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

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°, 15° and 21° 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.

Visual functions of workers exposed to organic solvents in petrochemical industries

“…The effect of organic solvents on the visual acuity of an individual has not been reported in the literature, except by Costa et al . [10] Our study showed the best corrected visual acuity of ≥0.01 LogMAR units and near vision of N6 in workers and age-matched controls, suggesting that vision was not affected, which is in agreement with Costa et al . [10]…”

“…have reported that contrast sensitivity was reduced at all spatial frequencies from 1.5 cpd to 20 cpd among furniture factory workers and painters. [101112] The contrast sensitivity function was reduced in the worker group compared to controls at 12 cpd. Although the difference was statistically significant, it was not clinically significant because the mean difference was less.…”

Recent advances in occupational and environmental health hazards of workers exposed to gasoline compounds

“…A cross-sectional study by Costa et al [189] assessing the visual outcome of chronic exposure to a mixture of organic solvents among 25 gas station workers reported significantly higher color discrimination thresholds, along the protein, deutan, and tritan confusion axis, and higher ellipse and ellipticity areas in the exposed workers as compared with control groups. Sirdah et al [190] also found significantly more complaints of eye itches, redness, and pain among workers at liquefied petroleum gas stations in the Gaza governorate.…”

RPSO, Volume 4 - Julho a dezembro de 2017

“…Estima-se que 25% da população trabalhadora exposta seja portadora de PAINPSE em algum grau (25)(26)(27)(28) . Este trabalho poderá contribuir para a redução da incidência de perdas de audição geradas por altos níveis de pressão sonora, minimizando os danos causados pelo ruído a trabalhadores por meio de um programa de conservação auditiva.…”

“…Alguns autores destacam que é mais frequente a perda discriminativa do azul-amarelo 25,26 , ainda que outros também mencionem o vermelho-verde. A discromatopsia é atribuída à maculopatia secundária aos danos nos fotorrecetores em cone, bem como nas células ganglionares e desmielinização do nervo ótico.…”