TEAR FUNCTION AND OCULAR SURFACE CHANGES IN DIAIJRTIC PATIENTS

Diabetes mellitus (DM) is a multisystem disease that can affect the eyes in many ways. A number of ocular complications have been reported to be associated with DM, many of which can lead to blindness (Goebbels, 2000). Although ocular
complications such as chronic inflammation of the lids, orbital infections, cataract,diabetic papillopathy, and diabetic retinopathy have been recognized and studied extensively, the studies on corneal and conjunctival complications of diabetes are still few (Dabbs and Meredith, 1991).
Many diabetic patients complain of dry eye symptoms, such as burning and foreign body sensation. Thus the question as to whether DM is correlated with tear film anomalies or there is a primary surface disease or metabolic alternations of the conjunctival or corneal epithelial cells, independent of the tear film anomalies (Goebbels, 2000).
Schultz et at. (1981) reported that, 47% to 64% of diabetic patients have cor eal lesions during their life time as epithelial fragility, superficial punctate keratopathy, persistent epithelial defects. and recurrent corneal erosions (Schultz et al.,
1981). Different studies have reported structural. metabolic, and functional abnormalities in the conjunctiva and cornea of diabetic patients, and have suggested that these abnormalities may be responsible for the clinical corneal manifestations of DM (Taylor and Kimsey, 1981; Friend et al., 1982; Azar et al., 1989; Tsubota et al., 1991). The tear film has been reported to be unstable and to have higher osmolarity in diabetics (Seifart and Strempel, 1994). Other study also demonstrated  decreased Schirmer test readings and pronounced signs of conjunctival squamous metaplasia in patients with insulin dependent DM (Goebbels, 2000). How these ocular surface disorders and tear film changes related to clinical parameters of DM, are still controversial.The aim of this work is to study ocular surface disorders in diabetic patients byperforming Schirmmer test, tear break up time lest (BUT), and conjur~ctivailm pression cytology analysis. The results arc studied and correlated with different clinical parameters of DM; the results are also compared with those of healthy controls.