[Laser in situ keratomileusis (LASIK) and scanning laser ophthalmoscopy].
BACKGROUND
To determine the influence of Laser in situ keratomileusis (LASIK) on the measurements of retinal thickness and optic nerve head topography using the Retinal Thickness Analyzer (RTA).


METHODS
RTA measurements were performed before and after LASIK. Forty-eight eyes of 25 healthy subjects were included. Mean age was 40.0+/-10.6 years. Mean preoperative refractive error (spherical equivalent) was -3.3+/-3.6 dpt, and 0.2+/-0.9dpt postoperatively. Correlation between ablation depth and duration and change of retinal thickness postoperatively was performed. All patients received a pachymetry preoperatively.


RESULTS
Postoperatively, mean retinal nerve fiber layer thickness (MRNFL) and cross sectional area (RNFL cross section area) significantly decreased after LASIK (MRNFL preop: 0.18 mm, postop: 0.11 mm, P =0.026, RNFL cross section preop: 1.17 mm(2), postop: 0.71 mm(2), P =0.015). Ablation depth revealed a significant correlation with changes in retinal thickness measurements postoperatively (Delta MRNFL: Ablation depth, P =0.001, r=-0.5). Duration of the ablation was not significantly correlated to the MRNFL measurements postoperatively (P =0.27, r=-0.08). No correlation was found between the central corneal thickness and the change in retinal thickness after LASIK (P =0.51).


CONCLUSIONS
Due to changes in corneal architecture after LASIK, measurements using RTA reveal a decrease in MRNFL and RNFL cross section area. These changes are likely artifacts. Further studies with a longer follow-up are desirable.
Hoffmann
E M
EM
Univ.-Augenklinik Mainz. ehoffman@mail.uni-mainz.de
Dick
H B
HB
Grus
F H
FH
Pfeiffer
N
N
D000328:Adult; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D011379:Prognosis; D012030:Refractive Errors / Q000175:diagnosis*; D054140:Refractive Surgical Procedures; D015203:Reproducibility of Results; D042262:Retinoscopy / Q000379:methods*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome