Cataract studies support femtosecond laser use

24 Oct 2011

Two new studies detailed at the American Academy of Ophthalmology's annual meeting suggest a safer and more effective treatment.

New data on the use of femtosecond laser procedures in cataract surgery backs the argument that the technology may be safer and more efficient than the standard procedures used today, says the American Academy of Ophthalmology (AAO).

The use of ultrafast lasers in one of the most common eye procedures worldwide is one of the hot topics under discussion at the AAO’s annual meeting, being held this week in Orlando, Florida. According to two studies reported at the event, using a femtosecond laser to fragment the existing lens in patients’ eyes has twin benefits.

One is that pre-treatment with the laser step reduces the degree of ultrasound needed to soften the cataracts. Ideally, surgeons want to reduce the amount of ultrasound used, as it has been associated with slower recovery of vision in a small number of patients, says the AAO.

A study by William Culbertson from the University of Miami School of Medicine treated 29 patients, using a femotosecond laser in one eye, and standard procedure in the other. The laser surgery element comprised a capsulotomy step, where a circular incision is made in the lens capsule, followed by laser lens fragmentation – where the laser splits the lens into sections, and softens it by etching cross-hatch patterns on its surface.

The standard procedure relies on manual incision and ultrasound emulsification, and in both approaches the damaged lens is subsequently removed, before a clear intraocular replacement is inserted.

Ultrasound requirements reduced by half
In the laser-treated eyes, less than half of the normal amount of ultrasound energy was required to soften the natural lens, found Culbertson and colleagues – although he points out that the study only looked at grade 1-4 cataracts, and that the result may not apply to more severe cases.

“In clinical practice, surgeons would expect safer, faster cataract surgery when laser pre-treatment is performed before cataract removal,” Culbertson said in an AAO statement. “The combination of precision and simplification that is possible with the femtosecond laser represents a major advance for this surgery.”

In the second study, which featured 225 eyes treated with laser lens fragmentation, Mark Packer from Oregon Health and Sciences University found that the approach had no impact on corneal endothelial cells. The protection of those cells is important, since they preserve the clarity of the cornea, and do not regenerate.

Packer found that the 63 eyes treated using the standard procedure as a control showed cell loss of 1-7%. He said: “This procedure is safer than standard cataract treatment and is likely to mean better vision and fewer eye health concerns for cataract patients, over the longer term.”

The two studies add to a growing body of evidence in favor of femtosecond laser surgery, said the AAO. Although ultrafast lasers have been used in refractive surgery for many years, where they reshape a patient’s cornea, the key challenge with cataracts is that the lens sits much deeper within the eye. Only in 2009 was a new femtosecond laser source capable of reaching that deep approved by the US Food & Drug Administration.

• At the Vienna Congress of the European Society of Cataract and Refractive Surgeons last month, the giant eyecare company Bausch + Lomb unveiled a new femtosecond laser system that can perform both cataract and refractive surgery – said to be the first of its kind.

The system was developed in collaboration with Technolas Perfect Vision, and the ability to perform both procedures with the same platform is seen as providing a competitive advantage for ophthalmologists by improving workflow. Bausch + Lomb has previously estimated that some 15 million cataract surgeries take place each year around the world, indicating the size of the potential market.