Figure 4 In patients who underwent surgery to implant Intacs segments (Addition Technology) to treat keratoconus and return to contact lens but were left with residual astigmatism, they might be able to achieve vision without the need for contact lenses by undergoing laser ASA correction of the residual astigmatism after Intacs implantation (astigmatism requires removal of the least amount of tissue with the excimer laser, which is the most common disorder in cases of keratoconus).
Also, Intacs acting like braces are stabilizing this cornea. Crosslinking also can be done before and after if needed.
Figure 5 shows a patient who had undergone RK, LASIK, and cataract surgeries. The image shows displaced portions of the cornea between the RK incisions, which is typical in some cases when LASIK is performed on corneas after a previous RK procedure.
In these cases, irregular replacement of the corneal sections can result in irregular astigmatism and poor vision. Laser refractive correction can be performed in such patients in the ASA mode, with the effect of placing a new carpet over broken tiles, and result in emmetropic outcomes despite malpositioning of those corneal portions.