Mr. Phillip R. Riera Profile

Phillip R. Riera

at WaveFront Dynamics Inc

SPIE Involvement:

Author

Publications (4)

SPIE Journal Paper | 30 November 2022 Open Access

Dynamic aberrometer/topographer designed for clinical measurement and treatment of highly aberrated eyes

Daniel Neal, Xifeng Xiao, Richard Copland, Lyle Kordonowy, Dan Hamrick, Daniel Medina, John Dixson, Phillip Riera, Paul Pulaski, Tristan Turner, Jeff Kolberg, Ron Rammage, Steve Farrer, Dean Rusk, Matt Haugo

OE, Vol. 61, Issue 12, 121808, (November 2022) https://doi.org/10.1117/12.10.1117/1.OE.61.12.121808

KEYWORDS: Equipment, Eye, Wavefronts, Refraction, Wavefront sensors, Cornea, Optical spheres, Optical engineering, Monochromatic aberrations, Imaging systems

Read Abstract +

The human eye is a complex optical system with multiple elements. It is aspheric, nonsymmetric, and time dependent; yet, overall it has incredible performance. There have been various instruments developed over the years to measure and then to guide treatment to correct for ocular aberrations. As the development of these instruments (and treatments) has progressed, we have sought to correct more difficult cases, which may be more aberrated, time-dependent, or difficult in some other way. To this end, we have developed a new dynamic aberrometer that expands the boundaries of measurement capability with the aim of measuring and treating more difficult cases. This aberrometer has been designed that incorporates high-resolution Shack–Hartmann wavefront sensing, full gradient (spot) corneal topography, dynamic acquisition, and a subjective digital refractometer. This instrument is designed to measure extremely high aberrations and to provide information for treatment in multiple modalities. A small clinical study was conducted with subjects ranging from 23 to 64 years old to evaluate the effectiveness of the dynamic analysis at selecting a refraction. Examples are presented for measurements with keratoconus, irregular corneas, and tear-film irregularity. In the clinical study, young subjects showed an overall +0.27 D reduction in instrument induced myopia using dynamic measurement compared to a snapshot. The instrument has a large dynamic range for measuring subjects with keratoconus and other aberrated corneal conditions. The new instrument is effective at providing information needed for treatment in multiple modalities. The subjective digital refractometer corrects the fixation target for the objectively measured low-order aberrations (defocus and astigmatism). This provides immediate subjective feedback on the objective refraction and, with the ability to manually adjust the refraction parameters, the ability to compare objective and subjective refractions in the same setting.

DOWNLOAD PAPER

Proceedings Article | 14 October 2004 Paper

Measurement of lens focal length using multicurvature analysis of Shack-Hartmann wavefront data

Daniel Neal, R. James Copland, David Neal, Daniel Topa, Phillip Riera

Proceedings Volume 5523, (2004) https://doi.org/10.1117/12.561772

KEYWORDS: Wavefront sensors, Wavefronts, Distance measurement, Collimation, Error analysis, Sensors, Monochromatic aberrations, Charge-coupled devices, Manufacturing, Optical testing

Read Abstract +

Proceedings Article | 11 December 2003 Paper

Computation of the circle polynomials of Zernike

Phillip Riera

Proceedings Volume 5162, (2003) https://doi.org/10.1117/12.507565

KEYWORDS: Zernike polynomials, Wavefronts, C++, Matrix multiplication, Matrices, Mathematics, Wavefront sensors, Computer programming, Optical properties, Control systems

Read Abstract +

Proceedings Article | 4 September 2002 Paper

Efficient computation with special functions like the circle polynomials of Zernike

Philip Riera, Geoffrey Pankretz, Daniel Topa

Proceedings Volume 4769, (2002) https://doi.org/10.1117/12.481181

KEYWORDS: Zernike polynomials, Wavefronts, C++, Matrix multiplication, Matrices, Mathematics, Optical analysis, Computer programming, Wavefront sensors, Spherical lenses

Read Abstract +

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years