Refractive Lens Exchange (RLE) is an eye surgery that is gaining in popularity. But it's not new! It involves removing the natural lens in the eye and exchanging it for a new intra-ocular lens (IOL). To understand how refractive lens exchange works, it helps to understand how the natural lens works and changes with age.
 

How the Natural Lens Works

The cornea (the clear window on the front of the eye) and the natural lens work together to focus light rays onto the retina. In many people, the amount of focus provided by the cornea and the lens doesn't bend light rays quite the right amount. They either cause the light to focus in front of the retina (nearsightedness) or behind the retina (farsightedness). Another common focusing issue is astigmatism. When the cornea is not round like a basketball, but instead is more shaped like a football, the light rays fall in different places rather than into a sharp focal point. The term for bending light rays is "refraction." These "refractive errors" - nearsightedness, farsightedness, and astigmatism - are corrected most commonly by wearing glasses or contact lenses. The glasses or contact lenses are prescribed in just the right curvature to compensate for the mismatch between the refracting power of the cornea and the lens and the overall length of the eye.
 

Why Might You Need Refractive Lens?

People who have good vision without glasses in their youth will still end up needing reading glasses, progressive glasses, or special contacts designed to help with reading vision when they reach their mid-40s. That's because the natural lens loses flexibility as we age. In our youth, most people can unconsciously and effortlessly change the shape of the lens to shift from focusing in the distance to focusing up close. But as the lens becomes stiffer with aging we can no longer change the lens shape to shift the focus. Instead, we must add reading glasses or wear progressive glasses or bifocals to shift the focus close up for tasks like reading and computer work.

To correct refractive errors, your primary eyecare provider will prescribe glasses. But you can also address this focusing problem by changing the shape of the cornea (this is what LASIK does) or by changing the power of the lens inside of the eye. A refractive lens exchange procedure involves changing the power of the lens inside the eye by exchanging the natural lens for a new lens.

I mentioned that RLE is not a new procedure, and it isn't. Ophthalmologists have been performing cataract surgery in its modern form for decades. Cataract surgery involves removing the natural lens when it has become cloudy (cataract is the term for a natural lens that has become cloudy) and exchanging it for a new intraocular lens. Ophthalmologists (eye surgeons) perform a few million cataract surgeries in the US each year. All of those surgeries have led to significant advances in technology and surgical technique. Today's cataract surgery has improved significantly in safety and outcomes from previous decades. These improvements have led to many patients choosing to have refractive lens exchange, which is essentially cataract surgery before a visually significant clouding of the lens has occurred.

New intraocular lenses offer more options for RLE and cataract surgery patients than ever before. In the past, intraocular lenses were designed to correct near- or farsightedness, but they couldn't help with astigmatism, and they couldn't address the issue of needing additional help - like readers - to see for near tasks. Today, toric IOLs help correct astigmatism. Extended depth of focus and multifocal IOLs help restore a range of vision from distance to near. Another exciting advance in intraocular lens technology is the light-adjustable lens. After the light-adjustable lens is implanted and the eye is allowed to heal for about four weeks, the residual refractive error (need for glasses to sharpen vision) is measured, and light treatments are given which change the shape of the new light-adjustable lens that is already inside of the eye. With the light-adjustable lens, we can customize the vision specific to an individual patient.

All of these improvements in technology add up to more options for you to correct your vision. Our goal is for you to have a clear, comfortable vision that fits your lifestyle. For some patients, that is an excellent pair of glasses or a comfortable pair of contact lenses. But for more and more patients, that choice also includes the option of refractive lens exchange.

Rebecca Dale, MD

Dr. Dale performs cataract surgery and refractive lens exchange for patients with all of the IOL technology noted above. Refractive lens exchange is usually reserved for patients 50 years old or more. If you would like more information on refractive lens exchange, please click here to receive a free e-book with more specific details about the refractive lens exchange process.
 

Dr. Rebecca Dale