New Lens Technology

When the natural lens is removed during cataract surgery, an IOL (intraocular lens) is inserted to take its place. Before IOLs were developed, one had to wear thick glasses or special contact lenses to be able to see after surgery. Now there are several different types of IOLs available for patients undergoing cataract surgery. Before surgery is performed, our ophthalmologist in Los Angeles, CA, will measure the eyes to determine corneal astigmatism and the correct power of IOL for you.

Traditional IOLs

For several decades, monofocal lens implants have been extremely successful. The power of the IOL is selected to allow the eye to see best at either near, far or intermediate distance without glasses. Many patients select an IOL that provides good distance vision without eyeglasses and they wear reading glasses for near.

Astigmatism

The outermost portion of the eye is the cornea. The cornea is a clear dome that provides most of the focusing power of the eye.  Since it is a biological tissue, corneas are rarely perfectly round, or spherical.  Sometimes the surface of the cornea is more like a football than a basketball. The degree to which a cornea is not round is called astigmatism. While the power of a traditional monofocal IOL is calculated to correct near-sightedness (myopia) or far-sightedness (hyperopia), a person who has both cataract and corneal astigmatism will not regain high-quality distance vision after surgery to remove the cataract unless the astigmatism is also corrected.

Corneal astigmatism may be corrected at the time of surgery in two ways. Limbal relaxing incisions may be used to change the surface contour.  Anatomically, the limbus is the zone where the cornea meets the white of the eye. Calculations are done to determine the length of one or two fine peripheral corneal incisions. The astigmatic correction is made at the start of cataract surgery, which then proceeds in the usual fashion.

A Toric IOL may be implanted during cataract surgery to replace the clouded lens. This is a Monofocal IOL that makes it possible to reduce or eliminate both refractive error (myopia or hyperopia) and corneal astigmatism, to significantly improve uncorrected vision.

Presbyopia

With a monofocal lens set for distance, reading glasses are needed for close-up vision. This same condition – the need to wear eyeglasses to change focus – affects everyone by middle age due to a natural aging condition known as presbyopia. Presbyopia develops as the natural lens loses flexibility, making zooming in up close more difficult, so reading glasses become necessary.

Many patients expect to be free of glasses following cataract removal. To become less dependent on eyeglasses for both near and far after cataract surgery, multifocal, extended depth of focus, and adjustable IOLs have been designed.

Multifocal IOLs use specially designed focal zones on the surface of the lens. Light rays are focused through the different zones to provide sharply focused images at both near and far. Many patients report that they don't have to wear glasses for any activities. They can read a book, work on the computer, drive a car day or night, and play golf or tennis with an increased freedom from glasses.

An accommodative IOL has design features that allow the natural focusing mechanism of the eye to move or flex the lens implant. The movement results in some adjustment to focus, which in turn improves the ability to see clearly at different distances without eyeglasses when compared to a traditional monofocal IOL. Crystalens is the first and only FDA-approved accommodating lens. This vision enhancement system requires absolute accuracy in pre-operative measurements of IOL power, corneal curvature and refraction to optimize the capabilities of the accommodating Crystalens.  Achieving these standards requires the doctor and his clinical staff to focus on precision, predictability and personalized patient care.

An extended depth of focus (EDOF) IOL is designed to provide a continuous range of vision rather than a single fixed focal point. Instead of splitting light the way multifocal lenses do, an EDOF lens elongates the eye's focal zone so vision stays sharp from far away through intermediate distances like a computer screen or car dashboard. Because light is not divided between separate focal points, these lenses tend to produce fewer halos and less glare at night than traditional multifocal options. Most patients enjoy crisp distance and intermediate vision with reduced dependence on glasses, though some may still prefer readers for fine print.

An adjustable IOL, such as the Light Adjustable Lens™ (LAL) from RxSight®, can be fine-tuned after surgery. Once your eye has healed, your surgeon uses a series of quick, painless UV light treatments to reshape the lens and customize your vision based on how you see. Most patients need two to four of these light treatments, each lasting only a few minutes, before the final prescription is locked in place. The result is sharper, more personalized vision, and many patients enjoy greater freedom from glasses than a standard lens implant can provide.

All of these IOL systems work well. The success rate of cataract surgery is one of the highest among all surgeries. As with any surgery, there are potential risks. You should fully understand the risks, benefits, and alternatives before you make a decision regarding cataract surgery. You must consider how important it is for you to reduce your dependence on wearing eyeglasses after cataract surgery.  You’ll also need to think about cost. Cataract surgery with a traditional Monofocal IOL is covered by Medicare, MediCal, and nearly all health insurance plans. However, while the cataract surgery itself remains a covered service, special IOLs that provide the convenience of seeing better without eyeglasses are not considered medically necessary, therefore, their additional cost is not covered by health insurance. Patients who want the benefits provided by these enhanced IOLs must pay the additional cost of these lenses out-of-pocket.