15 Questions / Answers about Trans PRK

Questions & Answers about eye surgery techniques: TransPKR, PKR, Lasik, or femtosecond laser:

How much does TransPKR cost?
Starting at €2,200 with the SmartPulse option on the Amaris 1050 RS laser.

Price of pre-operative consultation: 75 euros. Not reimbursed by Social Security, but may be reimbursed by mutual insurance depending on the terms of your contract. A receipt will be provided.

Is TransPKR really a contactless technique?
Absolutely. Everything is done from a distance, making it a completely painless treatment; we can even avoid using the eyelid retractor for those who are put off by that prospect.
In fact, it is the only truly contactless technique, unlike the femtosecond laser, which is sometimes misleadingly referred to as “100% laser.” This terminology could suggest that femtosecond does not involve manipulation of the eye, which is incorrect.

Is Femtolasik or femtosecond laser contactless?
Absolutely not: it necessarily includes, regardless of the femtosecond used, a phase of direct intervention in contact with the eye, namely:
– First, the placement of an eyelid retractor,
– Then, the application of the femtosecond laser head directly in contact with the eye, with suction to immobilize the eye,
– Followed by the (sometimes delicate) separation and lifting of the corneal flap with a metal cannula.
We are far from a contactless procedure... However, this laser may still have certain benefits in some cases.

Post-Lasik ectasia
Haze (a type of scar fog) which is normally only encountered with surface treatments such as PKR and which is never seen in classic Lasik with micro-keratome.
Transient photophobia
Rainbow glare which would be due to the diffraction of light through an interface treated in a grid by the femtosecond laser. Recently, we were able to highlight, using a confocal microscope, images of the altered cornea of ​​one of these patients treated at the Rothschild Foundation with the Alcon FS200 laser.

As we can see, the list of potential complications of the femtosecond laser is long, some of which seem to us to be all the more important because they are specific to femto and do not exist with classic Lasik, such as difficulty or even impossibility of lifting the flap, complications due to gas bubbles, Haze, transient photophobia, halos - rainbow glare.
It should also be remembered that the femtosecond laser was supposed to reduce or even prevent the risk of ectasia on keratoconic cornea, which is absolutely not the case.
We do not entirely share the optimism of some who would attribute these complications to a kind of youthful defect suggesting that latest generation femto lasers would improve things, as we see in particular with these rainbow glare cases which concern a very recently released laser and we believe that there are indeed complications specific to the femtosecond laser as in any new technology and candidates must be informed of them.

If TransPKR is really so interesting, why hasn't it replaced all other techniques?
First, it is not suitable for all visual defects.
Second, it is certainly completely painless during the operation, but it is more painful afterwards (especially the first night).
In addition, it takes longer to recover optimal vision.
For those who want to be corrected and operational the next day, Lasik remains essential.
TransPKR is, in our experience, indisputably superior to other surface Excimer laser techniques such as classic PKR, epi-Lasik, Lasek: several studies have demonstrated this.

Is TransPKR really interesting for my case?
Cases where TransPKR is really irreplaceable:
1/ All thin corneas with irregular, asymmetrical, suspicious topography, leading to fears of complications if the cornea is weakened by Lasik or femtolasik.
2/ All patients who are resistant to the prospect of any contact or manipulation on their eyes: it is the only non-contact technique where the treatment is done remotely.
3/ Patients whose profession (firefighters, military, police officers) or sporting activity (boxing, combat sports, rugby) involves frequent and violent shocks.
In any case, only a preliminary examination will allow the technique to be chosen on a case-by-case basis.

Is transPKR really risk-free?
Zero risk does not exist, it will never exist.
But with this technique we are getting very close to it:
No contact: therefore minimized risk of infection.
No cutting or corneal flap: therefore no risk of tearing or displacement of the flap if the cutting goes badly or if we move during the operation or if we rub our eyes afterwards.
It is truly the safest technique par excellence.
Let us also remember that it is an improvement on PKR for which we have almost 40 years of experience.

The TransPKR operation is painless, but what happens afterward?
The operation is very brief: about twenty seconds per eye with the Schwind Amaris 1050 laser that we use, which is the fastest laser in the world.
At the end of the procedure, the surgeon often (but not always) places a contact lens as a bandage to facilitate healing: the patient does not have to worry about it, as they live and sleep with it, and it is forgotten on the eye. The surgeon will remove it after 3 to 4 days; sometimes this lens is lost or falls out before that: this is not serious, as it is mainly useful for the first night, and less so afterward.
Upon leaving the clinic immediately after the operation, the patient sees blurry but well enough to navigate and perform daily activities: there is a strict prohibition on driving, and work is discouraged for 48 hours.
Pain begins after 1 to 2 hours and lasts one night, with discomfort in bright light (photophobia) that will disappear within 24 to 36 hours: the discomfort is greater the more significant the defect to be corrected; in the case of minor myopia, the discomfort is minimal.
Vision begins to improve significantly after 48 to 72 hours. To be truly perfect, it may take a week or even two.
This is an operation we often perform on Thursday evenings after a regular workday for the patient (but without contact lenses).
A long recovery weekend should be taken afterward, and most patients we have operated on Thursday evening can return to work by Monday, except those with significant visual needs: professional drivers, SNCF staff, or aviation personnel.
Those individuals, and those who fear being impaired at work on Monday (high myopia, important visual demands), can benefit from unilateral treatment rather than bilateral: in this case, the second eye is operated on 1 or 2 weeks later, which further minimizes professional incapacity.

Is it sometimes said that Trans-PKR is not really a new technique, but a remake of a procedure from the 90s: PTK-PKR?
It is true that TransPKR is an improvement of PKR, which was the first type of Excimer laser surgery: this is reassuring, as we have nearly 40 years of hindsight and have never seen any deleterious, undesirable, or degenerative effects appear in the millions of people who have benefited from it around the world.
Where does this optimization of results compared to classic PKR come from?
Firstly, the new generation lasers we use cause less healing delay, notably due to new algorithms and larger treatment areas with smooth transitions.
The fact that this procedure is done in one step rather than two, as in PKR preceded by PTK, reduces corneal dryness that can lead to imprecision in treatment.
The single-step procedure of TransPKR allows the area of corneal epithelium ablation to be limited to what is strictly necessary and to be precisely superimposed on the myopia treatment area: this will accelerate visual recovery and minimize postoperative pain.
There is no peeling of the epithelium as in classic PKR, thus avoiding any mechanical or alcohol-related aggression.
Finally, compared to PTK + PKR, there are other advantages that represent very appreciable improvements, such as:
– Taking into account the different ablation rates of the epithelium and the stroma ++++
– Considering the different thickness of the epithelium at the center compared to the periphery, which prevents any refractive shift +++
– The possibility, thanks to modern corneal imaging, to benefit from extremely precise epithelial thickness maps that we did not have in the past, which helps avoid fluctuations in results depending on the thickness of the corneal epithelium. Our corneal imaging module is FDA-approved with a precision of 5 microns.
– Allowing treatment that compensates for possible irregularities of the cornea smoothed by the epithelium.
– In the case of personalized treatment: a treatment 100% tailored to the measured situation.
No, really, Trans-PKR is a genuine scientific advancement validated by numerous studies; it is undeniable, but it is true that it remains a surface treatment: it is the ultimate surface treatment.

Can Trans-PKR be performed on machines other than those used at the Paris Ouest Ophthalmological Center?
True transPKR as we practice it is currently only possible on lasers offered by the German brand Schwind, inventor of TransPKR.
And this is from the Amaris 500 model (and also on the Amaris 750) which are models equipping other French or foreign clinics.
We have the most recent and most powerful Schwind laser: the Amaris 1050 RS which is the first to have been installed in France. It is already in service in other countries: Japan, Hong Kong, Canada, Germany, Australia, Iran, Oman, Guatemala, Brazil, Colombia, Mexico, Sweden, Korea, Singapore, and France.
The Amaris 1050 is, as its name suggests, twice as fast as the 500.

Do you still practice other surface techniques (PKR, epilasik)?
Yes, because in some cases, TransPKR is not recommended, such as in cases of irregularity or ineligibility of the surface epithelium: this is relatively rare but does happen sometimes.
All of this is part of the preliminary examination before any refractive surgery.
Only after this preliminary examination can we determine the candidate's eligibility and the choice of the appropriate technique.
It should be noted that we also frequently perform interventions such as Lasik with microkeratome or femtosecond laser Lasik, which maintain their indications and undisputed effectiveness.

Can transPKR correct presbyopia?
Yes, myopia, hyperopia, astigmatism, and presbyopia can benefit from it.

What are the complications of transPKR?
We know much less about it compared to other techniques.
The main complication is "haze," a type of inflammatory reaction that delays healing and visual recovery.
Haze is more common in high myopia (from 5 diopters), and corticosteroid eye drops prescribed post-operatively will reduce it.
TransPKR results in significantly less inflammatory reaction than other techniques like PKR: this is supported by numerous international scientific studies (see the study published by Professor Burillon's department at the civil hospitals of Lyon during the main congress of French ophthalmologists in 2011 and published by the SFO (Société Française d’Ophtalmologie)).

I suffer from dry eye; can I undergo surgery?
True "dry syndrome," as found in certain autoimmune diseases like Sjögren's syndrome, is a contraindication.
Common dryness, such as that experienced by many contact lens wearers who have overused them, is generally not a true contraindication.
However, this point should be mentioned to the ophthalmologist during the pre-operative visit (as well as any history of taking anti-acne medications like Roaccutane).
The pre-operative examination will confirm the possibility of surgery, often necessitating the use of hydrating eye drops such as artificial tears for a few weeks.
The presence of dry eye may be an additional factor leaning the decision towards surface techniques like transPKR without Lasik cutting, but not always.

This remains to be clarified during the pre-operative examination.

I intend to have another pregnancy; is there a risk that my vision will change afterward?
Not more than any other myope, even after several pregnancies, with or without Lasik.
This is a long-standing myth. When myopia is stabilized (this notion should be carefully assessed during the pre-operative examination), there is no reason for the future mother's vision to regress or change more than that of the future father!
As with all falsehoods, there is always some truth behind it: there is certainly the caution that one should not operate on a pregnant woman; refractive surgery is a comfort procedure that is not performed on pregnant women, but it is routinely and safely performed on women who wish to become pregnant afterward.
That said, the few pregnant women we have inadvertently operated on (either they "omitted" to inform us or the early pregnancy was only discovered after Lasik) did not experience any different outcomes than others, neither for the baby nor for the visual results of the Lasik.

And breastfeeding?
It should be mentioned during the pre-operative visit, as the pre- and post-operative medications will be adjusted for breastfeeding. Moreover, the hormonal influence of breastfeeding could affect the outcome.

Should operations be avoided in summer because of the sun?
All serious candidates who have done their research before taking the plunge ask us this question, fearing they will have to spend the entire summer in the shade of dark glasses. It has even become a test for me: when, at the end of the pre-operative visit, they timidly ask, "It's soon going to be nice weather; maybe it’s better to wait until autumn," I immediately think to myself, "Good, this person is conscientious and cautious: they will follow the pre- and post-operative instructions to the letter," which is one of the keys to success.
It is true that in the Paris region, this issue is less pronounced than in the Antilles or Réunion, where our colleagues operate without worry all year round. However, a patient may have surgery in Paris and then immediately leave for a month in the tropics.
This question, which worries many LASIK candidates, seems somewhat overestimated in the eyes of many ophthalmologists, yet it still requires clear answers:
Yes, you can have surgery in any season.
Yes, you will need to wear tinted filter lenses (class 3 seems sufficient under our latitudes); there are photochromic class 3 lenses that turn into class 4 in sunlight.
Brown lenses are often preferred by myopes but are not mandatory.
No, they should not be worn all day, only during periods of high sun exposure (for about 3 months for PKR or TransPKR, and a little less for LASIK). That said, today tinted lenses are recommended for everyone, even those without laser surgery, as they prevent many problems related to solar toxicity, particularly macular issues.

Are Google Glass incompatible with LASIK?
What are Google Glass?
It is difficult to define them, as the project is innovative; Wikipedia defines them as a pair of glasses equipped with a built-in camera, a microphone, a touchpad on one of the arms, mini-screens, internet access via WiFi or Bluetooth, and since version 2, a mini-USB earphone connected to the right arm of the glasses.
They allow access to most of Google’s features: Google Calendar, voice recognition, Google+, clock/alarm, weather, messages (SMS, MMS, email), camera, GPS (Google Maps), etc.
Google Glass come in different models. Google has just announced a partnership with Luxottica, the largest eyewear frame group.
The development of this type of glasses opens immense perspectives and poses new technological challenges as well as societal issues.
The medical sector is particularly interested in Google Glass due to the numerous applications they open up in this field. "Augmented reality" allows access to real-time information while maintaining complete freedom of movement.
In France, Dr. Collin from the Rennes University Hospital was the first French surgeon to operate using Google Glass while communicating with his colleagues in Japan over 10,000 kilometers away.
On February 27, 2014, researchers from the University of California, Los Angeles, published a study involving Google Glass. The application, based on "Rapid Diagnostic Tests," particularly used for detecting malaria, allows for almost instant medical diagnoses. This type of application could be extremely valuable in medically underserved areas in the future.
However, curiously, Google strongly warns the public about the potential dangers of wearing Google Glass for individuals who have undergone LASIK.
They explain that the flap created during LASIK (a sort of corneal lid) never fully heals, and in the event of trauma, Google Glass could damage the cornea of a LASIK patient even years after the procedure.
Google therefore recommends that LASIK patients consult their ophthalmologist regarding potential incompatibility, but given the novelty of this device, it is likely that most opinions will adopt a certain degree of precaution as a principle.
This very cautious approach may seem somewhat alarmist, but truthfully, having never seen Google Glass apart from a few photos, we cannot completely rule out an increased risk for LASIK patients.
That said, from our own experience, we have never encountered problems of dislocation or rupture of the flap after a period of 2 to 4 weeks post-LASIK, even under extreme conditions (combat sports, rugby), which could be more dangerous than this modest device, whose edges do not appear particularly sharp or cutting.
More generally, today the public is divided between two trends: the growing desire of some to no longer wear glasses or contact lenses, encouraged by the real successes and normalization of LASIK.
Paradoxically, the interest in wearing glasses as an accessory remains strong: non-prescription lenses for computers, sunglasses, tinted lenses, and photochromic lenses are still in high demand.
One could summarize this double trend as a "no to corrective glasses" for correcting a significant visual defect, but a "yes to accessory glasses": fashion, sports, computers, comfort…
What will the famous Google Glass be in 10 or 15 years? A gigantic project that has failed, or on the contrary, a fantastic communication tool that will change our daily lives, as mobile phones or the internet did a few years ago? We should know soon.
And what about LASIK patients in all of this? Will they be left behind? Or perhaps the most likely hypothesis will prevail, showing in due course that LASIK and Google Glass are not incompatible.
In the meantime, this could only strengthen interest in non-contact and non-incision techniques like TransPKR, which do not present this exposure to the mentioned risk.

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