Epidemiology of Intravitreal Injections in Iran: Indications and Referral Patterns in a Tertiary Hospital

Mohammad Zarei,1 Ramak Roohipoor,1 Raziyeh Mahmoudzadeh,1 Mehdi Yaseri,2 Hamid Riazi-Esfahani1 1Retina Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran; 2Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, IranCorrespondence: Hamid Riazi-EsfahaniRetina Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Qazvin Square, South Kargar Street, Tehran 1336616351, IranTel +98 9123779108Email Hamidriazi@gmail.comPurpose: To study the relative contribution of major indications and geographic referral patterns for intravitreal bevacizumab injections in a tertiary hospital.Methods: In this retrospective study, hospital electronic registry was used to categorize patients who had received intravitreal injections (IVIs) during the 2014– 2016 period into different groups based on indications. Relative contribution of each indication and odds of being resident of provinces other than Tehran were determined.Results: The most prevalent indications for IVI were pathologies related to diabetes mellitus (DM) followed by choroidal neovascularization (CNV)/age-related macular degeneration (AMD) and retinal venous occlusion (RVO)-related complications. From 38,043 patients, 61.8% were residents of Tehran province. Patients in the CNV/AMD group were the oldest. Patients from Tehran province were significantly older (62.44 ± 11.42 (12– 99)) than patients who were referred from other provinces (59.23 ± 11.39 (11– 102)) (p=< 0.001). The majority of patients in all indication categories were from Tehran province, except for patients with retinopathy of prematurity (ROP). Odds of being referred from outside Tehran province for the ROP group compared to the DM-related, CNV/AMD, RVO-related and miscellaneous groups were 3.32, 4.27, 3.13 and 2.83, respectively (p< 0.001).Conclusion: DM-related ocular complications outnumber all other indications of IVIs combined. Considering the preventable nature of these complications, efficient health policies can significantly reduce the burden of IVIs in Iran. The contribution of each indication category in overall burden of IVIs seems to vary considerably between different countries which merits further studies. The disproportionately high ratio of ROP patients who are referred from other provinces to the capital province for treatment indicates a suboptimal distribution of ROP care services throughout the country.Keywords: epidemiology, indications, intravitreal injection, diabetes, retinopathy of prematurity, referral patterns