How do I decide what lens type to have?
When your clouded lens is removed, it is replaced by an intraocular lens — or IOL for short. By learning about your visual needs and goals, Ms Pearsall can choose the type of IOL that is right for you.
IOLs are designed to stay in your eye for life. We can offer a variety of options designed for different conditions and lifestyles, but each one is built to help keep your vision clear and sharp over time.
CAN ENHANCE YOUR VISION AT DISTANCE
First of all ask yourself…
Cataract surgery is a unique opportunity to address other visual conditions, like presbyopia and astigmatism, without an additional procedure.
Your lens, which helps you focus, is removed during the operation and is replaced with an artificial lens, the intraocular lens implant. There is a choice of different strengths (powers) of lenses which, just like different strengths of glasses lenses, affect how clearly you see when looking into the distance or when looking at near things such as reading a book.
During your initial assessment, we will discuss with you whether you want to have better focus for close vision or for distance vision. Most people choose to aim for good distance vision after the operation. If you choose this option, you will usually need reading glasses and you may still need glasses for fine focusing in the distance.
Some people choose to aim for good close vision, especially if they like to read without glasses or do a lot of detailed close work such as embroidery. If you choose this option, you will need glasses for distance.
The TECNIS® Monofocal IOL is designed to deliver excellent, high-quality vision. It can help you see far away, which means you’ll likely need glasses to focus on near objects.
The pre-operative measurements usually allow your surgeon to choose a lens implant which gives the desired near or distance vision, but individual patient responses vary and it is not possible to guarantee absolute accuracy.
Sometimes, patients can have an unexpected need for moderately strong glasses following surgery despite correctly taken measurements and uncomplicated surgery.
Astigmatism is a condition in which the eye is not a perfect sphere but slightly more egg shaped and means that light is focused differently depending on which direction it approaches the eye. The effect is blurred vision, and can be corrected by glasses, contact lenses or laser surgery, just like other focusing errors.
Any significant astigmatism can be corrected with glasses but if you are having any form of lens surgery you have the opportunity to have your astigmatism corrected using toric intra-ocular lenses which can reduce your dependence on glasses. The less astigmatism you have, the better your distance vision will be, but, as with standard lenses, you will still need to wear glasses to read.
Benefits of toric lenses are maximised by making sure that the lenses are put in exactly the correct position so the the direction or “axis” is accurately aligned. The axial position of the lens is not important in non-toric lenses but in toric lenses it is of paramount importance.
TECNIS® Toric IOLs address astigmatism at the time of cataract surgery. They are available in monofocal for distance vision and in extended depth of focus for continuous vision across the full range.
These images are for illustrative purposes only and do not represent actual data derived from studies. These illustrative simulations are intended to help you better understand your vision in certain eye conditions.
Toric 1-Piece lens is useful for the visual correction of pre-existing corneal astigmatism in adult patients with or without presbyopia, to improve uncorrected distance vision, reduction of residual refractive cylinder and increased spectacle independence for distance vision.
Toric lenses are not required if you are happy wearing glasses for distance, and are not suitable if you have other eye problems apart from cataract and high astigmatism, or if the astigmatism is not caused by the shape of your cornea (the clear window of your eye).
What are the risks of toric lenses?
The surgery is the same as standard cataract surgery except, once the toric lens has been inserted, it is carefully rotated to the correct position (angle) for each patient. A standard lens does not need to be placed so precisely.
There are some potential risks with toric lenses:
A toric IOL corrects astigmatism when it is placed correctly in the eye. There is a chance that the toric IOL could be placed incorrectly or could move within the eye. We may need to move the lens to the right position following surgery. If the toric lens is not placed correctly, you may have visual distortions. A second surgery may be needed to properly position the lens.
A toric lens may not fully correct the astigmatism and you may still need glasses for distance. Further correction of this remaining astigmatism may not be possible.
If complications occur during cataract surgery, it may not be possible to insert a toric lens and a non-toric lens may need to be used.
The lens can rotate and a second operation may be needed to rotate the toric lens back into position for best vision, with the additional risk of further surgery.
Some patients may require further surgery to remove the toric lens and replace it with a standard lens.
There are some alternative options to using toric lenses for those with high astigmatism. You may choose surgery with standard lenses and correct the astigmatism with glasses or contact lenses. Standard cataract surgery can be combined with additional cuts in the cornea (limbal relaxing incisions) to reduce the astigmatism, but this is less accurate.
The significant benefit these offer beyond the traditional monofocal lens implants is that the allow you to see clearly for both near and distance, independent of glasses. Multifocal contact lens design has been around for over a decade, but recent advances have brought this technology to the point that most patients needing cataract surgery.
We will carefully examine and evaluate you to determine the best option for you. Often we may recommend a different lens type in each eye to ensure you achieve the best all round visual freedom.
If you have significant astigmatism, we may decide that a multifocal toric lens is the best option to achieve visual freedom. These lenses are custom made for your eye and combine multifocal lens implant with a topic lens implant.
The TECNIS® Multifocal 1-Piece Intraocular Lenses are ideal for adult patients with and without presbyopia in who wish to have near, intermediate, and distance vision with increased spectacle independence.
The TECNIS Symfony® Extended Range of Vision IOL, model ZXR00, is ideal for primary implantation for those who wish to have useful vision over a continuous range of distances including far, intermediate and near, and increased spectacle independence.
Who is the multifocal lens not suitable for?
They are not necessary for people who are quite happy wearing glasses. They are not advised for people with very high distance vision requirements or who drive frequently at night. Patients with cataract in only one eye. Patients with other eye disease as well as cataract. Some patients with high refractive errors, especially astigmatism.
How well does the multifocal lens work?
Most people with multifocal lenses in both eyes will be able to perform their usual daily tasks without glassesThese lenses offer reduced dependence on glasses, with around 1 in 3 people achieving total freedom from glasses, and most people finding they can do without glasses most of the time, with most of the remainder still using reading glasses for very small print or prolonged reading. As with monofocal (standard) lenses around 1 in 5 people find they prefer to wear glasses all the time for best vision
What are the risks of presbyopic lenses?
Multifocal lenses do not work for all patients and may cause some visual quality problems. Routine cataract surgery risks, irrelevant to lens selection, could be minor, temporary, or affect patients’ vision permanently. Rare complications are worsening of vision, bleeding, or infection.
If your eye is unhealthy (including glaucoma), vision may not be good even after cataract removal; patients may not get full benefit of the TECNIS Symfony® IOL. Before surgery, we will check for any eye diseases.
Whereas your use of glasses may decrease, it may come at the cost of some sharpness of your vision. There is also a chance that your vision with a multifocal IOL may not be good enough to perform very near or detailed “up-close” work without glasses. Depending on the type of TECNIS® Multifocal 1-Piece IOL you choose, the lens is designed for near vision from 33 to 50 cm.
Rarely it may also make some types of retinal treatment (e.g., retinal tear repair) more difficult. You should avoid any activity that could harm your eye while you are recovering from surgery. We will tell you what activities to avoid while you are recovering from surgery.
Risks related to use of this lens include a slight loss in vision sharpness with decreased use of glasses. Even with glasses, loss of sharpness may worsen under poor visibility conditions such as dim light or fog. Patients may also notice halos, starbursts, glare, and other visual symptoms with extended range of vision and multifocal IOLs. This may lead to driving difficulties, and not detecting road hazards as quickly at night or in fog. This may impact patients when there are bright lights at night. Therefore, you may need to take extra care when driving, especially in poor light conditions. A small number of patients may want their TECNIS Symfony® or TECNIS® Multifocal IOL removed because of lens-related optical/visual symptoms.
Day and Night
With a presbyopia-correcting IOL, you may see halos, glare and starbursts, especially at night around bright lights. This is normal and may potentially become less noticeable after a few months.