The modern office environment desiccates the eyes?

Abstract

Eye irritation is a common complaint in the office environment. The purpose of this overview is to merge knowledge within indoor air science, ophthalmology, and occupational health to promote understanding eye irritation symptomatology, the cause of which is still partly unknown. High periocular relative humidity appears to protect the pre-corneal tear film against desiccation and sensory irritating pollutants and reduces the development of eye irritation symptoms. This is particularly relevant for intensive computer work, where the pre-corneal tear film is altered resulting in dry spot formation and eye dryness, in addition to enhanced susceptibility towards sensory irritating pollutants. The workplace, thermal conditions, and work schedule (including breaks) should be planned in such a way to help maintain a normal eye blink frequency to minimize alterations of the pre-corneal tear film. The role of relative humidity on eye irritation symptoms should not be underestimated. Multiple short breaks are justified by the beneficial effect on the pre-corneal tear film. In addition, longer breaks in tasks, which require demanding visual work, should be considered. In addition, air temperature as well as certain alkene oxidation products by ozone may worsen eye irritation symptoms, but the latter factor may be smaller at higher relative humidity.

Is dry eye an environmental disease?

“…Emission of the volatile organic compounds (VOCs) from the synthetic materials used in homes and offices together with other micro environmental variables such as temperature, humidity, lighting and airborne substances can also contribute to EDED. They can cause ocular symptoms, tear film instability, and alterations in ocular surface characteristics of EDED (40,62,(71)(72)(73)(74) . In 1992, Norn described that "sick building" workers have "pollution keratoconjunctivitis" with decline in BUT values and epithelial alterations detected by lissamine green staining (31) .…”

“…Based on the studies performed using questionnaires, it ranges from 5%-40% (62,75) . This large range may be due to the design of questionnaire, types of reported symptoms, inclusion of confounding variables that include contact lens wear, medications, and differences in recall periods.…”

“…If more than one factor is involved, depending upon their characteristics they may interact at lower threshold values and induce EDED. Accordingly, the detrimental effects of environmental toxic agents on EDED epidemiology are not entirely understood (43,44,(60)(61)(62) . The impact of urban pollution and environmental toxins on the ocular surface has been evaluated in a few case-control studies.…”

Humidification of indoor air for preventing or reducing dryness symptoms or upper respiratory infections in educational settings and at the workplace

“…Epidemiological and clinical studies suggest that 40% RH is a favourable condition for the precorneal tear film (Wolkoff 2008). Some studies have shown a correlation between increasing RH and more stable pre-corneal tear film measured by break-up time (Brasche 2005;Norbäck 2006;Wolkoff 2006). In a study conducted by Wyon 2006, the blink frequency was significantly lower at 35% than at 5% RH.…”

Trigeminal Chemesthesis

“…As noted, the trigeminal nerve also innervates the eyes, so vapors reaching the ocular mucosa can give rise to eye irritation, a key symptom invariably mentioned in studies of indoor air pollution (Korpi et al, 2009;Wolkoff et al, 2006;Wolkoff et al, 2003). Eye irritation thresholds (EITs) were measured in normosmics for homologous nalcohols, acetate esters, 2-ketones, n-alkylbenzenes, for various terpenes, and for cumene, using a methodology analogous to that described above for NPTs, including vapor quantification via gas chromatography (Cometto-Muñiz and Cain, 1991;Cometto-Muñiz et al, 1998b).…”