Abstract
Purpose::
To evaluate the corneal thinnest point location and its movement before and after myopic LASIK (laser in situ keratomileusis) from Orbscan II system
Methods::
410 eyes (207 patients) were measured with Orbscan II system to compare the corneal thinnest point locations relative to three different reference points (Orbscan II system default origin, pupil center, fixation point) between pre-LASIK and post-LASIK.
Results::
Using system default origin as the reference point, half of corneal thinnest points were in the inferior temporal quadrant for pre-op (52.6 %) and post-op (49.5 %). The thinnest point significantly moved nasally and superiorly from pre-op to post-op (mean distance, 0.285 ± 0.343 mm). While using pupil center and fixation point as the reference point respectively, the results were similar to above. Further analysis showed the ratio (postoperative distance to origin divided by preoperative one for each reference point) which pupil center was the reference point (0.666) was significant smaller than the other two ratios (0.733 and 0.741).
Conclusions::
After LASIK for myopia, the distance from the corneal thinnest point to each reference point is significant smaller than the preoperative one. Pupil center is just the target of corneal thinnest point movement after myopic LASIK with pupillary eye tracker. Meanwhile, this movement is also close to system default origin and fixation point.
Keywords: refractive surgery: corneal topography • refractive surgery: LASIK