Evaluating the outcome of screening for glaucoma using colour fundus photography-based referral criteria in a teleophthalmology screening programme for diabetic retinopathy

• Published in: British journal of ophthalmology Vol. 108; no. 7; p. 933
• Main Authors: Tan, Rose, Teo, Kelvin Yi Chong, Husain, Rahat, Tan, Ngiap Chuan, Lee, Qian Xin, Hamzah, Haslina, Wong, Tina, Aung, Tin, Cheng, Ching Yu, Lamoureux, Ecosse Luc, Tan, Colin S, Wong, Hon-Tym, Wong, Tien Y, Tan, Gavin Siew Wei
• Format: Journal Article
• Language: English
• Published: BMA House, Tavistock Square, London, WC1H 9JR BMJ Publishing Group Ltd 01.07.2024; BMJ Publishing Group LTD
• Subjects: Aged; Case-Control Studies; Clinical science; Diabetes; Diabetic retinopathy; Diabetic Retinopathy - diagnosis; Diagnostic tests/Investigation; Female; Fundus Oculi; Glaucoma; Glaucoma - diagnosis; Humans; Intraocular Pressure - physiology; Macular degeneration; Male; Mass Screening - methods; Medical diagnosis; Medical referrals; Middle Aged; Optic nerve; Patients; Photography - methods; Population; Predictive Value of Tests; Primary care; Public health; Referral and Consultation; Retrospective Studies; Sensitivity and Specificity; Singapore; Telemedicine; Singapore; Glaucoma; Telemedicine; Public health; Diagnostic tests/Investigation
• ISSN: 0007-1161; 1468-2079
• DOI: 10.1136/bjo-2023-323339

AimsTo evaluate the effectiveness of glaucoma screening using glaucoma suspect (GS) referral criteria assessed on colour fundus photographs in Singapore’s Integrated Diabetic Retinopathy Programme (SiDRP).MethodsA case–control study. This study included diabetic subjects who were referred from SiDRP with and without GS between January 2017 and December 2018 and reviewed at Singapore National Eye Centre. The GS referral criteria were based on the presence of a vertical cup-to-disc ratio (VCDR) of ≥0.65 and other GS features. The final glaucoma diagnosis confirmed from electronic medical records was retrospectively matched with GS status. The sensitivity, specificity and positive predictive value (PPV) of the test were evaluated.ResultsOf 5023 patients (2625 with GS and 2398 without GS) reviewed for glaucoma, 451 (9.0%, 95% CI 8.2% to 9.8%) were confirmed as glaucoma. The average follow-up time was 21.5±10.2 months. Using our current GS referral criteria, the sensitivity, specificity and PPV were 81.6% (95% CI 77.7% to 85.1%), 50.6% (95% CI 49.2% to 52.1%) and 14.0% (95% CI 13.4% to 14.7%), respectively, resulting in 2257 false positive cases. Increasing the VCDR cut-off for referral to ≥0.80, the specificity increased to 93.9% (95% CI 93.1% to 94.5%) but the sensitivity decreased to 11.3% (95% CI 8.5% to 14.6%), with a PPV of 15.4% (95% CI 12.0% to 19.4%).ConclusionsOpportunistic screening for glaucoma in a lower VCDR group could result in a high number of unnecessary referrals. If healthcare infrastructures are limited, targeting case findings on a larger VCDR group with high specificity will still be beneficial.