Abstract:  Objective To compare the incidence of positive anterior chamber reaction after intravitreal injection of ranibizumab and conbercept, and analyzing the influencing factors. Design Prospective cohort study. Participants 877 patients received intravitreal injection of ranibizumab or conbercept in the day care unit of Fundus Department of Beijing Tongren Hospital between January 2020 and October 2020. Methods Intravitreal injection was performed according to the unified operation standard. At the first day after operation, the patients were examined and recorded for pain, blurred vision. Slit lamp examination was conducted to observe the ciliary congestion, anterior chamber cells, aqueous flare and hypopyon. Anterior chamber cells and aqueous flare were recorded according to the scheme determined by the standardized uveitis nomenclature (SUN) working group. Anterior chamber reaction was recognized as positive if anterior chamber cell or aqueous flare> 0 and following treatment were recorded. The incidence of positive reaction in ranibizumab and conbercept injection groups was compared, and its influencing factors were analyzed by generalized additive mixed model (GAMM). Main Outcome Measures Incidence of anterior chamber reaction and its risk factors. Results There were 418 males and 459 females with an average age of 60.8 ± 14.4 years (range, 11~92 years). The average injection times per person were 2（1~3）, and the total number of injections was 1148.  Among the 1148 intravitreal injections, 27 eyes (27 patients) had positive anterior chamber reaction. The anterior chamber cell grade was 0.5+~2+, and the aqueous humor flash grade was 1+~2+. The incidence of positive anterior chamber reaction after ranibizumab or conbercept intravitreal injection was 2.5% (18/721 injection) and 2.1% (9/427 injection), respectively. There was no significant difference between the two groups (χ2=0.176, P=0.674). No patients had complaints of eye pain or vision loss, and no ciliary hyperemia or hyphema was detected. All patients were followed up without additional treatment except one case, for whom prednisolone acetate eye drops were prescribed. Multivariate regression analysis showed that the incidence of positive anterior chamber reaction decreased with the increase of injection times (OR=0.48, 95%CI: 0.26~0.88, P=0.0179), and the risk of anterior chamber reaction increased by 8.27 times (P＜0.001) and 9.6 times (P＜0.001) in patients with vitreous hemorrhage or neovascular glaucoma, respectively. There was no correlation with age, gender, eye laterality and diagnosis (P>0.05). Conclusion The incidence of positive anterior chamber reaction after intravitreal injection of ranibizumab and conbercept was 2.5% and 2.1%, respectively. The patients with vitreous hemorrhage, neovascular glaucoma and the first-time injection were prone to positive anterior chamber reaction. (Ophthalmol CHN, 2021, 30: 283-289)

Key words: ranibizumab, conbercept, anterior chamber cell, aqueous flare, intravitreal injection