Assessing the effect of laser beam width on quantitative evaluation of optical properties of intraocular lens implants

Abstract

The design and manufacture of intraocular lenses (IOLs) depend upon the identification and quantitative preclinical evaluation of key optical properties and environmental parameters. The confocal laser method (CLM) is a new technique for measuring IOL optical properties, such as dioptric power, optical quality, refractive index, and geometrical parameters. In comparison to competing systems, the CLM utilizes a fiber-optic confocal laser design that significantly improves the resolution, accuracy, and repeatability of optical measurements. Here, we investigate the impact of changing the beam diameter on the CLM platform for the evaluation of IOL dioptric powers. Due to the Gaussian intensity profile of the CLM laser beam, the changes in focal length and dioptric power associated with changes in beam diameter are well within the tolerances specified in the ISO IOL standard. These results demonstrate some of the advanced potentials of the CLM toward more effectively and quantitatively evaluating IOL optical properties.

Quantifying the Multiwavelength Dispersion Effect on Dioptric Power Measurement of Intraocular Lenses

“…1. Various continuouswave laser beams were coupled using an objective lens ðO in Þ with a 1 Â 2 single-mode optical fiber coupler (Newport Corp., Irvine, CA) and combined with a 10 Â infinite corrected objective lens (Edmund Optics Inc., Barrington, NJ) to create the collimated paraxial Gaussian beam ðO C Þ required for CLM experiments [20]. As required in the ISO Standards, the laser beam diameter was set at 3 mm using a pinhole aperture (A).…”

“…Due to the paraxial Gaussian shape of the focal point profile from the CLM technique, changes in diameter of the laser beam profile as well as longitudinal spherical aberrations are negligible [20], resulting in a highly accurate platform to measure dioptric powers.…”

Noncontact method for sensing thickness and refractive index of intraocular lens implants using a self-calibrating dual-confocal laser caliper

“…Recently, our group has developed and implemented test methodologies to measure dioptric power of various IOL designs with high precision. [4][5][6][7] However, despite their significance in IOL characterization, 8 conventional techniques employed for IOL thickness and refractive-index measurements show some specific drawbacks and limitations in precise IOL testing. For instance, the use of simple mechanical devices such as vernier calipers or micrometers for IOL thickness measurement can affect the IOL optical quality caused by the contact measurement, and the lens curvature introduces additional inaccuracies for precise measurement.…”

“…Confocal reflection intensities for the thickness measurement of an IOL using 60× objective lens.Journal of Biomedical Optics067004-4 June 2018 • Vol. 23(6) …”