Purchase this article with an account.
S. Haque, T. Simpson; Light Scatter Analysis of the Incision Interface After LASIK, Using Optical Coherence Tomography . Invest. Ophthalmol. Vis. Sci. 2005;46(13):2757.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purposes: To monitor recovery of the stromal incision (flap) interface after LASIK using light backscatter profiles obtained by optical coherence tomography. To analyse central OCT scans to yield the scatter intensity and width of the incision interface. Methods: Both eyes of twenty–seven LASIK patients are reported in this study. Central corneal OCT measurements were taken pre–operatively (baseline) and at one day, one week, one month and six months following the surgery. Raw OCT scans were analysed using custom built software to yield values for pre–incision and post–incision light scatter intensity, as well as for width of incision (interface defined by the band of increased scatter either side of the incision). Intensity values were converted into signal–to–noise ratios. Results: One day post–operatively, the flap interface could be clearly seen on the OCT image, represented by a large peak on the respective scan profile. Signal–to–noise ratio of the incision peak significantly increased pre– and post–incision, on Day 1 from baseline (p<0.001). Pre–incision intensity was significantly greater than post–incision and remained so throughout the six months [F(4, 104)=8.41, p=0.000]. Scatter intensity (pre– and post–incision) did not decrease to baseline levels, still significantly different at six months (p<0.001). However, the interface was not always visible in the OCT images at this time. The width of the incision interface was greatest at one week post–operatively (59.8 ± 13.1um), decreasing significantly to 52.4 ± 12.0um at six months (p<0.05). Conclusions: There was a greater increase in light scatter on the anterior side of the incision (nearer epithelium) than the posterior side (mid–stroma) during healing of the LASIK cornea. The band of interface scatter decreases with time, suggesting a reduced area of healing at six months. These results suggest that both interface signal–to–noise ratio and width may be used as indices of healing following LASIK.
This PDF is available to Subscribers Only