Microstructure and Chemical Analysis in Pseudoexfoliation Syndrome

ABSTRACT

Purpose: The aim of this study is to show the pseudoexfoliation syndrome (PES) material accumulated in the lens anterior capsule and the trace elements directly with using scanning electron microscopy (SEM) and to investigate the effect of PES materials on aqueous humor by chemical analyses.

Methods: The study groups consisted of 30 patients with PES and 30 patients without PES. 0.1–0.3 mL of aqueous humor was aspirated from anterior chamber and anterior capsule sample was obtained by applying continuous curvilinear capsulorhexis. The level of selected elements (Zn, Cu, Se, Fe, Si, Al, Ca, K) were determined from aqueous humor samples via Inductively coupled plasma – optical emission spectrometry (ICP-OES) machine. The morphology and elemental distribution of anterior lens capsules were carried out via a Zeiss Sigma 300 scanning electron microscope with energy dispersive X-ray spectroscopy (semiquantitative EDX).

Results: For aqueous humor, the ICP-OES results show that Cu and Zn levels is higher (p < .001, both of them) in PES group than that the obtained from control group. It was noticed that the ratio of Cu/Zn was higher (p = .008) in aqueous humor, while Cu/Se ratio was higher in both aqueous humor (p < .001) and anterior capsule (p < .001) for PES group. The SEM images show that different metal precipitates were obtained from anterior lens capsules with PES. However, there is no obvious element precipitates on the anterior lens capsules without PES.

Conclusion: The results observed that the level of selected elements can be obtained at different level in both PES group and control group. Especially, if the oxidative behavior of these elements which is thought to play a role in PES formation can be clarified, new approaches will be done to evaluate the structure of PES.

KEYWORDS:

• Cataract surgery
• electron microscopy
• glaucoma
• pseudoexfoliation
• trace elements

Acknowledgments

This article was previously presented as an electronic poster at the 37^th Congress of The ESCRS, 14-18 September 2019 in Paris. The authors have no proprietary or financial interest in the products mentioned in this study. The authors declare that they have no competing interests.