whether the astigmatism is regular or irregular. The reason this is important is because if the astigmatism is regular, patients may benefit from having a toric lens inserted at the time of cataract surgery. This helps reduce dependence on glasses after surgery.
+ Does it matter I have had laser vision correction before?
It is quite common for patients who’ve had previously laser vision correction to develop cataract and need cataract surgery. Surgery in these patients normally proceeds very well without any problems. It is however important to note that there is a slightly higher risk of refractive surprise after cataract surgery. This may mean an increased dependence on glasses after surgery.
+ What types of anaesthetic are available for cataract surgery?
Cataract surgery typically takes about 20 minutes and in most patients is done under a local anaesthetic. There are various types of anaesthetic and I will discuss them in turn:
+ What happens on the day of surgery?
On the day of surgery, you will be shown to your room where you will be able to get comfortable and relax. The nurse will put drops in your eyes to begin the dilation of the pupil ready for surgery. This can take 30 minutes to an hour. I will then come and see you as your surgeon where I will check to see if you have any questions and confirm your consent. I will also put an arrow above the eye to be operated on as this is an important safety measure.
There will then be a bit of a wait until the pupil is well dilated and when the operating theatre is ready. When you are sent for, the porters will help bring you to the operating theatre where you will have your procedure.
After the operation, you will have a short period of recovery and then you can go back to your room where you can enjoy a nice cup of tea and a bite to eat. There is no problem with you going home the same day. You will have a shield on the eye to protect it. This can be removed the following day ready to put drops in.
+ What happens during a cataract operation?
When you are in the anaesthetic room, the nurse will put antiseptic and anaesthetic drops in to cleanse and numb the eye. After this, you will go into the operating theatre where I will help position you on a trolley. It is important that you’re comfortable, so you will have good neck and knee support throughout and plenty of fresh air to breathe. A drape will be used to keep the operation sterile, but there will be plenty of fresh air to breathe from a tube under your chin.
After instilling more anaesthetic into the eye, I will make small incisions into the cornea which will then allow me to make a round opening in the front of the lens. This is called a capsulorhexis. I will then use ultrasound power to break up the cataract in a process called phacoemulsification. Any remaining cortical parts of the cataract are then removed with suction. This leaves behind the lens capsular bag. The acrylic intraocular lens is then inserted into the eye in an injected form and this opens up inside the capsular bag, where it is held securely. To finish off, antibiotics are instilled into the eye to prevent infection.
+ What if I move, cough or blink during the surgery?
In my experience, many patients are naturally concerned about moving, coughing or blinking during the operation. These anxieties are very natural but not well-founded. Most patients are positioned in a very comfortable way with plenty of neck and knee support so that moving is not particularly necessary. The eye is held open with a little clip, so blinking is not a problem at all. Most patients are worried about coughing but this isn’t an issue in the great majority. For patients who do have a significant cough, they are instructed to give the surgeon a few seconds of warning by raising their hand before they can cough in a safe way.
+ What happens after cataract surgery?
After cataract surgery, the eye will be covered by a plastic shield to protect it. This should remain on the eye for the day of surgery and can be removed the following day to get drops started. It’s a good idea to wear the shield at night for the first week to protect the eye from your pillow.
You can wash your hair and shower as normal, but avoid getting water directly into the eye for the first week after surgery.
Almost all patients will need drops after the operation to prevent infection and to help the eye settle after surgery. These drops are usually four times a day for four weeks.
Most patients tend to be reviewed at around 3 weeks after surgery although this may change if there are pressing clinical needs.
Patients naturally ask about how quickly their vision will improve after surgery. This does vary but most of the improvement happens in the first week, with full improvement taking one month. After one month, patients can go and see their optician for new glasses unless they are considering having their second cataract operation done sometime soon.
+ Can I have cataract surgery if I have macular degeneration?
Cataract surgery can improve the vision significantly even in patients with macular degeneration. It is important to note that the macular degeneration will not be changed by removal of the cataract so we tend to talk of a guarded prognosis for cataract surgery. This means that the vision will be limited by the severity of the macular degeneration but nevertheless, cataract removal can improve vision very significantly indeed.
+ What types of intraocular lenses are there?
The field of intraocular lenses can be very confusing for patients due to the many different manufacturers as well as the many different types, all with slightly varying nomenclature. I will try and simplify things by talking broadly in terms of categories. I only use the best hydrophobic acrylic lenses on the market from the most trusted of manufacturers.
+ What are toric lenses?
These lenses correct for astigmatism in the cornea. They are a good idea in patients who have more than one diopter of astigmatism in the cornea as this can necessitate the need to wear glasses for distance, intermediate and reading. Toric lenses have been proven to reduce glasses dependence and should be considered when there is significant corneal astigmatism. Most quality monofocal, multifocal and EDOF lenses come in toric varieties to correct for corneal astigmatism.
+ Will I need glasses or contact lenses after cataract surgery?
About 80% of patients having a monofocal lens during their cataract surgery will not need glasses for distance vision. However, all will need glasses for reading as well as for using a computer or tablet.
For patients who are having a multifocal lens during cataract surgery, the dependence on glasses for reading and using computers will be drastically reduced.
For patients having extended depth of focus lenses, reading glasses will be needed for fine print but the majority will not need glasses for distance or using a computer or tablet.
Unfortunately, none of the above can be guaranteed as all of this is based on computer prediction, but the accuracy of this is relatively high.
+ What are the complications of cataract surgery?
Cataract surgery is the most commonly performed operation in the world and generally has a very high success rate. Nevertheless, it is important to talk about the potential side effects and complications so that patients are well informed before embarking on surgery.
+ Will my cataract return?
Once removed a cataract does not return. However, it is quite common for patients to get clouding of the capsule holding the lens in position. The scientific term for this is posterior capsule opacification. This happens in about 20% of patients. The treatment for this is a laser procedure that is painless and usually done in clinic. In total, this normally takes about 10 minutes to do and patients experience an almost instant improvement in their vision.
+ Will the new lens need to be replaced?
Modern intraocular lenses have a superb safety record. They are designed to remain in the eye for life and the great majority will never need to be removed. Further surgery on the lens may be needed if the lens becomes cloudy or moves out of position. However, this is very rare and certainly not the norm. In fact, removal of the lens as a later procedure presents its own complexities and is something to be avoided wherever possible.
Cataract surgery is a wonderful procedure and can improve the vision in patients with visually significant cataract. Nevertheless, due to the associated risks, the operation should only be undertaken in patients who have significant symptoms that cannot be overcome with glasses. New generation lenses can reduce the need for glasses after cataract surgery, but multifocal lenses can give patients glare and halos when driving at night.
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