- Medically Reviewed by: Mr Mfazo Hove, Consultant Ophthalmic Surgeon
- Author: Mr Mfazo Hove
- Published: October 15, 2026
- Last Updated: October 15, 2026
TL;DR: Implantable collamer lens (ICL) surgery and hydroxychloroquine treatment require different clinical tests, but both depend on reliable long-term monitoring. Blue Fin Vision® takes responsibility for monitoring the ICLs it implants, while the prescribing service is responsible for ensuring hydroxychloroquine monitoring is arranged and its results acted on. Clear ownership, reliable records and organised recall are the shared lessons, not
Shared lessons from long-term ICL and hydroxychloroquine monitoring: how Blue Fin Vision® organises follow-up for its ICL patients, and what that experience could offer rheumatology colleagues, specialists in joint conditions and related immune-system disorders.
Two Treatments, One Practical Question
An implanted lens and a rheumatology medicine are very different treatments. One is a single operation that corrects a prescription; the other is a daily tablet that protects people from the consequences of lupus, rheumatoid arthritis and related conditions. Their risks, mechanisms and monitoring tests have little in common.
Yet they raise a similar question. When monitoring needs to continue for years, sometimes decades, who makes sure the patient remains within it?
At Blue Fin Vision®, we answered that question for the ICL with a simple principle: we put the lens in, so its monitoring is ours. We recently published a full account of why ICL surgery requires a lifetime care plan.
This essay distils that account and argues that the same principle applies to hydroxychloroquine: responsibility for monitoring follows the decision to treat, and for a medicine that decision belongs to the prescriber.
Why an ICL Needs a Care Plan for as Long as It Stays
An ICL sits behind the iris, the coloured part of the eye, and in front of the natural lens, which stays in place. The operation takes minutes; the implant stays for decades. The eye keeps ageing around it: the natural lens slowly thickens, reading glasses arrive in the mid-forties, and cataract, clouding of the natural lens, eventually becomes possible.
The modern evidence is reassuring:
- In the US Food and Drug Administration study of central-port EVO lenses, which have a small central opening to allow fluid to pass through, 90.7% of eyes examined at three years were within 0.50 dioptres of their target. Dioptres are the units used to measure an eye prescription. Mean endothelial cell density, the number of cells lining the inner surface of the cornea per unit area, was 6.7% below its preoperative level. The cornea is the clear front surface of the eye. The study was sponsored by the manufacturer.¹
- A Japanese series reported stable vision to eight years, although only around a third of eyes were examined at that point.²
- A Korean study followed 103 eyes with V4c lenses, another central-port ICL model, for ten years. It found stable vision alongside a gradual decline in both vault, the gap between the implant and the natural lens, and endothelial cell density.³
That last finding explains why monitoring continues when vision is excellent. Vault cannot be judged from how well the patient sees; quantitative imaging, scans that provide numerical measurements, allows it to be measured reproducibly and compared over time.
Endothelial cells, which keep the cornea clear and do not regenerate, can be lost without symptoms until the loss is advanced. Eye pressure and the clarity of the natural lens can also change silently. The manufacturer’s labelling advises continued endothelial monitoring for as long as the lens remains implanted.⁴
Monitoring is justified by the information it gives over time, not by any suggestion that modern ICL surgery often fails. A single reading shows where things stand today; a series shows which way they are moving.
Having put the lens in, we could not identify that need and then leave its continuity to the patient, or to whichever clinician the patient happened to see next. The implant was ours, so the monitoring had to be ours too.
What Blue Fin Vision® Has Put in Place
These are current arrangements, not proposals.
Enrolment at Surgery
Every patient who has ICL surgery at Blue Fin Vision® is enrolled in our published ICL Lifetime Monitoring Protocol™ at the point of surgery. There is no subscription, separate fee or expiry.
A Defined Schedule
After the early postoperative reviews, with the first endothelial cell count at three months, each patient has a consultant review at 12 months and then every year. This includes vault imaging, an endothelial cell count, eye pressure and slit-lamp examination, a detailed examination using a microscope and a narrow beam of light.
The full scheduled annual visit, including the consultant review, these assessments and the written report, is included at no additional cost for as long as the ICL remains in the eye.
Why the Monitoring Is Included
This was a deliberate choice. In our practice experience, when each monitoring visit carries its own fee, many patients attend for a year or two, see that everything is stable, and stop paying for reassurance.
Normal early results do not remove the need for continued monitoring, because the changes we look for are slow and silent.
Folding the defined monitoring into the surgical fee removes the yearly decision to pay, so attendance no longer depends on whether a patient still feels it is worth the money.
Results Against the Patient’s Own Baseline
After each visit, patients receive a written report of their vault measurements and endothelial cell counts. Endothelial counts are compared with the preoperative baseline, the starting measurement taken before surgery, and previous years; vault is compared with earlier postoperative measurements.
A reading of 2,400 cells/mm², meaning cells per square millimetre, means something different in an eye that measured 2,900 three years earlier than in one that has held steady since surgery.
Defined Action Thresholds
A vault outside 250–750 µm, or a significant drift from baseline, is a signal to act. The symbol µm means micrometres, with one micrometre equal to one-thousandth of a millimetre.
So is an endothelial density trending below 2,000 cells/mm², or loss steeper than expected for age.
Depending on clinical judgement, the next step may be a repeat measurement to confirm the finding, closer surveillance at shorter intervals or further assessment.
These are our clinical reference points, not regulatory ones, and they are not automatic triggers for surgery.
A Register, Reminders and a Backup
Every ICL patient enters our monitoring database. The system sends reminders for the next follow-up, and we keep a hard-copy record in case the electronic system fails.
A Route to Treatment
If the measurements point to a problem, ICL exchange, removal and cataract surgery are carried out within Blue Fin Vision®, and cataract surgery after an ICL follows a pathway priced in advance.
The commitment is precisely defined. It does not make every future eye treatment free: unrelated conditions, appointments outside the protocol and travel are not included, and monitoring takes place only at our UK sites.
These are practical decisions intended to reduce the chance that necessary surveillance is lost through cost, memory or system failure.
Hydroxychloroquine: The Same Question Across More Services
Hydroxychloroquine is one of the most valuable medicines in rheumatology, and nothing here argues for withholding it from patients who are monitored and benefit from it.
Its retinal toxicity, meaning its potential to damage the light-sensitive tissue at the back of the eye, is the reason for monitoring. Early damage is silent and irreversible, and risk rises with dose by actual body weight and with duration of use. Under active screening, most detected cases are mild.⁵ ⁶
UK guidance recommends annual monitoring after five years for most patients, noting that monitoring may begin after one year where additional risk factors exist.
Results are reported to the prescriber, the patient and the GP as normal, possible or definite retinopathy, meaning retinal damage. The prescribing doctor is responsible for ensuring patients are monitored and for acting on the results.⁵
The American Academy of Ophthalmology’s 2025 revision differs, including on baseline testing, so the two should not be conflated.⁷
The evidence that monitoring matters has strengthened. In a national UK study, people whose retinopathy was found on monitoring had better visual acuity, the ability to distinguish fine detail, and visual fields, the areas they could see, at diagnosis than those diagnosed after developing symptoms. The comparison is observational, meaning it compares existing groups rather than randomly assigning patients to different monitoring arrangements.⁸
The same study estimated that between July 2018 and February 2020, only around 2.6–5.5% of long-term users who should have been monitored were being reached. That figure was estimated indirectly and describes provision at the time; services have developed since.⁸
The uncomfortable question is not only whether the right tests exist. It is whether the patient reliably reaches them, repeatedly, over many years.
What Could Transfer
The clinical protocols are different. The organising functions are not.
- A register: everyone who needs monitoring, when it should begin and when the next assessment is due.⁵
- A named owner for referral, recall, communicating results and acting on overdue patients. Responsibility can be distributed across services, but it should be explicit.
- Current risk data linked to the eye record: dose, actual body weight, duration, kidney function and relevant medicines, because the risk category changes when they do.⁶ ⁷
- Each result tied to a defined action. Our vault and endothelial thresholds do the job that normal, possible and definite do in hydroxychloroquine monitoring: every result leads somewhere specific.
- Fewer access barriers. A fee at every visit can create a yearly point at which patients stop attending, which is one reason we built ours into the surgical fee. That private model does not translate into an NHS pricing recommendation. The NHS equivalents are commissioned capacity, meaning funded appointments and testing services, location and appointment access, with no repeated decision left for the patient to make.
- Resilient records that survive a system failure, a move or a change of doctor.
Meredith and colleagues describe a commissioned programme in Hampshire and the Isle of Wight using dedicated software, technician-led community imaging, two levels of grading, hospital referral and a failsafe attached to one patient record.⁹ Grading means assessing the images for signs of damage; a failsafe is a tracking process designed to identify incomplete follow-up.
Of the 1,865 people on its starting list, 352 attended but were no longer taking the drug: a reminder that a register is only as good as the prescribing data feeding it.
Its two-year cost was £199,000, against an estimated £354,000 or more for hospital-based monitoring. It is a short service report, and all its authors were employed by the provider.
My hydroxychloroquine essay sets out, field by field, what such a register should hold.
Responsibility Follows the Treatment
The principle is the same for both treatments. We implanted the ICL, so we carry its monitoring. The clinician who prescribes hydroxychloroquine carries the equivalent responsibility, and UK guidance already says so: ensuring monitoring happens, and acting on its results, sit with the prescriber.⁵
Our own private hydroxychloroquine service shows why this matters. Patients there pay per visit, and many decline to keep paying for annual monitoring once the first results are normal.
As the testing service, we are responsible for accurate testing, clear reporting to the patient, prescriber and GP, and any follow-up we have agreed to provide. Making sure monitoring is arranged in the first place remains with the prescriber.
Carrying that responsibility does not mean a rheumatologist must take the scans. It means the prescribing service makes sure monitoring happens:
- The patient is registered, referred and recalled.
- Results come back and are acted on.
- The cost or route to the test is not left for the patient to solve each year.
In an NHS pathway the barrier is less often a fee than a missing referral or a lost recall.
When a Patient Declines Monitoring
Responsibility does not end when a patient stops attending.
If repeated, documented recall fails, the prescriber should explain the retinal risk again and review the balance of benefit and risk with the patient, including whether to continue, change or stop the drug, and record the decision.
The retinal damage is permanent, and a repeat prescription issued without monitoring remains a prescribing decision. What should not happen is years of repeat prescribing with no monitoring and no conversation about it.
What the System Cannot Promise
Our arrangements have limits. Reminders do not guarantee attendance, included assessments do not remove travel or distance as barriers, and the existence of a system is not evidence of its effectiveness.
The measures that matter are attendance, overdue patients, completed follow-up and action on abnormal results, and those are what future audit should examine.
Hydroxychloroquine pathways span more services than ours, and colleagues have been building them for some time; we offer our experience as one worked example, not a template.
Address Our Responsibility, Share What We Learn
We cannot take responsibility for every long-term monitoring pathway. We can take responsibility for the one created by the treatment we provide.
We put the ICL in, so we included its monitoring, registered every patient, built reminders and a backup record, and removed the yearly decision to pay, rather than simply advising patients to return next year.
Hydroxychloroquine needs a different clinical protocol and a more distributed service, but the principle holds: whoever starts a treatment owns the monitoring it creates, until that responsibility is explicitly handed to someone who accepts it.
Who needs monitoring, when are they due, and who makes sure it happens? For a prescription, the answer to the last question begins with the prescriber. If our experience helps colleagues build that, it is worth sharing.
Further Reading
These articles and service details explore the monitoring arrangements discussed here:
- Why ICL Surgery Requires A Lifetime Care Plan – Why an implanted lens needs continuing checks, even when vision remains clear, and what long-term follow-up should assess.
- ICL Lifetime Monitoring Protocol™ – The published schedule, included assessments, monitoring locations and service terms for ICL patients at Blue Fin Vision®.
- The Hydroxychloroquine Conundrum: What I Would Weigh Before Taking It – The balance between treatment benefits and retinal risk, the limits of eye testing and the questions to discuss with your prescribing specialist.
Service Documentation
These describe Blue Fin Vision® service commitments and are not independent outcome evidence. The monitoring database, reminders and hard-copy backup are practice-confirmed operational facts.
Blue Fin Vision®. Why ICL Surgery Requires A Lifetime Care Plan. Published 13 October 2026; updated 14 October 2026.
Blue Fin Vision®. ICL Lifetime Monitoring Protocol™. Service information.
References
- Parkhurst G, Brinton JP, Faulkner A, Moshirfar M, Kugler LJ, Stahl JE, Zavodni Z, Thompson VM, Price FW, Wiley WF, Aronsky M, Whitman JD, Solomon JD, Perkins SA, Packer M, Egamino J. Three year results from the United States FDA prospective multicenter clinical study of the EVO/EVO+ Implantable Collamer Lens. Clin Ophthalmol. 2025;19:3237-48. doi:10.2147/OPTH.S537739.
- Kamiya K, Shimizu K, Takahashi M, Ando W, Hayakawa H, Shoji N. Eight-year outcomes of implantation of posterior chamber phakic intraocular lens with a central port for moderate to high ametropia. Front Med (Lausanne). 2021;8:799078. doi:10.3389/fmed.2021.799078.
- Chung B, Choi JY, Kang DSY, Kim K, Kim BY, Kim TI. Ten-year clinical outcomes of V4c Implantable Collamer Lens implantation: longitudinal analysis of visual acuity, endothelial cell density, and vault dynamics. Am J Ophthalmol. 2025;269:1-10. doi:10.1016/j.ajo.2024.08.007.
- US Food and Drug Administration. EVO/EVO+ Visian Implantable Collamer Lens: professional directions for use and patient labelling, P030016/S035. Silver Spring, MD: FDA; 2022. Available from: https://www.accessdata.fda.gov/cdrh_docs/pdf3/P030016S035C.pdf
- Yusuf IH, Foot B, Lotery AJ. The Royal College of Ophthalmologists recommendations on monitoring for hydroxychloroquine and chloroquine users in the United Kingdom (2020 revision): executive summary. Eye (Lond). 2021;35(6):1532-7. doi:10.1038/s41433-020-01380-2.
- Melles RB, Jorge AM, Marmor MF, Zhou B, Conell C, Niu J, McCormick N, Zhang Y, Choi HK. Hydroxychloroquine dose and risk for incident retinopathy: a cohort study. Ann Intern Med. 2023;176(2):166-73. doi:10.7326/M22-2453.
- Marmor MF, Ahn SJ, Ehlers JP, Melles RB, Mieler WF, Sarraf D, Yusuf IH; American Academy of Ophthalmology. Special AAO report: recommendations on screening for hydroxychloroquine retinopathy (2025 revision). Ophthalmology. 2026;133(4):439-50. doi:10.1016/j.ophtha.2025.11.001.
- Yusuf IH, Han RC, Downes SM, Sharma SM. The incidence, monitoring coverage and clinical characteristics of hydroxychloroquine retinopathy in the United Kingdom. Eye (Lond). 2024;38(14):2796-804. doi:10.1038/s41433-024-03168-0.
- Meredith SP, Palmer S, Beharrell H, Coe S, Hobbs H, Kirby P. Systematic hydroxychloroquine retinopathy monitoring programme: cost benefit comparing to a hospital-based system. Eye (Lond). 2024;38(9):1772-3. doi:10.1038/s41433-024-03002-7.
ABOUT THE AUTHOR
Mr Mfazo Hove
Consultant Ophthalmic Surgeon
MBChB MD FRCOphth CertLRS
Mr Mfazo Hove is a Consultant Ophthalmic Surgeon with experience spanning more than 57,000 procedures. He completed 6.5 years of specialist training at Moorfields Eye Hospital and served for five years as a consultant at the Western Eye Hospital, Imperial College Healthcare NHS Trust. He is the founder of Blue Fin Vision®, a consultant-led private ophthalmology practice operating across London, Essex, and Hertfordshire. His clinical expertise encompasses advanced cataract surgery, refractive lens replacement, laser vision correction, and implantable Collamer lenses (ICL).
A ZEISS Key Opinion Leader, Mr Hove is a respected international speaker with five invited engagements across seven cities in 2026:
- ZEISS China tour (Changsha, Shanghai, and Hangzhou, April – ZEISS APAC User Meeting)
- RCOphth Annual Congress – May – Manchester
- ZEISS EMEA User Meeting (Istanbul)
- ZEISS Lausanne User Meeting (Lausanne)
- European Society of Cataract and Refractive Surgeons Annual Congress (ESCRS, London)
Discuss Your ICL Monitoring Plan
If you are considering ICL surgery or need an assessment of an existing implant, book a paid, consultant-led consultation with Blue Fin Vision® to discuss your options and long-term monitoring needs.
Existing Blue Fin Vision® ICL patients can contact the team to arrange their scheduled monitoring under the Lifetime Monitoring Protocol™. The team will confirm the appropriate location for each test, including Harley Street for endothelial cell counts.
