Effects of lorazepam on vision and oculomotor balance.

BACKGROUND: Previous studies have shown an effect of the tranquilizer lorazepam on visual perception. We explored the effects of the drug on binocular vision, visual acuity and accommodation. SUBJECTS AND METHODS: Twenty-four paid healthy volunteers (13 women, 11 men) were recruited from the University of Strasbourg (mean age: 23.6 years, mean weight: 66.8 Kg). They were randomly assigned to one of two parallel groups of 12 subjects each (a placebo group and a lorazepam 0.038 mg/kg group). Visual acuity was measured for each eye separately (Snellen chart and Parinaud scale). Binocular vision was studied using the cover tests, measurement of the fusional amplitudes (with Berens prisms), and the Duane Scale Test (near point rule) measuring convergence and/or accommodation in centimeters or diopters as a function of age. RESULTS: Regarding vision, there was no lorazepam effect, at either 33 cm or 5 m. An esophoria was observed after the intake of lorazepam (0Delta before intake and 2.8Delta after intake, p=0.001). Both fusional convergence and fusional divergence amplitudes decreased by lorazepam, (p=0.008, and p=0.002). Lorazepam also impaired the near point of convergence but did not affect accommodation. CONCLUSION: A single dose of lorazepam induces an esophoric oculomotor imbalance and impaired fusional convergence and divergence amplitudes without impairing visual acuity or accommodation.

[On-screen work and visual fatigue and its course after ophthalmologic management]. / Travail sur écran et fatigue visuelle et son évolution après prise en charge ophtalmologique.

INTRODUCTION: The number of staff subjected to significant amounts of on-screen work with visual complaints is currently increasing. OBJECTIVE: This epidemiological study aimed to observe the influence of changes in working conditions and an ophthalmological treatment on vision and eye complaints due to on-screen work. MATERIALS AND METHODS: This comparative study included a transversal initial study on the visual symptoms and function as well as a longitudinal follow-up of the efficacy of the recommendations given by the company medical officer. The studied subjects were be exposed to screen irradiation for at least 4 hours a day during the study. The control group was selected according to the age, sex, and education level of the investigated group. RESULTS: We examined 814 subjects under investigation and 325 control subjects. The subjective signs of visual fatigue with on-screen work (burning or stinging eyes, diplopia or blurred vision after work, tearing, globe heaviness and fatigue, and headaches, the latter particularly in female subjects) were significantly more frequent in the exposed group than in the control group. A statistically significant correlation was found with the following factors: poor working conditions, frequent keyboard data entry, far vision optic correction, far vision significantly more often corrected to less than 10/10 at least in one eye, and, finally, near vision exophoria more than 7 diopters. We re-examined 465 exposed and 139 control subjects 1 and 2 years after consultation with the company medical officer. Following the recommendations proved to be effective in 50.5% of the employees. Improving vision by changing the optical correction showed the strongest statistical relation with the decrease in visual fatigue complaints. Organizational and material improvements also led to positive effects on functional discomfort. DISCUSSION: The far vision of those exposed to screen irradiation was significantly worse than in those who were not exposed. The people from the exposed group had vision correction significantly more often. The probable relation between progressive myopia and on-screen work is not excluded, but further investigation is needed. The proposed measures were effective for preventing visual fatigue. However, 49.5% of the study group had persistent visual symptoms, probably because of not following the recommendations, not having an ergonomic correction, or because modifications of blinking, tear film, and the ocular surface were ot taken into account. CONCLUSION: The coordination between the occupational medicine and ophthalmology departments during this study has significantly reduced visual fatigue. Nevertheless, there is still a considerable number of people from the exposed group with persistent symptoms.

Selective and early increase of IL-1 inhibitors, IL-6 and cortisol after elective surgery.

After trauma, inflammatory, immunological and hormonal changes are well documented. Surgical intervention is a form of programmed trauma. Through the study of surgical patients, changes in early endogenous mediators of inflammation, immune response and tissue repair can be investigated. Here we analysed changes in serum levels of IL-1 inhibitors, IL-1 beta, IL-6, tumour necrosis factor-alpha (TNF-alpha) and cortisol in patients undergoing elective surgery. C-reactive protein (CRP) was measured as a marker of the acute-phase response. Rises in serum levels of IL-1 inhibitors, IL-6 and cortisol were detected as early as 1 h after the intervention. Peak levels were reached between 2 and 5 h. Serum levels of IL-6 and cortisol remained elevated for several days implying a persistent production. Serum levels of IL-1 and TNF did not change after the intervention. CRP levels peaked on day 2. The communication system sustained by endogenous mediators is activated after surgery as shown by selective changes in IL-1 inhibitors, IL-6 and cortisol. These mediators have different kinetics in serum and IL-6 is not the only early mediator detected. Some IL-1 inhibitors might be involved in the immunological depression observed after major surgery, in the regulation of the inflammatory response or in tissue repair. IL-6 and cortisol seem to act synergistically to activate the acute-phase response. A systemic role for IL-1 and TNF is not evident, even if the possibility that these lymphokines may act locally is not ruled out.