Thinner abuse alters optokinetic nystagmus parameters

Eye Movement Abnormalities in Glaucoma Patients: A Review

Glaucoma is a common condition that relies on careful clinical assessment to diagnose and determine disease progression. There is growing evidence that glaucoma is associated not only with loss of retinal ganglion cells but also with degeneration of cortical and subcortical brain structures associated with vision and eye movements. The effect of glaucoma pathophysiology on eye movements is not well understood. In this review, we examine the evidence surrounding altered eye movements in glaucoma patients compared to healthy controls, with a focus on quantitative eye tracking studies measuring saccades, fixation, and optokinetic nystagmus in a range of visual tasks. The evidence suggests that glaucoma patients have alterations in several eye movement domains. Patients exhibit longer saccade latencies, which worsen with increasing glaucoma severity. Other saccadic abnormalities include lower saccade amplitude and velocity, and difficulty inhibiting reflexive saccades. Fixation is pathologically altered in glaucoma with reduced stability. Optokinetic nystagmus measures have also been shown to be abnormal. Complex visual tasks (eg reading, driving, and navigating obstacles), integrate these eye movements and result in behavioral adaptations. The review concludes with a summary of the evidence and recommendations for future research in this emerging field.

Drugs of abuse and ocular effects

Illicit drugs and substances of abuse are increasingly used by adults and teenagers, with novel substances constantly becoming available. Many substances can cause ocular effects or visually threatening conditions. Current literature informing eye-care practitioners on these effects is scant. The present scoping review reports the ocular effects of most commonly used drugs and substances of abuse in the teenage and adult populations of North America. Ovid MEDLINE and Ovid EMBASE databases were searched for publications from 1980 to 2019 regarding ocular effects of drug use. The selected papers regarded human subjects, in either teenage or adult population and included all types of studies, including case reports. Publications in English or in French were included. Exclusion criteria were publications about the use of prescriptions drugs, drug withdrawal, and publications about the use of alcohol, tobacco, or cannabis. Some 241 papers were retained and analysed. The use of various drugs and substances can lead to damage to structures throughout the eye, including but not limited to corneal conditions, glaucoma and other optic neuropathies, maculopathies and endophthalmitis. The data presented in this review may help guide clinicians in their diagnosis and treatment of certain ocular conditions, which could otherwise not be linked to drug use.

“It Might Be a Scummy-Arsed Drug but it's a Sick Buzz”: Chroming and Pleasure

Arguing that the role of pleasure in young people's decisions to use inhalants has been underexplored, this paper provides a typology for the kinds of pleasurable experience young people report from chroming (an Australian term for inhalant use involving aerosol paints). The paper draws on in-depth interviews with young people with experience of chroming and with expert workers in Melbourne, Australia. Seven categories of pleasurable experience related to chroming are identified through thematic analysis of these interviews: feeling, escaping and relocating, imagining, doing, socializing, communicating, and consuming. In the context of use by marginalized young people, chroming has powerful and often deeply pleasurable effects. Understanding more about the kinds of enjoyment that young people seek and experience through chroming—and by implication what workers are asking them to give up when they try to make them stop using these drugs—is important in designing policy interventions.

Thinner abuse alters peak of frequency of EEG spectra analyses

STUDY OBJECTIVE

The aim of the investigation was to use electroencephalography (EEG) to study whether long-term thinner abuse may result in the slowing, disorganization and asymmetry of the EEG cortical rhythms.

METHOD

Twenty-two patients attending with antecedent of thinner abuse only, and twenty two controls without alcohol, smoking, and drug abuse in the same age range and gender were studied. EEG recording were compared by means of the analyses of peak of frequency (POF), frequency of disorganization, and asymmetry of the background activity in patients and controls at rest eyes-closed condition in electrodes P3, P4, O1, and O2.

RESULTS

Significant differences in POF among groups was observed in P3 and P4 location showing lower values in thinner abusers, but not in O1 and O2 locations. Frequencies of disorganization and asymmetry showed significantly higher proportions in thinner abusers. Bivariate correlations among POF at the four electrode location and time of thinner abuse showed significant values. However after partial correlation calculation correcting for age, significant values disappeared.

CONCLUSION

Thus thinner abuse relates with slowing of POF in the EEG of patients with thinner abuse associated with disorganization, and asymmetry depending on time of abuse.