Traditional and new intraocular lenses
Artificial intraocular lenses (IOL) were first approved by FDA in 1981, before which patients had to wear thick eyeglasses or particular contact lenses in order to offset the focus distortion brought by cataracts removal. But now, most surgeons are concerning about the surgical technique and lenses design of various IOLs, such as premium IOL, toric IOL and so on. Both patients and doctors are more careful about the functions of different IOLs.
Single-vision and multifocal IOLs
Monofocal IOLs can offer aid vision at only one visual zone, so that they are suitable for cataract patients with blurred vision at a single distance. However, if a patient after cataract surgery can not see objects clearly at both remote and intermediate zones, monofocal IOLs are not the right choice. IOLs that can provide vision correction at more than one distance are needed, and they are called multifocal IOLs. IOL products of this kind include Crystalens, Tecnis and Rezoom. Another form of premium IOL is presbyopia-correcting IOL, which also requires an associated extra surgery cost.
Two kinds of toric IOLs for astigmatism correction
In fact, toric IOLs that are designed to correct astigmatism will also be charged with an extra fee, since they provide a special visual effect. There are two types of toric IOLs that have been approved by the FDA, namely Staar Surgical IOL and AcrySof IQ Toric IOL. While the first type can correct up to 3.5 diopters of astigmatism, the latter type is capable of rectifying astigmatism between 1.5 and 3.0. These toric IOLs can even be applied to lenticular astigmatism, although the procedure is more complex and its risk is higher. Currently, most of the cataract surgeries involve making incisions in the cornea.
Monovision with IOLs bring a monovision effect
Similar with contact lenses, IOLs can also take use of a technology named monovision, creating monovision with IOLs. Monovision with contact lenses are designed to correct presbyopia, which is the same target of monovision with IOLs. If a patient has presbyopia in both eyes, the cataract surgery may implant an IOL for near vision in one eye and another IOL for distance vision in the other eye. Once accustomed to them, patients can get both good distance vision and satisfying near vision.
Aspheric IOLs benefit young patients more than the seniors
Younger cataract surgery receivers can benefit more from the new type of aspheric IOLs, which have flatter periphery and provide better contrast sensitivity. In addition, the Akreos AO Aspheric IOL can reduce visual aberrations, and the Tecnis Z9000 is adjustable in a variety of light conditions. Nevertheless, aspheric IOLs may be ineffective for old people. Contrast sensitivity is determined by the retina’s ganglion cells, which disappear with aging.
UV and blue light blocking IOLs
Since UV lights are suspected to cause cataracts, IOLs that are capable of blocking them out are helpful. AcrySof Natural is one of the products of this type that uses a transparent yellow tint to filter out both UV and blue lights. These artificial IOLs just perform in the way as the eye’s natural lens.
Piggyback IOL and IOLs combination
A piggyback lens refers to a lens that is covered over another first lens. This fitting technology is useful if the first artificial lens can not provide satisfying vision aid for the patient. And for people with severe myopia or astigmatism, a combination of two IOLs will be implanted within a single time, in order to provide enough vision correction.
There are many factors about IOLs that worth a careful consideration. Experienced surgeons are more confident to deal with all situations that happen in an unexpected way during the procedure. Even though cataract removal and IOL implantation have high success rates, patients should be aware about the IOLs type, incision size and potential risks. Most of the traditional IOLs have been covered by Medicare and some insurance plans, whereas multifocal and newer types require out-of-pocket expense. Since people are increasingly willing to accept new IOLs, some insurance companies will cover them for sure.