Intuitively, using a femtosecond laser for cataract surgery seems like a safer and better method than using manual instruments. But, because the technology is so new, not much data has been compiled to confirm this, or to quantify any improvement in outcomes.
At last month’s annual meeting of the American Academy of Ophthalmology in Chicago, three presentations finally provided preliminary outcome measures that showed more predictable cataract surgery results with the femtosecond laser and a few signals of potential improvements for patients.
• Burkhard Dick, M.D., of Germany, reported the results of 850 cases of cataract surgery using femtosecond laser (using the Catalys system, OptiMedica). Compared to techniques using handheld surgical instruments, the femto laser creates a more precise capsulotomy size and shape, as well as less shrinkage of the capsular bag, he said.
Nearly all (99%) of the laser capsulotomies required no manual dissection to complete the capsulorhexis.
The laser also reduced effective phaco time for lens fragmentation by 96% on average—and phaco time was reduced somewhat even for the hardest lenses. Proponents of femto cataract surgery believe that reducing the eye’s exposure to phaco energy will be more sparing of the corneal endothelium and may reduce the incidence, or at least the severity, of post-op cystoid macular edema.
Dr. Dick also noted that post-operative inflammation on day one was reduced by about 19%, and best-corrected visual acuity was also improved during the first two months post-op.
• Pavel Stodulka, M.D., Ph.D., of the Czech Republic, reported his experience with 1,000 consecutive cases of laser-assisted cataract surgery (using the Victus laser, by Bausch + Lomb; not approved in the U.S.). The system achieved a complete circular capsulotomy in all cases. Capsulotomy radial tear developed in 0.2% of eyes during laser phaco, compared to a rate of 0.79% to 5.6% in manual cataract surgery.
• Michael A. Lawless, M.D., of Australia, reported on 500 consecutive cases (using the LenSx system, Alcon). Of these cases, zero had posterior capsule tears, compared to his rate of 1% by manual surgery. He also reported zero posterior lens dislocations, and a 0.2% rate of anterior radial tears.
“Laser cataract surgery is safer than I can achieve with my best manual technique,” Dr. Lawless said.
In regard to visual and refractive outcomes, Dr. Lawless noted only slight statistically significant improvement overall; however, a subset of patients implanted with one multifocal IOL achieved a better visual result.
Specifically, 75% of patients who received laser cataract surgery had visual acuity of 20/25 or better unaided, compared with 60% in the manual cataract surgery group.