Understanding the Dual Dilemma of Dry Eye and Glaucoma: An International Review.

Glaucoma-related ocular surface disease (G-OSD) is a significant, yet often underdiagnosed, ocular co-morbidity affecting 40% to 59% of glaucoma patients worldwide. Although the use of topical glaucoma medications represents a proven strategy to control the untoward effects of high intraocular pressure, this treatment can profoundly disrupt the homeostasis of the tear film. The cumulative effect of medications, preservatives, and excipients alter underlying cellular structures which results in tear film abnormalities and instability of the ocular surface. Furthermore, these chronic inflammatory changes have been shown to impact efficacy of glaucoma treatment, patient compliance with therapy and overall quality of life. The pathogenesis of G-OSD is multifactorial and involves a vicious self-perpetuating cycle of inflammatory cytokines and proteins. The diagnosis of such disease is based on similar tests used in assessing traditional dry eye, taking into consideration findings specific to this patient population. The hallmark of treatment for these patients is to minimize the ocular surface inflammatory response by choosing glaucoma therapies that spare the ocular surface such as preservative free formulations and initiating dry eye treatment early in the course of care. In summary, glaucoma affects millions of patients around the world and chronic use of topical glaucoma medications may negatively impact the patient's ocular surface, symptoms, and vision. Understanding the pathogenesis of G-OSD, recognizing its risk factors and incorporating diagnostic and therapeutic strategies that restore and maintain ocular surface homeostasis will result in improved care for our patients.