Anzeige
Erschienen in:
01.05.2011 | Refractive Surgery
The change in internal aberrations following myopic corneal laser refractive surgery
Erschienen in: Graefe's Archive for Clinical and Experimental Ophthalmology | Ausgabe 5/2011
Einloggen, um Zugang zu erhaltenAbstract
Background
In virgin eyes, the internal aberrations compensate corneal aberrations, and it has been suggested that the compensation may be feedback-driven and developmental, with active or passive adaptive mechanisms potentially responsible for the aberration auto-compensation. The purpose of this study is to investigate the internal higher order aberrations (HOA) following laser in situ keratomileusis (LASIK).
Methods
Prospective corneal and internal HOA were measured pre-operatively and 6 months post-operatively on 50 consecutive LASIK patients with the OPD-Scan.
Results
There were increases to corneal HOA terms \( {\hbox{Z}}_4^0 \) (0.215 ± 0.092 μm to 0.381 ± 0.180 μm), \( {\hbox{Z}}_6^0 \) (0.002 ± 0.018 μm to 0.049 ± 0.034 μm) and \( {\hbox{Z}}_6^4 \) (0.010 ± 0.017 μm to 0.018 ± 0.016 μm) with corresponding increases to internal HOA terms \( {\hbox{Z}}_4^0 \) (-0.176 ± 0.102 μm to −0.218 ± 0.121 μm), \( {\hbox{Z}}_6^0 \) (0.004 ± 0.022 μm to −0.010 ± 0.036 μm) and \( {\hbox{Z}}_6^4 \) (0.008 ± 0.106 μm to −0.015 ± 0.054 μm). The increases in internal aberrations attenuated the increase in corneal aberrations, providing an overall lower quantity of total aberration. A greater increase in corneal spherical aberration and associated compensation was found to occur with greater degrees of attempted myopic correction.
Conclusion
Corneal spherical aberration and \( {\hbox{Z}}_6^4 \) increased with corresponding increases in the internal spherical aberration and \( {\hbox{Z}}_6^4 \) following LASIK. This may be an active compensatory mechanism of the internal optics to change, in order to reduce the effect of induced corneal HOA.