Abstract
Purpose: :
To determine the transoperative central corneal thickness, the thickness of the flap and the residual stromal bed in patients who underwent LASIK with ultrasonic pachymetry. To compare the flap thickness of the different microkeratomes and its reproducibility.
Methods: :
A prospective, comparative and interventional study was made. Adult patients underwent Laser in Situ Keratomileusis (LASIK) at the Fundación Hospital Nuestra Señora de la Luz, IAP from July to October 2007. All patients were measured in 3 different steps of the LASIK procedure with AccuPach V ultrasonic pachymeter (Accutome, Inc. 10.5 MHz). Results were reported according to the microkeratome used (Hansatome 160 and Moria 90-130).
Results: :
We included 109 eyes of 60 patients. Twenty male and forty female. With a corneal thickness central average of 562.38µm (±29.48 SD) with a range of 498 - 654µm (p=0.28257). Corneal bed post-ablation average was 367.57µm (±45.70 SD) with a range of 277 - 469µm. We included 18 eyes with the Moria 90 microkeratome, we expected a flap thickness average of 130µm. The flap thickness average was 103.94µm (±30.77 SD) with a range of 61 - 166µm. We included 63 eyes with the Moria 130 microkeratome, we expected a flap thickness average of 160µm. Thickness of the flap average was 130.94µm (±32.03 SD) with a range of 57 - 212µm. We included 28 eyes with the Hansatome 160 microkeratome, we expected a flap thickness average of 130µm. Thickness of the flap average was 119.89µm (±24.01 SD) with a range of 79 - 171 µm.
Conclusions: :
The average flap thickness was thinner than expected. The same way the ablation platform used in this study consumes less tissue than expected. There is a safe range in the residual stromal bed post-ablation.
Keywords: cornea: clinical science • refractive surgery: LASIK • refractive surgery: comparative studies