Femtosecond intrastromal presbyopia correction effective for Asian eyes

The minimally invasive, flapless treatment showed strong refractive and corneal biomechanical outcomes.

A flapless intrastromal laser correction procedure for presbyopia yielded positive visual and refractive outcomes with minimal complications, according to a surgeon.

Vincent W. Lee

The IntraCor intrastromal treatment performed with the Technolas femtosecond laser (Technolas Perfect Vision) is a minimally invasive procedure, which involves reshaping the cornea to enhance near vision without compromising distance vision, The procedure time of 15 to 20 seconds minimizes ocular trauma and speeds recovery, Vincent W. Lee, MD, told Ocular Surgery News.

“The short procedure time and the minimally invasive nature lead to more patient comfort and cooperation,” he said. “It also leads to faster visual recovery. There is little wound healing or risk of infection, as the epithelium and Bowman’s layer were not affected.”

Patient criteria

Dr. Lee described outcomes for 43 eyes of Asian patients with a mean age of 53 years who underwent IntraCor treatment. Twenty-one left eyes and 20 right eyes were treated.

Inclusion criteria were stable distance refraction for at least 1 year; minimum spherical equivalent refraction of 0.25 D; astigmatism of less than 0.75 D; near addition of more than 1.5 D; keratometry readings between 40 D and 46 D; pachymetry of more than 500 µm; and no ocular pathology.

In addition, for bilaterally emmetropic patients who were motivated to eliminate reading glasses, the nondominant eye was treated.

Uncorrected near and distance visual acuity, near and distance best corrected visual acuity, near and distance refraction, and topography were assessed preoperatively and at 1 day, 1 week and 1 month postoperatively.

Outcomes and patient satisfaction

Mean preoperative manifest refractive sphere was 0.85 D. After surgery, mean sphere was –0.05 D at 1 day, 0.01 D at 1 week and –0.12 D at 1 month.

Mean cylinder was –0.35 D preoperatively. After surgery, mean cylinder was –0.3 D at 1 day, –0.23 D at 1 week and –0.28 D at 1 month.

Mean preoperative manifest refractive spherical equivalent was 0.68 D. After surgery, mean manifest refractive spherical equivalent was –0.21 D at 1 day, –0.11 D at 1 week and –0.04 D at 1 month.

Mean preoperative uncorrected distance visual acuity was 0.9. After surgery, mean uncorrected distance visual acuity was 0.77 at 1 day, 0.82 at 1 week and 0.84 at 1 month.

The 1-month follow-up data showed a mean gain of uncorrected near visual acuity from J10 to J2 (range: J1+ to J5). Most patients gained up to six lines of near visual acuity, and no patient lost any lines of near visual acuity.

Results showed central steepening that produced a 2 D to 3 D change in refractive power. There was no additional corneal weakening, no change in endothelial cell density, no regression and no significant IOP elevation, Dr. Lee said.

Visual disruptions such as rings and halos were rare and diminished after 1 month. One patient reported dryness in the treated eye 1 day after surgery; her symptoms were attributed to punctate keratopathy and had dissipated completely within 1 week, Dr. Lee said.

“Only one patient complained of halos and glare. … All patients are able to return to work the next day,” he said.

Investigators plan to initiate the IntraCor procedure in patients with broader indications, Dr. Lee said. – by Matt Hasson

• Vincent W. Lee, MD, can be reached at Hong Kong Laser Eye Centre, 1602, New World Tower 1, 18 Queen’s Road Central, Hong Kong, People’s Republic of China; +852-2526-3333; e-mail: vincentwlee@netvigator.com.