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

Abstract Purpose To assess whether routine fundus photography (RFP) to screen for posterior segment disease at community eye clinics in South India increases referral to the urban hospital for ophthalmology care. Design Stepped-wedge, cluster-randomized trial. Participants Patients aged 40-75 and those aged 20-40 with a known history of hypertension or diabetes mellitus presenting to four technician-run, community eye care centers (vision centers) associated with the Aravind Eye Hospital, Pondicherry, India. Methods Vision centers (clusters) were randomized to standard care or RFP across five 2-week study periods (steps). Patients in each cluster received standard care in the first step. At the start of each subsequent step, a randomly chosen cluster crossed over to providing RFP to eligible patients. Patients in 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 technician eye exams, mandatory 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 due to fundus photography findings as well as urgency of referral (urgently in ≤2 weeks vs. non-urgently 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 to standard care. Results 1447 patients were enrolled across the vision centers, including 737 in the standard care group and 710 in the RFP group. Compared to standard care, the RFP group had a higher proportion of referrals due to fundus photography findings (11.3% vs. 4.4%), non-urgent 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 two-fold increased odds of being referred due to photography findings compared to standard care (odds ratio=2.07, 95% confidence interval=0.98-4.40, p=0.058). Conclusion Adding RFP to community eye clinics was associated with an increased odds of referral compared to standard care. This increase in referral was mostly attributed to non-urgent posterior segment disease.