Keratoconus
Keratoconus is a condition in which the cornea, the clear window at the front of the eye, gradually thins and bulges forward into a cone shape. Because the cornea does most of the eye's focusing, even a small change in its shape distorts vision in a way that ordinary glasses struggle to correct. Older textbooks put the prevalence at roughly 1 in 2000, but New Zealand data suggest it is far more common here: a Wellington high-school screening study found keratoconus in about 1 in 190 students overall and about 1 in 45 Māori students, and the national Aotearoa Research into Keratoconus (ARK) study found Māori and Pacific peoples over-represented and more severely affected, with just over half of patients male. It usually develops in the teenage years, although it can begin before the age of ten or not until adulthood, and progression usually slows through the twenties and thirties.
Book a keratoconus appointment online: new to us — New Keratoconus assessment (45 minutes). Already a patient — Keratoconus review (30 minutes), or Keratoconus 45 minutes (if we have not seen you for two years) if it has been a while or you would like extra time. If your vision has dropped suddenly, please call us on (07) 847 3195 rather than booking online.
Why Rose Optometry is the natural referral centre
Rose Optometry in Frankton, Hamilton, is the home of the Rose K contact lens. Paul Rose designed the Rose K series here in the Waikato, and it went on to become the one of the most widely prescribed keratoconus lens designs worldwide. That heritage is why optometrists and ophthalmologists refer keratoconus patients to us from across New Zealand and, at times, from overseas. We fit these lenses every week and hold extensive fitting sets on site.
Early diagnosis matters. Keratoconus is often first noticed in a teenager whose prescription keeps changing, or who has been told they have "astigmatism" that never quite corrects. If we find it early, we can monitor the shape of the cornea and refer for corneal cross-linking while there is still plenty of healthy tissue to protect. If a young person in your whānau has needed several new pairs of glasses in a short time, we would rather see them early than late.
How we diagnose and monitor keratoconus
Keratoconus is diagnosed by measuring the shape and thickness of the cornea, not by guessing from a prescription. We use corneal topography and tomography, including Pentacam and Medmont mapping, to build a detailed picture of the front and back surfaces of the cornea and how thick it is at every point. You can read about this equipment on our Technology page.
The first scan gives us a baseline. Repeat scans at each review are compared against it, so we can tell the difference between a stable cornea and one that is progressing. That comparison drives every decision: whether a lens needs refitting, whether it is time to refer for cross-linking, and how soon we need to see you again.
The treatment ladder
Treatment is matched to the stage of the condition, and most people sit comfortably on one of the lower rungs for years.
- Spectacles. In early keratoconus, glasses may give perfectly good vision, and some people manage with spectacles alone.
- Soft and specialty soft lenses. Custom soft lenses for mild irregularity, useful when comfort is the priority.
- Rose K rigid gas permeable lenses. A rigid lens creates a new, smooth optical surface over the cone and typically gives the sharpest vision. Small fitting adjustments make a large difference to comfort. If your lenses are bothering you, read why your rigid lenses might feel uncomfortable, and the simple fix.
- Scleral lenses. Larger lenses that vault over the cornea and rest on the white of the eye. Excellent for advanced or very irregular corneas.
- Referral for corneal cross-linking. If your scans show progression, we refer you to an ophthalmologist for cross-linking, a procedure that stiffens the cornea to slow or halt further change. It does not reverse keratoconus, so catching progression early is valuable.
- Corneal transplant. Rarely needed. A small minority go on to require surgery, usually because of scarring or lenses that no longer fit.
Living with keratoconus
Allergy, hay fever, eczema and asthma are common in people with keratoconus, and itchy eyes lead to eye rubbing, which is one of the few things we can control. Managing allergy and keeping hands away from the eyes is part of the treatment plan. Good lens care matters too. Our guide to the best contact lens solution for RGP lenses in New Zealand covers what we recommend.
One warning sign to know: a sudden drop in vision, often with pain, watering and a cloudy cornea, may be corneal hydrops, a split in the inner layer of the cornea that lets fluid rush in. It is uncommon but needs same-day attention. Read sudden vision loss with keratoconus: it could be corneal hydrops so you know what to do.
Learn more
- What is keratoconus?
- Causes and progression of keratoconus
- Treatment options for keratoconus
- Sudden vision loss with keratoconus: it could be corneal hydrops
- Why your rigid lenses might feel uncomfortable, and the simple fix
- Best contact lens solution for RGP lenses in New Zealand
Frequently asked questions
Is keratoconus genetic?
Keratoconus is thought to have both genetic and environmental causes, and it does run in some families. Eye rubbing and allergy appear to influence how it behaves. If you have keratoconus, it is sensible to have your children's corneas mapped in their early teens.
Will I go blind?
Keratoconus very rarely causes blindness. Most people keep good, functional vision throughout life with the right lenses, and the small minority who need surgery generally do well.
Can it be cured?
No. Lenses restore vision and cross-linking can slow or stop progression, but nothing yet reverses the corneal change. It usually stabilises on its own around 30.
Is corneal cross-linking available in New Zealand?
Yes. Cross-linking is performed by ophthalmologists in New Zealand, and we refer directly when your scans show progression, then continue your lens care afterwards.
How often will I be reviewed?
Younger patients and anyone showing change are usually seen every six months; stable adults typically annually. Your scans decide the interval.
Book or refer
We see keratoconus patients from Hamilton, Cambridge, Te Awamutu, Morrinsville, Huntly, Raglan and the wider Waikato, and we accept referrals from across New Zealand.
- First visit to Rose Optometry — New Keratoconus assessment (45 minutes)
- Existing patient, routine review — Keratoconus review (30 minutes)
- Existing patient, not seen for two years — Keratoconus, extended appointment (45 minutes)
Or call (07) 847 3195 or email info@roseoptom.co.nz with "Keratoconus" in the subject, and we will arrange your assessment at 38 Lake Road, Frankton, Hamilton. If your vision has dropped suddenly, please phone us rather than booking online.
References
- Papali'i-Curtin AT, Cox R, Ma T, Woods L, Covello A, Hall RC. Keratoconus Prevalence Among High School Students in New Zealand. Cornea. 2019;38(11):1382-1389. PMID 31335534. doi:10.1097/ICO.0000000000002054
- Gokul A, Ziaei M, Mathan JJ, et al. The Aotearoa Research Into Keratoconus Study: Geographic Distribution, Demographics, and Clinical Characteristics of Keratoconus in New Zealand. Cornea. 2022;41(1):16-22. PMID 33630812. doi:10.1097/ICO.0000000000002672
- Godefrooij DA, de Wit GA, Uiterwaal CS, Imhof SM, Wisse RP. Age-specific Incidence and Prevalence of Keratoconus: A Nationwide Registration Study. Am J Ophthalmol. 2017;175:169-172. PMID 28039037. doi:10.1016/j.ajo.2016.12.015
- Ferdi AC, Nguyen V, Gore DM, Allan BD, Rozema JJ, Watson SL. Keratoconus Natural Progression: A Systematic Review and Meta-analysis of 11 529 Eyes. Ophthalmology. 2019;126(7):935-945. PMID 30858022. doi:10.1016/j.ophtha.2019.02.029
- Chilibeck CM, Brookes NH, Gokul A, et al. Changing Trends in Corneal Transplantation in Aotearoa/New Zealand, 1991 to 2020: Effects of Population Growth, Cataract Surgery, Endothelial Keratoplasty, and Corneal Cross-Linking for Keratoconus. Cornea. 2022;41(6):680-687. PMID 34267061. doi:10.1097/ICO.0000000000002812

Frequently asked questions
In NZ an optometrist can calculate the prescription for glasses, fit contact lenses, diagnose and treat eye conditions and infections with medication. They can also manage ocular injuries including removing foreign objects. If surgery or specialist treatment is required they can refer to an ophthalmologist (eye surgeon), hospital, or other health care specialist. NZ-trained optometrists must complete a 5-year degree at the University of Auckland before becoming registered.
A dispensing optician has formal training in optical dispensing. They are qualified to help a client choose frames, read a prescription, discuss lens options, take measurements, order and fit glasses.
An ophthalmologist is a medical doctor who has specialised in the treatment of serious eye disease and ocular surgery such as cataract removal. They do not typically prescribe glasses or contact lenses.
While payment is generally required on the day of appointment, we do offer a number of payment options including Afterpay, Genoapay, QCard, and GoCardless.
Yes, we do.
Yes, you can.
Yes, if you are under 16 years of age you may be eligible for a subsidy for glasses. MSD criteria apply.
No. We are closed on public holidays and long weekends as we believe our staff should have the chance to enjoy this time with friends and family.
If your eyes are straightforward, almost any good optometrist can look after you well, and we would rather say that than pretend otherwise. Come to us when something is not straightforward: a prescription that will not settle, a cornea that has changed shape, a child whose short-sightedness is moving faster than it should, an eye surface that has stopped being comfortable, or a diagnosis you have been given but do not understand. Those problems are decided by measurement, and measuring them properly needs instruments most practices do not have.
Yes, and you do not need to justify it. A second opinion is not a criticism of whoever saw you first — very often they were right, and what you actually needed was the finding explained and the numbers put in front of you. What we can add is measurement. We can image the layers of your cornea and retina, map the epithelium, quantify how far your cornea sits from normal, measure the length of your eye and check your tear film objectively. That turns “something is not right” into a number, and a number either explains the problem or rules it out. Bring any previous scans, prescriptions and letters. Comparison against your own past results is often the most valuable thing in the room.
Usually. Complex is what this practice was built around — keratoconus, corneal grafts, irregular corneas after surgery or injury, severe dry eye, high prescriptions, and eyes that have been told they are not fittable with contact lenses. The Rose K lens for keratoconus was designed in this practice, and lenses of that family are now the most frequently prescribed in the world for the irregular cornea. If we cannot help, we will tell you at the first appointment and tell you who can, rather than taking you through a course of treatment that was never going to work.
Not necessarily. “Not fittable” usually means not fittable with the lens designs and the measurements available at the time. Corneal mapping, epithelial thickness imaging and modern scleral and custom lens designs have moved a long way, and eyes that were genuinely unfittable ten years ago are often routine now. What we can promise is an honest answer after we have measured, not before.
Measure things that are usually not measured. Swept-source OCT of the cornea gives us tomography, full-thickness mapping, epithelial thickness mapping and an objective ectasia risk score. Retinal OCT with autofluorescence shows cellular-level change without any dye being injected. Optical biometry measures the length of the eye to a hundredth of a millimetre, which is how myopia is properly monitored. Objective tear film assessment and osmolarity replace guessing about dry eye. Most of these produce a baseline you can be compared against for the rest of your life, and that comparison is frequently worth more than any single result.
No. Anyone can book directly. Many of our patients are referred by their own optometrist, their GP or an ophthalmologist, and just as many simply ring us. A referral letter is useful because it saves repeating history, but it is not a requirement and it is not a condition of being seen.
No, and we would not build a referral practice on that basis. We accept referrals every week from optometrists across the Waikato and well beyond — Specsavers, OPSM, Bailey Nelson, Visique, For Eyes and independent practices alike. The patient comes to us for the part that needs our instruments or our lens work, and goes back to you with a written plan and the imaging. We are also glad to talk a case through before you refer, and if you have an OCT but no biometer we can help you get objective myopia measures out of the instrument you already own. Please contact us for co-management.
Waiting is the one thing that cannot be undone. Short-sightedness is axial — the eye is physically growing too long — and that length does not come back. What treatment does is slow the rate of growth, so the earlier it starts the more length is saved. We measure axial length directly on two independent biometers and plot it against normal growth curves, which means we can see a child drifting off their expected curve before the prescription changes. There is a free 15-minute myopia chat if you want to understand the options before committing to anything. It is worth being precise about what we are all trying to achieve. Myopia control does not stop a child's eyes changing and no practice should tell a parent it will. What it does, reliably and across many published trials, is slow the rate at which the eye lengthens — and because the risk of retinal detachment, myopic maculopathy and glaucoma in later life rises with every extra millimetre, slowing that growth is how a child is kept out of the range where sight is genuinely at risk. After seventeen years of focusing on this, we are now seeing children on customised plans whose axial length is not progressing at all over a monitoring period, and in some cases measurements that come back slightly shorter than the ones before them. That is our own clinical observation in our own patients rather than a trial result, and it has to be read carefully, because the choroid thickens when treatment is working and part of an apparent reduction can be that thickening rather than the eye itself shortening. That is precisely why we measure both. We are not yet able to tell a parent that we can stop myopia in its tracks, and we will not say it until we can.
Two things: we measure it before treating it, and we hold every current treatment technology in one building. Most dry eye is treated on the basis of symptoms, which is why drops so often fail. A tear film can be failing because the oil layer is blocked, because the water layer is short, because the surface is inflamed, or because the lids are the problem, and those need different treatments. We assess the tear film objectively with TearCheck — tear film stability, the oil layer, lid and gland imaging, and an inflammation measure — and measure tear osmolarity, the saltiness of the tears, which is the closest thing to a laboratory number for dry eye. Then we treat the cause. Rose holds intense regulated pulsed light for inflammation and gland function, LipiFlow thermal pulsation to clear blocked meibomian glands from the inner lid surface, Blephasteam controlled-humidity warming, Tixel thermomechanical treatment for the lids, and Rexon-Eye quantum molecular resonance for the more severe and treatment-resistant cases. At the time of writing, and to the best of our knowledge, no other optometrist or ophthalmologist in New Zealand has all of these available under one roof. We say that as a statement of fact rather than a boast, and we would be glad for it to stop being true. Dry eye is one of the most common and most under-treated conditions we see, and there are far more people living with it than one practice can look after. Any practice wanting to build this kind of service has our encouragement and our help — please contact us for co-management, and send us the cases you are not yet set up for. Why holding all of them matters is simple. A practice with one dry eye machine will offer you that machine. Holding all of them means the assessment decides the treatment, rather than the equipment deciding it — and when the first approach does not work, the next one is in the next room rather than in another city.
Yes — from around six weeks of age. Babies and toddlers are tested with Cardiff acuity cards and retinoscopy, neither of which needs the child to read a letter, name a picture or say a word. Most of the findings that matter in a young child cause no symptoms and are invisible to a parent, which is exactly why they need looking for.
There is one good reason: a baseline. Almost everything we look for — glaucoma, macular change, a cornea beginning to alter shape, an eye that is lengthening — is diagnosed by comparison over time rather than by a single reading. A scan taken while everything is normal is the reference every future scan is measured against, and it is the one you cannot go back and take later.
Because measurement takes time and we would rather not split it across visits. A first appointment usually involves imaging as well as examination, and you should expect to have the results shown to you and explained rather than summarised. If a problem is genuinely straightforward we will say so and keep it short.
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