Abstract: PURPOSE: The aim of the study is to evaluate the short-term effects of 2 kinds of artificial tears, both containing 0.4% hyaluronic acid in an aqueous solution yet having different osmolarity, on the typical symptoms of patients suffering from dry eye and on the vitality of corneal and conjunctival epithelial cells. METHODS: A cross-over, randomized, balanced, single-blind study involving 28 patients was divided into 2 treatment groups: group A (unpreserved 0.4% hyaluronic acid eye drops 300 mOsm/L) and group B (unpreserved 0.4% hyaluronic acid eye drops 150 mOsm/L). Both treatments were administered for 7 days, being dosed as a 1 solution drop 4 times daily. After a 1-day wash-out period, the patients in group A passed over to group B and vice versa. RESULTS: Treatment with hypotonic solution gave better results in relieving symptoms, along with a statistically significant improvement (P < 0.001) in the state of the corneoconjunctival epithelium, than the isotonic solution. At the end of the study, 60.7% of the patients declared that they preferred hypotonic solution and only 10.7% preferred isotonic solution; the remaining 28.6% did not notice any difference between the 2 treatments. CONCLUSIONS: By reducing the osmolarity of tear film, the hypotonic solution not only improves the characteristics of tear film and the vitality of the epithelial cells of the cornea and conjunctiva but also proves to be effective in reducing dry eye symptoms.
Abstract: The aim of this research was to evaluate the Ergovision Screener (ES) accuracy e validity by a confrontation with the conventional ophthalmic check (OC), for the medical evaluation of job fitness. A population of 100 VDU operators was considered. Each subject underwent randomly both the ES and the ophthalmic check visit. Several test carried out by the Ergovision Screener were not consistent with the conventional ophthalmic check. In a number of cases, high false positive ratio have been found, which could lead to unnecessary further examinations. For all these reasons we believe that the ES is not an appropriate instrument for the medical evaluation of job fitness.
Abstract: Thirty-two voluntary subjects were selected, not suffering either from any degenerative ophthalmic diseases or refraction and ocular motility alterations. Each subject underwent close visual task experimental sessions (e.g. PC usage), under monitored experimental conditions. Aim of the study is the assessment of working efficiency effects caused by lighting conditions characterized by "according to law" illuminations, yet in presence of high or low luminance ratios in the occupational visual field". An analysis of the data showed that high luminance ratios conditions show a decrease of the performance (decrease overall efficiency, increase in the number of errors and time of execution), which where not detected with low luminance ratios conditions. Asthenopia did not show clear differences, possibly due to the effects of the intense near work which was present in both the experimental sessions.
Abstract: To achieve a common base for understanding work related eye complaints in the office environment, it is necessary to merge approaches from indoor air science, occupational health, and ophthalmology. Based on database searches, it is concluded that precorneal tear film (PTF) alteration leads to eye complaints that may be caused by: (1) thermal factors (low relative humidity; high room temperature); (2) demanding task content (attention decreases blinking and widens the exposed ocular surface area); and (3) individual characteristics (for example, tear film alterations, blinking anomalies, gland dysfunctions, and use of contact lenses). These factors and conditions are able to progressively increase water evaporation and faster thinning of the PTF, which causes dryness and dry spot formation on the cornea, possibly followed by corneal and conjunctiva epithelial alterations and eye complaints. Another possible cause of eye complaints is certain irritating chemical compounds, in addition to oxidation mixtures that are formed in reactions between ozone and unsaturated organic compounds (alkenes). The effect may be exacerbated by low relative humidity.
Abstract: Modern work activities often require an intense and prolonged visual effort on near objects. At the same time, occupational asthenopia caused by accommodation and binocularity overloading is a very common complaint in these working populations. Moreover, blinking rate seems to be a sensitive parameter with 'indoor-near-work operators', possibly increased by both chemical and physical environmental agents and decreased by cognitive effort. In this paper, a new piece of electronic equipment used to measure the observation distance and blinking rate is described.
