Treating capsule contraction syndrome with a femtosecond laser

Investigators in Germany have devised a new technique to treat capsule phimosis using a femtosecond laser. They say the technique is effective and offers advantages over existing treatment methods, such as manual extension of the capsulorhexis and YAG laser capsulotomy.

There are 3 main steps:

1. Careful detachment of the IOL from the fibrotic anterior capsule. OVD was used to increase the space between the anterior capsule and the optic.
2. Extension of the capsulorhexis using the femtosecond laser. Imaging with SD-OCT is used to differentiate the anterior capsule from the surface of the IOL. The laser parameters were adapted to each case, according to phimosis stage and form.
3. Removal of the additional capsule ring with microforceps. The remaining OVD is removed and the corneal incisions are hydrated with balanced salt solution.

Watch a video of the femtosecond laser–assisted phimosis rescue.

The authors successfully performed this technique in 3 patients using the LenSx femtosecond laser (Alcon). All 3 capsulotomies showed excellent circularity and reproducible and homogenous cutting patterns. No OVD leakage occurred during applanation of the cornea with the laser's curved interface. IOL position remained stable throughout nearly 2 years of follow-up, with no signs of reoccurrence. 

The authors also developed semi-quantitative criteria to grade each case on a scale of 1 to 4. In the 2 cases classified as Stage 3, the femtosecond laser left tissue bridges between the inner ring of the phimosis and the outer part of the capsule. With care, the inner ring of fibrotic tissue was easily removed after it was cut with microscissors.

In 1 case classified as Stage 2, the femtosecond laser inadvertently cut into the anterior surface of the IOL, causing minimal damage to the material. However, visual outcome was unaffected and the IOL remained clear for the subsequent 1.75 years. The authors suggest that a safe distance of at least 150 μm should be maintained between the anterior capsule and the IOL surface.

Despite the small number of patients treated to date, the authors found that femtosecond laser shows considerable promise as a safe and effective surgical treatment for Stages 2 and 3 capsule phimosis. More data are required to evaluate clinical outcomes for different stages of capsule contraction syndrome.