Intracorneal rings (ICRs) are plastic inserts placed in the cornea. The rings flatten the central cornea to correct low levels of myopia (nearsightedness). Unlike other refractive surgery procedures, ICR procedures can be reversed. When the inserts are removed, the cornea usually returns to its preoperative shape and vision is once again myopic.

The ICR procedure is generally performed on an outpatient basis, using eyedrops for anesthesia. It is a quick procedure and can take less than half an hour.

Research is being done on intracorneal rings for correcting presbyopia (farsightedness) and astigmatism. Rings have recently been used with success in treating corneal disorders such as keratoconus, irregular astigmatism, and progressive corneal thinning that follows other corneal refractive procedures.

Complications with intracorneal rings are rare but can include undercorrection, overcorrection, induced astigmatism, infection, glare, halos, and extrusion of the insert. Minimal scarring may also occur in the area of the rings.

(c) 2007 The American Academy of Ophthalmology