PURPOSE:The purpose is to study the ocular surface changes among patients with diabetes mellitus (DM) and to correlate them with tear film markers such as insulin-like growth factor (IGF)-1, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α levels.MATERIALS AND METHODS:The study was carried out on diabetic patients (>5 years' duration) and healthy age- and gender-matched controls with 21 individuals in each group. Schirmer's test for basal and reflex tear secretion, tear film breakup time (TBUT) for tear stability, ocular staining score (OSS) for dryness severity, ocular surface disease index (OSDI) for symptomatic assessment of dryness and conjunctival impression cytology (IC) for epithelial cell integrity, keratinization, squamous metaplasia, and goblet cell density was studied. Thirty microliters of tears were collected to test IGF-1, IL-1β, and TNF-α levels.RESULTS:Patients with DM showed significantly low Schirmer's, TBUT, and OSS values than controls. OSDI score showed moderate-severe dryness in patients with DM and only mild symptoms among controls. An abnormal IC score was seen among cases and controls. The level of TNF-α was significantly increased in patients with DM and positively correlated with Schirmer and TBUT values (P < 0.05).CONCLUSION:Dry eye is more prevalent in patients with DM compared to controls as evidenced by poor OSDI score, Schirmer, TBUT, and OSS. TNF-α in the tears of patients with DM is a useful marker that showed a good correlation with Schirmer, TBUT, and dry eye symptoms. IC could not conclusively differentiate the dry eye status in patients with DM from controls.