Broader corneal characterization with PulseESPI applied to elasticity measurements.

PURPOSE: A novel application of pulsed electronic speckle pattern interferometry (PulseESPI) techniques in important corneal elasticity measurements is presented in this pilot study. For laser-ablative procedures like laser-assisted in situ keratomileusis, it has been found that elastic properties of the cornea have a role in the outcome of corneal refractive surgery, while for optimal ablative laser power calculations this measurement method may possibly be helpful. It may also help in earlier diagnosis of degenerative corneal disorders such as keratoconus.

METHODS

The approach of this study is to observe dynamic behavior of cornea against stresses as mapped with PulseESPI. For this purpose, strain was induced to the cornea using a fine rod with a mechanical vibrator.

RESULTS

It was found that cornea has a response pattern to the dynamic stressing. Its surface exhibits a resonance frequency which can be measured with PulseESPI. This information of resonance frequency can be characteristic to the cornea.

CONCLUSIONS

PulseESPI may help in important corneal elasticity measurements used for complication-free optimized ophthalmic surgery. It seems to be a promising method to conduct stress-related investigations on biological samples. To our knowledge, this is the first time that PulseESPI has been used for such ophthalmic measurements.