The prevalence of glaucoma contributes to significant costs that are both direct and indirect.
13 Direct medical costs include ocular hypotensive medication(s), physician and hospital visits, and glaucoma-related procedures while direct nonmedical costs include transportation, government purchase programs, guide dogs, and nursing home care. Indirect costs reflect lost productivity, such as days missed from work, and can include the productivity costs borne by caregivers such as family members and friends.
Direct cost estimates for the approximately 2 million US citizens
13 and 300 000 Australian citizens
14 with glaucoma are $2.9 billion and Aus$144.2 million, respectively. However, these figures likely underestimate the true societal costs if all were to be treated since about half of patients with glaucoma are unaware.
7-11 A Markov model populated with data based on US Medicare claims data from 1999 to 2005
15 estimated the incremental costs of a case of POAG from the payor's perspective, including both direct and indirect medical costs. The average lifetime cost of medical treatment in the glaucoma cohort was $1688 greater than in the control cohort without glaucoma over their expected lifetime (mean = 12.3 years). Although the difference between the POAG and control cohorts was not statistically significant, the authors estimated the average annual incremental cost to Medicare attributable to POAG to be approximately $137 per patient per year.
The financial burden of glaucoma increases as disease severity increases (). A US study
16 found a 4-fold increase in direct ophthalmology-related costs as severity increased from asymptomatic ocular hypertension/earliest glaucoma (stage 0) through advanced glaucoma (stage 3) to end-stage glaucoma/blindness (stage 5): average direct costs per patient per year were $623, $1915, and $2511, respectively. The majority of costs were medication-related at all severity stages. A similar trend was seen in Europe, where direct costs of treatment increased by approximately €86 for each incremental increase in glaucoma stage, ranging from €455 per person year (stage 0) to €969 per person year (stage 4).
17 Medication costs ranged from 42% to 56% of direct costs at each disease stage. A retrospective medical chart review in the United States (1990 to 2002; n = 151) and Europe (1995 to 2003; n = 194) found that increased annual costs were associated with higher initial IOP level, higher baseline glaucoma stage, use of ocular hypotensive medication, and glaucoma-related surgery.
18The direct cost burden is observed even in the early stages of glaucoma. In France and Sweden, total annual direct treatment costs per patient in a cohort in whom the majority was in early stages of glaucoma were estimated to be €390 and €531, respectively.
19 Medication costs comprised nearly half of total costs in both countries. Individuals with late-stage disease incur significant additional indirect costs and constitute a substantial burden on health care resources.
20,21 Late disease leads to greater indirect costs (eg, family/home help and rehabilitation costs) that become the predominant driver of overall costs. Indirect costs are difficult to measure, and studies have used various methods to estimate these costs, including patient/family diaries and interviews. In Europe, the average annual direct health care cost of glaucoma-related blindness has been estimated to be between €429 and €523 per patient while annual total costs, including rehabilitation costs and costs to families, were estimated to be between €11 758 and €19 111.
20 In 2005, the annual health care costs of individuals with late-stage glaucoma averaged €830 per patient across France, Denmark, Germany, and the United Kingdom; the largest contributor to total annual maintenance costs was assistance in the home, ranging from €633 in Germany to €4878 in France.
21Efforts have been made to estimate the cost effectiveness to identify and to treat glaucoma and ocular hypertension.
22-25 A computer model of 20 million people aged 50 or older in the United States simulated routine ophthalmologic care and resulting glaucoma diagnoses and medical treatment.
22 Glaucoma treatment was highly cost-effective when costs associated with diagnostic assessments were excluded and when optimistic assumptions about treatment efficacy were made. Furthermore, costs compared favorably with standards established by the World Health Organization even when efficacy assumptions were conservative. Stewart et al
23 developed a Markov model to evaluate the long-term cost effectiveness of treating ocular hypertension in the United States to prevent progression to glaucoma. While treating all patients with ocular hypertension did not prove to be cost effective, treating those with risk factors identified by the Ocular Hypertension Treatment Study did seem to prevent the onset of glaucoma cost effectively. Similarly, Kymes et al
24 concluded that treating individuals with an IOP ≥24 mm Hg and a ≥2% annual risk of developing glaucoma met cost-effectiveness standards accepted in most developed countries. An Australian team
25 estimated that implementing an intervention package, VISION 2020, targeting visual impairment would cost Aus$5591 per quality-adjusted life-year in the first year and would be cost saving in subsequent years.
In summary, the economic burden of glaucoma is significant and increases as the disease worsens. Analysts have used a variety of approaches to quantify the economic burden of glaucoma, making direct comparisons among studies and across populations difficult. Results of a collaborative effort to delineate guidelines for calculating the economic burden of visual impairment recently have been published,
26 and it is hoped that future studies will implement its recommendations.
The publisher's final edited version of this article is available at 
