Prevalence and factors associated with depressive symptoms among adults with glaucoma at a tertiary hospital in Tanzania: A cross-sectional study

This cross-sectional study of 297 adults with glaucoma at a tertiary hospital in Tanzania found that 11.1% experienced probable depressive symptoms, with strong and moderate social support identified as significant protective factors against depression.

The Gist

Imagine your eyes are like a high-end camera. Glaucoma is a slow, silent thief that steals the lens's ability to focus, eventually making the picture go dark. It's a chronic condition, meaning it doesn't go away, and for many, it leads to permanent vision loss.

Now, imagine carrying a heavy backpack that gets heavier every day. That's what living with a chronic illness like glaucoma feels like. It's not just the physical burden; it's the worry, the fear of going blind, and the struggle to do everyday tasks. This paper asks a simple but crucial question: How many people carrying this heavy backpack are also carrying a heavy emotional one (depression)?

Here is the story of the study, broken down into simple parts:

1. The Setting: A Busy Eye Hospital in Tanzania

The researchers went to a big, busy hospital in Dar es Salaam, Tanzania (Muhimbili National Hospital). They looked at 297 adults who were there to get treatment for glaucoma. Think of this as a "snapshot" in time—they didn't follow these people for years, they just checked in on them during a few months in late 2024 to see how they were feeling.

2. The Tools: Checking the "Mood Battery"

To see if these patients were feeling down, the team used two main tools:

• The PHQ-9: Imagine a mood thermometer with 9 questions. It asks things like, "Have you felt down or hopeless lately?" or "Have you had little interest in doing things?" If the score is high, it suggests the person is struggling with depression.
• The Social Support Scale: This was like a "safety net check." It asked: Do you have someone to talk to? Do you feel people care about you? Can you count on your neighbors?

3. The Big Discovery: The "One in Ten" Rule

The study found that about 1 in 10 people (11.1%) with glaucoma were experiencing significant depressive symptoms.

• Most people (77%) were doing okay emotionally.
• Some had mild or moderate struggles.
• Crucially, no one reported "severe" depression in this specific group, which is good news, but the 1 in 10 statistic is still a wake-up call.

4. The Magic Shield: Social Support

This is the most important part of the story. The researchers found a "magic shield" that protected people from feeling depressed.

• The Metaphor: Imagine you are walking through a storm (glaucoma). If you are walking alone, the rain feels much heavier. But if you have a group of friends holding umbrellas over you (social support), the storm feels much more manageable.
• The Finding: People who felt they had strong social support (family, friends, community) were 92% less likely to be depressed. Those with "moderate" support were also much safer than those with "poor" support.
• The Surprise: Surprisingly, it didn't matter if you lived alone or with a spouse, or if you had a college degree or not. What mattered most was the quality of your connections. You could live with 10 people but feel lonely, or live alone but feel deeply connected. The feeling of being supported was the key.

5. What Didn't Matter (As Much)

The researchers expected that older age, being female, or having worse vision (more severe glaucoma) would make people sadder.

• The Twist: In this specific group, worse eyesight didn't automatically mean worse depression.
• Why? The researchers suggest that maybe the fear of losing sight hurts more than the actual loss. Or, perhaps the strong community support in Tanzania helped buffer the blow of bad vision. It's like having a broken leg; if you have a great team helping you walk, you might not feel as defeated as someone with a minor scratch who has no one to help.

6. The Takeaway: We Need a "Two-Doctor" Approach

The authors conclude that eye doctors (ophthalmologists) shouldn't just look at the eyes; they need to look at the whole person.

• The Analogy: Currently, eye clinics are like car repair shops that only fix the engine (the eyes) but ignore the driver's stress (the mind).
• The Recommendation: We need to integrate mental health check-ins into eye visits. If an eye doctor sees a patient struggling, they should be able to say, "Hey, let's get you some help for your mood, too."
• Community Action: Families and communities need to step up. Being there for someone with glaucoma isn't just about driving them to the hospital; it's about listening, caring, and making them feel they aren't fighting the storm alone.

In a nutshell: Glaucoma is a tough battle, but you don't have to fight it in the dark. Having a strong support network acts like a lighthouse, keeping depression at bay and helping people manage their condition with hope.

Technical Summary

1. Problem Statement

Glaucoma is a leading cause of irreversible blindness globally, with prevalence rates rising significantly. The chronic, progressive nature of the disease often leads to visual disability, which is strongly linked to the development of comorbid psychiatric conditions, particularly depression. Depression in glaucoma patients can severely impact treatment adherence, quality of life (QoL), and overall health outcomes.

While global studies indicate a depression prevalence among glaucoma patients ranging from 10% to 57%, there is a critical lack of data regarding this comorbidity within the Tanzanian context. Existing literature suggests that psychosocial factors (e.g., social support, living arrangements) and clinical factors (e.g., disease severity) influence depression risk, but these dynamics remain unexplored in Tanzania. This study aims to fill that gap by determining the prevalence of depressive symptoms and identifying associated factors among adults with glaucoma at a tertiary hospital in Dar es Salaam.

2. Methodology

• Study Design: A facility-based, analytical cross-sectional study.
• Setting: The ophthalmology clinic at Muhimbili National Hospital (MNH), a tertiary referral hospital in Dar es Salaam, Tanzania.
• Participants:
  • Inclusion: Adults (≥18 years) with a confirmed glaucoma diagnosis within the past six months, attending the clinic between July and November 2024.
  • Exclusion: Individuals with critical illness preventing communication.
  • Sample Size: Initially estimated at 312 (based on a 24.4% prevalence assumption from Nigerian data). The final analyzed sample was 297 participants (response rate 95.2%).
• Sampling: Consecutive non-probability sampling was used to recruit eligible patients.
• Data Collection:
  • Tools: Interviewer-administered structured questionnaires (translated to Swahili) and medical record reviews.
  • Depression Assessment: Patient Health Questionnaire-9 (PHQ-9). A score ≥9 indicated "probable depression." Validity in Tanzania was noted (Sensitivity 78%, Specificity 87%).
  • Social Support Assessment: Oslo Social Support Scale (OSSS-3), categorizing support as poor (3–8), moderate (9–11), or strong (12–14).
  • Clinical Variables: Glaucoma severity (graded by cup-to-disc ratio), duration of disease, comorbidities, medication usage, and history of surgery.
• Statistical Analysis: Data were analyzed using STATA version 16. Bivariable analysis (Chi-square/Fisher's exact) identified potential associations (p<0.2), which were then entered into multivariable logistic regression to calculate Adjusted Odds Ratios (AOR) with 95% Confidence Intervals (CI). Significance was set at p<0.05.

3. Key Contributions

• First Local Data: This is the first study to quantify the prevalence of depressive symptoms specifically among glaucoma patients in Tanzania.
• Protective Factor Identification: It empirically identifies social support as a statistically significant protective factor against depression in this specific population, a finding with direct implications for clinical management.
• Contextual Nuance: The study challenges some global assumptions (e.g., the link between disease severity and depression) within a low-resource, high-stigma setting, suggesting that subjective perception and social networks may outweigh objective clinical metrics in predicting mental health outcomes.

4. Key Results

• Demographics: The mean age was 63.6 years (SD ±12.8); 53.5% were female; 72.4% were aged ≥60; 63.6% reported strong social support.
• Prevalence of Depression:
  • Probable Depression (PHQ-9 ≥9): 11.1% of participants.
  • Severity Breakdown: 8.7% moderate, 2.4% moderately severe, 0% severe.
  • No/Minimal Symptoms: 77.1%.
• Factors Associated with Depression:
  • Social Support (Significant): This was the only factor significantly associated with depression in multivariable analysis.
    • Moderate Social Support: AOR 0.14 (95% CI: 0.04–0.47; p=0.001).
    • Strong Social Support: AOR 0.08 (95% CI: 0.03–0.25; p<0.000).
    • Interpretation: Patients with moderate or strong social support had an 86% and 92% lower odds of probable depression, respectively, compared to those with poor support.
  • Non-Significant Factors: Unlike some global studies, no significant association was found between depression and:
    • Glaucoma severity (objective clinical measures).
    • Age or Sex.
    • Education level or Employment status.
    • Living arrangement (living alone vs. with family).
    • Duration of glaucoma or history of surgery.

5. Significance and Recommendations

• Clinical Implications: The findings underscore the necessity of integrating mental health screening into routine ophthalmology care. The low prevalence of severe depression but high rate of moderate symptoms suggests an opportunity for early intervention before conditions worsen.
• Multidisciplinary Approach: The study advocates for a collaborative model where ophthalmologists and mental health professionals work together. Screening tools like the PHQ-9 should be standard in glaucoma clinics.
• Public Health Strategy: Given the protective nature of social support, public health initiatives should focus on strengthening community and family support networks for ocular disease patients.
• Limitations & Future Directions: The study was limited by its single-site, urban design and potential recall bias. Future research should include rural populations, larger sample sizes, and potentially use tools specifically validated for the elderly (e.g., Geriatric Depression Scale) given the high mean age of the cohort.

Conclusion: Approximately 1 in 10 adults with glaucoma in this Tanzanian tertiary setting experiences depressive symptoms. While clinical severity of the eye disease did not predict depression, the presence of robust social support was a critical protective factor. Integrating psychosocial support into glaucoma management is essential for improving patient adherence and quality of life.