@entity1912 -induced @entity940 in eyes with sphere XXXX correction: Superior hinge using a rotating microkeratome versus nasal hinge using a linear microkeratome.

@entity1 @entity1912 @entity940 @entity1714
PURPOSE: To compare the effect of a rotating microkeratome (M2) and a linear microkeratome (SBK) on the change in the astigmatic component in eyes with preoperative plano refractive cylinder. SETTING: University Medical Centre Hamburg-Eppendorf, Hamburg, Germany. DESIGN: Retrospective case series. METHODS: An Allegretto excimer laser was used to perform laser ablation in myopic eyes of consecutive @entity1 . The laser in situ keratomileusis (LASIK) procedure included mechanical @entity1912 preparation using a microkeratome, either a linear type with a single-use 90  m head to create a nasal hinge or a rotating type with a single-use 90  m head to create a superior hinge. The Alpins vector method was applied to describe the effects of LASIK on postoperative refractive cylinder. RESULTS: The study evaluated 1045 eyes of 852 @entity1 . Although the mean overall efficacy and safety indices indicate the procedure was highly precise, safe, and efficient, there were statistically significant differences in surgically induced @entity940 (SIA) between the microkeratomes (P  =  .002). The postoperative refractive cylinder (ie, SIA) was 0.75 diopter (D) or more in 116 eyes (11.1%), 44 (12.8%) of 344 linear cases and 72 (10.3%) of 701 rotating cases. Independent of the type of microkeratome used, the SIA was slightly higher in eyes treated first; the mean magnitude of the induced @entity940 was 0.35 D. CONCLUSIONS: In approximately 10% of eyes with preoperative plano refractive @entity1714 , the astigmatic component tended to be overcorrected. Nevertheless, independent of the type of microkeratome, the maximum mean magnitude of refractive cylinder documented was 0.35 D. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
