This prospective trial compared the healing times of clear corneal incisions after femtosecond laser-assisted versus steel bevel knife-assisted cataract surgery.
The study included 58 eyes with 2.2-mm femtosecond laser-assisted biplanar clear corneal incisions, and 34 eyes with 2.2-mm manual single-plane clear corneal incisions.
All patients were evaluated on postoperative day 1, week 1, month 1 and month 3 using spectral-domain OCT (RTVue-XR Avanti, Optovue Inc). The authors assessed the rates of Descemet's membrane detachment, posterior wound gape and posterior wound retraction in each group.
Compared with the control group, the femtosecond group had a lower rate of posterior wound gape on day 1 and a lower rate of Descemet's membrane detachment at all time points. However, the posterior wound retraction rates at months 1 and 3 were significantly higher in the femtosecond group than in the control group.
Posterior wound gape and Descemet's detachment decreased over time in both groups. Inner and outer corneal incision thickness decreased over time in both groups, but was thinnest in the femtosecond group.
The femtosecond incisions were biplanar, whereas the manual incisions were single plane. This may have increased the incidence of postoperative wound gaping in the manual group.
Clear corneal incision were made at 120 degrees for manual cases, but the authors did not disclose the location of femtosecond incisions. Ideally, incisions should be made in the same location to minimize confounding variables.
Both groups expereinced low rates of Descemet's detachment and posterior wound gape over time, probably due to wound healing. However, the increased rate of posterior wound retraction in the femtosecond group suggests a distinct healing pattern that likely occurred in response to the laser energy. This patttern may significantly impact posterior corneal astigmatism and affect the predictability of outcomes in femtosecond laser-assisted cases.
Another interesting point is that the manual group had a higher posterior wound gape on postoperative day 1, which could increase the risk of postoperative infection via the clear corneal incision. The lower incidence of Descemet's detachment in the laser group could reflect a lower degree of corneal edema adjacent to the incision, which might explain why the inner and outer corneal thicknesses were reduced in the femtosecond group.