Abstract
Purpose: :
Keratectasia after LASIK is a rare but severe complication. Penetrating keratoplasty is the common way of treatment to stabilize or improve visual function. We report about a new technique of molecular cross linking of corneal stroma to avoid progression of the disease.
Methods: :
We treated 16 eyes of 16 patients with keratectasia after myopic LASIK. The presurgical refraction was –3 – –6.5 D and the corneal thickness before LASIK was > 530 µm in 15 of the patients, just one had a corneal thickness of < 500 µm. All patients were treated with riboflavin/UV light (370 nm, 30 min) cross linking. Visual acuity, corneal pachymetry and corneal curvature were measured before and after the treatment. The follow up time was 3 – 36 months.
Results: :
In the first weeks after cross linking visual function was reduced (–0.5 snellen lines +/– 1 snellen line) but after 3 months the patients showed an improvement of vision by 1.4 +/– 1 snellen lines. The corneal thickness showed no significant change after treatment (mean value 525 µm). During the follow up time of one year the astigmatism values remained stable (mean: 4.5 +/– 2D). In all of the patients a progression of keratectasia could be avoided by the cross linking technique.
Conclusions: :
To avoid keratectasia after LASIK the guidelines of the committee for refractive surgery must be respected. After LASIK a long term follow up is necessary because keratectasia can develop slowly but also very rapidly. Riboflavin/UV light cross linking is a new technique which stops progression of keratectasia by stiffening the anterior part of the corneal stroma.
Keywords: keratoconus • refractive surgery: complications • refractive surgery: corneal topography