Long-Term Occupational Exposure to Organic Solvents Affects Color Vision, Contrast Sensitivity and Visual Fields

Author(s)

Costa, Thiago Leiros ^{[1, 2]} ; Salgueiro Barboni, Mirella Telles ^{[1, 2]} ; de Araujo Moura, Ana Laura ^{[1, 2]} ; Oliveira Bonci, Daniela Maria ^{[1, 2]} ; Gualtieri, Mirella ^{[1, 2]} ; de Lima Silveira, Luiz Carlos ^{[3, 4]} ; Ventura, Dora Fix ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Inst Psicol, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Nucleo Neurociencias & Comportamento, Sao Paulo - Brazil

^[3] Fed Univ Para, Dept Fisiol, BR-66059 Belem, Para - Brazil

^[4] Fed Univ Para, Nucleo Med Trop, BR-66059 Belem, Para - Brazil

• Document type: Journal article
• Source: PLoS One; v. 7, n. 8 AUG 15 2012.
• Web of Science Citations: 16

Abstract

The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males) and 25 controls with no history of chronic exposure to solvents (10 males). All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6 +/- 6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT). Visual field assessment consisted of white-on-white 24-2 automatic perimetry (Humphrey II-750i). Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd). Results from both groups were compared using the Mann-Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01). Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01), and their ellipse area and ellipticity were higher (p<0.01). Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9 degrees, 15 degrees and 21 degrees of eccentricity (p<0.01) and in MD and PSD indexes (p<0.01). Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01) except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05), indexes of the Lanthony D15d (rho = 0.52; p<0.05), perimetry results in the fovea (rho = -0.51; p<0.05) and at 3, 9 and 15 degrees of eccentricity (rho = -0.46; p<0.05). Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created. (AU)

• FAPESP's process: 08/58731-2 - Vision as a sensitive indicator of conditions threatening retinal and central nervous system function
• Grantee: Dora Selma Fix Ventura
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 07/55125-1 - Electrophysiological and psychophysical evaluation of ON and OFF visual pathways in Duchenne muscular dystrophy young patients
• Grantee: Mirella Telles Salgueiro Barboni
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/07089-1 - Visual repercussions of the occupational exposure to solvents
• Grantee: Thiago Leiros Costa
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 02/12733-8 - Sensory losses caused by mercury intoxication: psychophysical and neurophysiological studies in patients and in animal models
• Grantee: Dora Selma Fix Ventura
• Support Opportunities: Research Projects - Thematic Grants