LASIK
There is a lot of media attention regarding LASIK (Laser Assisted In-Situ Keratomileusis). Information about the procedure can be difficult to understand and is often downright misleading. It is very important to understand that LASIK is primarily a distance vision correction; if you're over forty you will still need glasses to read. However, it is possible to have the correction set up as monovision (one eye distance, one reading) although it would be very wise to try this setup in contact lenses first.
The most likely reason a patient may not be considered a candidate for LASIK is thin corneas. The procedure corrects nearsighted, farsighted and astigmatism combinations by gently reshaping the front surface of the eye with a beam of light. The surgeon uses a special instrument called a microkeratome to cut a flap in the cornea. This flap is then pulled back, the corneal “bed” is lasered, and the flap replaced. IntraLASIK is very similar, except that instead of the microkeratome, a laser is also used for the creation of the flap.
Results are immediate, and both ocular pain and recovery time are minimal. Generally patients are back at work in the next day or two. Some patients notice halos at night for a week or so; this has been reduced as a long-term issue with improvements in the surgical technique.
At Mansfield Vision Center, Dr. Cooke is happy to co-manage your LASIK procedure with the refractive surgeon. He has a considerable amount of experience with LASIK management, and can determine if you are a good candidate based on your prescription and corneal curvature, help schedule your procedure, discuss in detail the procedure's risks and benefits, and provide follow-up care. In addition, you will receive 20% off non-prescription sunglasses or prescription reading glasses upon completion of your surgery.
LENS IMPLANT PROCEDURES
Lens implants have been around for years – they are used in cataract surgeries after removal of the human lens to replace the refractive power lost by that removal (otherwise post-cataract patients would require ridiculously thick glasses). Surgeons have become so skilled in calculating implant power that usually a post-cataract patient’s distance vision is close to perfect, assuming there is little pre-operative astigmatism. We have also been recommending lens implants for patients with prescriptions too high for LASIK for some time now, regardless of whether or not a cataract is present. There are even toric implants now available for patients with significant astigmatism. Quite often the patient’s distance problem could be eliminated following implantation; unfortunately, without fail they would still need glasses to read and for computer use.
What if we could come up with a way to correct both the patient’s distance AND near vision, thus completely eliminating the need for any spectacle correction after surgery? Understand that until now, the reason a patient receiving a lens implant required a post-operative reading prescription is because we require our biological lens to change thickness and focus for us up close – without it, we lose that ability. The concept of a “bifocal (or accommodating) implant” was debated and researched, and has now become reality.
There are three main designs as of this writing (July 2007): Crystalens™, ReSTOR®, and the ReZoom™ implant. The optimal design for any given patient is best decided between the patient and
their surgeon.
Crystalens™ was the first to be approved by the FDA in 2003. This implant mimics the eye’s natural accommodation – the ability to change focus from far to near or vice-versa. In natural accommodation, the ciliary muscle inside the eye contracts to move the lens forward, bending it somewhat to accomplish close focusing. With presbyopia, beginning around age forty, the lens begins to lose its flexibility and it becomes harder for the ciliary muscle to move and re-shape it.
The Crystalens™ implant is designed to move within the eye, changing focus so that you can see clearly at distance, arm’s length, and near. Its design features flexible hinges that move the implant forward when the ciliary muscle contracts, and backwards as it relaxes.
The ReSTOR® implant uses apodized diffractive technology to provide near, intermediate, and distance vision. This design responds to how large or small the patient’s pupil might be. Utilizing an optics phenomenon called “simultaneous vision”, the implant creates a clear image of a distant object while at the same time a second de-focused image is created for near vision that is generally not perceived. For near viewing, the opposite is true: a sharp image for the near object and a de-focused, non-perceived distance image. The lens does not move within the eye. After surgery, 80% of patients report never needing glasses for any activity.
The other available multifocal implant is the ReZoom™ lens. This implant distributes light over five optical zones to provide the full range of vision. Like the ReSTOR® implant, the concept of“simultaneous vision” is in play; the two differ somewhat in their actual physical design. In one study, 93% of patients reported needing glasses “never” or “occasionally” following the procedure.
Patients with a cataract are now given the option prior to surgery to upgrade from the classic monofocal implant to one of the new types. More on this on the Educational page, under “Cataracts”.
So how do the new implant procedures compare to LASIK?
Pros: No after-surgery readers for most patients
Corrections for higher prescriptions
Patient will never have cataracts
Thinner corneas no problem
Cons: More invasive procedure translates to slightly more risk of infection or trauma
More expensive
Possible long-term haloing at night, more so than with LASIK
Not as proven a procedure
I will generally tell patients who are considering refractive surgery, and want to know which procedure would be best for them, the following:
If you do not mind the idea of only reading glasses after forty and beyond, consider LASIK. It is more affordable, less invasive, and extremely accurate. If you have the attitude of “if I spend all that money, I better not need glasses for anything after the surgery,” then the implant procedures are the only game in town – and there is still a 10-20% chance you will occasionally need readers.
NOTE: Some vision insurance providers have benefits towards these procedures which can affect the cost or even cover a portion of the facility fees. Please call for a consultation with Dr. Cooke.