Modeling the influence of LASIK surgery on optical properties of the human eye

Abstract

The aim was to model the influence of LASIK surgery on the optical parameters of the human eye and to ascertain which factors besides the central corneal radius of curvature and central thickness play the major role in postsurgical refractive change. Ten patients were included in the study. Pre- and postsurgical measurements included standard refraction, anterior corneal curvature and pachymetry. The optical model used in the analysis was based on the Le Grand and El Hage schematic eye, modified by the measured individual parameters of corneal geometry. A substantial difference between eye refractive error measured after LASIK and estimated from the eye model was observed. In three patients, full correction of the refractive error was achieved. However, analysis of the visual quality in terms of spot diagrams and optical transfer functions of the eye optical system revealed some differences in these measurements. This suggests that other factors besides corneal geometry may play a major role in postsurgical refraction. In this paper we investigated whether the biomechanical properties of the eyeball and changes in intraocular pressure could account for the observed discrepancies.

Keywords:

• myopia
• refractive error
• LASIK surgery
• eye model

Acknowledgements

This work was partially supported by the Ministry of Science and Higher Education (Grant No. N N518406738) and by the Wroclaw University of Technology, Wroclaw, Poland within the research program “GRANT – Support of the Research Projects by Scholarships for Ph.D. Students” granted by EC and Regional Government (No. GRANT/III/37/2009), as well as by the Fellowship (Publication/Project) co-financed by European Union within European Social Fund.