Clinical Report: Diabetic Retinopathy Screening in Rural Northern Norway

Overview

This study evaluated the prevalence of diabetic retinopathy (DR) and the safety of a two-step screening model in a rural high-latitude community in Finnmark, Northern Norway. Among 300 screened patients, DR prevalence and screening accuracy were assessed, demonstrating the feasibility and safety of nurse/optometrist-led primary grading with ophthalmologist secondary review.

Background

Diabetic retinopathy is a leading cause of blindness globally and often progresses without symptoms, necessitating regular screening for early detection. Norway updated its national DR screening guidelines in 2018 to a two-step model involving primary grading by certified nurses or optometrists and secondary grading by ophthalmologists. Finnmark, a rural northern county with higher diabetes prevalence and an older population, implemented this model in 2020, but data on DR prevalence and screening safety in this region were lacking.

Data Highlights

Key Findings

• The prevalence of diabetic retinopathy in the screened population was consistent with previous Norwegian estimates (~30%).
• The two-step screening model using primary grading by nurses/optometrists and secondary grading by ophthalmologists was successfully implemented in a rural setting.
• Retinal photography without OCT was used for primary screening, with OCT scans reviewed by ophthalmologists for diabetic macular edema assessment.
• Image quality criteria ensured reliable grading, with gradings masked between primary and secondary graders to reduce bias.
• Consensus grading with a retina specialist was used to resolve discrepancies, enhancing diagnostic accuracy.

Clinical Implications

The two-step DR screening model is a practical and safe approach for rural high-latitude communities with limited ophthalmologist availability. Utilizing trained nurses and optometrists for initial image grading can reduce specialist workload without compromising detection of sight-threatening disease. Regular quality control and consensus review remain essential to maintain screening accuracy.

Conclusion

This study supports the feasibility and safety of a two-step diabetic retinopathy screening program in a rural northern Norwegian population, providing important regional prevalence data and validating task-shifting strategies to optimize resource use.

References

1. Norwegian Directorate of Health 2018 -- National recommendations for diabetic retinopathy screening
2. International Clinical Disease Severity Scale for DR 2017
3. Finnmark Hospital Trust 2020 -- Implementation of two-step DR screening
4. Systematic Review 2015 -- Global prevalence of diabetic retinopathy