Keratoconus and Cataract Surgery: Should You Choose a Premium IOL?
- Posted
- Medically Reviewed by Mr Mfazo Hove Consultant Ophthalmologist
- Author: Chris Dunnington
- Published: August 11, 2025
Living with keratoconus presents unique daily visual challenges – and as age brings the possibility of cataracts, the journey towards clearer vision is rarely straightforward. Thanks to advances in cataract surgery and intraocular lens (IOL) technology, there is new hope for better sight. At Blue Fin Vision® Eye Clinic, our team of top doctors, specialists, and leading surgeons in London, Chelmsford, Hatfield, Harley Street, and Weymouth Street is dedicated to offering world-class guidance for keratoconus and cataract patients.
Understanding Keratoconus and Cataract Surgery
Keratoconus is a progressive eye condition where the cornea thins and bulges outward, leading to irregular astigmatism and significant visual blur. It often begins in adolescence or early adulthood and may progress for years. In early stages, vision can sometimes be managed with glasses or soft contact lenses, but advanced cases may require rigid gas permeable or scleral lenses, or procedures like corneal cross-linking.
When cataracts develop in keratoconic eyes, surgery becomes more complex. The irregular cornea can interfere with the accuracy of crucial ocular measurements needed to select the correct IOL power. Each case requires highly individualised planning, relying on meticulous biometry, advanced diagnostic tools, and experienced hands.
Why Premium Lenses Are Rarely Used in Keratoconus
At Blue Fin Vision®, we do not use premium lenses in keratoconic patients as a rule. This is because the astigmatism in keratoconus is almost always irregular, making premium IOLs (such as multifocal, trifocal and extended depth of focus lenses) poorly suited for these eyes. These lenses split light into multiple focal points and can produce unwanted visual effects – halos, glare, and reduced contrast – when used in irregular corneas.
Instead, monofocal IOLs are almost always the preferred recommendation for keratoconus. They offer better predictability and less risk of postoperative distortion, which is vital when dealing with irregular corneas.
Key Challenges in Cataract Surgery for Keratoconus
- Biometric Uncertainty
Accurate lens calculations are more difficult, as the irregular corneal surface can lead to inconsistent keratometric readings – even with advanced diagnostic technologies. Conventional measurement formulas assume a regular cornea and can be inaccurate in keratoconic eyes. Surgeons often use several IOL formulas and cross-check results, occasionally using the patient’s historical refraction to guide decisions. Newer formulas such as the Barrett Universal II and Kane Keratoconus formula are improving predictive outcomes, but a degree of uncertainty remains.
- Disease Stage and Previous Treatments
The best approach differs for mild, stable keratoconus compared to advanced, progressive stages. Advanced cases with corneal scarring or steep, highly irregular astigmatism often need a more conservative strategy, where the main goal shifts from spectacle independence to improving overall functional vision. Some may benefit from combined corneal and cataract surgery, such as deep anterior lamellar keratoplasty (DALK) alongside phacoemulsification.
- Contact Lens Considerations
Many patients rely on rigid or scleral contact lenses for the best vision. These reshape the cornea, affecting measurements. To allow for accurate biometry, a “washout period” is advised – discontinuing lenses for days or weeks before measuring the eye. Not all patients can tolerate this, so historical data may sometimes guide surgical planning.
- Managing Expectations
Achieving perfect 6/6 vision may not be realistic for many keratoconic patients. For some, the goal will be improving comfort, enhancing contact lens tolerance, or gaining better overall vision clarity after surgery. Clear communication about realistic results is vital.
- Postoperative Visual Recovery
Visual recovery can take longer in keratoconic eyes – sometimes weeks or months to reach best-corrected acuity. Often, additional correction with glasses or contact lenses will be needed after surgery, and a tailored postoperative plan is essential.
Advanced Technologies and Blue Fin Vision®’s Approach
- Double Biometry for Precision: Every patient at Blue Fin Vision® undergoes measurements with two separate devices to cross-check results for maximum accuracy.
- Comprehensive Assessment: Preoperative imaging with corneal topography and tomography helps to determine stability and suitability for surgery.
- Personalised Plans: Each patient receives a recommendation based on their corneal shape, disease stage, previous treatments, and functional goals.
- Expertise in Complex Cases: Blue Fin Vision®’s leading surgeons have extensive experience in both cataract and corneal surgery, with expertise in managing keratoconic patients.
- Holistic Aftercare: Ongoing support is provided to manage expectations, adjust correction, and maintain long-term ocular health.
The Pros of Cataract Surgery in Keratoconus
- Improved Visual Clarity: Removal of the cloudy lens can offer meaningful improvement in brightness and clarity – even if some spectacle or lens correction is still required.
- Greater Comfort and Tolerance: Many patients find it easier to tolerate contact lenses, or even transition to softer lenses after surgery, improving their quality of life.
- Functional Vision Gains: Even if 6/6 vision is not achievable, gains in functional vision – driving, reading, or general daily tasks – are significant for most patients.
Important Considerations and Cons
- Outcome Uncertainty: IOL power calculations remain imprecise due to corneal irregularity.
- Possible Residual Refractive Error: Glasses or contact lenses are commonly needed afterwards, though many patients adapt better than before.
- Visual Disturbances with Premium IOLs: Halos, glare, and decreased contrast sensitivity can occur – highlighting why monofocal IOLs are almost always advised for keratoconic patients.
- Potential for Disease Progression: Keratoconus may continue to progress after surgery, especially if not previously stabilised. Corneal cross-linking may be recommended beforehand in some cases.
Emerging Research and Innovations
- Future Technologies: Research is underway on AI-assisted IOL power calculators, wavefront-guided IOLs, and light-adjustable lenses, which may eventually benefit keratoconic patients.
- Combined Procedures: In some cases, combining cataract surgery with corneal cross-linking is considered to minimise future disease progression risk.
- Custom Approaches: Enhanced diagnostics and individualised surgical workflows continue to improve outcomes for complex eyes
Why Choose Blue Fin Vision® Eye Clinic?
- Top-rated Clinics: Located on Harley Street and Weymouth Street in London, as well as Chelmsford and Hatfield.
- Deep Keratoconus Expertise: National and international leaders in keratoconus and cataract care.
- Personalised, Evidence-based Approach: Every plan is uniquely tailored for your eyes and vision goals.
- Commitment to Technology: Only the latest imaging, diagnostic, and surgical systems are used for your safety and the best possible outcomes.
Take the First Step Towards Better Vision
If you or someone you love has keratoconus and cataracts, entrust your care to the very best. Blue Fin Vision® Eye Clinic in Harley Street, London, and beyond will always provide a thorough and honest assessment – including why monofocal lenses are almost always chosen in keratoconic eyes for maximum safety and predictability.
Book your comprehensive assessment today at Harley Street, Weymouth Street, Chelmsford, or Hatfield. With Blue Fin Vision®, you gain clarity, comfort, and confidence – supported by the most advanced, compassionate care available.
Your vision is precious. Let Blue Fin Vision® Eye Clinic guide you to clarity with expertise, individual attention, and the right technology for your unique needs.
