In this study, we evaluated the impact of environmental factors on the presence of dry eye symptoms in construction workers when compared with office workers. We found that office workers present more severe symptoms than construction workers, and the risk of suffering from DES persisted after adjusting for all the studied variables. Different factors can influence these results, but, perhaps, mainly by the office workers’ exposure to sustained computer use in significantly drier environments since in our study, we found that the office environment was 50% drier than air in the outdoor space. A report from Kawashima et al. supports these results, they showed that DES are commonly reported by personal using video screens.[12] Similarly, Uchino et al. reported an increased risk of DES when video screens are used for more than four hours.[8] Lee et al. studied 6023 participants and showed that besides computer use, other environmental factors could influence the development of DES. In their study, 16% of the participants presented dry eye symptoms, with professionals, managers, legislators, and senior officers presenting more risk of DES than factory workers. Also, he described that people who work outdoors have a lower risk of dry eye symptoms.[13]
In accord with many other reports,[8, 13, 15–22] in the present study, women presented higher scores OSDI scores than men; thus, gender differences may have influenced differences between the two groups since there was a higher ratio of women among office workers. However, after correction for gender in the multivariate analyses, statistically significant differences linked to gender disappeared.
Contact lens use has been associated with DES,[15, 18, 20, 23, 24] in our study, we found a higher score on the OSDI questionnaire in CL users compared with nonusers. However, when performing multivariate analysis, this influence lower the OR, probably due to the presence of more CL users among office workers[23] than among construction workers.
In this study, a previous diagnosis of ocular or systemic disease was associated with an increased risk to present DES. Previous studies have shown a high prevalence of ocular DES in patients attended by the ophthalmologist,[25, 26] in addition to the ones with specific diseases such as glaucoma,[8] diabetic retinopathy[27] and ocular surface diseases.[28, 29] The relationship between DES and systemic diseases has been extensively studied, Paulsen et al. showed that various systemic diseases such as allergies, arthritis, thyroid disease and the use of drugs such as systemic antihistamines and steroids are related to the presence of dry eye.[24]
Smoking has been reported to be a risk factor for DES.[22, 30] Wolkoff reported that cigarette smoke affects the pre-corneal tear film and the break-up time.[23] Lee et al. reported a higher prevalence of dry eye symptoms in smokers.[13] De Kluizenaar et al.[7] and Ranciere et al.[31] documented that tobacco smoke has been associated with a higher prevalence of DES. In this study, smokers presented lower OSDI scores, and the multivariate analysis ultimately revealed no real associations between smoking and OSDI scores. The OSDI score differences between smokers and non-smokers, most smokers were part of the group with the lower OSDI scores (construction workers). In comparison, non-smokers were mostly office workers (the group with higher OSDI scores), hence, as suggested by the multivariate analysis, we speculate that the workers’ occupational exposure influenced these results.
Due to the nature of the selected and studied occupations, the population was heterogeneous regarding gender, and this situation may have induced some artifacts and limitations to this study. This study did not include a clinical evaluation of the ocular surface, and thus, all that was measured were symptoms of dry eye and not ocular surface or dry eye disease. Based on results observed with some variables, such as the smoking habit and CL use, the sample size is limited to draw firmer conclusions.
The findings of this study underline the serious need to inform the population working in offices, the largest workforce in western countries, on the risks of developing dry eye symptoms, and provide advice on measures to minimize them. These measures should include avoiding long uninterrupted periods of computer work, regular breaks to allow for regular blinking and ciliary relaxation, and to demand better humidity controls in the workplace