Abstract
Purpose :
Diabetes mellitus is a systemic metabolic disease that is known to cause damage to several organs including the eyes. Hyperglycemia is the key trigger for diabetes-mediated organ damage and the long-term complications. Several clinical studies have demonstrated that a large proportion of diabetic patients suffer from dry eye. The present study investigates the impact of the duration and degree of diabetes-induced hyperglycemia on the onset and severity of dry eye.
Methods :
Mouse models of type I and type II diabetes were used in the study. Type I diabetes was induced in C57 mice by single intraperitoneal injection of streptozotocin (150 mg/kg). For type II diabetes, db/db mouse model was used. Blood glucose was quantified using tail clip method. Tear secretion was quantified using phenol red thread test and tear osmolarity was measured using a chip-based commercially available device.
Results :
Blood glucose quantification revealed an average blood glucose >450 mg/dl in C57 mice injected with streptozotocin confirming successful induction of diabetes. The average blood glucose levels in db/db mice was around 300 mg/dl. The high blood glucose in streptozotocin injected mice was accompanied by a significant decrease in tear secretion and an increase in tear osmolarity. A significant decrease in the tear secretion was also observed in db/db mice but the average increase in tear osmolarity was <10% and not statistically significant. The onset of decrease in tear secretion occurred significantly earlier in streptozotocin-injected mice compared to db/db mice. The tear secretion continued to decline as a function of time in both models with the decease being significantly more severe in streptozotocin-injected mice compared to db/db mice at all the tested time points.
Conclusions :
Our data demonstrates the diabetes mellitus negatively impacts tear secretion and tear osmolarity. The diabetes mellitus-mediated deterioration of tear secretion and osmolarity directly correlate with the severity and duration of hyperglycemia.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.