UNDERSTANDING NON-LASER OPTION FOR VISION CORRECTION

In all those patients where the laser option is not suitable, they can go in for the non-laser option. Also, the non-laser option of vision correction may also be chosen as a first choice for its own benefits.

1. Implantable Collamer Lenses (ICL / Phakic IOLs)
2. Clear Lens Exchange

1. Implantable Collamer Lenses (ICL / Phakic IOLs)

Surgically implanted lenses, also called phakic IOLs (intraocular lenses), are a new option for people seeking more permanent correction of common vision errors such as myopia (near-sightedness). These implants, which resemble contact lenses, are placed just behind the iris in the eye.

Unlike traditional contact lenses, you cannot feel a phakic IOL in your eye — like a dental filling, which you know is there but creates no sensation. Also, phakic IOLs require no maintenance.

Implantable lenses are a surgical alternative to LASIK and, in some cases, produce better vision than LASIK.

Both procedures alter the way light rays enter the eye, to achieve sharper focus. LASIK does this by removing tissue from the eye’s cornea to change its shape. Implantable lenses function like eyeglasses or contact lenses, except they do it from within your eye through the addition of an artificial lens to compensate for biological defects.

Implantable lenses are similar to the intraocular lenses (IOLs) used in cataract surgery. However, implantable lenses are placed in eyes that retain their natural lens, unlike in cataract surgery where IOLs replace a natural lens that has turned cloudy.

Eye surgeons may consider implantable lenses when other vision correction procedures aren’t a good option, such as when a person has thin corneas or myopia between -3.00 and -20.00 dioptres. With some patients receiving phakic IOLs, LASIK may be used as a follow-up to refine vision correction.

The FDA-approved implantable lens available in Angel Eyes is:

Visian ICL. (Staar Surgical, Monrovia, Calif.) The Visian ICL or Implantable Collamer Lens received FDA approval for marketing in the United States in 2005. The Visian ICL is made partly from collagen, a biocompatible material. The ICL is foldable, which means smaller surgical entry incisions and potentially quicker recovery times (in about one day, like LASIK). FDA approval is for patients older than 21 who are near-sighted in moderate to severe ranges of -3.00 to -20.00 dioptres. Many years before FDA approval, the Visian ICL was approved and marketed in many countries outside the United States, including Europe.

The Visian ICL (Implantable Collamer Lens).

Visian ICL Product Specifications

Known generically as a posterior chamber phakic intraocular lens (P-IOL) and referred to as implantable contact lenses outside of the United States, the Visian ICL (Implantable Collamer Lens) and the new Visian TICL (Toric Implantable Collamer Lens) are becoming a popular choice in refractive error correction.

Visian ICL Product Overview

The advantages of the Visian ICL are evident:

1. Excellent quality of vision
2. Biocompatible with eye
3. Wide treatment range
4. Stable results
5. Small incision required
6. Removable, if necessary

There have been over 1,000,000 Visian ICLs implanted worldwide. Extensive development has been undertaken to deliver the most recent version of the Visian ICL – V4. Version 4 of the Visian ICL is optimally vaulted to produce consistent clearance from the crystalline lens, an improvement over earlier versions of the lens. Ongoing development of sizing methods has virtually eliminated previous problems due to inadequate vaulting through under sizing.

The Visian ICL is currently available outside the United States in three models: ICM for myopia, ICH for hyperopia, and TICM, or Visian TICL, for myopia. 

How the STAAR Surgical Company’s Phakic Intraocular Lens Works

The Visian ICL (Implantable Collamer Lens) and the Visian TICL (Toric Implantable Collamer Lens) are posterior chamber phakic intraocular lenses. Made of Collamer, STAAR Surgical Company’s proprietary collagen copolymer, the lens rests behind the iris in the ciliary sulcus.

The Visian ICL is used for treatment of myopia between -3D and -20D. The Visian Toric ICL is capable of correcting near-sightedness with astigmatism. A hyperopic model of the Visian ICL available internationally is capable of correcting farsightedness.

1. Implantation of the Visian ICL
2. Optical and Mechanical Advantages of Collamer
3. Learn more on STAAR Surgical Company website https://us.discovericl.com/

Implantation of the Visian ICL

The surgical procedure for the Visian ICL and Visian TICL* is similar to the procedure used to implant IOLs for the treatment of cataracts. However, unlike cataract IOL implantation, in which the eye’s natural crystalline lens is removed, the Visian ICL rests in front of the eye’s lens, leaving it intact. The implantation procedure allows for a small incision and offers predictable outcomes in an outpatient setting.

Before surgery, numbing drops are placed in the eye. An instrument is attached to hold open the eyelids, and then an incision is made into the eye.

The refractive lens is gently inserted into a syringe and injected through a 3.0 mm temporal, clear corneal incision. The folded Visian ICL is inserted just behind the eye’s iris and in front of the natural lens. After being placed through the microincision, the artificial lens unfolds to its full width after implantation, which requires no sutures. After the lens unfolds, footplates on the lens are used to manipulate the lens posterior to the iris plane and into the sulcus. After the six-minute procedure, the Visian ICL is invisible to the naked eye because of its location behind the iris. It can be seen only with a microscope during eye exams.

Unlike laser refractive surgery, the phakic refractive intraocular lenses created by STAAR Surgical Company are removable and do not permanently alter the shape or structures of the eye.

After the procedure, vision often improves instantly, though you may have a feeling of mild scratchiness. You should rest at home for the remainder of the day and then return the next day for an eye examination in the office. It’s essential that you follow your eye surgeon’s post-operative instructions carefully to avoid any complications.

Most people are able to resume driving and return to work within a day. A series of follow-up visits with the eye doctor also are required.

Optical and Mechanical Advantages of Collamer

The biocompatibility of Collamer makes Visian ICL an ideal choice for a lifetime of refractive correction.

The slight negative charge in the collagen in the Collamer material creates a charge-charge repulsion with negatively charged proteins and cells naturally circulating in the aqueous fluid, inhibiting protein deposition on the surface of the lens.  This feature reduces the risk for long-term inflammation.  

Furthermore, the collagen in the lens attracts fibronectin, which coats the surface of the lens and makes it immunologically “invisible,” shielding the lens from the body’s immune system.  

Collamer composition creates a lens that offer an excellent quality of vision.

The composition of a Collamer lens allows for a higher water concentration at the surface of the lens, instead of throughout the bulk of the lens. The gradual change in the refractive index at the surface results in a significant reduction in glare.

Collamer has been shown to produce fewer higher order aberrations than other lens materials.  

Expected Visual Outcomes for Lens Implantation

FDA studies showed that about 95 percent of 294 myopic patients receiving the Visian ICL implant achieved 20/40 or better vision without need for glasses or other correction.

In a study reported in September 2009 in Journal of Refractive Surgery, researchers found that the Visian ICL also produced better accuracy in outcomes and superior results when both eyes were assessed together (binocular vision).

A British study — with results announced in May 2010 — compared outcomes of phakic IOL implantation versus refractive surgery for correction of moderate to higher levels of near-sightedness, also referred to as short-sightedness. In findings involving 228 eyes of 132 patients, people who underwent phakic IOL implantation instead of refractive surgery procedures such as LASIK generally had clearer vision as well as better contrast sensitivity.

Reversibility may be one of the procedure’s main advantages over laser vision correction such as LASIK. While the implants are intended to stay in the eye permanently, they can be removed if the eye changes, complications occur or the phakic IOL correction is no longer effective. 

Risks of Phakic Lens Implantation

As with any surgical procedure, complications are rare but can occur after implantation of phakic IOLs.

Possible complications include increased chance of a detached retina, loss of cells in the thin layer inside the cornea (endothelium), inflammation, infection and cataracts.

The FDA warns of other potential complications such as sometimes severe vision loss. Problems also can develop with night driving and may include halos, increased eye pressure (intraocular pressure) that can damage the eye’s optic nerve and inadequate lens power that may not properly correct vision. After surgery, your doctor will continue monitoring your endothelial cell counts, an indicator of how healthy your corneas are and how well they heal afterward.

In Visian ICL studies performed after approval, patients had lower rates of glaucoma and endothelial cell loss and higher rates of retinal detachment and cataracts, compared with clinical trials. In certain studies, however, even when lens opacities did develop in some patients, very few progressed to clinically significant cataracts during the follow-up periods of several years.

Because phakic IOLs are a relatively new technology, long-term effects and potential risks of lens implantation are unknown.

2. Refractive Lens Exchange (RLE) – Clear Lens Exchange (CLE)

Alternative to Lasik, PRK, LASEK, Epi-Lasik, and Phakic-IOL

Refractive Lens Exchange (RLE) replaces the natural crystalline lens of the eye is with an artificial lens that is hidden behind the iris.

Refractive Lens Exchange (RLE) is essentially cataract surgery, but exclusively for refractive purposes. RLE is sometimes called Clear Lens Exchange (CLE), Clear Lens Extraction (CLE), and Refractive Lens Replacement (RLR). RLE is often an appropriate alternative to conventional or wavefront Lasik, PRK, LASEK, Epi-Lasik if the patient is presbyopic.

Refractive Lens Exchange (RLE) is a surgical procedure designed to reduce or eliminate the need for distance glasses or contact lenses and it can be used to treat a wide range of far-sightedness and near-sightedness. Unlike other refractive procedures that change the shape of the cornea, Refractive Lens Exchange (RLE) corrects vision by removing the crystalline lens in the eye and replacing it with a new artificial lens of a different focusing power, much like what happens in cataract surgery. State-of-the-art ultrasound instruments are used to measure your eye for the correct lens power, taking your lifestyle and activities into consideration. These custom measurements are entered into sophisticated formulae to calculate your personal implant power.

Exchange the Natural Lens

In RLE the natural lens of the eye is removed and replaced with a silicone or plastic intraocular lens (IOL). The replacement IOL is of a power to correct most, if not all, of the patient’s hyperopia or myopia. RLE alone is not very successful at correcting astigmatism. To correct astigmatism, conventional or custom wavefront Lasik, All-Laser Lasik, PRK, LASEK, CK, or Epi-Lasik may be required in addition to RLE.

The Choice of Implant and Reading Vision

1. The traditional implant is monofocal (i.e. is only perfectly focused at one particular distance) and usually chosen for distance vision but for near the patient will need reading glasses even if they did not need them before.
2. The multifocal lens is made of either silicone or acrylic and has refractive optics consisting of concentric zones. The lens provides two separate areas in focus simultaneously. Previous versions of these lenses used to cause halos and glare but this has largely been eliminated. In one study of patients given a multifocal implant 80% did not need distance glasses and 40% did not need reading glasses at all (compared to nearly 100% needing reading glasses with monofocal implants).

These are impressive results but they demonstrate that only a minority of patients can expect to be completely glasses free. The majority will enjoy reduced dependence on reading glasses but still need them for more taxing near activities. There are ways of reducing this dependence even further. Your surgeon will discuss with you whether you are suitable for these implants.

1. The accommodating implant is one of the newest types of implant. It is designed to change position in the eye when you try to read so you can have good distance vision and also good reading vision. The ability to read with these implants varies from person to person but on average give 1.4 dioptres of accommodation equivalent to a weak pair of reading glasses. Even if this type of implant does not work very well for you the end result would be little different from having a monofocal lens; also, this lens does not degrade the quality of your vision or have an effect on night driving as may occur with multifocal lenses.

Advantages of RLE

Though there are few advantages of RLE over other forms of refractive surgery, but the disadvantages far outweigh any benefits you get with this procedure. Some of the most obvious are that the surgery has years of successful history and the cornea is relatively untouched. If you have a thin cornea, dry eyes, or other minor cornea problem, RLE may be a better alternative. RLE may be the only option for people with high refractive error. Also, if the exact desired refractive change is not achieved, the IOL may be exchanged for one of a different power, or a cornea-based refractive surgery technique such as conventional or custom wavefront Lasik, All-Laser Lasik, PRK, LASEK, CK, or Epi-Lasik may be used in combination with RLE to “fine tune” the correction. Because RLE removes the natural lens, there is no possibility of developing a cataract in the future.

Disadvantages of RLE

A big disadvantage with RLE is that it is a significantly more invasive surgery than any cornea-based refractive surgery or even Phakic -IOLs. An extremely myopic patient would have an elevated risk of vitreous or retina problems after RLE.

If you have accommodation (those below 40 years of age), you will lose almost all of accommodation power of your eyes. In such cases, you will be fully dependant on reading glasses for all your reading and other near distance work. If you are already fully presbyopic and need powerful reading glasses or bifocals, the reduction of accommodation with RLE may not be a problem because you already have a very limited range of accommodation.

Because, you lose your fully functional natural crystalline lens in this procedure, it should be done only as a last resort in those who really need to get rid of their glasses and are unfit for all other vision correction procedures.

See Distant and Near 

Most IOLs cannot accommodate by changing focus from distance to near like a young and healthy natural lens. Your eye will be set to either near vision or far vision. You may also have multifocal IOLs implanted that help with near and distance vision. You will need to discuss with your doctor if a multifocal is appropriate for your circumstances. It is possible to be corrected for monovision with RLE. Monovision is another method to receive some advantage of near and distant vision and resolve presbyopia.

If you already have cataracts starting to form, RLE may make a lot of sense. If you are already presbyopic, RLE may be a better alternative. There is little need to have surgery affecting the cornea if within a short period of time you will be having cataract surgery anyway or you already cannot change focus from distance to near.