Cataract implant – Monofocal, toric, multifocal
A cataract is the clouding of the lens, the eye's natural focusing lens. Once removed, the cataract must be replaced with an artificial lens to restore focusing. This is called an intraocular lens implant. Implants are available in different focusing powers, just like glasses or contact lenses. Your surgeon will measure the length of your eye and the curvature of your cornea. These measurements are used to determine the focusing power of your implant, which will be personalized and adapted to your visual needs. Cataract implants are perfectly tolerated, painless, and invisible to the naked eye.
How are implants made?
Most implants are made of acrylic or other plastic derivatives.
The implant may be colorless or slightly tinted yellow.
It is treated with a special filter that helps protect your eyes from the sun's harmful ultraviolet (UV) rays.
In order to be injected into the eye through a micro-incision, the implants are slightly flexible.
The different implants
Each implant has its own specific characteristics in order to correct myopia, hyperopia, astigmatism and presbyopia.
Monofocal implant
These are the most commonly used cataract implants. They have only one focusing distance: distance (emmetropia) or near (residual myopia).
Most patients prefer distance vision correction, in order to avoid wearing glasses in many daily activities.
You will need to use a pair of supplementary glasses to correct near vision if emmetropia is chosen, or distance vision if residual myopia is preferred.
Multifocal implant
Multifocal implants have several focal distances. They allow for the correction of presbyopia.
Current implants are trifocal; they correct distance vision (driving, cinema, etc.), intermediate vision (computer, cooking, meals, etc.) and near vision (reading, smartphone).
These are the most technologically advanced implants.
Because their production cost is higher, they are sold at a higher price by the laboratories and the additional cost is passed on to the patient.
However, they allow for substantial savings on the purchase of glasses.
Be aware that multifocal implants are not magic. Only carefully selected patients will be satisfied. They are energy-intensive, their optical quality is disappointing in the dark, and halos around the eyes can be bothersome when driving at night.
Contraindications to multifocal implants
Multifocal implants are contraindicated if you do not have perfect visual health apart from cataracts. Therefore, you are not eligible for multifocal implants if you have: macular degeneration or macular edema, advanced glaucoma, severe dry eye, or irregular astigmatism.
EDOF depth-of-field implants
Deep-field implants were developed after multifocal implants.
These are implants that correct distance and intermediate vision. Near vision is more limited, but can be corrected with a pair of glasses.
Less energy-intensive and producing few halos, depth-of-field implants are a good compromise for patients wanting some independence from glasses without the constraints of multifocal implants.
Contraindications are much rarer.
Toric implant
If you suffer from astigmatism greater than 1 diopter, it can be corrected with a toric implant.
The implant has a different power in one of its axes in order to compensate for the uneven curvature of your cornea (definition of astigmatism).
The toric implant is placed along the axis of the astigmatism. The correction is not always perfect, and a small, residual, and non-problematic astigmatism may persist.
To improve refractive outcomes, surgeons at the Daviel Ophthalmology Institute in Paris's 17th arrondissement use the Callisto system. This system projects your astigmatism directly into the operating microscope using augmented reality. This digital aid allows for extremely precise implant placement.
Toric implants are available in all ranges: monofocal, multifocal and Edof.
What will my vision be like with my implants?
While the choice of implant often falls within the surgeon's purview, discussing your visual expectations with them to select the most suitable implant is the best approach. Here are the possible visual results:
Emmetropia – Distance vision
This is the most frequently chosen visual option for patients. The surgeon aims for perfect distance vision correction in both eyes, so that the patient is independent of glasses in everyday life: while driving, and in all other visual situations where the object is more than one meter away.
For visual activities requiring close-up vision (less than one meter), such as using a computer or reading, you will absolutely need a spare pair of glasses. If you prefer not to switch between glasses, you can wear progressive lenses that correct distance, intermediate, and near vision.
This is the most frequently chosen visual option for hyperopic or emmetropic patients.
Residual myopia – Near vision
Residual myopia is a frequently chosen option for myopic patients, who are used to removing their glasses to read.
This way your near vision will be clear and independent of glasses.
For all activities located more than one meter away, you will need a pair of glasses that correct myopia.
Multifocality – Clear vision at a distance and up close
Multifocal lenses allow for the correction of distance, intermediate, and near vision. This visual result is achieved with multifocal implants.
Your vision will be independent of glasses in over 90% of daily activities. However, for reading very small print, such as on insurance contracts, you will need to use a small pair of magnifying glasses.
Multifocal vision is frequently requested by patients. However, the optical function of these implants can sometimes cause discomfort, particularly for patients who enjoy reading in the evening or driving at night. If this is contraindicated, consider an EDOF implant or monovision.
Monovision, also known as flip-flop
Monovision, also called monovision correction, is an optical correction technique that allows you to remain independent of glasses 70 to 80% of the time. The surgeon corrects your dominant eye for distance vision, while maintaining a slight myopia in your non-dominant eye.
When properly dosed, this technique eliminates the need for glasses without the drawbacks of multifocal implants. However, binocular vision is sometimes slightly impaired.
Side effects and complications
Intraocular implants are made of inert materials. They are therefore perfectly tolerated. If your eye itches after the operation, it's not because you can feel the implant, but because your eye is irritated. Here are some rare side effects of implants:
TASS – This is an inflammatory reaction triggered by the implant's storage fluid. The eye becomes red and very painful when the anti-inflammatory eye drops are stopped.
Dysphotopsia – These are bright streaks in the periphery of the field of vision, caused by the edge of the implant. They tend to disappear spontaneously.
Implant dislocation – Sometimes the implant can shift because the capsular bag containing it is fragile. In this case, further surgery is required to replace the implant.
Price of a cataract implant
The price of a cataract implant varies depending on the model. Depending on the complexity of the implant chosen, the clinic may pass on part of the cost to you. Here are some price ranges:
Monofocal implant – It is always free and included in the hospitalization package. This is the standard implant.
Toric implant – Toric implants often have a controlled surcharge, rarely exceeding €150. They are ordered in advance and sometimes custom-made!
Multifocal implants – Multifocal implants always come at an additional cost. From the perspective of social security, they are considered a cosmetic accessory that allows one to become independent of glasses. Their price varies on average from €200 to €300.
Multifocal toric implant – These are the most complex implants, with prices ranging from €350 to over €550. Their manufacture is expensive and highly technological.
EDOF implant – Its price varies enormously from one manufacturer to another! They may have no additional cost, or on the contrary be sold at a high price.
Choosing your implant
Planning the procedure with your surgeon will help you choose your implant. One thing is certain: skimping on the price is a shame, as it will remain in your eye for life and correct your vision.
Discuss your visual expectations with your surgeon so that their choice of implant is as close as possible to your expectations and budget.
Remember that some health insurance companies cover the extra cost of the implant because they make substantial savings on the price of your glasses afterwards!
Frequently Asked Questions
Can a cataract implant be changed?
Yes! Touch-ups are possible: implant replacement, laser correction, etc. However, the benefit-risk balance is not always in favor of a new intervention.
Which implant is best for cataract surgery?
There is no perfect universal implant! However, here are some tips on choosing an implant:
Correct your astigmatism with a toric implant if it exceeds 1 diopter (1D).
Opt for a multifocal implant if you wish to be independent of glasses and do not frequently drive at night.
If there is a contraindication to a multifocal implant, discuss with your surgeon the possibility of an EDOF (depth of field) implant.
What is the best implant for cataracts?
Implants sold in France meet strict European standards, so they are all of high quality. The best implant is therefore the one that best suits your visual habits.
Toric if you are astigmatic.
Multifocal or EDOF if you do not wish to wear glasses.
Can the cataract implant move or shift?
Yes! The situation is rare but not exceptional. The implant can dislodge following trauma or in the case of a genetic condition called "pseudo-exfoliation".