Dry eye symptoms and signs in long-term contact lens wearers.

The aim of this study is to analyze the relationship between the self-reported symptoms and objective signs of dry eye disease in long-term rigid gas-permeable (RGP) or soft contact lens (SCL) wearers. The study included 32 eyes of Caucasian RGP and SCL wearers between the age of 21 and 42 who wore contact lenses continuously on a daily basis for more than 2 years. Symptoms were assessed according to the Ocular Surface Disease Index (OSDI). Clinical assessments included corneal fluorescein staining according to the National Eye Institute (NEI) staining grid, tear film break-up time (TBUT) and Schirmer II test. There were more male (62.5%) than female (37.5%) patients with a higher proportion of RGP wearers among males (40% vs. 17%) in the study. The mean duration of daily lens wear was 10.6 +/- 5.37 hours, with a significantly higher proportion of patients who wore their lenses for prolonged hours in the soft contact lens group (p < 0.05). There was a trend towards a higher proportion of self reported mild and moderate dry eye in females and soft contact lens wearers. No RGP wearer in this study had a NEI corneal staining grid score higher than 2. A moderate negative correlation was found between daily lens wear duration and TBUT (Pearson's coefficient, r = -0.47) as well as Schirmer II values and higher OSDI score, i.e. mild and moderate dry eye categories (r = -0.50). A strong positive correlation was found between and TBUT and Schirmer II values (r = 0.74). The results of the study emphasize the importance of early and accurate diagnosis of dry eye disease for successful long term RGP and SCL contact lens wear which will hopefully motivate future larger scale investigations on dry eye related problems in contact lens wearers.