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

Summary

This protocol describes the scanning light scattering profiler (SLSP) that enables the full-angle quantitative evaluation of forward and backward scattering of light from intraocular lenses (IOLs) using goniophotometer principles.

Abstract

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.

Introduction

The scanning light scattering profiler (SLSP) approach was first introduced to address the need to quantitatively evaluate light scattering characteristics of intraocular lenses (IOLs) in a non-clinical setting¹. Developing a test methodology to evaluate the light scattering tendencies of IOL designs and materials is of significant interest in order to help identify potential unwanted light scattering problems. Light scatter is commonly reported by patients and observed as glare, glistening, optical imperfections, and other forms of dysphotopsia², sometimes leading to a patient requesting the IOL explantation. In additio....

Protocol

1. SLSP Measurement Platform Preparation

NOTE: All alignment steps require precision and patience to ensure accurate quantitation when measuring light scatter. An overview of the SLSP setup in provided within Figure 1. Here, an illustration (Figure 1a) shows the basic concept of the SLSP setup. In addition, Figures 1b and 1c help define the various angles referenced within the discussion. Specifically, the following three angles are defined within Figures 1b and 1c: ˚R (sensor rotational angle), ˚S (sensor angle of measurement), and....

Results

Goniophotometry measurements can produce 360˚R of signal when the sensor is not located on the plane of the light source. However, to collect measurements from scattered light on the plane of the light source (0˚I) the sensor will need to eclipse the light source, resulting in less than 360˚R of signal. In our experiments, it was determined that ~20˚R of signal was blocked as the sensor eclipsed the light source.

Experiments fou.......

Discussion

The results from the SLSP platform experiments have found that using simple goniophotometry principles can lead to a powerful tool for evaluating the properties of light scatter associated with unique IOL designs and materials. Specifically, the SLSP platform has observed a direct correlation between the amount of detectable scattered light and the beam diameter of the light source. In addition, the multiple scattered peaks found in multifocal IOLs were easily observed with the SLSP. Furthermore, as the source of light a.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
PD300 series Photodiode Sensor	Ophir-Spiricon Corp	7Z02410	PD300-1W, RoHS
URS Series Precision Rotation Stage	Newport Corp.	URS75BCC
ESP301 1-Axis Motion Controller and Driver	Newport Corp.	ESP301-1N
LabView Software	National Instruments Corp.	776671-35
Origin	OriginLab Corp.	N/A
Single Mode FC/APC Fiber Optic Patch Cables	ThorLabs Inc.	P3-460B-FC
10X Olympus Plan Achromat Objective	ThorLabs Inc.	RMS10X	RMS10X - 10X Olympus Plan Achromat Objective, 0.25 NA, 10.6 mm WD