January 18, 2011 Accepted:
January 18, 2011
Glaucoma is a leading cause of blindness worldwide and is the second most frequent cause of non-accidental blindness in industrialised countries.1–8,13,14 In glaucoma, the optic nerve is progressively damaged, causing defects in the visual field, usually asymptomatic until the central vision is affected.10 Primary open angle glaucoma (POAG), the most common form of glaucoma observed in developed western countries,9 is associated with intraocular pressure (IOP) increased to a level likely to interfere with the health of the optic nerve. In normal-pressure glaucoma (NPG), there is no increase of IOP. Ocular hypertension (OH) defines a group of patients in whom the optic nerve and visual field are still normal, but IOP is elevated to potentially dangerous levels. The visual field examination is the standard practice to assess vision in glaucoma for detection, follow-up and staging. With this type of testing, the eye’s ability to detect small points of light of varying brightness centrally and peripherally is measured. With the automatic static threshold technique, values from age-matched normal individuals are compared with those of the patient being examined.10 The goal of glaucoma management is to preserve the patient’s quality of life.10,11 The only treatment option that has been proved to prevent the loss of vision is lowering the IOP to a level deemed safe for the eye.12 The recommended steps for lowering IOP in POAG are topical medications first, followed by laser trabeculoplasty and, lastly, incisional surgery.10 The global prevalence of glaucoma was estimated at 67 million people in 2001. A projection of these data to European countries estimates 9.25 million glaucoma patients in Europe, of whom 4.6–6.9 million were undiagnosed and untreated.15
In 2000, the prevalence of glaucoma in the UK was estimated to be as high as 3.3% in people over 40 years of age, and up to 5% in those aged 80 years and over.16 In Italy, approximately 50,000 people are visually handicapped by glaucoma, while an estimated 540,000 people over 40 suffer from glaucoma, half of whom are undiagnosed.17 In Germany, glaucoma was reported as the third leading cause of blindness (1.6/100,000), and an estimated one-fifth of all cases of legal blindness in persons aged 75 and older were due to glaucoma (22.8/100,000).18 Approximately 500,000 patients in France are followed and treated for POAG, with a similar number of cases undiagnosed.19,20 Glaucoma costs the US healthcare system an estimated US$2.5 billion annually: US$1.9 billion in direct costs and US$0.6 billion in indirect costs.20 The annual direct medical cost of treating newly diagnosed open-angle glaucoma was estimated at US$1,055 per patient.21 Standard treatment costs were put at FFr2,289 per patient (France) and £380 (UK).22
Several international retrospective chart reviews have considered the economic burden of the management of glaucoma, particularly in the first two years after diagnosis.20,21 However, limited data exist on resource consumption as a function of disease severity and, in particular, of treatingadvanced-stage disease. A study in Canada showed an increase in direct costs with more severe damage.23 We have published data on resource utilisation and direct medical costs associated with the long-term management of glaucoma of different severities in five European countries (Austria, France, Germany, Italy and the UK), and showed that resource consumption and direct costs increase as disease severity worsens.24 In our study, data collected included patient demographics, glaucoma risk factors, number of ophthalmologist visits, number and type of glaucoma medications and surgeries and visual field results. All clinical tests documented in the charts were recorded. Essential examinations, such as IOP assessments, optic nerve assessments, retinal or macular examinations, slit-lamp examinations and gonioscopies, as well as more specialised tests, such as diurnal curves of IOP measurements, retinal nerve fibre thickness assessments and optic disc photographs, were considered. The results can be summarised simply in one graph (see Figure 1). In examining medical resource consumption associated with a chronic, potentially blinding disease such as glaucoma, one may postulate that as disease severity worsens, greater medical effort will be prompted by the desire of physicians to slow disease progression, as well as by increased patient concern. In particular, as glaucoma is often asymptomatic in the early phases, resulting in delayed diagnosis, a consequently increased medical vigilance after diagnosis is likely as the disease progresses.
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