Monitoring corneal structures with slitlamp-adapted optical coherence tomography in laser in situ keratomileusis.
OBJECTIVE
To monitor corneal structures with slitlamp-adapted optical coherence tomography (OCT) in laser in situ keratomileusis (LASIK).


METHODS
Department of Ophthalmology, Vivantes Klinikum Neukölln, Berlin, Germany.


METHODS
In this prospective, nonrandomized, comparative clinical case series of consecutive patients who had LASIK for myopia and myopic astigmatism, the corneal structures were studied with slitlamp-adapted OCT at a wavelength of 1,310 nm. The central corneal thickness (CCT) and epithelial, flap, and residual stromal thicknesses were assessed preoperatively, immediately after surgery, on postoperative day 1, and then, on average, after 8, 35, and 160 days.


RESULTS
Twenty-five eyes of 13 patients were included. The attempted mean spherical equivalent correction was -6.11 diopters (D) +/- 2.16 (SD) with a mean calculated stromal ablation depth of 92 +/- 24 microm. The CCT was 516 +/- 26 microm preoperatively and 453 +/- 40 microm postoperatively (P<.001). The epithelial thickness increased from 57.0 +/- 7.7 microm preoperatively to 61.0 +/- 7.5 microm postoperatively (P =.04). Imaging of the hyperreflective interface was possible in all patients for up to 15 months. The flap and residual stromal thickness was 211 +/- 28 microm and 344 +/- 48 microm, respectively, immediately after LASIK and 164 +/- 21 microm (P<.001) and 284 +/- 32 microm (P<.001), respectively, on postoperative day 1. There were no further significant changes during the follow-up. The overall mean reproducibility was +/-4.50 microm (coefficient of variation [CV] 0.94%) for CCT, +/-4.99 microm (CV 8.57%) for epithelial thickness, +/-6.25 microm (CV 3.55%) for flap thickness, and +/-7.09 microm (CV 2.42%) for residual stromal thickness.


CONCLUSIONS
Slitlamp-adapted OCT can be used to longitudinally monitor the variable structures of the cornea, epithelium, flap, and residual stroma in LASIK.
Wirbelauer
Christopher
C
Klinik für Augenheilkunde, Vivantes Klinikum Neukölln, D-12351 Berlin, Germany.
Pham
Duy Thoai
DT
D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000601:surgery; D003319:Corneal Stroma / Q000473:pathology*; D003941:Diagnostic Techniques, Ophthalmological; D019573:Epithelium, Corneal / Q000473:pathology*; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009216:Myopia / Q000601:surgery; D011184:Postoperative Period; D011446:Prospective Studies; D013524:Surgical Flaps / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*