(Editing) recovery after LASIK
the LASIK makes it easy to make "adjustments" in its suites, even late, provided that the cornea has a sufficient thickness: in particular, the posterior residual wall (the part located under the flap) must have a sufficient thickness to authorize the issuance of the additional laser correction. After the recovery, we need this residual thickness is at least 250 microns because do not thin the cornea of excessive risk of decompensation of the Biomechanics of it (risk of ectasia) otherwise.
Technique of recovery after LASIK
The technique of choice to perform the recovery is to use the cut initially flap. Even if it sticks enough to the corneal tissue to keep it in place and resists eye rubbing or light trauma, It is possible to surgically him resoulever even several years after the original LASIK starting by cleaving its circular edge, after having identified him to the slit lamp, using a high magnification to the operating microscope to laser and lateral lighting as needed (see video below). The adhesion of the deep surface of the flap to the stroma underlying corneal (interface) is mainly by capillarity. The absence of SCAR and fibrous reaction explains the maintenance of corneal transparency, and it is easy to find then split the initial interface. The stromal flap can then be simply resouleve, and we find ourselves in a situation of conventional LASIK where you can deliver the necessary correction in the cornea, under the flap of LASIK. Once the complementary photoablation is issued on the remaining posterior stroma, we rest the flap who will then rejoin the underlying corneal tissue in a few hours.
It is not recommended to try to rejigger to the femtosecond laser (or mechanically) a new flap of LASIK, even finer (or thicker) than the first flap, under penalty to reduce the Visual quality of the reoperated eye (creating a dual interface in the cornea, risk of microplis of flap in secondary case of flap shallow end, etc.).
It must be so always start by consider a technique with a re-uprising of the original LASIK flapwhich is not a problem for a trained surgeon. The flaps as 'old' as 17 years of age were able to be resoulevés no particular problem as shown in the following video:
Period of editing after LASIK
There are "early" alterations and later alterations
Early editing after LASIK
They are made in the course of the initial surgery: the most common causes of editing are the correction after LASIK for nearsightedness (high myopia in particular), for astigmatism pronounced (the persistence of a slight astigmatism can be visually awkward)...
It is generally recommended to wait until the vision is stable before proposing a recovery, which requires at least a month to consider an editor for sous-correction. In case of over-correction, especially after correction of hyperopia, it is often better to wait at least 3 months because scar remodeling phenomena are more extended in this situation.
Late editing after LASIK
They are considered when myopia "re appears"after a few years. " Strong myopia in particular (beyond 6 Diopries), again sometimes evolve during the existence, even after a stabilisation phase to the age of 30 or 35 years.
However, it is possible to re - raise the same flaps very old (10 years or more: the oldest flap that I had to lift had been done 17 years previously!), for the reasons indicated above: only the circular from the flap edge being scarring causing a grip to the adjacent cornea. It is possible to practice the redecoupe"manual. Just separate the peripheral corneal ring flap, and drag the end of a suitable instrument to achieve a gradual dissection of the edge of the flap, following its original route, which is usually not problems. Once the cleaved edge, a spatula is slipped into the interface and the flap is lifted without difficulty.
Example: video of post LASIK recovery
The following video shows a reprocessing in LASIK procedure.
The initial intervention was performed in LASIK in 2000. Short-sightedness and light astigmatism have gradually reappeared in a few years, which the patient wished to correct. A mechanical microkeratome was used in 2000 for the cutting of the LASIK flap. The thickness of this flap was estimated to be 190 microns based on OCT imaging cuts, which is higher than the current recommendations (the Femtosecond laser now allows the thickness of a LASIK flap to be contained around 120 microns). For this reintervention, a real-time corneal thickness Measurement system ("Live OCT"), which equips the Excimer laser used for this recovery (Alcon/Wavelight EX500), is used in a peroperative way. This technology allows to control the thickness of the posterior residual wall and thus to avoid excessive thinning of the cornea. This is particularly interesting for repeats, and LASIK surgeries for correction of strong myopia (in this example, the programmed optical area was slightly reduced during the procedure to decrease the depth of laser ablation).
Precautions before recovery
Before considering a late editing after LASIK, he must ensure that the absence of a corneal ectasia, exclude a possible nuclear cataract (which can cause myopia of index) and ensure that the residual corneal wall thickness is sufficient to be able to deliver a further correction in the corneal stroma. Product real-time measurement techniques used to control the thickness of tissue removed in order to ensure good security in the execution of the times post LASIK.