Social and Economic Impact of Glaucoma and Glaucoma Care in Ageing Population

Glaucoma is one of the leading causes of visual impairment and blindness worldwide. Vision loss is associated with worsened well-being, increased use of health care services, and loss of productivity due to increased difficulties in daily living, socialization, functional capacity, and work ability. Glaucoma is strongly associated with ageing, and both glaucoma and glaucoma-related vision loss are expected to rise globally along ageing populations. Therefore, there is a growing interest in evaluating the impact of glaucoma and glaucoma care on quality of life, mental health, visual function, and health care resource use, particularly at the population level. Glaucoma remains commonly undetected, and there are difficulties in glaucoma treatment in preventing the irreversible loss of vision. These challenges further underline the significance of this type of epidemiological study on glaucoma.

The aims of this thesis work were to investigate the social and economic impact of glaucoma and glaucoma care in Finland between the years 2000–2011. The thesis consists of four sub-studies. In Study I, the time trends in prevalence and incidence of glaucoma in comparison with two other major vision-threatening eye diseases, cataract and retinal degeneration, were investigated, and the impact of these diseases on generic health-related quality of life, mental health, and distance visual acuity were evaluated. Study II evaluated these associations with a focus on glaucoma and its treatment. The aim of Study III was to provide estimates on the health care resource use and the direct and indirect costs of glaucoma and glaucoma care. Finally, in Study IV, the aim was to investigate the time trends in glaucoma-related visual impairment in the past four decades.

The study populations in Studies I, II, and III consisted of participants aged 30 years or older from two nationally representative health examination surveys: Health 2000 and Health 2011. The surveys included cross-sectional data from 2000 and 2011 as well as longitudinal, 11-year follow-up data on participants who partook in both the surveys. In Study IV, the study population consisted of persons with visual impairment due to glaucoma registered in the Finnish Register of Visual Impairment between 1980 and 2019.

For Studies I, II, and III, the Health Surveys included an interview and questionnaires with self-reported questions on diseases (including glaucoma, cataract, and retinal degeneration), socio-economic status, and use of health care services. Validated instruments on generic health-related quality of life and mental health were included. Bilateral, habitual distance visual acuity was measured at a health examination carried out in both the surveys. The survey data were complemented with register-based information from the Care Registers for Social Welfare and Health Care and the Social Insurance Institution of Finland, which included inpatient, outpatient, and glaucoma medication data on the survey participants. Glaucoma patients were selected based on the self-reported survey interviews and the register data. Continuous variables were analyzed with Mann– Whitney U-test, Wilcoxon’s signed-rank test, or Kruskal–Wallis test. Discrete variables were analyzed with a chi-squared test. The impact of background factors and confounders, i.e., age, sex, visual impairment, and common co-morbidities was estimated and controlled by including them in regression models.

According to Studies I and II, the prevalence of glaucoma increased from 2.3% to 2.6% between 2000 and 2011 in Finland. The prevalence of cataract and retinal degeneration increased as well. Eye diseases and visual impairment were associated with significantly worsened health-related quality of life and mental health. However, glaucoma diagnosis and its treatment did not show direct impact on these factors. Rather, the detrimental impact of glaucoma and other vision-threatening eye diseases on these factors was primarily caused by the reduced visual acuity than the awareness of the disease itself. As a positive trend, the detrimental impact of eye diseases and visual impairment on these factors diminished between 2000 and 2011.

The results of Study III indicate that glaucoma patients use health care services more often and have greater productivity losses due to early retirement than persons without glaucoma even after adjusting for age and sex. Consequently, at 2019 cost level, glaucoma was associated with total additional direct and indirect costs of EUR 202 million and EUR 67 million per year in Finland, respectively, after adjusting for age and sex. The share of eye care of the total additional direct costs of glaucoma was only 13%. Most of these additional costs were linked to the reduced visual acuity caused by the disease as well as an increased number of co-morbidities due to the generally higher age of glaucoma patients.

Based on Study I, the prevalence of overall visual impairment decreased from 1.6% to 1.3% between 2000 and 2011 in Finland. Similarly, in Study IV, the incidence of reported glaucoma-related visual impairment per 10 000 treated glaucoma patients decreased from 32 to 21 between the 1980s and the 2010s, with a notable shift to older age groups. Glaucoma-related visual impairment has also mildened in the past four decades, and it occurs at a later age. These positive trends in visual impairment are likely explained by the improvements in diagnostics, therapies, and awareness of glaucoma and other vision-threatening eye diseases. Because vision loss significantly worsens the quality of life and work ability of glaucoma patients and increases their health care use as observed in Studies I, II, and III, maintaining the reduction of visual impairment and the improvement in the well-being of the visually impaired as the population keeps ageing will be crucial.

In conclusion, the information directed to the public about glaucoma and other eye diseases and their risks should be strengthened to promote early diagnosis and adherence to treatment. Doing this would consequently prevent or at least reduce the detrimental effects of declining vision on the patient and the society. In addition, the endorsement of equal and easy access to aids and rehabilitation of vision loss can equalize and milden the difficulties and problems caused by visual impairment. Further investigation in other countries and populations is required to address the social and economic implications of glaucoma at a larger scale and to confirm the validity and generalizability of the results of this thesis.