Ophthalmic Findings of Acute Mercury Poisoning in Primary School Students

Abstract

Purpose: To report ophthalmic findings in acute mercury poisoning in the primary school students. Methods: Seventy two children exposed to mercury vapor and 42 healthy controls were enrolled in the study. Full ophthalmologic examination including best corrected visual acuity, external eye examination, a slit-lamp examination, funduscopy, intraocular pressure measurements, Visual Field (VF), Visual Evoked Potential (VEP) and Color Vision (CV) tests were performed at the presentation and after six months. The parametric values of VF, Mean Deviation (MD) and Pattern Standard Deviation (PSD) were compared between groups. Results: The visual acuity less than two lines in ETDRS chart in 7(9.7%) patients, color vision impairment in 6(8.3%) patients were determined with ophthalmic examination. There were a significant difference in the color confusion index of patients, (p<0.05). The mean parametric VF values of MD and PSD were found statistically, significant difference (p<0.001, p<0,001 respectively), The latency values of VEP were 7% of 20 patients over 100 ms. There were no correlation between ophthalmic findings and mercury levels in urine and blood. Conclusion: While visual acuity minimally affected, advanced visual functions were significantly impaired in a way independent of mercury level. The goal of this paper is to draw attention to the importance of public education on potentially hazardous effects of mercury in terms of preventive community health. In particular, both primary school teachers and students should be trained concerning poisonous gases such as mercury.