[Surgery for convergent strabismus in childhood: why and when?]

The authors explain the reasons for and the timing of surgery for convergent strabismus, or esotropia, in children as a function of the particular type of strabismus. The goal of surgery is to correct the cross-eyed deviation by choosing the most opportune time so as to obtain the best binocular result with the minimum number of surgeries. The authors take a position in the debate over age at time of surgery for childhood esotropia, which is still controversial. Their arguments are based on recent neurophysiological and clinical data.

[Quality of life of visually impaired adults after low-vision intervention: a pilot study]

OBJECTIVE

To demonstrate the benefits of a low-vision intervention upon the quality of life of visually disabled adults.

METHODS

The survey was proposed to patients who sought a low-vision intervention at the Colmar and Strasbourg hospital centres over a period of 9 months. Patients in agreement with the survey were asked to complete the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ25) in interview format by telephone, once they had attended the first meeting and again 2 months after the end of the low-vision intervention.

RESULTS

The low-vision intervention led to overall improvement as judged by the 25 items of the questionnaire. Some items involving visual function and psychological issues showed significant benefits: the patients reported a more optimistic score concerning their general vision, described better nearby activities, and felt a bit more autonomous.

CONCLUSION

More than mainstream psychological counselling, low-vision services help patients cope with visual disabilities during their daily life. The low-vision intervention improves physical and technical issues necessary to retaining autonomy in daily life.

Impairment of contrast sensitivity in long-term lorazepam users

RATIONALE

Oculomotor balance and contrast sensitivity are known to be impaired after an intake of a single dose of lorazepam. To the best of our knowledge, these effects have not been explored in long-term users of lorazepam, despite the potential importance of such deficits in everyday life.

OBJECTIVE

We tested the ophthalmological effects and contrast sensitivity for static stimuli in long-term lorazepam users.

MATERIALS AND METHODS

There were 15 lorazepam users and 15 sex-, age- and education level-matched control subjects tested, using a simple blind procedure.

RESULTS

The ophthalmological effects were scarce, with a discrete exophoria. Visual acuity was preserved. Contrast sensitivity, however, was more markedly impaired, consistent with the effects of an acute dose of lorazepam. The effects were not correlated with anxiety or sedation.

CONCLUSIONS

The results are discussed in terms of their possible impact on everyday life. As visual acuity does not allow the detection of the impairments that are observed in the present study, it is suggested that a more systematic exploration of contrast sensitivity be carried out in long-term users of benzodiazepines.

[On-screen work and visual fatigue and its course after ophthalmologic management]

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.

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.