Visual field losses in workers exposed to mercury vapor.
Visual field losses associated with mercury (Hg) exposure have only been assessed in patients exposed to methylmercury. Here we evaluate the automated visual field in 35 ex-workers (30 males; 44.20+/-5.92 years) occupationaly exposed to mercury vapor and 34 controls (21 males; 43.29+/-8.33 years). Visual fields were analyzed with the Humphrey Field Analyzer II (model 750i) using two tests: the standard automated perimetry (SAP, white-on-white) and the short wavelength automated perimetry (SWAP, blue-on-yellow) at 76 locations within a 27 degrees central visual field. Results were analyzed as the mean of the sensitivities measured at the fovea, and at five successive concentric rings, of increasing eccentricity, within the central field. Compared to controls, visual field sensitivities of the experimental group measured using SAP were lower for the fovea as well as for all five eccentricity rings (p<0.05). Sensitivities were significantly lower in the SWAP test (p<0.05) for four of the five extra-foveal eccentricity rings; they were not significant for the fovea (p=0.584) or for the 15 degrees eccentricity ring (p=0.965). These results suggest a widespread reduction of sensitivity in both visual field tests. Previous reports in the literature describe moderate to severe concentric constriction of the visual field in subjects with methylmercury intoxication measured manually with the Goldman perimeter. The present results amplify concerns regarding potential medical risks of exposure to environmental mercury sources by demonstrating significant and widespread reductions of visual sensitivity using the more reliable automated perimetry.
Barboni
Mirella Telles Salgueiro
MT
Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, SP, Brazil. mirellabarboni@usp.br
da Costa
Marcelo Fernandes
MF
Moura
Ana Laura de Araújo
AL
Feitosa-Santana
Cláudia
C
Gualtieri
Mirella
M
Lago
Marcos
M
Medrado-Faria
Marcília de Araújo
Mde A
Silveira
Luiz Carlos de Lima
LC
Ventura
Dora Fix
DF
D000328:Adult; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008628:Mercury / Q000633:toxicity*; D008630:Mercury Poisoning / Q000503:physiopathology*; D008875:Middle Aged; D016273:Occupational Exposure; D014794:Visual Fields / Q000502:physiology*
D000395:Air Pollutants, Occupational; D008628:Mercury