Presbyopia is a reduced ability of the eye’s natural lens to focus at near. This occurs naturally with increasing age and is mostly noticed as we enter our mid-40s. Near vision becomes more blurred and we hold material further away to read it. Soon afterwards we may need to start using reading glasses.
Patients that undergo cataract surgery with a monofocal lens implant also need to use reading glasses to see clearly at near distances. This dependance on reading glasses may be reduced by opting for a multifocal lens implant at the time of initial surgery.
The most appropriate treatment option for each individual will depend on several factors. These include your exact spectacle prescription, the precise clinical examination findings, your age, your job and hobbies, if you have any other eye conditions, and other issues that will be discussed at your consultation.
In principle, treatment options will include:
Refractive lens exchange with a choice of lens implant options
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Presbyopia Correction & Refractive Lens Exchange Treatments
Multifocal Intraocular Lenses (mIOL’s)
Multifocal Intraocular Lenses (mIOL’s) employ new technology to mimic the process of accommodation – they are sometimes called pseudoaccommodative IOL’s.
They create focal points for light coming from far, intermediate and near objects – but the patient only sees the object of interest.
The eye’s lens has the ability to change shape. This allows it to focus light on the retina whether the light is coming from far away (the lens becomes thin), from a near object (the lens becomes thick) or from anywhere in between. This process is called accommodation, and is strongest in early life. However, the lens’s ability to accommodate declines with time because of a natural loss of its elasticity. Presbyopia is the result of these changes and is noticed when we reach our 40’s and 50’s. This is why reading glasses become necessary – they provide the extra focusing power required to see near objects.
When the natural lens becomes cloudy with the passage of time, this is called cataract. During cataract surgery, the natural lens is removed and replaced with a clear plastic lens. This new lens is monofocal, and is best able to focus light on the retina from one distance. Spectacles are then required to see clearly at other distances. Usually, patients like to see clearly in the distance and use spectacles for intermediate (computers, painting, sheet music) and near (reading) work. However, there are some exceptions.
I am considering cataract surgery or refractive lens exchange, but I don’t want to rely on glasses to read afterwards”. Instead of a standard lens implant, you may consider choosing a ‘premium’ lens to reduce your reliance on glasses for reading and other ‘near vision’ activities. Such lens implants include multifocal and accommodating lenses.
Multifocal Intraocular Lenses (mIOL’s) employ new technology to mimic the process of accommodation – they are sometimes called pseudoaccommodative IOL’s. The main mIOL’s I currently use in my practice are illustrated below. They create focal points for light coming from far, intermediate and near objects – but the patient only sees the object of interest.
It is not usual to implant a monofocal IOL in one eye and a multifocal IOL in the other. The eyes most commonly receive the same kind of lens, although each case is treated individually and each patient is advised with their best interests in mind. Depending on an individual patient’s requirements, the same mIOL may be used for both eyes or a “mix-and-match” approach to mIOL implantation may be advised.
With most multifocal lenses, astigmatism needs to be accurately corrected before or after the lens has been implanted and there are several ways of doing this. However, the Trifocal lens is available in a ‘Toric’ form. This means that the lens implant corrects astigmatism in addition to giving good distance and reading vision. This is all done in one operation and avoids multiple surgeries with higher expenses.
The lines on the lens mark the axis of astigmatism correction. This allows the surgeon to place the lens in exactly the correct orientation in the eye that allows patients to enjoy their full visual potential without glasses: Far and Near.
No, but the chances are significantly increased compared to a standard lens. The vast majority of patients are able to see satisfactorily at all distances without using glasses. However, some people may need to wear spectacles for some tasks, such as using a computer, reading for prolonged periods of time or driving at night. It is important to understand that there is a difference between “satisfactory” vision and “crystal clear” vision. For example, a patient may have vision that is “crystal clear” (or 20/20 vision) for distance and near tasks and “satisfactory” (or 20/40 vision) for intermediate distance. When analysing reports about these lenses, it is also important to be aware that some studies give the proportion of patients who “never wear spectacles” whereas others give the proportion who “either never or only occasionally wear spectacles” – these are different measures and should not be compared as though they are the same thing.
Glare, halos and reduced contrast sensitivity. Glare and halos may occur after implantation of regular monofocal IOL’s as a result of lens design. They are more likely with mIOL’s because, in addition to lens design effects, mIOL’s create in-focus images for distance and near objects simultaneously and this overlay of images can cause symptoms. Contrast sensitivity is the ability to differentiate between an object and its background. A reduction is inevitable following implantation of mIOL’s, and the tolerability of this depends on the patient’s expectations. Unrealistic expectations often lead to disappointment in the visual outcome. The following table is provided as a brief summary of outcomes. Please note that a great number of studies have been performed to look at the outcomes of lens surgery and implantation of monofocal as well as multifocal IOL’s. You should ask any questions you have before you make a decision regarding your desire to have mIOL implantation.
A small proportion of patients (between 0 and 2% in different studies) have experienced symptoms of such severity that they have requested the mIOL be removed.
No. People who are long-sighted (hyperopic) or emmetropic (no spectacle correction required) tend to have favourable outcomes more often than those who are short-sighted (myopic). Astigmatism may need to be corrected before mIOL implantation, depending on the examination findings. Most surgeons would advise against mIOL implantation for the following categories of patients: Patients that are hypercritical with unrealistic expectations Patients with excessive complaints about their prescription Patients who drive at night for a living or whose occupation or hobbies require night vision Patients who are amateur or commercial airline pilots Patients who have life long complaints about glare Patients who are happy wearing glasses Patients who want guarantees on surgical outcomes Those with co-existing eye problems e.g. corneal problems, glaucoma, and macular degeneration, amongst others.
Our Most Popular Procedures
When the natural lens becomes cloudy with the passage of time, this is called cataract.
During cataract surgery, the natural lens is removed and replaced with a clear plastic lens.
A monofocal lens is best able to focus light on the retina from one distance.
This dependance on reading glasses may be reduced by opting for a multifocal lens implant at the time of initial surgery.
Presbyopia Correction & RLE
Presbyopia is a reduced ability of the eye's natural lens to focus at near. This occurs naturally with increasing age and is mostly noticed as we enter our mid-40s.
This dependance on reading glasses may be treated by replacing the natural lens with a multifocal lens implant. This is called Refractive Lens Exchange (or RLE).
Piggyback Lens Implants
A Piggyback Lens Implant can be implanted after previous cataract or RLE surgery but where the patient still requires glasses for seeing in the distance, for reading, or both. Piggyback lenses can reduce this dependance on glasses.