The ocular surface comprises the cornea, conjunctiva, eyelids and lacrimal glands and any disorder in these structures can be classified as an ocular surface disorder (OSD). OSD includes Dry Eye Disease (DED), blepharitis and meibomian gland dysfunction (MDG), allergic eye diseases (AED), chemical and thermal burns; all these conditions can severely affect eyesight and quality of life, and sometime even blindness. Patients with OSD can develop photophobia, corneal scarring, intermittent blurred vision, pain, limited ability to perform daily activities, reduced vitality, poor general health and, in many cases, depression.
Glaucoma, one of the leading causes of irreversible blindness, is an optic neuropathy characterized by thinning of retinal nerve fiber layer and increase of optic disc cupping , whose main risk factor is closely related to the intraocular pressure (IOP) levels. Thus, the management of the disease consists in the lowering IOP through medical, laser or surgical therapy . However, IOP reduction is most commonly achieved using topical ocular medications, which often contain preservatives employed to maintain stability and sterility of the product. Preservatives can be associated with undesirable adverse effects such as allergy, local irritation and inflammation . The long-term use of anti-glaucoma medications produces several alterations of ocular surface components, especially at the conjunctival level where epithelial modifications, dendritic cell activation, conjunctiva-associated lymphoid tissue activation, and goblet cell (GCs) loss easily occur GCs play crucial tasks in the homeostasis of the ocular surface being the main source of mucoproteins, essential to maintain tear film stability. Thus, the loss of GCs progressively leads to the happening of an iatrogenic OSD . Moreover, advancing age is a significant risk factor for both OSD and glaucoma, further complicated by treatments for each condition, which can interact among them and yield counterproductive effects . For these reason glaucoma is often associated with OSD .Ocular surface inflammation is crucial in the pathophysiology of OSD, therefore anti-inflammatory therapy, including corticosteroids, may be of benefit to OSD patients . However, in susceptible individuals steroid-induced glaucoma or ocular hypertension can occur after steroid use. Individuals who develop an increase in IOP following steroid use are referred to as "steroid responders" . In a recent study Kallab et al. have found that dry eye treatment with low hydrocortisone dose reduced ocular inflammation without inducing increases in IOP ; glaucomatous patients were excluded from this study. Herein we evaluate the safety and efficacy of hydrocortisone eye drops in the treatment of OSD patients with and without glaucoma.
