Abstract
Purpose::
To compare corneal thickness mesurements made by ultrasound and elevation topography (orbscan II) in normal eyes and after myopic laser in situ keratomileusis (LASIK).
Methods::
We included all the patients undergoing myopic LASIK at the cornea department from May to September 2006. Ultrasound pachymetry (UP) of the central cornea orbsacan II topography was done to every patient one week before the procedure. Standard LASIK was done using a Hansatome microkeratome (160 microns plate) and a Chiron Technolass 217 laser plataform. We excluded patients with any transoperative or postoperative complication. Follow-up consisted of both UP and elevation topography 1 week, 1 month and 3 months after the procedure. All the exams were made by the same technician to avoid interpersonal skew.
Results::
A total of 91 eyes from 48 patients were included. Forty three patients had LASIK in both eyes, in 5 patients just one eye;27 female, 21 male, average age was 31 years. The preoperative central corneal thickness was PU= 569.9µ, orbscan 572.3µ. Mean pachymetries recorded 1 week after surgery were: UP = 496.02µ, orbscan= 449.43µ. One month after surgery UP= 485.3µ, orbscan: 465.6µ,and 3 months postoperative UP= 475.1µ, orbscan: 444.2µ.
Conclusions::
UP and orbscan had similar results in the preoperatory. The pachymetry taken with orbscan is underestimated after myopic LASIK surgery.
Keywords: cornea: clinical science • refractive surgery: LASIK • imaging/image analysis: clinical