Refractive surgery developments emerge in 2009

December 15, 2009

The past year saw a continuation of developments and refinements of refractive surgery technologies.

The past year saw a continuation of developments and refinements of refractive surgery technologies, with new IOLs being introduced, more data on the effect of collagen cross-linking becoming available, interest in corneal inlays increasing, and greater preference of femtosecond lasers over microkeratomes in refractive procedures, among other highlights.

Advances in IOLs

However, for those who are accustomed to reading books at the distance of 40 cm or who work at a desktop computer at the distance of 50 cm, this IOL could not provide the best uncorrected visual acuity, said Hiroko Bissen-Miyajima, MD, who is director and professor, Department of Ophthalmology, Tokyo Dental College, Suidobashi Hospital, Tokyo, Japan.

She said she has been impressed with a new lens to correct presbyopia in cataract patients (AcrySof IQ ReSTOR+3.0 D, Alcon Laboratories).

"[The new IOL] (model SN6AD1), which is designed for +2.0 D of additional power at the spectacle plane, has been providing a higher rate of satisfaction for these patients," Dr. Bissen-Miyajima said. "The level of intermediate vision also has been [an] issue for patients who [had] a diffractive multifocal IOL with +4.0 D of add [implanted]. As we recognize the loss of intermediate vision because of the defocus curve, some patients complained of the decrease in the intermediate vision with the additional +4.0 D in the IOL. With the +3.0 IOL, patients rarely complain of decreased intermediate vision.

"Thus, the indication for implantation of a diffractive multifocal IOL with +3.0 [D] add seems to be more common in most countries," she said. "For patients with smaller body sizes, such as Asian patients or those with high myopia or who are accustomed to reading small print closer to their eyes, a diffractive multifocal IOL with +4.0 [D] of add would be preferable."

She also referred to a potential future application-mixing IOLs with different powers.

"The term 'mix and match' has been used for the combination of diffractive and refractive multifocal IOLs or diffractive multifocal and accommodative IOLs," she said. "Now we have yet another tool to achieve good distance and near visual acuity levels between 30 and 50 cm. This is more realistic for a spectacle-free lifestyle and I am looking forward to further developments in this area."

In addition to the new +3.0 IOL, Eric Donnenfeld, MD, clinical professor of ophthalmology, New York University Medical Center, New York, said he likes another multifocal IOL (Tecnis Multifocal IOL, Advanced Medical Optics) because he believes it provides excellent near vision.

"The availability of both of these aspheric multifocal IOLs is an enormous advance in refractive cataract surgery. The lenses have changed the quality of vision dramatically. The ReSTOR +3.0 IOL provides much better intermediate vision than the ReSTOR +4.0 and the aspheric optics provide very high-quality distance vision," said Dr. Donnenfeld, who also is a founding partner of Ophthalmic Consultants of Long Island, Rockville Centre, NY.

"The Tecnis multifocal IOL provides better reading vision than the ReSTOR +3.0 and has good, not excellent, intermediate vision. These two lenses have resulted in multifocal IOLs becoming the dominant choice for treating presbyopia in patients requiring lens extraction," he continued.