ICL Surgery Risks
Implantable Collamer Lens surgery has a very high safety profile and is suitable for a wide range of patients, but no eye surgery is completely risk free. Blue Fin Vision® provides consultant-led care, using detailed assessment and audited outcomes to minimise risk and manage any complications safely.
How Safe is ICL Surgery?
Serious loss of vision after ICL surgery is uncommon, with modern techniques delivering excellent outcomes for the vast majority of patients. In most cases, ICL surgery improves vision and quality of life significantly, and permanent sight loss in the treated eye is regarded as rare.
ICL surgery in the UK follows strict safety standards, including detailed pre-operative assessment, standardised theatre protocols and careful post-operative monitoring. At Blue Fin Vision®, audited outcomes and consultant-led decision-making support safe practice, especially in more complex eyes.
Normal Side Effects After Surgery
Some changes in the first few days after ICL surgery are expected and usually settle as the eye heals. These short-term effects are not usually classed as complications:
- Mild blurred or cloudy vision in the first few days as the eye adjusts to the new lens and the cornea recovers from surgery.
- Mild discomfort, grittiness, light sensitivity or redness that improve with prescribed drops and time.
- Fluctuating or slightly misty vision related to temporary corneal swelling or dry eye, which typically settles over days to weeks.
Most patients notice that vision becomes clearer over the first week, with more stable results over several weeks, provided they use post-operative drops as advised. If symptoms worsen rather than improve, this can suggest a treatable complication, so early review is important.
Short Term Risks and Treatable Complications
A minority of patients experience issues that require extra drops, closer follow-up or, occasionally, further procedures. Many of these complications are treatable, particularly when recognised early.
Inflammation and Corneal Swelling
All eyes develop some degree of inflammation after surgery, which is why anti-inflammatory drops are prescribed. In some cases, the front of the eye or cornea becomes more swollen than expected, leading to hazy or steamed-up vision that often responds to a longer or stronger course of drops.
Patients with pre-existing corneal concerns, such as Fuchs’ endothelial dystrophy or borderline anterior chamber depth, are more prone to corneal swelling and need particularly careful planning and follow-up. In these eyes, risk is often reduced through detailed pre-operative imaging and tailored surgical techniques.
Raised Eye Pressure
Eye pressure can rise temporarily after ICL surgery, either due to the procedure itself or to steroid drops used in the early healing phase. This is usually detected at routine follow-up and managed with pressure-lowering drops, especially in patients with glaucoma or ocular hypertension.
With careful monitoring, most patients do not experience lasting damage from these temporary pressure changes. Patients at higher risk are often offered closer follow-up in the early weeks.
Infection Inside the Eye (Endophthalmitis)
Endophthalmitis is a rare but serious infection inside the eye that can occur after ICL surgery. Modern antibiotic measures and sterile technique mean the risk is very low.
Symptoms typically include severe eye pain, rapidly worsening blurred vision and marked redness, usually within days of the operation. This is a true emergency and requires urgent assessment and treatment to protect vision, which is why patients are given clear written instructions on when to seek help.
Lens Deposits or Haze
In rare cases, protein deposits can develop on the surface of the ICL over time, or mild haze can occur in the space between the lens and cornea. These are usually mild and do not significantly affect vision, but if troublesome, they can be managed with targeted drops or, very rarely, lens cleaning or repositioning.
Dry Eye
Some patients experience dry eye symptoms after ICL surgery, particularly in the first few weeks. This is usually temporary and improves with regular use of preservative-free lubricating drops. If dry eye persists beyond the first month, additional treatments such as lid hygiene measures or punctal plugs may be recommended.
Long Term Risks After ICL Surgery
Complications can also appear months or years after a seemingly straightforward operation. These issues are usually treatable and often relate to natural changes in the eye.
Vault Changes and ICL Position
The ICL develops a ‘vault’ – the space between the lens and your natural lens – which is critical for long-term corneal health. In rare cases, the vault may change significantly, either narrowing (high vault) or widening (low vault). Significant changes are usually detected on routine follow-up through imaging and managed with closer monitoring or, very rarely, lens repositioning or exchange.
Residual Refractive Error
Even with modern biometry, a small number of patients have a final prescription that is not exactly at the planned target. This might mean needing glasses for some tasks or noticing that one eye feels slightly out of focus compared to the other.
At Blue Fin Vision®, we offer enhancement options to fine-tune your vision if a residual error of 1 dioptre or more remains. These include laser eye surgery (LASIK) on top of the ICL or, in select cases, exchange of the ICL lens.
Lens Tilt or Rotation (Toric ICL)
In rare cases, a toric ICL may shift or rotate slightly from its intended position, which can reduce the benefit of astigmatism correction and affect vision quality. Modern toric lenses have excellent stability features, and significant rotation is uncommon. If detected, repositioning surgery is usually straightforward.
Endothelial Cell Loss
The inner layer of the cornea (endothelium) contains cells that maintain corneal clarity. ICL surgery causes some degree of endothelial cell loss, which is why pre-operative endothelial cell counts are measured. Long-term studies show that this loss stabilises over time and does not affect most patients, but careful monitoring ensures early detection of any concerns.
Rare But Serious Complications
A very small proportion of patients experience rare complications that can threaten sight if not treated promptly. These risks are important to understand, even though they occur in only a tiny minority of cases.
Retinal Detachment
Retinal detachment occurs when the light-sensitive layer at the back of the eye peels away from the supporting tissue. ICL surgery slightly increases this risk, especially in very short-sighted eyes, although the overall likelihood remains low.
Symptoms can include sudden flashes of light, a shower of new floaters or a dark curtain over part of the vision. Prompt retinal surgery often restores useful vision, which is why patients are advised to seek urgent help if these signs appear.
Corneal Decompensation
In patients with pre-existing corneal endothelial weakness, the stress of surgery can lead to corneal swelling that does not fully resolve. This can result in persistent blurred or hazy vision. In severe cases, corneal transplantation may be needed, although this is rare.
Careful pre-operative assessment with corneal imaging helps identify at-risk eyes, allowing surgeons to plan appropriate techniques and closer monitoring. This is one reason why endothelial cell counts are measured before surgery.
Severe Bleeding or Catastrophic Infection
Severe bleeding inside the eye during or after surgery is very rare but can lead to permanent sight loss in the treated eye. When combined with the rare risk of severe infection, the overall chance of permanent serious loss of vision remains very small for modern ICL surgery.
Strict sterile technique, appropriate antibiotic use and careful selection of patients all help to keep this risk extremely low. Consultant-led teams and adherence to audited standards further reduce the likelihood of these events.
Severe Inflammation (Uveitis)
In rare cases, the eye develops marked inflammatory reactions that do not respond adequately to topical steroids. This can be associated with severe pain and blurred vision. Systemic anti-inflammatory treatment or, very occasionally, additional surgical intervention may be required.
Patients with a history of uveitis or other inflammatory eye conditions need careful pre-operative assessment and planning.
ICL Explantation (Lens Removal)
In very rare cases, the ICL may need to be removed due to persistent complications or patient dissatisfaction. Modern ICLs are designed to be safely removed, if necessary, though this is an additional procedure requiring recovery time.
Bilateral ICL Surgery
In bilateral ICL surgery, both eyes are treated in the same surgical session under strict separation protocols. When this technique is used appropriately, the risk of complications affecting both eyes simultaneously is considered extremely low.
Both eyes are treated consecutively (one after the other, not simultaneously) using separate, sterile instruments for each eye and complete re-sterilisation between procedures. This rigorous separation ensures infection risk is equivalent to or lower than treating eyes on separate days.
Suitability for bilateral ICL surgery is assessed on an individual basis, balancing the convenience of one combined recovery with the need for maximum safety. This assessment usually includes the general health of both eyes, co-existing conditions, vault positioning in each eye and the patient’s overall health. Both eyes will be monitored carefully during recovery to detect any differences in healing or vault development early.
Who Has Higher Risk?
Some patients have a higher baseline risk of complications or are more likely to have a slower recovery. In these cases, surgery may still be appropriate, but the discussion is more individualised and expectations are tailored.
Higher-risk features can include:
- Pre-existing eye disease such as glaucoma, macular degeneration, diabetic retinopathy, keratoconus, corneal dystrophy or previous retinal problems.
- Borderline anterior chamber depth, low endothelial cell counts or other anatomical variations that require specialist planning.
- Very high short-sightedness or long-sightedness, previous retinal detachment, significant trauma or previous eye surgery.
- Systemic health problems that affect healing, such as poorly controlled diabetes, autoimmune disease or connective tissue disorders.
- Unstable prescriptions or unrealistic expectations about outcomes.
These factors do not automatically rule out ICL surgery, but they may influence lens choice, surgical technique and the intensity of follow-up after the operation. Patients with complex eyes often benefit from consultant-delivered assessment and advanced imaging before a final plan is agreed.
Red Flag Symptoms to Act On
Understanding which symptoms are expected and which need urgent attention is a key part of safe ICL surgery. Patients receive written instructions, but it can help to have a simple checklist in mind.
Seek urgent eye care if you notice:
- Sudden, severe eye pain, especially if vision is worsening rather than improving.
- A rapid drop in vision, a dark curtain over part of your sight, or a sudden shower of new floaters with flashes of light.
- Marked redness with increasing sensitivity to light and reduced vision, which can be a sign of infection or severe inflammation.
- Increasing blurring after initial improvement, or vision that does not improve as expected.
- Discharge, pus or unusual drainage from the eye.
Milder symptoms such as slight blurring, dryness or mild discomfort are often part of normal healing, but if there is any doubt, it is safer to contact the clinical team for advice. Early review allows most complications to be treated promptly, helping to protect vision and support a smoother recovery.
Blue Fin Vision® Safety Standards
At Blue Fin Vision®, we follow rigorous protocols to minimise surgical risk:
- Detailed pre-operative assessment including corneal topography, anterior chamber measurements, endothelial cell counts and retinal imaging.
- Advanced biometry with AI-powered vault prediction to optimise ICL power and positioning.
- Consultant-led surgical technique with micro-incision approach and appropriate anaesthesia.
- Premium ICL lenses and cutting-edge equipment for optimal surgical precision.
- Standardised theatre protocols with strict infection control measures.
- Structured post-operative follow-up at key intervals, including vault measurements and endothelial cell monitoring.
- Lifetime aftercare and annual check-ups to detect long-term changes early.
- Audited outcomes to ensure consistent safety and efficacy.
Your safety and vision are our absolute priority. If you have concerns about your suitability for ICL surgery or want to understand your individual risk profile, our expert team is here to discuss all options openly and help you make an informed decision.
Book your consultation today to discuss ICL surgery and understand how it can be tailored to your needs.
