Screening of DR with Single-Field vs Six-Field





Study Overview
- Title: Screening and Monitoring of Diabetic Retinopathy in Community Care
- Journal: *Retina*, February 2025
- DOI: 10.1097/IAE.0000000000004311
- Objective: Evaluate the effectiveness of single-field fundus photography for diabetic retinopathy (DR) screening and monitoring compared to multifield imaging in a community setting.

---

Key Findings
1. Diabetic Retinopathy (DR):
   - DR is a leading cause of vision impairment in diabetic patients.
   - Prevalence in China: 22.4% among diabetics; 1.7% in the general population.
   - Early detection and intervention are critical to prevent irreversible vision loss.

2. Fundus Photography:
   - Single-field fundus photography (45° centered on the macula) is practical for community screening.
   - Multifield imaging (e.g., ETDRS seven-field protocol) is the gold standard but is time-consuming and less feasible in primary care.

3. Artificial Intelligence (AI):
   - AI integration has improved the efficiency and cost-effectiveness of DR screening.

---

Methods
1. Study Design:
   - Prospective cohort study (Fushun DR Cohort Study) in Jiangjun Subdistrict, Fushun, China.
   - Baseline (2012–2013) and follow-up (2014) visits with 1,456 participants (2,416 eyes).
   - Fundus photography: Single-field vs. six-field (modified ETDRS protocol).

2. DR Grading:
   - Graded by experienced technicians using the Modified ETDRS criteria.
   - Severity levels: No DR, mild NPDR, moderate NPDR, severe NPDR, proliferative DR (PDR).

3. Statistical Analysis:
   - Gwet first-order agreement coefficient (AC1) to assess agreement between single- and six-field grading.
   - Sensitivity and specificity of single-field referral recommendations using six-field as reference.

---

Results
1. DR Screening:
   - Single-field vs. six-field agreement:
     - Baseline: 81.9% agreement (AC1 = 0.79).
     - Follow-up: 80.6% agreement (AC1 = 0.77).
   - Referral sensitivity:
     - Baseline: 72% sensitivity, 100% specificity.
     - Follow-up: 70% sensitivity, 100% specificity.

2. DR Progression:
   - Single-field detected:
     - 10.6% regression, 11.0% progression.
   - Six-field detected:
     - 13.2% regression, 14.7% progression.
   - Agreement for progression detection: AC1 = 0.71.

3. Referral Changes:
   - Six-field identified:
     - 10.8% progression from nonreferral to referral.
     - 17.1% regression from referral to nonreferral.
   - Single-field identified fewer progressed cases, indicating delayed detection.

---

Discussion
1. Single-Field Photography:
   - Effective for community-based DR screening and monitoring.
   - Substantial agreement with multifield imaging for disease severity and progression.
   - Limitations: Lower sensitivity for detecting progression and peripheral DR lesions.

2. Trade-Offs:
   - Single-field photography offers accessibility and cost-effectiveness but compromises sensitivity.
   - Multifield imaging provides comprehensive retinal evaluation but is less feasible in primary care.

3. Future Directions:
   - Ultrawide field fundus photography (up to 200°) may improve DR screening by capturing peripheral lesions.
   - AI and telemedicine can enhance the efficiency of DR screening in resource-limited settings.

---

Conclusion
- Single-field fundus photography is a practical and effective tool for DR screening and monitoring in community settings.
- While it shows substantial agreement with multifield imaging, its lower sensitivity for detecting progression and peripheral lesions should be considered.
- Integrating advanced imaging technologies (e.g., ultrawide field photography) and AI can further improve DR screening and monitoring in primary care.