Investigation of Trace Elements in Pterygium Tissue

Purpose: In this study, we compare the concentrations of the essential trace elements chromium (Cr), copper (Cu), selenium (Se), manganese (Mn), boron (B) and zinc (Zn) in both pterygium and normal conjunctiva and investigate the role they play in the development of pterygium. Methods: Included in the study were 38 patients with pterygium and 38 control patients in matching age groups who had been operated on for strabismus or cataracts and in whom conjunctiva samples were collected from the nasal limbus area. All conjunctiva samples were kept at -80 degrees C until the performance of the biochemical investigations. The B, Cr, Mn, Cu, Zn and Se levels in the samples were then measured. The levels of all tissue trace elements were determined by using Agilent 7500a Inductively Coupled Plasma-Mass Spectrometer (Agilent Technologies, Santa Clara, CA). Results: Cr, Mn, Zn and Se levels are significantly lower in the study group as compared to those of the control group (p<0.001 for all four values). Regarding the level of B, there was no significant difference between the groups. The Cu levels of almost all subjects in the control group and all subjects in the pterygium group were under the detection limit. Conclusions: These findings indicate that remarkable differences in Mn, Zn, Se and Cr levels exist in pterygium tissues. Further investigation of electrolyte composition of the conjunctiva is needed to understand the genesis and developmental mechanism of pterygium.