Abstract： Objective:To study the long-term effects and outcomes of adjuvant intravitreal injection of conbercept (IVC) therapy in juvenile Coats disease.Methods:A retrospective case series study. From January 1, 2015 to December 31, 2018, 40 patients (40 eyes) who were diagnosed as juvenile Coats disease at Beijing Tongren Hospital Affiliated to Capital Medical University were included in the study. Among them, there were 37 males (37 eyes) and 3 females (3 eyes). All patients had unilateral Coats disease. The average age was 55.00 (44.75, 81.25) months. Five eyes were in stage 2B, 15 eyes were in stage 3A, 19 eyes were in stage 3B and 1 eye was in stage 4. Idiopathic retinal vascular telangiectasia associated with extensive subretinal fluid (SRF) (stage 3 or above) or massive foveal exudation and edema (stage 2B) were found in fundus examination. All affected eyes underwent wide-field color fundus images and fluorescein fundus angiography. Thirty-one eyes underwent best corrected visual acuity (BCVA) examination. The BCVA was carried out using a standard logarithmic visual acuity chart, which was converted into the logarithmic minimum angle of resolution (logMAR) visual acuity. All cases received adjuvant IVC combined with treatments such as retinal photocoagulation. The average number of injections was 4 (1, 5). The average follow-up after initial treatment was 59.00 (52.50, 63.00) months. The changes in BCVA, occlusion of abnormal blood vessels in fundus, absorption of SRF and ocular and systemic complications were observed.Results:At last follow-up, among 31 affected eyes with the examination of BCVA, 13 (32.5%, 13/40) eyes had an improved vision, 12 eyes(30.0%, 12/40) had a stable vision and 6 eyes (15.0%, 6/40) had a decreased vision. The difference between average logMAR BCVA of the affected eyes in each stage after treatment and that before treatment was not statistically significant ( Z=-0.56, -1.80, -0.84; P>0.05). Abnormal blood vessels in fundus were all partially or completely occluded, and SRF was obviously or completely absorbed in all cases; of which, 28 eyes (70.0%, 28/40) were completely occluded, and 12 eyes (30.0%, 12/40) were partially occluded. No patient underwent eye enucleation. Nineteen eyes (47.5%, 19/40) developed vitreoretinal fibrosis; 8 eyes (20.0%, 8/40) developed tractional retinal detachment; 15 eyes (37.5%, 15/40) developed complicated cataract. None had ocular or systemic complications related to IVC therapy during follow-up. Conclusions:IVC combined with classic treatments such as photocoagulation in juvenile Coats disease can keep or improve the visual acuity in most juvenile patients by reducing SRF. IVC is a long-term safe and effective adjuvant therapy in juvenile Coats disease.