Alternative methodology for intraocular lens characterisation.

Purpose: To present an alternative methodology to characterise intraocular lenses (IOLs) using an optical setup with a Hartmann-Shack wavefront sensor.
Methods: The methodology was inspired by the ANSI Z80.30 Standard, which addresses IOL optical properties and test methods, and aims to simplify the procedure to allow complete IOL characterisation with a reduced number of measurement steps.
Results: Seven spherical and three toric IOLs were characterised with the alternative methodology and by commercial equipment. Three spherical IOLs measured with the alternative methodology obtained dioptric spherical errors larger than the tolerance established by the ANSI Z80.30 Standard when compared to the IOLs theoretical designs, probably due to manufacturing deviations. All cylindrical dioptric power measurements were within the Standard tolerance. The longitudinal spherical aberration of the IOLs were measured and 2-dimensional Modulation Transfer Functions (MTF) were calculated in order to complementarily assess manufacturing and design quality.
Conclusions: The alternative methodology allows complete IOL characterisation with a reduced number of steps compared to those required by the Standard ANSI Z80.30, achieving satisfactory results in measurements of IOL dioptric power, spherical aberration, cylindrical power and MTF. Although MTF measurements were not performed with a model eye, they may contain additional relevant information regarding the design of ophthalmic lenses.
(© 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.)