77 ± 21.68 (p = 0.01), and it differed significantly from the placebo group (p = 0.04). In the KRG group, the OSDI-symptom subtotal improved the most, from 35.42 ± 16.42 to 23.40 ± 18.65 (p < 0.01), which was thought to affect the greater part of the total OSDI score improvement. Compared to the baseline, six of the 12 items were significantly improved in the KRG group after the 8-week supplementation:

three items (painful eye, blurred vision, selleckchem and poor vision) of the OSDI-symptom; two items of OSDI-function (driving at night and working with a computer); and one item (feeling uncomfortable in air-conditioned areas). In addition, five of these items, except blurred vision, displayed significant differences between the KRG and placebo groups. Patients with full-blown glaucoma suffer from the disease itself. However, most patients, particularly those in the early to moderate stages of glaucoma, complain more about their dry eye symptoms caused by topical glaucoma Selleck AZD2281 medication until the disease progressed. Many earlier studies reported that patients with glaucoma suffer a higher prevalence of ocular surface disease than the normal population [7], [8], [9] and [10]. Leung et al [10] found that 59% of patients with primary open-angle glaucoma (OAG) and ocular hypertension (OHT) reported dry eye symptoms, whereas severe symptoms were noted by 27% of these

patients. The authors concluded that a large proportion of the patients with OAG or OHT had signs and/or symptoms of dry eye, and that the presence of dry eye and the use of benzalkonium chloride (BAK)-containing medications may affect quality of life. Our study similarly demonstrated that dry eye is prevalent in patients treated for glaucoma by showing that almost all the participants had OSDI scores consistent with the presence of dry eye symptoms. The cause of DES in patients with glaucoma is thought to be multifactorial and may include an active ingredient and

a preservative, most commonly BAK [9] and [32]. Several previous studies Oxalosuccinic acid reported that BAK may cause inflammation and potentially other ocular diseases, including allergy, blepharitis, DES, and anatomical eyelid abnormalities [33] and [34]. The prolonged use of preserved topical drugs is an extrinsic cause of increased tear evaporation, which induces a toxic response from the ocular surface. BAK has a well-known dose-dependent toxicity and is most commonly used as a preservative in ophthalmic solutions, particularly in antiglaucoma eye drops [33] and [35]. Its cellular toxicity has been demonstrated experimentally in in vitro studies of conjunctiva-derived and corneal cells [36] and [37]. BAK induces the expression of inflammatory cell markers at the ocular surface [38] and causes epithelial cell damage, apoptotic cell death, and a decrease in goblet cell density, resulting in tear film instability and tear hyperosmolarity [39] and [40].