Intraocular motility, electrophysiological tests and visual fields in drug addicts

Abstract

The effects of drugs on intraocular motility, retina function and central pathways in a drug addicts population have been studied. The study group were made up of 15 drug addicts. Fifteen healthy subjects who had never used drugs acted as a control group. Refractive state, accommodation, tonometry, assessment of pupillary reflexes, campimetry, visual evoked cortical potential (VECP) and ERG were performed in all cases. All the subjects studied used heroine, 12 used cannabis and 12 used cocaine. Refraction was normal in all cases. Accommodation amplitude in normal subjects ranged from 8.5 to 11.5 D, and from 3.5 to 9.5 D in the drug addicts group. Tonometry indicated a tendency to lower intraocular pressure values. Direct and consensual pupillary reflexes were normal in eight subjects, but were sluggish in the rest. Campimetry showed relative and absolute scotoma in five subjects. VECP were found to be normal in two of the cases, moderately pathological in six and pathological in the remaining seven cases. As for the ERG, it showed non-specific altered traces in 11 cases. Accommodation amplitude was lower than normal in 20 eyes. The decrease of VECP with altered traces but with an increase of latency, seem to indicate the presence of an alteration in the optical pathway or in the cortical centres. The findings in ERG point out a decrease of amplitudes and an increase of latency in more than half the population studied.

A Multisite, Double-blind, Placebo-Controlled Clinical Trial to Evaluate the Safety and Efficacy of Vigabatrin for Treating Cocaine Dependence

“…In addition, because electroretinography-measured cone voltages are known to be associated with (and perhaps predictive of ) visual field loss, [29][30][31] electroretinography testing was conducted on all patients in 5 sites where it was available on the same days as the visual field measures. Because cocaine abuse itself can produce electroretinography changes in a small fraction of users, 32 participants exhibiting such changes during screening were excluded from the study.…”

Electroretinography in psychiatry: A systematic literature review

“…We found 15 articles evaluating the effects of various substances on ERG [6,[11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Of these, nine studied the effects of cocaine, three studied cannabis, two studied alcohol, and one studied mixed drug use.…”

Lasting effects of prenatal exposure to Cannabis in the retina of the offspring: an experimental study in mice

“…One case report described OCT imaging of subretinal blebs following vision loss in a strong hashish user [ 22 ]. González-Pérez et al found electroretinographic signal reduction in a cohort of Cannabis users, also suggesting photoreceptor damage [ 23 ]. Electroretinographic changes were also suggested by further studies in Cannabis users [ 21 , 24 ].…”