Laser Thermo-Keratoplasty. This is a technique using laser energy to heat (and thereby shrink) corneal tissue, thereby altering corneal curvature and the refractive state of the eye. A circular pattern of 8 or 16 spots is placed in the mid-periphery of the cornea. LTK is only able to correct small amounts of farsightedness. Though recently (2002) approved by the FDA for very limited amounts of farsighted correction, there is significant disagreement about whether the results are stable over time. LTK is now virtually obsolete.
