Hi Lydia
The surgical treatment options for people with very high myopia may still include laser techniques like LASIK, as well as Implantable Collamer Lens (ICL) surgery.
LASIK can be considered if the cornea happens to be thicker than average, say for example, above 600 microns in central thickness. Practically speaking, the upper limit at which LASIK can still give satisfactory visual quality is around -10 to -11D (1000 to 1100 degrees) or so, although I know of rare cases which had even higher myopia than this corrected with LASIK.
The main issue with regard to LASIK for such high powers is a higher risk of compromised visual quality. This goes with the smaller optical zone that needs to be used (to avoid thinning the cornea excessively), with the smaller zone increasing the risk of night time halos and poorer vision in the dark, as well as a somewhat higher risk of regression (getting shortsighted power again).
ICL surgery avoids most of these issues with visual quality. A mild thin halo may be noticed in the dark with ICL, but usually patients are not disturbed by this and after a while, stop noticing it.
Of course, LASIK and ICL are 2 very different procedures each with their own pros and cons. I would almost never do ICL for a low myope (unless the cornea appeared weak), while on the other hand I almost always prefer to do ICL for patients with very high spectacle power-whether that is myopia, hyperopia or astigmatism, if possible. ICL is intraocular surgery and carries a very small risk of things like cataracts, although since it is reversible, it can be removed if problems are seen so that they do not get worse. On the other hand, while there is no risk of LASIK causing a cataract, the visual quality issues can be a bit too much of a con for those with very high spectacle powers.
One thing I think you should also note is that as a wearer of RGP lenses, you are used to very crisp, clear vision. That is the great strength of RGP lenses, and very few (if any) methods can give comparable visual quality. If absolute sharpness of vision is your ultimate goal, I think you should stick to your RGP lenses. If you are unable to wear them, or prefer not to for various reasons, and prioritise convenience over absolute sharpness, then ICL surgery would probably be the method of choice (provided your eyes meet eligibility criteria).
