Bimanual microincision surgery advantageous for RLE

July 1, 2005

Washington, DC—Accumulating experience demonstrates the efficacy and safety of refractive lens exchange (RLE) performed with bimanual microincision phaco, said I. Howard Fine, MD, at the annual meeting of the American Society of Cataract and Refractive Surgery.

Washington, DC-Accumulating experience demonstrates the efficacy and safety of refractive lens exchange (RLE) performed with bimanual microincision phaco, said I. Howard Fine, MD, at the annual meeting of the American Society of Cataract and Refractive Surgery.

"For a variety of reasons, we believe bimanual microincision surgery is the least invasive and safest technique for lens removal, and we have used it in refractive lens exchange procedures with implantation of multifocal and accommodating IOL technology to achieve excellent outcomes," said Dr. Fine, clinical professor of ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland.

"Currently patients with presbyopia and hyperopic presbyopia are the best candidates for RLE," Dr. Fine said. "However, with fabulous new IOL technology on the horizon that allows the lens to fill the capsular bag and stabilize the vitreous face, the indications will expand to include those with high myopia as well."

Reviewing his experience with RLE using different IOLs, Dr. Fine demonstrated excellent refractive accuracy was achieved in a series of 144 eyes with the foldable silicone zonal progressive multifocal IOL (Array, AMO) implanted. Among 82 patients with bilateral implants, 45% had binocular distance UCVA of 20/25 or better and could read J2 or better at near. Corresponding to those results, 44% of patients considered themselves to be spectacle independent, Dr. Fine noted.

Even better functional outcomes have been achieved more recently using the accommodating IOL (crystalens, eyeonics). Initial experience with that device in the FDA-monitored study showed that among 24 cataract surgery patients enrolled at Dr. Fine's center, 100% achieved binocular UCVA of 20/32 or better at distance and saw J3 or better at intermediate and near, while 71% saw 20/20 or better at distance and J1 or better at intermediate and near.

Data collected at 11 to 15 months after surgery for 124 patients who underwent bilateral RLE with implantation of the accommodating IOL showed similar outcomes. In that series, 73% of patients achieved 20/25 or better UCVA at distance and J2 or better at near and intermediate, while the same proportion indicated they either did not wear spectacles at all (25.8%) or wore them almost none of the time (47.7%).

"The results from this study along with the outcomes achieved using the multifocal IOL provide a strong argument that distance UCVA of 20/25 combined with near and intermediate vision of J2 is a relevant outcome for measuring spectacle independence," Dr. Fine said.

His technique for performing bimanual RLE begins with capsulorhexis followed by cortical cleaving hydrodissection. The lens is then hydroexpressed into the plane of the capsulorhexis for extraction, which is performed by carouseling the lens with the irrigator kept on top and the phaco tip used to eat away at the equator of the lens from the outside in.

"This approach offers exceptional safety," Dr. Fine said. "The lens material is removed totally with fluidics and because it takes place midway between the posterior capsule and endothelium, it is almost impossible to cause damage to the posterior capsule or endothelium."

Once the nucleus is removed, the phaco tip is tilted back into the bag, and the residual cortex, previously cleaved with hydrodissection, comes out in a single piece.

Listing the advantages of bimanual microincision surgery, Dr. Fine noted that its smaller incisions are safer. In addition, the technique approaches nearly ideal fluidics because it is almost a closed system. As a result, there is improved anterior chamber stability, better followability of nuclear fragments, the incoming stream of irrigating fluid can be used as a manipulating tool, and I/A is easier.