Biochemical studies of tears in patients with diabetes mellitus and dry eye syndrome

Aim. To study the lacrimal fluid glucose level in patients with diabetes and dry eye syndrome with hyperglycemia and after compensation.Methods. Glucose oxidase method was used to determine the level of glucose in tears of 40 patients with diabetes (80 eyes) who were treated at the endocrinology department. Of these, the diagnosis of diabetes mellitus (DM) type 1 has been established in 17 (42.5%) patients, type 2 - in 23 (57.5%). The study also included the control group, which included 20 healthy volunteers (40 eyes) aged 25 to 45 years (12 females, 8 males). Three groups were formed: healthy subjects, patients with diabetes mellitus and no signs of dry eye syndrome, patients with diabetes mellitus and clinical signs of dry eye syndrome.Results. Glucose level in the tear fluid of healthy individuals did not exceed 0.2 mmol/l. No signs of «dry eye» syndrome were found in patients with blood glucose levels up to 9 mmol/l (2nd clinical group). Patients of 3rd group were observed with the clinical symptoms with «dry eye» syndrome if there was an increase of blood glucose level over 17 mmol/l, tear glucose levels were also increased to 7 mmol/l. After the treatment the level of blood glucose in the patients of the second group decreased from 9 to 5 mmol/l, while tear glucose levels decreased from 1.2 to 0.5 mmol/l. In the third group the same clinical pattern was observed: reduction of blood glucose from 17.1 to 7 mmol/l was accompanied by a decrease of tear glucose levels from 7 to 1 mmol/l. There was a reduction of the subjective complaints characteristic for dry eye syndrome in patients from the third group.Conclusion. «Dry eye» syndrome is associated with increased tear glucose levels. The blood glucose level control is one of the methods of dry eye syndrome prevention in patients with diabetes mellitus.