Assessment of axial length before and after myopic LASIK with the IOLMaster.

PURPOSE: To assess the relationship between theoretical ablation depth and axial length change after LASIK with the IOLMaster (Carl Zeiss Meditec, Dublin, CA). METHODS: Ninety-nine eyes were examined preoperatively and 1 and 3 months after LASIK. RESULTS: Mean ± standard deviation (SD) spherical equivalent before LASIK was -4.06 ± 1.91 diopters (D). Mean ± SD ablation depth was 83.13 ± 30.31 μm. Mean ± SD postoperative axial length of 25.11 ± 0.14 mm at 1 month was significantly shorter than mean ± SD preoperative axial length of 25.20 ± 0.14 mm (P < .001) with no subsequent change thereafter (P = .450). An increase in ablation depth of 1 μm led to a decrease in axial length of 0.00118 ± 0.00005 mm. Ablation depth correlated strongly with change in axial length (adjusted R(2) = 0.9039). CONCLUSIONS: The IOLMaster showed a decrease in axial length after LASIK that correlated well with theoretical ablation depth.