Limbal Relaxing incisions (LRI) got their start almost a century ago, when ophthalmologists noticed that incisions in the curve of the cornea affected the refractive power. Initially performed on injured eyes, these findings prompted Dutch and Japanese eye surgeons to purposely place incisions in healthy eyes to improve vision.
During the mid-1970s in Russia, a surgeon named Fyodorov began treating myopia in patients using radial or spoke cuts through 90-95% of the cornea. Technically referred to as radial keratotomy (RK), this procedure weakened the peripheral cornea and caused it to balloon in shape, thereby flattening the central cornea. Results, although not as accurate as laser correction, were fair but occasionally unstable, both visually and anatomically. Limbal relaxing incisions are a variation on the theme of RK, but less drastic, much safer and more reliable.
Limbal Relaxing incisions are for those:
- Who have astigmatism
- Want to reduce or eliminate their dependence on glasses or contacts
- Have no health issues affecting their eyes
Limbal relaxing incisions are often combined with cataract surgery to reduce pre-existing astigmatism. The result is better vision without glasses. This procedure can also be used outside of cataract surgery, in individuals whose primary refractive error is astigmatism.
Limbal relaxing incisions is considered a non-medical procedure and will not be covered by either your medical or eye insurance. Dr. Northam does offer several payment options (link to financing options page) though to make LRI affordable for you.
How does it work?
The outer layer of the eye can be divided into three basic areas: the cornea, the sclera and the limbus. The cornea is the clear part, or the window that covers the iris and the pupil. The sclera is the white part of the eye. The limbus is the thin area that connects the cornea and the sclera.
Limbal relaxing incisions treat low to moderate degrees of astigmatism. Astigmatism is present when the cornea is not rounded, but instead, is steeper in one meridian than the opposite meridian, 90 degrees away. Thus, a cornea with astigmatism may be thought of as being more football shaped rather than the normal basketball shape.
Limbal relaxing incisions 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. Limbal relaxing incisions are routinely applied to 0.5-3 diopters of astigmatism. Limbal relaxing incisions can be performed either at the time of cataract surgery or as an independent procedure.
Limbal relaxing incisions have relatively few risks and are not typically associated with glare or starbursts, as often used to occur with direct corneal incisions such as RK and AK. The procedure is completed in a few seconds after numbing the eye with anesthetic drops and there is usually little if any post-operative discomfort. Furthermore, the cornea is usually stable within 2 to 3 weeks, indicating that visual fluctuations have typically resolved by that time interval.
At Collom & Carney Eye Institute Dr. Northam typically likes to use LRI in conjunction with cataract surgery for her patients that do not qualify for a Toric IOL. For her patients that have not developed cataracts she recommends either a LASIK or PRK procedure. Both of these procedures use an excimer laser where a more broad range and precise measure of astigmatism can be treated. Dr. Northam and her staff will be happy to discuss any of these options with you.