Refractive lens exchange (RLE)

In refractive lens exchange, the eye's own lens is removed and replaced with a synthetic lens. This procedure is only indicated in extreme cases of refractive errors.

This procedure has been used for the correction of cataract for many years. Because removal of the eye’s natural lens causes the eye to loses its ability to focus sharply on different distances ("accommodation"), it is only performed if accommodation is already reduced by aging (after approximately age 40); if the lens starts to develop opacity (starting cataract); or when other severe circumstances indicate this procedure.

Usually, the RLE procedure is an outpatient procedure performed under local anesthesia. It takes up to 30 minutes and consists of the following two steps:

	In the first step, the eye's own lens is removed. The anterior lens capsule of the human lens is opened with a small 2.8 mm circular peripheral incision.

	Through this small incision, the hard central nucleus of the lens is emulsified and removed with an ultrasonic needle (phacoemulsification) and then the soft cortex is aspirated.

	In the second step, a special instrument “injects” the synthetic lens into the empty lens capsule through the small peripheral opening.

	The strength of the new lens is calculated based on preoperative ultrasonic measurements. Each patient receives a custom-made synthetic lens with life long durability.

Cataract surgery, which has been performed since the 1960’s, uses this same method. With the successful placement of more than 400,000 cataract lenses annually in Germany alone and several million more worldwide, RLE is the most extensively practiced and proven method of refractive surgery. RLE is generally a very safe procedure, but because the eye looses its power of accommodation, this procedure is not used to correct minor refractive errors.