Biometric measurements inside the model eye using a two wavelengths Fourier domain low coherence interferometer.

We present a setup to measure biometric data of the eye using Fourier domain interferometry. The measuring depth of a Fourier domain system is basically limited owing to the spectral resolution. Combining two spectral domain interferometers with different wavelength ranges creates two measurement sections and allows for a simultaneous biometric measurement in terms of corneal thickness, anterior chamber depth, and axial length.

Real ray tracing simulation versus clinical outcomes of corneal excimer laser surface ablations.

Purpose: To investigate the recently reported discrepancy between theoretical expectations and clinical outcomes of corneal ablations after excimer laser corneal refractive surgery.

Methods: Thirty-four eyes of 25 patients who had laser epithelial keratomileusis (LASEK) for myopia (mean -6.26±2.

Customized aspheric intraocular lenses calculated with real ray tracing.

Purpose: To calculate the exact geometry of custom intraocular lenses (IOLs) for pseudophakic eyes and theoretically predict the residual wavefront error by real ray tracing based on Snell's law.

Setting: Centre for Ophthalmology, University Hospital, Tübingen, Germany.

Methods: Individual computer models were constructed based on measurements, including corneal topography and axial length.

Calculating intraocular lens geometry by real ray tracing.

Purpose: An implementation of real ray tracing based on Snell's law is tested by predicting the refraction of pseudophakic eyes and calculating the geometry of intraocular lenses (IOLs).

Methods: The refraction of 30 pseudophakic eyes was predicted with the measured corneal topography, axial length, and the known IOL geometry and compared to the manifest refraction. Intraocular lens calculation was performed for 30 normal eyes and 12 eyes that had previous refractive surgery for myopia correction and compared to state-of-the-art IOL calculation formulae.