Triamcinolone Acetonide Subconjunctival Injection as Stand-alone Inflammation Prophylaxis after Phacoemulsification Cataract Surgery

Purpose To compare the effectiveness and safety of a single injection of subconjunctival triamcinolone acetonide (TA) to postoperative topical prednisolone acetate (PA) with and without nonsteroidal anti-inflammatory drug (NSAID) for cataract surgery prophylaxis Design Retrospective comparative effectiveness cohort study Participants Patients undergoing phacoemulsification cataract surgery at Kaiser Permanente Northern California from 2018 through 2021 Intervention Anti-inflammatory prophylaxis exposure groups included topical PA with or without NSAID, and subconjunctival injection of TA (Kenalog®) 10 mg/mL or 40 mg/mL in low (1.0 - 3.0 mg) or high dose (3.1 - 5.0 mg). Main Outcome Measures The adjusted odds ratio (OR) and 95% confidence interval (CI) for the association of postoperative macular edema (ME) and iritis diagnoses 15 to 120 days following surgery (effectiveness measures) and a glaucoma-related event (safety measure) between 15 days to 1 year after surgery Results Of 69,832 eligible patient-eyes, postop ME, iritis, and a glaucoma-related event occurred, on average in 1.3%, 0.8% and 3.4% in the topical groups and 0.9%, 0.5% and 2.8% in the injection groups, respectively. In multivariate analysis, all injection groups had a trend of a lower OR of ME compared with the topical PA reference group, with the high dose TA 10 mg/mL group reaching statistical significance (OR 0.64, CI 0.43,0.97, P=0.033). The PA + NSAID group had higher odds (OR 0.88, CI 0.74,1.04, P =0.135). There was a trend of lower odds of a postop iritis diagnosis in the high strength (40 mg/mL) groups. For postop glaucoma-related events, compared with PA, the TA 10 mg/mL low dose group had lower odds (OR 0.69, CI 0.55,0.86, P=0.001), the TA 10 mg/mL high dose group had similar odds (OR 0.90, CI 0.70,1.15, P=0.40) and the TA 40 mg/mL low and high dose groups had higher odds (OR 1.46, CI 0.98,2.18, P=0.062), (OR 2.14, CI 1.36,3.37, P=0.001), respectively. Conclusions The TA 10 mg/mL high dose group, with an average dose of 4 mg, was associated with lower risk of postop macular edema and a similar risk of a glaucoma-related event compared with the topical groups.