Contrast Sensitivity and Tear Layer Aberrometry in Dry Eye Patients

Purpose. Dry eye disease is a common condition that affects millions of people world wide. The common findings of dry eye disease are blurred vision and tear film instability. The purpose of this study was to determine if long-term use of artificial tears altered visual disturbances and tear film instability of dry eye patients. Methods. Contrast sensitivity and optical aberrations were measured in 22 dry eye and 10 normal patients before and after daily use of artificial tears. The contrast sensitivity and optical aberrations were measured in response to the administration of a single drop of artificial tear placed in the eye. Results. The short-term effect (i.e., a few minutes) of a single drop of artificial tear placed in the eye was a decrease in contrast sensitivity and an increase in optical aberrations. Long-term daily use of the artificial tears (i.e., up to 2 weeks) resulted in less of a short-term effect in dry eye patients. No long-term effect was observed for normal subjects. Both contrast sensitivity loss and optical aberrations decreased by 35% per week of artificial tear use for the dry eye patients suggesting that the changes in contrast sensitivity were the result of optical aberrations. Conclusions. The results suggest that the changes in contrast sensitivity with artificial tear administration were the result of optical aberrations. It appears that long-term use of artificial tears may normalize the tear layer of dry eye disease patients. (Optom Vis Sci 2009;86:1059-1068)