Clinical and electrophysiological findings in three patients with toluene dependency

Abstract

We recorded the electrophysiological findings of three patients with toluene dependency who developed visual disturbance. In five of six eyes the peak latency of the pattern visual evoked cortical potential was prolonged as compared with that of normal subjects. The amplitude and the latency of the a-wave of the electroretinogram were decreased in five of the six eyes and prolonged in four. Those of the b-wave in patients were less affected than the a-wave: in one of six eyes the amplitude of the b-wave was decreased and in two the b-wave latency was prolonged. The amplitudes of the oscillatory potentials were decreased in three of six eyes. The electroretinogram was investigated in one patient and showed little increase in amplitude during light stimulation, so that a lowered light peak to dark trough ratio was obtained. Our findings suggest that any part of the visual pathway, including the distal part of the retina and retinal pigment epithelium, might be impaired by the chronic inhalation of toluene vapors.

Case of Unilateral Peripheral Cone Dysfunction

“…However, the severely decreased visual acuity and highly constricted visual field in both eyes do not agree with our diagnosis of peripheral cone dystrophy. These contradictory findings might be because our patient had psychogenic disorders induced by thinner sniffing and the possibility of unilaterally pronounced toxic effects cannot be denied [11]. But thinner sniffing has been reported to lead to mainly optic neuropathy [12, 13] but the normal visual evoked potentials of our patient indicated that this was not likely.…”

Efectos neurológicos en trabajadores expuestos a tolueno. Revisión sistemática

“…Cavalleri et al (25) y Campagna et al (26) refieren que la discromatopsia tipo III refleja posibles cambios en las capas externas de la retina. Muttray et al (28) informan que existen estudios que sugieren que el efecto tóxico del tolueno existente en personas con un gran abuso de esta sustancia (ej: inhalación de pegamento) puede producirse en cualquier parte de la vía visual, incluyendo la parte distal y el epitelio pigmentario de la retina (36,37) y concluyen que un efecto tóxico del tolueno en la retina parece posible, pero esta hipótesis no puede ser probada en base a los datos disponibles.…”

Toluene optic neurotoxicity: magnetic resonance imaging and pathologic features

“…This typically leads to a slow progressive decline in visual acuity ranging from 20/20 to 4/ 200 with associated diminished color vision in most patients [6,14,15]. Initial optic disc appearance is usually normal, but patients gradually develop optic atrophy.…”

“…Initial optic disc appearance is usually normal, but patients gradually develop optic atrophy. Visual fields reveal enlargement of the blind spot and central depression [6,14]. Treatment with vitamins, steroids, gabapentin, or cessation of toluene exposure revealed an improvement in visual acuity and symptoms in about half of patients [6,10].…”