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HomemieyecareOrthokeratology Ten Tips for Fitting Success

Orthokeratology Ten Tips for Fitting Success

Optometrists can make an enormous difference to longterm ocular health outcomes by using orthokeratology (OK) to slow myopia progression in children. In this article, Shonit Jagmohan explains why doing so has been one of the most rewarding aspects of his journey as an optometrist. And he provides his 10 top tips to get you on the OK journey with him.

As I say to my patients, “nothing beats seeing with your natural eyes”.

As one of only four students in my university class with no refractive error, I have always been drawn to eye care solutions for patients who want to live active lives without the inconvenience of wearing spectacles or daytime contact lenses.

Soon after graduating I became involved in the design of orthokeratology lenses; a role that included troubleshooting OK cases for practitioners across Australia and New Zealand. Over the past 16 years, I have witnessed the significant difference OK makes to the confidence and overall quality of life for both adults and children.

As the Fellowship Chair of the International Academy of Orthokeratology and Myopia Control (IAOMC) for the Oceania region, I am tasked with testing and acknowledging practitioners who demonstrate the highest level of knowledge, ethics, and patient care in the field of myopia management and OK.

The following 10 tips for OK fitting are fundamental to an OK clinician’s competency and success.


Whether fitting a new wearer or re-fitting an experienced wearer, it is imperative to establish a clear contractual agreement between the patient and the practitioner.

When all parties agree on what’s to be covered in an OK fitting process, we have accountability and trust from the beginning. This helps set clear patient/practitioner boundaries. Patients who seek second opinions after unsuccessful OK treatment often do so because clear expectations either were not set at the beginning, or not effectively managed.

Prioritising and communicating clear agreements when discussing treatment expectations and outcomes may seem time consuming, but it often sets the stage for a successful and more efficient fitting process, resulting in a mutually respectful and highly rewarding relationship.


Depending on the patient’s baseline prescription, corneal topography, and lens design, the OK treatment zone may continue to develop for weeks after initial wear. It can be tempting to make changes after initial reviews, but this is often a time to slow things down. Making changes too early can provide undesired results as your modifications will be based on analysing the results of a lens that has not yet reached its full treatment potential.

If early reviews suggest unexpected results, and reviewing of the lens on the eye confirms a good fit, one option is to have the patient cease wear for three nights before resuming wear of the same lens. This can be especially appropriate for new wearers who, when beginning treatment, are prone to tense lids, and in some cases, restless nights, which can result in unexpected results like lens decentration. Restarting wear after a short break can rectify the issue without making unnecessary changes to the lens parameters.


Asking specific questions when taking history is paramount because your patient’s routines and practices may change over time.

The hours spent wearing the lenses, time between insertion and fully closing the eyes to sleep, and hours since removing the lenses, all impact the results at a review, as do the cleaning regime, drops being used behind the lens before insertion, and where they are looking when inserting the lens.

While slight changes in routine can seem menial, they may significantly impact the OK treatment. For example, some children sleep more during school holidays, whereas adolescents will sleep less during exam periods, all of which can affect the OK treatment.

By taking a thorough case history at the start and asking the basics at every review, you will be able to ascertain whether your patient’s routine has changed and whether they are still following your clinical recommendations. This will help you tailor your professional recommendations to improve the results.


Capturing accurate baseline data is a must for successful OK treatment. It is well-worth taking the time to get accurate high quality baseline maps, as you will rely on these in comparative analysis for years to come.

Geometrically centred maps will give more corneal coverage than maps taken when a patient is fixating at the centre of the rings.

Comparing pre- and post-treatment placido rings will ensure the maps are taken at the same position on the eye. This is important because a slight variance in map positioning can result in inaccurate difference maps analysis.


A wide range of slit lamp imaging tools – ranging from built in slit lamp cameras to smart phone adapters – are now available. These will allow you to use photos and videos while developing your technical competency.

High quality images are beneficial when troubleshooting with colleagues and lens suppliers, as images offer objective data to assess. Comparing the effects of lens design changes with earlier images can also be an effective learning tool. Learning what did and didn’t work can help fit future cases that present with similar findings.


Regularly reviewing lenses on the eye when modifying lens parameters is invaluable for improving your knowledge and understanding how changing OK lens parameters effects corneal tissue changes. Assessing lenses on the eye, coupled with reviewing the resultant topographies, enhances your understanding of the dynamics of what is happening under the lens, and what changes you need to make to get the desired outcome.

I recommend reviewing the lens on the eye at least every six months as this will enable you to assess whether the lens is fitting well. This is especially relevant when lens fitting may be affected during growth spurts in children. It also allows you to review the over-refraction of the lens on the eye to measure refractive changes (e.g. myopia progression). And it will give you an opportunity to inspect the condition of the lens and eliminate risks associated with wearing scratched, cracked, or chipped lenses.


Having been involved in the design of OK and hard lenses, I understand that mastering the technicalities of lens designs is time consuming. Practitioners who make it a priority to build strong relationships with lens suppliers, by being actively involved in troubleshooting cases, expand their overall understanding of hard lens designs.

Suppliers like Gelflex offer a range of OK designs. They will happily talk you through their different designs, including the strengths and weaknesses of each, and advise you on the most effective design to prescribe for individual patients.


While it’s common for practitioners to embark on their OK fitting career by favouring one OK lens design, developing an understanding of the underlying principles behind OK will accelerate your overall learning.

I encourage practitioners to think about OK in terms of the fundamentals: base curve, reverse curve, alignment curve, and edge lift, and to think of OK fitting in this regard, rather than the nomenclature specific to each OK design. By taking this approach, you will improve your understanding of OK, and will be able to apply it to other OK designs with different proprietary nomenclature.


Like all complex contact lenses, increasing competency comes from experience, repetition, and learning from mistakes. An effective way to increase exposure to how lens parameter changes perform on the eye is to use the exchange options offered by lens suppliers.

The slightest alteration, no matter how insignificant, will often provide leaps in key learnings. Making slight adjustments, communicating what you are testing with the patient, and reviewing the results, can offer surprising results and contribute significantly to your professional development.

Many practitioners don’t use the customisation options available to them. This may mean that patients are missing out on the superior results of bespoke fitting. One example is the Menicon Alpha OrthoK, whereby practitioners routinely modify the optic zone diameter, overall diameter, and alignment curve angle, but fail to customise the reverse curve diameter that increases the paracentral steepening and myopia control effect. Customising this on a low myope could make an excellent lens perform even better.


Understanding OK, and being confident discussing treatment options with peers, is a major component of learning and is highly rewarding as a practitioner.

Becoming a member of the Orthokeratology Society of Oceania (OSO) and Cornea and Contact Lens Society of Australia (CCLSA), and attending their talks and conferences is not only a fun way to connect with colleagues and participate in workshops to learn from experienced practitioners, but a great opportunity to meet suppliers and learn firsthand about innovations in contact lenses. I encourage you to get involved.

Shonit Jagmohan B.Optom (Hons) is a therapeutically endorsed optometrist and the owner of Vision Camberwell in Victoria. In 2012, as a member of Innovative Contacts’ research and development team, he contributed to the development of Forge OrthoK lenses, EyeSpace Sclerals, and EyeSpace software.

With a special interest in fitting complex contact lenses and managing myopia, he is a Fellow of the International Academy of Orthokeratology and Myopia Control (FIAOMC) and in 2021, received the appointment as the Fellowship Chair of the International Academy of Orthokeratology and Myopia Control (IAOMC) for the Oceania region, reflecting his exceptional knowledge and contributions to the field of orthokeratology and myopia control.