Dr Sherif Ekram

Category: Cataract and Lenses

  • When a Lens Implant Needs Replacing: IOL Exchange and Scleral-Fixated Lenses

    By Dr Sherif Ekram, Consultant Ophthalmic Surgeon, complex anterior segment, glaucoma and refractive surgery

    Quick answer: A lens implant (IOL) is designed to last for life, but a small number need attention later. The common reasons are a lens that has moved or dislocated, a result that leaves the eye too long- or short-sighted, or unwanted visual effects from a multifocal lens. Options range from glasses or a laser touch-up to an IOL exchange, in which the implant is removed and replaced. When the eye’s natural support for the lens is weak, the new lens can be secured to the wall of the eye as a scleral-fixated IOL.

    Why would a lens implant need replacing?

    Most of the millions of lens implants placed each year never cause a problem. When they do, the reasons usually fall into four groups.

    1. The lens has moved or dislocated

    The implant sits inside a thin capsule held by tiny fibres called zonules. If these fibres weaken, the lens and capsule can drop, sometimes many years after surgery. Pseudoexfoliation, previous eye injury, high short-sightedness, previous retinal surgery and some inherited conditions all increase the risk. Symptoms include blurred or double vision, or seeing the edge of the lens.

    2. The prescription is not as expected

    Modern biometry is accurate, but eyes that are very long or short, or that have had previous laser surgery, are harder to predict. A small error is usually corrected with laser or glasses. A larger one may be better corrected by changing the lens.

    3. Unwanted visual effects from a premium lens

    Some patients with multifocal lenses notice persistent halos, glare or waxy vision. Many adapt within months. For those who do not, exchanging to a monofocal or EDOF lens can help. Our guide to premium IOLs and lens replacement explains how these lenses differ.

    4. Lens clouding or damage

    Rarely, some lens materials become cloudy over time, or a lens is damaged, and replacement is the only way to restore clear vision.

    Options before an IOL exchange

    Exchange is not always the first step. Depending on the problem, options include:

    • Glasses or contact lenses for a small residual prescription.
    • Laser refractive surgery (Femto-LASIK or PRK) on the cornea to fine-tune the result.
    • A piggyback lens, a second thin lens placed in front of the first.
    • Repositioning a slightly displaced lens without removing it.

    A surgeon who holds both refractive and lens skills can offer all of these, rather than defaulting to the one procedure they perform.

    What happens during an IOL exchange

    The original lens is freed from the capsule, often folded or cut inside the eye, and removed through a small incision. The new lens is then placed in the most stable position available:

    • In the capsular bag, if the capsule is intact.
    • In the sulcus, just in front of the capsule, if the capsule is torn but some support remains.
    • Fixed to the iris or the sclera, when there is no reliable capsular support.

    Early exchanges, within weeks of the first operation, are usually simpler because the capsule has not yet scarred around the lens. Later exchanges are still very achievable but require more experience.

    Scleral-fixated IOLs: when the lens has no support

    When the capsule and zonules cannot hold a lens, the implant can be anchored directly to the sclera, the white wall of the eye. Modern techniques, including sutureless intrascleral haptic fixation and sutured fixation, place the lens behind the iris in a natural position. This keeps it away from the cornea and the drainage angle, which matters for eyes that also have glaucoma.

    Scleral fixation is often combined with an anterior vitrectomy to clear vitreous gel from the front of the eye. In complex cases it may be part of a wider reconstruction, for example in eyes that also need glaucoma surgery or have had aqueous misdirection treated with an irido-zonulo-hyaloido-vitrectomy (IZHV). These eyes benefit from a surgeon who manages glaucoma as well as lens surgery. See our guide to MIGS and advanced glaucoma surgery.

    Recovery and results

    Recovery after an IOL exchange or scleral fixation usually takes a little longer than after routine cataract surgery. Expect drops for several weeks, some blurring in the first days, and a few follow-up visits to check pressure, inflammation and lens position. Most patients see clearly once the eye settles, and the final glasses prescription, if needed, is checked after about a month.

    Risks include raised eye pressure, inflammation, swelling at the back of the eye and, rarely, retinal detachment or infection. These are discussed in detail at consultation, together with the alternatives.

    Experience matters in complex lens surgery

    IOL exchange and scleral fixation are not routine operations. They draw on cataract technique, vitreous management and an understanding of how the lens affects the drainage angle. Dr Ekram has performed more than 16,000 cataract operations and specialises in complex anterior segment surgery, including IOL exchange and scleral-fixated IOLs, with a focus on combining speed and safety. If you are seeking a second opinion, our guide to choosing an eye surgeon in the UK lists useful questions to ask.

    Frequently asked questions

    Can a lens implant be replaced years after cataract surgery?

    Yes. Lens implants can be removed and replaced many years later, although the operation is more complex than an early exchange because the capsule scars around the lens over time.

    What are the symptoms of a dislocated lens implant?

    Sudden or gradual blurring, double vision in one eye, seeing the edge of the lens, or vision that changes with head position. Anyone with these symptoms should arrange an eye examination promptly.

    Is a scleral-fixated lens as good as a normal lens implant?

    When well positioned, a scleral-fixated IOL can give vision comparable to a lens in the capsule. The choice of lens type is more limited, which is discussed before surgery.

    Can I swap a multifocal lens for a different lens?

    Often, yes. If halos or glare do not settle, exchanging to a monofocal or EDOF lens is an established option. Other causes, such as dry eye or capsule clouding, are checked first.

    About the author
    Dr Sherif Ekram is a UK Consultant Ophthalmic Surgeon with over 18 years of experience in complex anterior segment, glaucoma and refractive surgery. He holds the RCOphth CertLRS and has performed more than 16,000 cataract, 8,000 refractive and 3,000 glaucoma operations. Explore more in the articles library.

    This article is for general information and does not replace a personal consultation.

  • Lens Replacement vs Laser Eye Surgery After 45: Which Gives Better Long-Term Vision?

    By Dr Sherif Ekram, Consultant Ophthalmic Surgeon and CertLRS refractive surgeon

    Quick answer: After 45, the eye’s natural lens starts to lose its focusing power (presbyopia) and, later, to cloud (cataract). Laser eye surgery such as Femto-LASIK or PRK reshapes the cornea and works best for younger patients with a clear, flexible lens. Lens replacement, also called refractive lens exchange (RLE), swaps the natural lens for a premium intraocular lens (IOL) and can correct distance and reading vision while preventing a future cataract. Which is better depends on your age, prescription, lens health and how you use your eyes day to day.

    Why the answer changes after 45

    Laser eye surgery and lens surgery fix vision in different parts of the eye. Laser reshapes the cornea, the clear window at the front. Lens surgery replaces the lens behind the pupil.

    In your twenties and thirties the natural lens is clear and flexible, so correcting the cornea with laser is usually all that is needed. From the mid-forties the lens stiffens, and reading glasses become necessary even for people who never needed glasses before. Later, the same lens develops cataract. Laser on the cornea does not stop either process. This is why a 50-year-old and a 30-year-old with the same prescription may get different recommendations.

    Laser eye surgery after 45: Femto-LASIK and PRK

    Femto-LASIK uses a femtosecond laser to create a thin corneal flap and an excimer laser to reshape the cornea beneath it. Recovery is fast, often within a day or two. PRK reshapes the surface of the cornea without a flap. Recovery takes longer, but it suits thinner corneas and people in contact sports or certain professions.

    Laser can still be a good choice after 45 when:

    • the natural lens is completely clear;
    • the prescription is mild to moderate;
    • the patient accepts reading glasses in future, or chooses blended vision (monovision), where one eye is set for distance and the other for near.

    The main limitation is time. Laser corrects today’s prescription, but the lens will keep ageing, and cataract surgery will still be needed later in life.

    Lens replacement (refractive lens exchange)

    Refractive lens exchange is technically the same operation as modern cataract surgery. The natural lens is removed through a small incision and replaced with an artificial lens chosen for your eye and lifestyle. Because the new lens never develops cataract, you will not need cataract surgery later.

    RLE is often the better option when:

    • you are over about 50 and already need reading glasses;
    • you have a high prescription, especially long-sightedness (hyperopia);
    • early lens changes or cataract are already present;
    • your cornea is too thin or irregular for laser.

    Choosing a premium IOL: monofocal, multifocal, EDOF or toric

    The lens implant decides much of the result. The main premium IOL options are:

    • Monofocal IOL: sharp vision at one distance, usually far. Reading glasses are still needed unless blended vision is used.
    • Multifocal (trifocal) IOL: clear vision at distance, intermediate and near. It offers the most spectacle independence, but some patients notice halos around lights at night.
    • EDOF (extended depth of focus) IOL: a continuous range from distance to intermediate (computer and dashboard), with fewer night-time halos than multifocals. Light reading glasses may be needed for small print.
    • Toric IOL: corrects astigmatism and is available in monofocal, multifocal and EDOF designs.

    Lens choice is also a medical decision. Patients with glaucoma, macular disease or a dry ocular surface may not suit a multifocal lens, because these lenses split light and need a healthy optic nerve and retina to work well. Dr Ekram’s dual subspecialty in glaucoma and refractive surgery is especially useful here.

    Side-by-side comparison

    Laser eye surgery (Femto-LASIK / PRK)Lens replacement (RLE)
    Part of the eye treatedCorneaNatural lens
    Best age rangeUsually 21 to mid-40sUsually 50+ (sometimes earlier)
    Corrects reading visionOnly with blended visionYes, with multifocal, EDOF or blended vision
    Prevents future cataractNoYes
    High prescriptionsLimitedWell suited
    Inside the eyeNoYes

    Risks to discuss before either procedure

    Both procedures are safe in experienced hands, but neither is risk-free. Laser surgery can cause dry eye, night glare and, rarely, corneal weakening (ectasia). Lens replacement is an operation inside the eye, with small risks of infection, swelling at the back of the eye and, especially in very short-sighted patients, retinal detachment. A small number of lens patients are unhappy with their optical result. When that happens, a laser touch-up or, occasionally, an IOL exchange can correct it, and both are easier in the hands of a surgeon who does laser and lens surgery.

    Why one surgeon for both options matters

    Many clinics offer only laser or only lens surgery, and the recommendation can follow what is available. Dr Ekram holds the Royal College of Ophthalmologists’ CertLRS and has performed more than 8,000 refractive procedures and more than 16,000 cataract operations. He can offer Femto-LASIK, PRK and the full range of premium IOLs, and combine them when needed, for example a laser fine-tune after lens surgery.

    If you are comparing clinics, our guide on how to choose an eye surgeon in the UK explains what to check before booking.

    Frequently asked questions

    Is lens replacement better than laser eye surgery after 50?

    For many people over 50, yes, because it treats presbyopia and removes the need for cataract surgery later. But a clear lens and a low prescription can still be treated well with laser. A full assessment decides.

    Can I have laser eye surgery if I already need reading glasses?

    Yes. Laser can correct distance vision, and blended vision can reduce dependence on reading glasses. It will not stop the lens from ageing.

    Do multifocal lenses cause halos?

    Some patients notice halos or glare around lights at night, especially in the first months. Most adapt. EDOF lenses cause fewer halos but offer slightly less near vision.

    Is refractive lens exchange available on the NHS?

    Refractive lens exchange for spectacle independence is generally a private procedure in the UK. Cataract surgery for a visually significant cataract is available on the NHS, usually with a standard monofocal lens.

    About the author
    Dr Sherif Ekram is a UK Consultant Ophthalmic Surgeon with over 18 years of experience, dual-subspecialised in glaucoma and refractive surgery, and holder of the RCOphth Certificate in Laser and Refractive Surgery (CertLRS). He has performed more than 16,000 cataract and more than 8,000 refractive operations. Read more patient guides in the articles library.

    This article is for general information and does not replace a personal consultation.