Depression is a multifactorial disease, with some well-established risk factors such as old age, presence of chronic illnesses, lack of bonds and social support. Beyond that, it has a complex pathophysiology with many supporting mechanisms and factors yet to be clarified. The importance of better understanding about its triggers is notorious, as the disease has a considerable prevalence worldwide, especially in the elderly, and courses with cognitive impairment, sleep disorders, physical symptoms and behavioral changes, resulting in a significant impact on the quality of life. 14
Berchuck et al evaluated the presence and the development of anxiety and depression among 3259 individuals mean age 60 years at baseline with glaucoma suspect for an average of 3.6 years, in which 911 (28%) were confirmed for glaucoma. Among the participants, 33% presented depression and 19% were diagnosed with depression and anxiety. There was a significant association between psychiatric disorders and the development of glaucoma. 15
One European population-based study assessed the presence of depressive symptoms in 14,657 individuals aged 35–74 years old using the Patient Health Questionnaire (PHQ-9), including 293 participants with self-reported glaucoma. A positive screening for depression was observed in 6.6% (95% CI 4.1–10.3) and 7.7% (95% CI 7.3–8.2) of the participants with and without glaucoma, respectively. 16 Another research, developed in Brazil, using the Hospital Anxiety and Depression Scale (HADS), found a prevalence of depression and anxiety of 3.10% and isolated depression of 2.3% among 129 glaucoma patients of mean age 70.14 years old. 17 When comparing gender and depression among glaucoma patients, some studies found a significant higher prevalence of depression in women. 15,17 In our data, there was no statistical difference regarding gender and age in terms of depressive symptoms.
Abe et al also pointed a higher prevalence of depressive symptoms in glaucoma patients with comorbidities. 17 In our data, there was no association of a positive screening for depression and isolated systemic or ocular comorbidities. Other factors that were described to be associated to a higher presence of depressive symptoms were low comprehension of glaucoma, IOP < 21mmHg. 18, 19 This study also evaluated the correlation of age and depressive symptoms, finding no statistical significance when comparing these variables. Glaucoma inpatients were also pointed to have more depressive symptoms and lower disease knowledge than day-ward patients in a study comparing volunteers who were about to receive a glaucoma surgery for the first time. 20 Although our study did not evaluate the comprehension of glaucoma among the participants, the frequency of GDS-15 > 5 was higher among glaucoma patients with lower schooling status, however there was no statistical significance in this analysis (p = 0.053).
Regarding the influence of the visual field in the development of depression, Agorastos et al utilized the Beck’s Depression Inventory–II (BDI–II) to assess depressive symptoms among glaucoma patients older than 50 years, pointing a higher prevalence among patients with moderate/severe visual field defects for six months. 21 Other studies also observed a higher prevalence of psychiatric diseases in patients with worse values of mean deviation (MD) in the perimetry. 15, 22, 23 Contrastingly, Abe et al did not observe statistical differences regarding MD and visual acuity in the presence of depression among glaucoma patients in a transversal study. 17
Jampel et al proposed that the visual function is more important to determine depressive manifestations than monocular best VA values. 24 Onwubiko et al, found a higher prevalence of depressive symptoms in glaucoma patients with worse BCVA 19 and an American data including 7584 participants suggests that elderly with self-reported visual impairment, independently of the cause, are more likely to evolve with depressive symptoms. 25 Our data suggested that the worsening of the BCVA was associated to a higher score in the GDS – 15 and to a positive screening for depression.
Among the limitations of the study, the cross-sectional design limited the assessment of the relationship between disease progression, BCVA variation and development of depressive symptoms. Furthermore, BCVA values were only arranged as better than or equal to 20/80 and worse than 20/80, limiting the comparison of depressive symptoms in a more detailed BCVA stratification. Beyond that, there was also no quantitative or qualitative evaluation of the visual perimetry effect and no estimation of visual functionality parameters. Furthermore, only elderly people were included in the study, which is the group in which there is scientific validation of the use of GDS-15, however this selection restricts the methodology of this study with regard to population inferences.