A novel full-angle scanning light scattering profiler to quantitatively evaluate forward and backward light scattering from intraocular lenses

James

et al. 2017

JoVE

Self Cite

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light scattering from intraocular lenses (IOLs) using goniophotometer principles. This protocol describes the SLSP platform and how it employs a 360° rotational photodetector sensor that is scanned around an IOL sample while recording the intensity and location of scattered light as it passes through the IOL medium. The SLSP platform can be used to predict, non-clinically, the propensity for current and novel IOL designs and materials to induce light scatter. Non-clinical evaluation of light scattering properties of IOLs can significantly reduce the number of patient complaints related to unwanted glare, glistening, optical defects, poor image quality, and other phenomena associated with the unintended light scattering. Future studies should be conducted to correlate SLSP data with clinical results to help identify which measured light scatter is most problematic for patients that have undergone cataract surgery subsequent to IOL implantation.

“…This figure has been modified from Walker, B.N. et al 1 Please click here to view a larger version of this figure.…”

Section: Representative Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Scanning Light Scattering Profiler (SLPS) Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

James

et al. 2017

JoVE

Self Cite

“…Various test methods have been employed to measure the clinical and nonclinical effects of vacuoles and light scatter in general, including subjective patient reports and VA tests [7, 10, 11, 13, 14, 16, 17, 19–21], integrating spheres and transmission measurements [16, 21, 24–26], C-Quant straylight meter measurements [18, 20, 27–29], and in vivo slit-lamp and Scheimpflug tests and measurements [7, 10, 11, 13–17, 19–21, 23]. In addition, two different methods have been independently developed to physically scan around the back of the IOL to measure forward scattered light [26, 27, 30, 31]. However, these methods and reported studies have only been correlated with vacuoles solely in terms of vacuole size and density.…”

Section: Introductionmentioning

confidence: 99%

Quantitative Multiparameter Evaluation of Vacuoles in Intraocular Lenses Employing a High-Magnification Digital Microscopy Method

Spiezio

Journal of Ophthalmology

et al. 2019

Self Cite

As small imperfections with micrometric sizes, fluid-filled vacuoles, also referred to as glistenings, in intraocular lenses (IOLs) have been known to induce significant unwanted light scattering that in several cases presumably cause complaints and sometimes lead to IOL explantation and replacement. This unwanted scatter is of particular concern for patients viewing bright light in reduced-light conditions such as when driving at night, as the scattered light toward the retina can cause temporary blindness. In this study, we have developed and implemented an accurate test methodology based on a high-magnification digital microscopy approach for quantitative multiparameter evaluation and classification of IOL vacuoles depending on their critical optical characteristics including vacuole size, density, shape, and orientation within the IOL material. Using the multiparameter database developed by evaluating vacuole characteristics, we established a classification grading system that can be used to evaluate vacuole effects on light scattering.

Experimental and analytical quantification of light scattering from vacuoles in intraocular lenses

Spiezio

J Cataract Refract Surg

et al. 2020

Purpose: To develop an advanced test methodology for quantification of scattered light from intraocular lenses (IOLs) and to evaluate the correlation between IOL vacuole characteristics and measured scattered light. Setting: U.S. Food and Drug Administration, Optical Therapeutics and Medical Nanophotonics Laboratory, Silver Spring, Maryland, USA. Design: Experimental and analytical study. Methods: Twenty-four IOLs containing vacuoles were evaluated using a digital microscopy approach for identifying and characterizing the vacuoles present. A scanning light scattering profiler (SLSP) was used to evaluate and quantify the amount of scattered light from each IOL and from a 25th control IOL without any vacuoles. A variety of IOLs and vacuoles were also modeled in a Zemax simulation of the SLSP, and the simulated scattered light was modeled. Results: The scattered light as measured with SLSP was well correlated with vacuole characteristics, specifically density and size, as measured under the digital microscope for the 24 vacuole-containing IOLs. Additional correlations were found between vacuole sizes, orientations, and the angle at which light was scattered most severely. These correlations were also present in the Zemax model. Conclusions: Vacuole optical characteristics can be well correlated with measured scatter, demonstrating an ability to predict scattered light based solely on microscope evaluation. Furthermore, the quantitative amount of scatter predicted with Zemax simulations trended closely with the experimentally measured trends.