Extended Depth of Focus (EDOF) Intraocular Lenses (IOLs)
Reading vision issues begin from our early 40’s and for some, distance vision issues can creep up too. It can feel like it happens overnight. One minute you’re carelessly looking at your phone, reading small print and menus and the next… you are squinting into the mirror and holding things further and further away.
This uncalled-for phenomenon is known as ‘presbyopia’. A gradual, age-related loss of the eyes’ ability to focus actively on nearby objects. The Gen X and Boomers of society are the current target in 2024.
The first port of call for a lot of people is to head to the Optometrist for an eye test & often, some new glasses. Or for others, a cheap pair of off the shelf readers to give that needed boost in vision.
But there is another option!
EDOF IOLs for Gen X & Baby Boomers
Extended Depth of Focus Intra-Ocular Lenses, or extended range of vision.
Conditions such as presbyopia and cataracts are a natural part of aging. Thankfully, there are options available to treat these occurrences and lens technology is better than ever. EDOF IOLs are a new development in the treatment of presbyopia. During a refractive lens exchange (RLE) or cataract surgery, a new EDOF lens is inserted into the eye(s).
Refractive lens exchange (RLE)
The aim of RLE surgery is to minimise the need for glasses and contact lenses. People want to live day to day without the inconvenience of visual aid. By replacing either one or both natural lenses within the eye(s), patients can achieve visual freedom. Vision results from RLE are permanent* and removal of the natural lens ensures that a cataract cannot form in your later years.
*Excluding the onset of vision impairment as a result of unrelated health conditions.
What vision improvement does an EDOF IOL offer?
There are various types of IOLs (intra-ocular lenses) that offer a variety of vision outcomes. The EDOF IOL provides clear distance and intermediate vision whilst offering improvements to near vision. Dr Furness describes your near vision outcome by saying ‘you will be able to read your phone or a menu at arm’s length.’ The opportunity to perform several near vision related tasks without visual aid that are not currently possible.
EDoF/EDOF IOLs as the name implies, are designed to provide that extra range of focus, without impairing distance vision clarity. They give good clarity similar to monofocal distance IOLs, however, give that little bit extra focus at the intermediate range. Most patients with EDOFs set up for distance, will find distance and arm’s length vision is good, but will still need glasses for near work (ie. small print, reading books). But EDOFs can be set up like monovision and reduce the need for optical aids.
There’s a spectrum of EDOF IOLs and how they work differs immensely as some still induce glare and halos whereas others have less potential of causing this issue. The EDOF IOLs (from the RayOne company) that Dr Furness is preferring now, has anecdotally not caused noticeable problems in terms of glare and halos.
Why are EDOF IOLs different to trifocal (TF) IOLs?
EDOF IOLs eliminate the overlapping of near and far images caused by traditional trifocal IOLs (also commonly referred to as multifocal – MF). As a result, glare and halo effects at night-time are vastly reduced/eliminated.
EDOF lenses also provide a continuous range of focus rather than 2-3 focal points.
Are EDOF lenses suitable for everyone?
There are various reasons for a patient not being suitable for this type of lens. Some common contraindications are age-related macular degeneration, glaucoma or corneal irregularities. A patient may also prefer a different vision outcome offered by a different IOL type.
Other vision outcomes include:
> Distance vision in both eyes – Distance vision and intermediate vision are of a high standard, but patients will require glasses for reading and other near vision activities
> Monovision – One eye, typically the dominant eye, is corrected for distance vision clarity. The other eye is corrected for near vision. This is a very popular vision outcome, however, approximately 20% of patients’ brains cannot adapt to this type of imbalance between the two eyes.
> Trifocal lenses – Trifocals (TF) offer distance, intermediate and near vision in both eyes. Vision at all three distances is slightly compromised to obtain the ability to see well without optical aids. Distance vision, in most cases, is not as clear with a TF as it is with an EDOF IOL.
What happens during RLE / cataract surgery?
To prepare your eye for surgery, Dr Furness recommends you begin an antibiotic eye drop three days prior to your procedure. On the day of your surgery, your procedure is likely to take only twenty minutes although you will be at the hospital for approximately 3 hours. During this time, you will be met by the nursing staff who will go over some pre-admission questions with you and prepare you for your procedure.
Most patients have a local anaesthetic to numb their eyes which is in the form of an eye drop and a mild sedation to help with any nerves or anxiety. Some have a general anaesthetic for various reasons which may include severe anxiety making them at risk of large movements, underlying health issues, preference and many more. Your eligibility for a GA will be assessed by your anaesthetist.
Your doctor will guide you through the procedure and advise you where to focus. You should NOT experience pain during your procedure. Occasionally, you might experience a small amount of pressure usually preceded with a caution from your doctor.
A 2mm slit is made in the cornea and your doctor will use a small instrument to break up and remove the (cloudy) lens from inside the eye. Once removed, your doctor will then insert the new lens and position it in place. No sutures are needed as the incision is so small and your eye begins to heal immediately.
What happens after your RLE / cataract surgery?
A quick post-operative check is performed on the day of your procedure or the following morning to check the pressure of the eye. It is very common to see a temporary increase in ocular pressure after surgery. Various solutions are available if you experience this so, please do not be alarmed.
You will attend the clinic for a post-operative check-up 10-14 days after each eyes surgery (if the procedures are performed on separate dates).
Related Pages
https://insighteye.com.au/monovision-contact-lens-rle-eye/
