Early intraocular pressure kinetics after intravitreal aflibercept 8 mg (0.07 mL) versus aflibercept 2 mg (0.05 mL) in nonglaucomatous eyes: a prospective comparative study.

BACKGROUND: Transient intraocular pressure (IOP) spikes after intravitreal injection (IVI) are expected. The higher-volume aflibercept 8 mg (0.07 mL) formulation has recently entered clinical use, yet its early IOP kinetics-particularly the immediate post-injection trajectory in eyes without known glaucoma or ocular hypertension-remain incompletely characterised. METHODS: In this prospective, non-randomised, single-centre comparative study, 48 eyes of 48 patients received intravitreal aflibercept 8 mg/0.07 mL (n = 25) or aflibercept 2 mg/0.05 mL (n = 23). Eyes with any history of glaucoma or ocular hypertension were excluded. IOP was measured at baseline and at 3, 10, and 30 min after injection using iCare IC200 tonometry. The primary objective was to assess within-group IOP changes from baseline in the 0.07-mL group. A hierarchical fixed-sequence procedure was applied using paired Wilcoxon signed-rank tests with Hodges-Lehmann (HL) estimates and 95% confidence intervals (CIs). Between-group differences were explored using a linear mixed-effects model adjusted for baseline IOP, age, sex, and lens status. RESULTS: Baseline characteristics were comparable between groups. In the 0.07-mL group, HL pseudo-median IOP changes from baseline were + 25.5 mmHg (95% CI 18.5 to 32.0; p < 0.001) at 3 min, + 11.0 mmHg (95% CI 8.0 to 15.0; p < 0.001) at 10 min, and + 3.5 mmHg (95% CI 1.5 to 5.5; p = 0.002) at 30 min. Adjusted between-group differences (0.07 mL minus 0.05 mL) were + 5.8 mmHg (95% CI 0.3 to 11.3; p = 0.038) at 3 min, + 2.8 mmHg (95% CI - 2.7 to 8.3; p = 0.31) at 10 min, and + 0.2 mmHg (95% CI - 5.3 to 5.7; p = 0.94) at 30 min. Two eyes in the 0.07-mL group received topical IOP-lowering medication after the 30-minute assessment; no paracentesis was performed. CONCLUSIONS: In eyes without known outflow disease, intravitreal aflibercept 8 mg (0.07 mL) was associated with a higher early IOP spike than aflibercept 2 mg (0.05 mL). However, the pressure increase was transient, and exploratory between-group analyses suggested convergence of IOP levels by 30 min. By defining the early IOP trajectory in eyes with intact outflow, these data provide a physiological reference for the short-term ocular safety of higher-volume anti-VEGF therapy and a benchmark against which exaggerated or delayed responses in at-risk eyes can be interpreted. TRIAL REGISTRATION: Not applicable (observational study).