Refractive lens exchange (RLE) involves removing and exchanging the eye’s natural lens with an artificial lens implant. This is done to correct moderate to high degrees of near and farsightedness. For each eye, the surgeon selects a lens implant that will enable the eye to focus as normally as possible. The results of RLE offer dramatic and quite predictable outcomes.

RLE is essentially the same operation that is routinely performed on 3 million Americans each year to remove and replace lenses clouded by cataracts. The only difference is that the natural lens it not clouded—it is removed and replaced to correct the eye’s focusing power.

With age, most people develop cataracts—a clouding of the eye’s natural lens. Although cataracts may begin to form while people are in their 50s, the average age for cataract surgery in the USA is about 72 years. The solution is surgical removal of the clouded lens and replacement with a lens implant. Having RLE earlier in life prevents the possibility of cataracts.

The early development of lens implants was inspired by British pilots injured in World War II. When the plexiglas canopies of their fighter plane’s shattered during attacks, tiny fragments of this material sometimes pierced and lodged in the pilots’ eyes.

Dr. Harold Ridley, an ophthalmologist in London, discovered it was often safer to leave these plastic fragments in the eye than try to remove them. Since the eye tolerated the material with no adverse reactions, he created an artificial lens implant to be placed inside the eye from PMMA—the same form of plexiglas. However, it was not until the early 1970s that artificial lens implants and surgery techniques developed to the point where the procedure was considered safe and effective.

RLE can correct a wide range of focusing problems from -20 diopters of nearsightedness to +8 diopters of farsightedness—and sometimes even more.

Although RLE is a sophisticated microsurgical process, it is relatively simple for those undergoing treatment. Patients relax in a reclining dental-type chair while assistants make sure they are comfortable in preparation for surgery. They are not put to sleep, but can be sedated with oral medications, if necessary. Only the tissue around the eye is numbed for surgery.

The procedure is performed under a high power microscope and involves two stages: First, the eye’s natural lens is removed. Second, an artificial lens is inserted to correct the eye’s focusing power. After the eye is numbed, the surgeon makes a very small opening at the edge of the eye that allows special instruments to reach inside. Using an ultrasonic probe with a tiny tip that vibrates 40,000 to 50,000 times per second, our skilled surgeons gently remove the natural lens of the eye. In a matter of seconds, they carefully guide the tip of the pulsating instrument to liquefy the lens material and suction it out of the thin membrane capsule that holds it in place.

Next, the lens implant is positioned inside the thin, membrane capsule—where the original lens used to be. Now, the treatment is complete. The opening into the eye is so small that it usually heals without any stitches.

Based on the amount of nearsightedness or farsightedness you have before surgery, the following percentages approximate your chances of achieving 20/20 or 20/40 vision without corrective lenses. These estimates are with standard lens implants, assuming that your eyes are healthy and that your best-corrected vision before surgery is 20/20 or better.

Amount of Nearsightedness				Achieve 20/20 or Better		Achieve 20/40 or Better
-2.00 -4.01 -7.01 -10.01 -15.01	to to to to to	-4.00 -7.00 -10.00 -15.00 -20.00		80% 80% 70% 70% 60%		98% 98% 98% 98% 98%
Amount of Farsightedness				Achieve 20/20 or Better		Achieve 20/40 or Better
+1.00 +3.01 +5.01	to to to	+3.00 +5.00 +8.00		70% 65% 60%		98% 98% 98%

When standard lens implants are used, reading glasses or bifocals will usually be required. Standard lens implants lack the ability to change focus from far to near. However, wearing glasses for near vision and reading may not be a problem for people in their 40s and 50s because they already suffer the effects of presbyopia, the age-related loss of near vision.

Two recently developed lens implants may restore some of the eye’s ability to focus both far and near—so reading glasses are not required as often. Although neither is perfect, each lens offers certain benefits:

• Multifocal lens—focuses simultaneously at numerous distances. People are usually able to focus attention on the images they choose while their brain discounts the others.
• Accommodating lens—adjusts focus between far and near as needed. Eye muscles that normally adjust vision cause this lens to move slightly and change focus.

The decision to have one of these implants is not simple. Those interested must be:

• Highly motivated to be less reliant on reading glasses, bifocals, or trifocals
• Prepared to accept limitations of the technology
• Willing to accept some risk of the unknown
• Willing to accept slight compromises to their vision

Read or download a PDF of our brochure titled Your Choice of Lens Implants.

Learn more by visiting the cataract section of our website or read our booklet on cataract surgery—as RLE is essentially the same procedure. If you have questions about this treatment option, talk with your optometric physician or call our refractive surgery counselors.

Pacific Cataract and Laser Institute
Refractive Surgery Counselors
800-884-7254