Application of Scanning Electron Microscopy With Energy-Dispersive X-Ray Spectroscopy for Analyzing Ocular Surface Particles on Schirmer Strips

Purpose: To demonstrate the application of scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM/EDS) for analyzing Schirmer strips for particle concentration, size, morphology, and type distribution.
Methods: A cross-sectional design was used. Patients were prospectively recruited from the Miami Veterans Affairs (VA) Healthcare System eye clinic, and they underwent a complete ocular surface examination. The size, type, and chemical composition of particulate matter on Schirmer strips (from the left eye) were analyzed using SEM/EDS.
Results: Schirmer strips from all 6 patients showed particle loading, ranging from 1 to 33 particles, whereas the blank Schirmer strip that served as a control showed no particle loading. Most particles were coarse, with an average size of 19.7 μm (95% confidence interval 15–24.4 μm). All samples contained organic particles (eg, pollen and mold), and 5 of the 6 samples contained nonorganic particles. The nonorganic particles were composed of silicon, minerals, and metals, including gold and titanium. The size of aluminum and iron particles was ≥62 μm, whereas the size of 2 other metals, zinc and gold, was smaller, that is,

Source: Cornea - May 9, 2017 Category: Opthalmology Tags: Techniques Source Type: research