Tear secretion and tear film stability in Nigerians with non-insulin dependent diabetes mellitus

It has been reported that many diabetic patients complain of dry eye symptoms. Thus this study was aimed at investigating tear secretion and tear film stability in patients with non-insulin dependent diabetes mellitus (NIDDM). Eighty (80) subjects within the age range of 50-60 years with mean age of 55 +/- 3.42 years were recruited for this study. They comprised of 40 NIDDM patients (19 males and 21 females) and 40 age and gender matched controls (18 males and 22 females) without diabetes. Schirmer test and invasive tear break up time (TBUT) were used to determine tear secretion and tear film stability respectively. Results showed an apparent reduction in both total and basal tear secretions for the NIDDM patients compared with that for control subjects. However this reduction was not statistically significant with the unpaired t-test. (p> 0.05). Unpaired t-test revealed a statistically significant reduction in TBUT of the NIDDM group compared with control subjects. Correlation analysis revealed a negative correlation between fasting blood sugar (FBS) levels and both basal and total tear secretions. (r = -0.51, p < 0.05) and (r = -0.54 p < 0.05) respectively. There was also a negative correlation between FBS and TBUT (r = -0.34 p = 0.03). The student t-test showed no influence of gender on both tear secretions and TBUT for NIDDM patients and controls. This study shows that both tear secretion and tear film stability are affected by NIDDM, and concurs with the findings that diabetic patients often complain of dry eye symptoms.