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Laser Lens Replacement

Laser Lens Exchange, Natural Lens Replacement, PRELEX, LLR

Laser Lens Replacement is the Centre for Sight terminology that literally describes the procedure to avoid any confusion. Also known as Natural Lens Replacement, Laser Lens Replacement (LLR), Presbyopia Lens Exchange (PRELEX) and branded by some as Clarivu™* or NuVu. This is a process where the natural lens of the eye is replaced with a multifocal/trifocal or high performance lens implant to correct vision. Use of lenses such as the Trifocal lens from Physiol or Zeiss, provides spectacle independence. We choose to perform ALL Laser lens replacement procedures with the highly sophisticaled Victus femtosecond laser introduced to the UK by us in 2012. With over 2000 laser lens replacement procedures Centre for Sight is amongst the most experienced centres providing this type of care in Europe.

Laser Lens Replacement / Exchange

The procedure is very much like cataract surgery, the most common surgical procedure performed in the world. It is performed as a day case where no overnight admission is needed. Patients are at the Centre for half a day and go home.  The goal of this procedure is to provide spectacle independence. In order to obtain consistently good outcomes, a phenomenal level of accuracy is required both in terms of planning and actual procedure. The procedure is performed through a microincision (1.8mm at Centre for Sight) and ALL patients are treated using the Victus femtosecond laser – no uplifts in price and no compromise!

Why Replace the Lens ?

As we advance in age, the natural lens in the eye becomes harder and does not deform or change shape sufficiently to alter focus. The lens needs to change shape in order to focus on objects close by for instance when reading. The natural lens starts to function poorly from early 40s onwards and gets progressively worse with increasing age. The requirement for glasses  to enable one to read or view close objects as a result of poorly functioning lens is called Presbyopia. The term “Dysfunctional Lens Syndrome” is also being used to literally describe the condition.

Keeping in with the theme of terminology, Natural Lens Replacement, Laser Lens Replacement, Presbyopia Lens Exchange (PRELEX) are all used to describe the same process.  Some providers in an attempt to “de-medicalise” the procedure use brand words such as Clarivu™ or NuVu. We at Centre for Sight believe this is confusing for those interested in vision correction. Patients often think the brand word is a type of lens implant.  In the interests of transparency and to avoid misleading our patients, Centre for Sight as a doctor-led organization prefers to use commonly used descriptive medical terminology.

The laser lens replacement procedure involves removal of the poor functioning or “dysfunctional” lens in the eye and replacing this with a high performance lens implant such as Multifocal (Trifocal), accommodative or extended depth of focus .  These implants correct distance, intermediate and near vision providing spectacle independence and the choice of lens used is based on many factors including amongst many others, age, optical system, medical and eye health, livelihood and hobbies of the person seeking vision correction. Note those who have Diabetes are not suitable for Lens replacement surgery unless they have cataracts. The choice of lens is also limited to Accoommodative Crystalens, the WIOL-CF extended depth of focus lens or monofocal lens implants. 

“Replacement of the “Dysfunctional” or poorly performing natural lens with a high performance lens implant can result in complete spectacle independence!”

Lasers replace the Human hand.

We at Centre for Sight choose to use a laser in ALL lens replacement surgery as we believe the level of precision of the laser which replaces many manouvers previously performed by hand to a completely new level of safety. Victus Laser Cataract performs absolutely perfect, repeatable and reliable surgery with a high level of accuracy to 1/1000th of a millimeter. It stands to reason being able to reproduce surgery in a precise fashion from eye to eye can only make the procedure safer and more accurate.  

The laser replaces all the following portions of laser lens replacement surgery previously performed by a steady hand :

  1. Laser made Micro-Incisions in the eye (rather than knives)
  2. A perfect circular opening in the lens capsule
  3. Fragmentation / destruction of the lens allowing easy removal
  4. Incisions to correct astigmatism

The laser uses online cross sectional microscopic imaging (OCT scan), very much like a real time MRI scan which guides the surgeon and the placement of laser activity during the less than 30 second procedure!  Although the laser portion only takes a short time, the overall process takes about 10 to 15 minutes.

Centre for Sight as a reference site for the manufacturer (Technolas Perfect Vision / Bausch and Lomb) in 2012 installed the 3rd commercial Victus femtosecond laser in the world. As a pioneering centre, fellow ophthalmic surgeons from the United States, Canada, Middle East and Europe visit us on a regular basis to observe our unique manner of delivering the procedure.

Innovative technique and new device invented at Centre for Sight!

“The technique and instrument speeds up lens removal. Quicker removal is safer for the eye…”

New Technologies open new doors and paves the way for innovation.  Surgeons at Centre for Sight devised a novel method of lens removal using the Victus Femtosecond Laser and demonstrated a statistically significant reduction in time taken to remove the cataract. Quicker removal is safer for the eye and causes less trauma and eye reaction. The technique named by Sheraz Daya the inventor is called “Translenticular Hydrodissection” was presented at the European Society of Cataract Surgery, Milan 2012 and American Society of Cataract and Refractive Surgery (ASCRS) Chicago 2013 has received great acclaim by international surgeons. The video demonstrating the technique won an “Oscar” at the ASCRS film festival in 2013. The technique requires use of a device invented at Centre for Sight and developed in collaboration with Bausch + Lomb. The “Daya Trans-Lens Hydrodissection Cannula” is now commercially available from Bausch and Lomb.  The technique was also published in the peer-reviewed literature and a copy of the article can be found by clicking this link

Lasers, online VDUs and sophisticated devices makes the operating theatre look like a scene out of Star Trek!

Laser Lens Replacement- The Process


The consultation is the most important part of the whole process. Good planning is very important and this can only be guided through obtaining numerous tests using a variety of machines and instruments that measure corneal shape, optical aberrometry, lens thickness and length of the eye. On completion of all necessary tests , a fellowship-trained consultant eye surgeon evaluates your medical record and test results, examines your eye and finally discusses the best available options for you specifically. The choice of procedure and lens is based on a number of factors including your age, eye condition, eye health as well as your lifestyle and visual needs. All issues including alternatives, benefits along with any risks, general or specific to you are discussed and to help understand the actual surgical process, you will also watch a series of schematic videos during your Centre for Sight “journey”. Be warned, this process can take a while depending on how quickly test results are obtained, so be prepared to spend 2.5 to 3 hours. 

The Procedure – just beforehand

At Centre for Sight in the interests of safety, one eye is treated at a time. Performed as a Day case operation the procedure only takes 15 minutes.  However as there is preparation time (dilation of the pupils and further tests) as well as recovery, again prepare to spend 2 to 3 hours at the Centre. You may have some additional tests, antibiotic drops and anaesthetic will be instilled and the Surgeon may need to mark your eye before the actual procedure to ensure accurate placement of laser astigmatic limbal relaxing or a toric (astigmatic) lens. 

In the Operating Theatre

You will get some sedation beforehand or at the time either as a tablet or intravenously in which case a small cannula will be inserted into your arm for vein access.  You will be wheeled into the operating theatre and then asked to lie on the bed of the Victus laser. More drops will be instilled while your surgeon preforms a series of pre-operative safety “flight checks” with the operating team. Don’t mind the conversation and checks – these are all in your best interest.  With the laser portion of the procedure , you may feel a little pressure of the suction ring that connects the eye to the laser and keeps the eye still. You also must hold still during this process as an online scan checks a series of measurements in your eye and determines where exactly the laser treatment needs to be directed.  You will hear a beeping sound when the laser in action. The laser performs a series of steps in sequence including a perfectly circular opening in your lens, fragmentation of the lens and when necessary incisions to correct your astigmatism.

Following the laser treatment, you will take a couple of steps onto the operating bed and the Surgeon will continue to remove the fragmented lens and implant the high performance intraocular lens implant. Many patients describe seeing a series of colours and flashing lights – enjoy the show!  At the end of the procedure, the Surgeon will inject antibiotic medication into the eye and ensure the eye is safe and secure. A patch and an eye shield will be placed on your eye and this will be removed the next day.

After Surgery

You will have a short time to stay lying down and once the sedation has worn off, you will have a chance to have some sandwiches and a cup of tea or coffee.   You will be given clear instructions on when and how to use your medications which will be provided to you in a toiletry bag.  You will then be able to go home to rest and relax for the remainder of the day. The next day, if you are being seeing later in the day, you will be advised to take off your shield and patch. Preserve the shield in case you are instructed to use this at bedtime. Commence your drops as instructed. You may have an appointment to be seen that day. If not someone will contact you from Centre for Sight to ensure your progress is as planned.

Visual Recovery

Patients are usually astounded by the rate of visual recovery.  Most obtain very good vision the day following surgery, however some sometimes require a little longer. Everyone heals at a different pace. Sometimes vision is blurred for one or two days.  If you have had a high performance lens like a trifocal lens implant, then you will find that you will be able to read. If you have had a monofocal lens, then you might need to get a temporary pair of off the shelf reading glasses.

Find out more about the types on lenses available at Centre for Sight:

* Clarivu™ is a trademark of Optegra and a brand name used for the procedure Laser Lens Replacement.