September 2014

 

COVER FEATURE

 

Options for presbyopia correction


by Ellen Stodola EyeWorld Staff Writer

 
   
Eye after a KAMRA

Dr. Smiths left eye 1 day postop after a KAMRA pocket procedure

An intraoperative photo An intraoperative photo of one of Dr. Smiths first Flexivue Microlens pocket cases Source (all): Dean Smith, MD

There are laser procedures and lens options for presbyopia correction, and a number of new technologies are being explored

For patients seeking presbyopia correction, technologies include inlays, IOLs, monovision, refractive lens exchange, and a number of other options. Dean Smith, MD, Mississauga, Canada; Sheraz Daya, MD, Centre for Sight, London; and M. Bowes Hamill, MD, Baylor College of Medicine, Houston, commented on the options available and the treatments plans that they use for different types of patients.

The options

In terms of presbyopia-correcting options, Dr. Smith said there are either laser-based procedures or lens-based procedures. It depends on a couple of factors, including the patient age, the prescription, and what the test results show, he said. Laser-based procedures include laser vision correction with monovision. There are also corneal inlays. Dr. Smith said he considers those laser-based procedures because patients go through a similar process as LASIK patients. Then there are implant options. These are simple monovision or multifocal lenses. With multifocals, surgeons can use multifocals in both eyes or a modified monovision where the surgeon uses a multifocal in just one eye.

Dr. Hamill said choosing an option depends almost entirely on an individual patients particular needs, the refractive error, what the eye exam shows, and what the patients goals are. Its so individual that you cant apply one approach across the board, he said. Additionally, there are a number of options that are not yet available in the U.S. that are available overseas. The choices available to U.S. patients at this point are spectacles, multifocal or monovision contact lenses, or implants to achieve both distance and near vision, he said.

Dr. Daya said the option he chooses depends on the patients age group and axial length. For hyperopic and myopic patients around the age of 50 and older, he would most likely do a refractive lens exchange using a trifocal diffractive lens.

For patients below that age group, he is using the presbyopic LASIK procedure SUPRACOR on the Bausch + Lomb (Bridgewater, N.J.) platform. SUPRACOR has been available to hyperopes for 3 years and myopes for only a few months in the U.S., Dr. Daya said, and he usually does this in one eye, if not both. Its a bit like monovision, but its got a greater depth of focus, so the vision initially is not brilliant at distance, but theyve got great near vision, he said. The procedure and treatment plan is similar for hyperopic patients. The distance vision improves with time, but Dr. Daya said this is one possible concern because it can take weeks, months, or in 10% of cases up to a year to improve.

For patients seeking presbyopia correction who have a cataract, there are different options. You have to divide those people into 2 groups: those who medically justify cataract surgery and those who want to have a clear lens extraction, Dr. Hamill said. There are indications and contraindications for each. Basically, he said, there is a choice between a single vision lens in monovision or a multifocal/accommodating implant lens.

Dr. Hamills preferred approach is monovision. It seems to give the best overall functional distance and intermediate vision with the least amount of complications, he said.

Dr. Daya said that for cataract patients who are seeking presbyopia correction, he would immediately choose a trifocal lens. Additionally, he has access to the trifocal toric, which may be an option for some of these patients.

For cataract patients, its strictly the lens implant options, Dr. Smith said. When choosing those, surgeons must look at a variety of factors, including the preexisting prescription of patients, what type of vision they had previously, and their visual demands. The other big considerations are the things that we find on the clinical exam, Dr. Smith said, including dry eye and other corneal conditions such as anterior basement membrane dystrophy (ABMD). He also takes a good look at the retina and performs macular OCT.

Dr. Smith said that the biometry has to be considered. The optical axial length measurement will determine what type of lens will be appropriate and if the lens is available in the strength required for the patient. The topography becomes important as well because it is key to treating astigmatism. Finally, surgeons need to be able to evaluate corneal wavefront. If patients have high aberrations on the corneal wavefront, we steer them away from multifocal implants and do more monovision, he said.

Dr. Smith said that the most common procedure that he performs for patients who have cataracts is mini monovision, which is distance vision in the dominant eye and intermediate vision usually somewhere between 1.0 and 1.75 in the nondominant eye. To achieve that, were using astigmatism and spherical aberration correcting implants, he said. The main reason for this approach is that not all people are candidates for multifocals.

Future options

A number of options for presbyopia correction are being explored. Some of the studies on options coming up, such as the laser surface ablation procedures to try to get multifocality, have promise, but they also have real issues, Dr. Hamill. PresbyLASIK is another option that he said still needs to be explored. Additional possibilities include scleral pocket expansion devices, but he is unsure where they fit into the treatment plan.

The treatment of presbyopia is the holy grail for current refractive surgery, Dr. Hamill said. Youve got all these ideas out there, but so far nothing has risen to the top. Dr. Smith spoke about newer forms of monovision where the depth of focus is increased with either laser or lens-based procedures. Corneal inlays are another option that are approved in some places and undergoing trials in others. In Canada, the KAMRA (AcuFocus, Irvine, Calif.) has been approved, and other inlays such as the Flexivue Microlens (Presbia, Irvine, Calif.) and the Raindrop (ReVision Optics, Lake Forest, Calif.) will be available in the future. Dr. Daya said that he is interested in a WIOL that is coming out from the Czech Republic. It combines a depth of field lens with some accommodation.

Light-adjustable IOLs

Dr. Smith thinks that the Light-Adjustable Lens (LAL, Calhoun Vision, Pasadena, Calif.) is a very powerful technology, not only for the correction of nearsightedness, farsightedness, and astigmatism, but also the potential for correcting higher order aberrations and for presbyopia correction involving increasing depth of focus. He plans to begin work with this technology soon.

Dr. Smith did note that a light-adjustable IOL is a fairly big undertaking for the patient because not only is it a bit more expensive than a multifocal IOL, there are additional treatments and visits that the patient must be willing to make. There are 2 to 3 light-adjusted treatments. It is necessary to wear ultraviolet protection during that time to prevent the lens from being affected by normal daylight. Dr. Daya does not expect to use the light-adjustable lens because his results using the trifocal lens are so good. He added that he does not find it practical to use a technology where a patient has to wear dark glasses and come back for follow-up appointments several times before the lenses are fully functional.

Im always interested in new technologies, Dr. Daya said, but added that it is important to examine if the new technologies will be better than what is already in use and how they will benefit the patient.

Editors note: Drs. Smith and Hamill have no financial interests related to their comments. Dr. Daya has financial interests with Bausch + Lomb, Carl Zeiss Meditec (Jena, Germany), and PhysIOL (Liege, Belgium).

Contact information

Daya: sdaya@centreforsight.com
Hamill: mhamill@bcm.edu
Smith: smithdean@rogers.com

New options for presbyopia correction New options for presbyopia correction
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