The Utility of Routine Fundus Photography Screening for Posterior Segment Disease: A Stepped-wedge, Cluster-randomized Trial in South India.

PURPOSE: To assess whether routine fundus photography (RFP) to screen for posterior segment disease at community eye clinics (vision centers [VCs]) in India increases referral to centralized ophthalmolic care. DESIGN: Stepped-wedge, cluster-randomized trial. PARTICIPANTS: Patients aged 40 to 75 years and those aged 20 to 40 years with a known history of hypertension or diabetes mellitus presenting to 4 technician-run VCs associated with the Aravind Eye Care System in India. METHODS: VCs (clusters) were randomized to standard care or RFP across five 2-week study periods (steps). Patients in each cluster received standard care initially. At the start of each subsequent step, a randomly chosen cluster crossed over to providing RFP to eligible patients. All clusters took part in RFP during the last step. Standard care involved technician eye exams, optional fundus photography, and teleconsultation with an ophthalmologist. RFP involved eye exams, dilation and 40-degree fundus photography, and teleconsultation with an ophthalmologist. MAIN OUTCOME MEASURES: Standard care and RFP clusters were compared by the proportion of patients referred for in-person evaluation by an ophthalmologist because of fundus photography findings and urgency of referral (urgently in ≤ 2 weeks vs. nonurgently in > 2 weeks). Generalized linear mixed models adjusting for cluster and step were used to estimate the odds of referral due to fundus photography findings compared with standard care. RESULTS: A total of 1447 patients were enrolled across the VCs, including 737 in the standard care group and 710 in the RFP group. Compared with standard care, the RFP group had a higher proportion of referrals due to fundus photography findings (11.3% vs. 4.4%), nonurgent referrals due to fundus photography (9.3% vs. 3.3%), and urgent referrals due to fundus photography (1.8% vs. 1.1%). The RFP intervention was associated with a 2-fold increased odds of being referred because of photography findings compared with standard care (odds ratio, 2.07; 95% confidence interval, 0.98-4.40; P = 0.058). CONCLUSIONS: Adding RFP to community eye clinics was associated with an increased odds of referral compared with standard care. This increase in referral was mostly due to nonurgent posterior segment disease.