The risk of glaucoma after surgery for pediatric cataract is substantial and particularly high for those below 9 months of age at the time of surgery. Because the increased risk persists for many years after surgery, careful continuous monitoring for glaucoma is mandatory.

PurposeThe purpose of the present study was to describe the prevalence, incidence and geographic variation of glaucoma in Denmark in the period from 1996 to 2011. Moreover, the aim was to identify the treatment patterns of glaucoma within the studied period.MethodsAll Danish citizens were included throughout the study period. The National Prescription Registry was used to identify all claimed prescriptions for glaucoma medication.ResultsA total of 116,592 incident glaucoma patients were identified. Average age at onset was 66 years (range: 0–105 years), 55% were women. The prevalence of glaucoma increased from 0.79% to 1.72% during the investigated period. In 2011 glaucoma affected 3.76% of the population above 50 years and 10% in patients above 80 years. The age-specific incidence rate of glaucoma seemed to be constant and the increasing prevalence was primarily attributed to an aging population. We found the highest prevalence of glaucoma in the capital region of Denmark. Within the studied period the use of prostaglandin analogs and combination drugs increased, whereas the use of β-blockers, carbon anhydrase inhibitors and parasympathomimetic drugs decreased (p<0.001). Finally, the use of α2-adrenergic agonists remained unchanged. A total of 75% of the patients were treated with two or more glaucoma medications.ConclusionsOver all, the present study is the first to assess the frequency and the development of glaucoma in Denmark over a 15-year period. We find that glaucoma affects a little less than 2% of the total population and increases with age to reach a prevalence of more than 10% amongst people above 80 years. Generally, the present study is the largest nation-wide study ever made and must be a close-to-real-life-picture of the utilization of glaucoma medication on a national scale. Our findings confirm other recent estimations on an increasing burden of glaucoma globally.

Preservatives used in topical glaucoma medications have a plethora of well-described toxic effects on the ocular surface. Such ocular toxicity is manifest clinically as ocular surface disease (OSD) and has been confirmed in epidemiologic, prospective clinical trials and studies in which patients are switched from preservative-added to preservative-free topical therapy. Such toxicity has implications not only for tolerability, but also for adherence and persistence with therapy that is known to be poor in glaucoma. Glaucoma medication is now widely available in preservative-free formulations, and the question arises as to which patients should receive preservative-free glaucoma therapy in preference to preservative-added medication. A case can be made for several subpopulations of patients who might particularly benefit from preservative-free medication: patients with existing OSD, older patients, younger adult patients, female patients, pediatric and juvenile patients, patients who work in air-conditioned environments or who use electronic screens frequently, patients with medical risk factors for OSD, patients in whom trabecular surgery may become indicated in the future, contact lens users, perhaps patients with Asian ethnicity and patients with severe or treatment-refractory glaucoma. Whilst arguments could be made for selecting patients for preservative-free medication on the basis of their existing risk of OSD, collectively, these patients form a significant proportion of the glaucoma patient population as a whole and, in the absence of any cost premium or positive indication for preservative-added medication, preservative-free glaucoma medication for all patients seems an appropriate strategy.