Limbal Relaxing Incision / Astigmatic Keratotomy (LRI / AK)
Limbal Relaxing Incisions (LRI)
Limbal Relaxing incisions (LRI) are a modification of astigmatic keratotomy (AK), a procedure to treat astigmatism. LRI’s can be effective in substantially reducing astigmatism even in high astigmatism cases. Astigmatism is present when the cornea is not spherical, e.g., it is steeper in one meridian than the opposite meridian 180 degrees away. The cornea with astigmatism may be thought of as being more football shaped rather than basketball shaped. LRI’s are incisions that are placed on the far peripheral aspect of the cornea (the limbus) resulting in a cornea that is more round. The astigmatism is thus reduced and uncorrected vision is improved.
Astigmatic Keratotomy (AK)
Astigmatic Keratotomy (AK) is the procedure that treats astigmatism. Surgeons make microscopic incisions over the corneal surface. These incisions are made in the steepest part of the cornea, allowing it to relax and become more round. AK is often performed in combination with other refractive procedures because astigmatism frequently accompanies nearsightedness or farsightedness.