Purchase this article with an account.
Thao Yeh, Nina Tran, Andrew Graham, Harry Green, Meng Lin; Relationships among Tear Film Stability, Tear Osmolarity, Corneal Staining History, and Dryness Symptoms. Invest. Ophthalmol. Vis. Sci. 2013;54(15):4332.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To explore the relationships among tear osmolarity, tear film stability, corneal staining history, and dryness symptoms in soft contact lens wearers and non-wearers.
This observational study recruited 101 non-contact lens (NCL) and experienced soft contact lens (CL) wearers between January and September 2010. The CL group included “stainers” and “non-stainers”. Stainers had a history of inferior corneal dehydration staining (DHS) at a minimum of 50% of their previous visits to the Clinical Research Center (CRC) and non-stainers presented with DHS at a maximum of 20% of their previous visits to the CRC, over a minimum of three visits. A dry eye questionnaire was administered and ocular parameter measurements including non-invasive tear breakup time (NITBUT), invasive tear breakup time (ITBUT), tear osmolarity, and corneal staining score were collected at a single morning visit. Room temperature and humidity were measured at the commencement of each visit. The TearLab Osmolarity System (TearLab Corporation, San Diego, CA, USA) was used to measure tear osmolarity. NITBUT was analyzed on the natural log scale to better approximate normality.
Ninety nine subjects (69 females, 30 males; 64 non-Asians, 35 Asians; 59 NCL, 40 CL) with a median age of 22 years (range 18-67 years) completed the study. Multivariate linear mixed effects modeling showed that tear hyperosmolarity was significantly associated with shorter NITBUT (p=0.002) but not with corneal staining history or dryness symptoms. Additionally, shorter NITBUT was significantly associated with positive corneal staining history (p<0.001), more severe dryness symptoms (p=0.003), as well as with Asian race (p=0.026) and female gender (p=0.029). The difference in NITBUT between genders was significantly greater for Asians than for non-Asians (p=0.039). ITBUT and corneal staining score did not appear to be associated with either osmolarity or NITBUT.
This study found that tear osmolarity and tear film stability are very closely related and that non-invasive tear breakup time is shorter on average for females, Asians, patients with a history of DHS and those with more severe dry eye symptoms.
This PDF is available to Subscribers Only