Abstract
Purpose:
Prolonged computer usage is a common cause of a constellation of ocular symptoms such as irritation, dryness and fatigue collectively known as computer vision syndrome (CVS). Using novel diagnostic tools we aim to objectively quantify the effects of computer usage on tear film dynamics.
Methods:
A prospective cohort study of 20 healthy volunteer subjects (40 eyes) were evaluated in the morning and again in the evening after prolonged computer usage. Outcome measures were tear osmolarity (TearLab Osmolarity System) and precorneal tear film thickness as measured by a modified Heidelberg ocular computed tomography (OCT). The average age of patients was 28.5 years (range 24-35), with 60% females. Computer usage times were measured by an evening survey. Data was analyzed using paired two tailed t-test, Pearson co-efficient and Chi-square analysis with p<0.05 for significance.
Results:
Patients with significant interval computer use (average of 6.55 hours, SD 2.59, range 2-11 hours) had statistically significant increases in tear film osmolarity between morning and evening (291.1 +/- 10.2 vs 297.8, +/- 10.9, p=0.0064). The precorneal tear film thickness did not show a significant difference between morning and evening measurements (0.039 +/- 0.008, 0.043 +/- 0.016, p=0.27). 6 patients (30%) identified themselves as having dry eyes, but tear film osmolarity was not significantly different compared to those who did not.
Conclusions:
Prolonged daily computer usage can cause an increase in tear osmolarity which may contribute to the symptoms of CVS. In this small study in healthy volunteers the precorneal tear film thickness did not change with computer use.
Keywords: 464 clinical (human) or epidemiologic studies: risk factor assessment •
486 cornea: tears/tear film/dry eye