Tear film secretion and stability in welders

PURPOSE Welders are prone to ocular injuries and ocular surface problems due to exposure to ultraviolet light. The aim of this study was to evaluate the tear film comprehensively and assess objective and subjective indices of dry eye in welders. METHODS In this historical cohort, welders with at least 5 years of experience were compared with controls. A complete evaluation of ocular health was done for all participants. The Schirmer test (invasive and non-invasive) and Invasive Tear Break-Up Time (ITBUT) were applied for objective evaluation and the Ocular Surface Disease Index (OSDI) was used for subjective assessment of the tear film status. The results were compared between the two groups using the SPSS software. RESULTS The results of 140 welders (mean age: 46.66 ± 13.01 years) and 172 controls (mean age: 45.05 ± 12.61) were analyzed. The values of the Schirmer test and ITBUT were significantly lower in welders than controls; the difference was more prominent for the Schirmer test as compared to TBUT (Schirmer difference = 4.98 mm, ITBUT difference = 2.23 s). OSDI values were also significantly lower in welders than controls (P < 0.001). Considering a cut-off point of 12, 81.2% of welders had degrees of dry eye which was severe in 46.2% while 35.5% of controls had dry eye. CONCLUSION The results indicate that the percentage of dry eye and tear problems is far higher in welders than non-welders. Most of the affected welders have severe dry eye. It seems that the main reason for dry eye in these people is aqueous deficiency.