Having reached lens fit stage your patient is likely to already know the basics, but it is worth taking some time to reiterate what successful ongoing vision correction with OrthoK is going to require. That is continued ongoing overnight wear of lenses, with the lenses removed on waking, properly cleaned and stored during the day so that they are ready for wear that night. It will take time to insert the lenses that will very quickly get easier and so take less time, but it will still take time. Sometimes it can seem a chore to spend two minutes brushing teeth before bed and from here on they will be adding to this with OrthoK lens insertion!
This is a good time to indicate that some might be able to skip some nights and still retain sufficient daytime correction. They may even be able to do this regularly, but not everyone can, so you should be honest about this and explain skipped nights as a possible lucky bonus rather than the likelihood. Your patient also needs to be aware that the refractive effect will begin to wear off during the day, especially at the start where they may indeed lose most of the effect during the day after the first night. Once past the first week, however, there should only be a small amount of daytime regression, and most lens designs take this into consideration by targeting slight overcorrection at the start of the day.
Visit schedule
Even the most perfect new OrthoK journey will generally require more chair time at the start. Once a successful fit has been achieved, however, aftercare can be easier than for more conventional contact lens types. The reason for the extra visits early on is because, unlike open eyewear lenses where you can assess fit immediately, with OrthoK you need to see how the eye responds to determine if a lens is working successfully, and this requires overnight wear.
The standard approach is to assess outcomes after the first night of lens wear. This is perhaps the most important for you to iron out any bad habits before they become ingrained. It is also likely to be your longest appointment. If all is going well you would normally continue wear and request a return visit around 1-week from starting wear, then 1-month, 3-months and if everything is still good then 6-monthly thereafter.
Just to be clear though, this is the best of best outcomes, so you should advise that this visit schedule is only a prediction and therefore subject to change. For example, outcomes from the first night of wear might lead you to want to reassess after a further few nights of wear rather than waiting for a week to decide on whether the lens needs to be changed - sometimes it can take a few days to get sufficient topography change to make a decision on lens fit.
Each time you alter the lens fit you are also going to need to factor in at least one additional follow up visit. Fortunately, it shouldn’t take any more than three different lens trials to reach full success, especially if you have followed my starter patient selection guidelines, and in most cases, you should achieve a successful outcome within one or two lens iterations.
Cost
Compared to conventional contact lenses where fit can often be perfected in a single visit, there is a greater upfront demand on chair time to achieve a successful fit outcome from OrthoK. Unless you or your employer are happy giving your time for free this upfront time investment on your part will need to be compensated, which introduces the need for a different pricing model.
How you go about billing for this time is going to depend on your practice setting, but a common model is to decide an overall fee to reach a successful outcome by a set date, after which the patient returns for aftercare as required. E.g. lenses and all required appointments within a 6-month period will be included in the set fee. This fee is then divided into two parts: an initial fee that is payable even if the outcome is unsuccessful and a final fee to cover remaining costs if the patient decides to go ahead.
This may be an uncomfortable approach to get your head around, but there really is no easy way to assess the likelihood of successful outcome without fitting some OrthoK lenses, and investing at least three appointments (initial fit, 1-day, and 1-week) to reach a point where a good judgment can be made. If your patient can’t get past initial fit, then you know not to even proceed to the first payment stage, however once passed this stage you would be wise be to ensure that your time investment to get the patient to 1-week of successful wear is covered.
Risk of eye infection
Before getting started your patient needs to be clearly informed that wearing OrthoK lenses will increase the risk of developing eye infections, which can be sight threatening, and that this risk is increased slightly from wearing them overnight. This should not be a dramatic statement intended to put them off wearing OrthoK but does need to be clearly stated to cover yourself in the unlikely event of them later suffering an eye infection.
In your next breath you I suggest you go on to tell them that current research reveals the risk of developing microbial keratitis (MK) from overnight OK wear to be no greater than open eyewear of daily disposable soft contact lenses. A case-control analysis study showed that the actual incidence of MK risk in OK is in the order of 7 per 10,000 patient wearing years, and around 13 per 10,000 patient wearing years for children wearing OK.1
Compare this to the risk of extended wear soft contact lenses, which is approximately double this rate; and daily wear reusable soft lenses, which is similar to the risk with pediatric OK wear.2 Of course, the safest way to wear contact lenses is daily disposables, which carry a risk of MK of 2 per 10,000 patient wearing years.2 In any case, the risk is remote, but it is an important note to make with the patient and parent for understanding.
Your final sentence on this subject should be that the risk of infection is further reduced if the cleaning and care systems that you will go on to recommend are followed. You don’t need to worry about what care system you are actually going to recommend at this stage, you are just reinforcing the notion that they are not playing with fire if they listen to what you say and follow your advice.
Because this is such an important message to get across I suggest you work out a script that you are comfortable following that includes the three main points just covered:
- OrthoK does increase the risk of eye infection compared to spectacle wear
- Infection risk is similar to reusable (eg. monthly) soft CLs
- With any choice, the risk is very low
- System and solution compliance helps reduce risk
Alternatives to OrthoK
Having got this far in finding a likely candidate you might not be too keen offering alternative vision correction options but again, to avoid any surprises further down the track and so that your patient can make an informed choice, you should advise your patient of the alternative contact lens options that they have available to them, and the drawbacks and benefits of these relative to OrthoK in general.
This is not to make a mountain out of a molehill, all I am really saying is don’t twist your patient's arm into being fitted with OrthoK. If they have been made aware of the alternative contact lens options, are happy with the cost and amount of time they are going to give up, don’t mind the risk of infection and are still wanting to choose OrthoK, then you are safe to proceed.
Myopia control
Myopia control has become the hot new topic of OrthoK thereby deserving its own mention. As a trainee OrthoK fitter, if you have followed my selection suggestions you won't be fitting children at this stage, making the most likely myopia control candidates you face as those with late-onset myopia who are keen to prevent this getting any worse. Unfortunately, there really isn’t much information to go on to know the best form of vision correction for this group of patients, because the published myopia control studies have enrolled younger children. We can’t even be sure if the same mechanisms are at play, as with their physical growth mostly behind them it may well be that their myopia is refractive in origin rather than due to increase in axial length.
If you are at a stage where you have sufficient experience to fit children, you instead face conjecture on the best OrthoK methods to follow for slowing progression of myopia. Anecdotal reports are suggesting that a smaller treatment zone diameter should be targeted for better myopia control. Yet, while this has been shown in simulation to create a more desirable peripheral refraction profile there is a lack of clarity on how best to achieve this effect. Furthermore, there are currently no published long-term clinical studies to validate that this type of profile is indeed beneficial. What we do know from current studies, however, is that standard OrthoK lens designs are effective in slowing progression of myopia by around 50% across a broad range of commercially available designs.
I will cover myopia control in more detail in future posts, but my general message, for now, is to stick to the demonstrated peer-reviewed evidence that OrthoK has been shown to be broadly effective at slowing progression of myopia in children, but is yet to have the same effect demonstrated for late-onset myopia. This is not to say that you shouldn't fit them in patients where there is the concern for late-onset myopia, just that you should be honest in saying to your patient that effect in these cases is yet to be scientifically validated.
References
- Bullimore MA, Sinnott LT, Jones-Jordan LA. The risk of microbial keratitis with overnight corneal reshaping lenses. Optom Vis Sci 2013;90:937-44
- Stapleton F et al. The incidence of contact lens-related microbial keratitis in Australia. Ophthalmol 2008;115:1655-62
About Paul
Dr Paul Gifford is a co-founder of Eyefit, an information resource to assist contact lens practitioners in all modes of practice. Learn more about him here.
