Monitoring corneal structures with slitlamp-adapted optical coherence tomography in laser in situ keratomileusis

Abstract

Slitlamp-adapted OCT can be used to longitudinally monitor the variable structures of the cornea, epithelium, flap, and residual stroma in LASIK.

Online optical coherence pachymetry to evaluate intraoperative ablation parameters in LASIK

“…This intraoperative continuous monitoring over time enabled the assessment of individual ablation depth and possible influencing factors. The intraoperative ablation depth had a significant positive correlation compared to the calculated stromal ablation depth, as was also reported previously in myopic corrections [26,30]. There was also a significant correlation between the attempted and achieved refractive correction.…”

“…The age was 41±12 (mean±SD) years (range 22 to 66 years). A complete ophthalmologic examination was performed on each patient preoperatively, as described previously [26,30,31]. For this study, uncorrected (UCVA) and best-corrected (BCVA) visual acuity measured in decimal fraction, subjective and objective refractions (Speedy-K, Nikon, Tokyo, Japan) were of particular interest.…”

“…The patients were then scheduled for elective refractive surgery. Eligibility and exclusion criteria have been reported previously [26,30,31]. Informed consent was obtained from each subject and all patients were treated in accordance with the Tenets of the Declaration of Helsinki.…”

“…The measured preoperative fluence ranged from 0.3 to 0.6 μm per pulse at a repetition rate of 200 Hz. All patients underwent an identical standardized surgical procedure and postoperative treatment, as described previously [27,[29][30][31].…”

Continuous monitoring of corneal thickness changes during LASIK with online optical coherence pachymetry

“…13 For intraoperative pachymetric representation of the cornea, the reflected light was analyzed and the intensity was converted to color-coded scattergrams, which were simultaneously recorded during the measurements ( Figure 2). In contrast to the previously presented corneal optical coherence tomography (OCT) method, [15][16][17][18] in this system no scanning was performed, and thus the images represented a single, central A-scan, which was resolved over time. From this type of imaging, changes in the CCT in real time were derived.…”