With Refractive Cataract Surgery the natural lens of the eye is removed. Without a replacement lens, the vision would be very poor indeed.
Therefore, inserting a new lens implant is what this surgery is all about. The type of lens implant you receive will determine the type of vision you have after your surgery.
Your vision goals
Once you’ve decided that you are going to have Refractive Cataract Surgery, the most important decision you will make is the type of lens implant you want to replace your natural lens with. This depends on how you feel about needing to use glasses for:
- Near activities such as reading, using your mobile phone, seeing labels on packets and prices in shops, sewing and doing arts and crafts, and other close-up tasks
- Intermediate distance activities such as using a computer, painting, reading sheet music, seeing a car dashboard, browsing labels in shops
- Far distance vision
Finding the perfect fit
The most important step in choosing the correct strength in the lens is called biometry.
Biometry is the set of measurements that are taken before the surgery, usually at the first consultation. The measurements are used to calculate the power of the lens implant that will be used during the surgery.
Several aspects of biometry are crucial in optimising the accuracy of the lens choice and the visual outcome of surgery.
Prof Mohammed Muhtaseb takes biometry extremely seriously and uses the latest technology to take the most accurate measurements which are then entered into the calculation formulae that are shown to give the most accurate refractive outcomes that are closest to the pre-operative planned targets.
One of the most important, and sometimes under-estimated, issues in pre-operative planning is that of astigmatism.
Once the biometry measurements have been taken, Prof Muhtaseb looks specifically for any pre-existing astigmatism and determines if a toric lens implant should be used to minimise post-operative astigmatism. Indeed, if astigmatism is not specifically accounted for during the pre-operative planning phase, the surgery itself can lead to a greater degree of astigmatism post-operatively and the need to use glasses at all times to achieve clear vision.
The lens range
The main types of lens implant are described below:
Providing a single point of focus the distance vision is usually good but glasses are needed for intermediate and near
Enhanced monofocal IOL
Provides good distance vision with a functional level of intermediate vision (e.g. for using the computer); glasses are required for seeing smaller fonts on the computer and for reading up close
Multifocal / Trifocal IOL
Provides the greatest range of focus with good vision at distance, intermediate, and near.
If you have astigmatism a toric version of the above IOL types may be recommended to achieve the best vision after your surgery. Almost all IOL types are available with a toric correction for astigmatism, and so patients that have astigmatism should be able to choose from the full range of IOL types.
Patients may choose a standard monofocal IOL if they are happy to wear glasses for intermediate and near activities.
However, many patients elect for a more advanced, or premium, trifocal IOL if they like the prospect of seeing in the distance clearly and then being able to read, look at an iPad, and use a computer without needing to look for their glasses.