Short-term intraocular pressure changes following intravitreal injections of aflibercept 8mg versus 2mg: A prospective comparative study

Purpose The increased injection volume of aflibercept 8 mg (0.07 ml versus 0.05 ml) raises theoretical concerns regarding intraocular pressure (IOP) effects. This study evaluated acute IOP dynamics following aflibercept 8 mg compared to aflibercept 2 mg and identified predictive factors for pressure elevation. Methods 140 eyes of 127 patients receiving aflibercept 8 mg (70 eyes) or 2 mg (70 eyes) between January-December 2025 were included. IOP was measured at baseline (T0), immediately post-injection (T1), and 30 min post-injection (T2). Linear mixed-effects models assessed the effects of time, treatment group, and time-by-treatment interactions. Multivariable mixed-effects logistic regression was used to identify predictors of IOP >21mmHg and IOP elevation >5mmHg at T2. Results Both formulations produced significant IOP elevations from baseline at T1 and T2 ( p < 0.001 within each group). Mean IOP increased from 14.0 mmHg to 39.3 mmHg (aflibercept 2 mg) and 14.5 mmHg to 39.3 mmHg (aflibercept 8 mg) immediately post-injection, with near-complete resolution by 30 min (16.9 vs 17.7 mmHg). No significant between-group differences were identified at any timepoint. Pre-existing glaucoma/OHT was the only consistent independent predictor of both IOP >21 mmHg (OR 3.00–3.31, p = 0.024–0.038) and IOP elevation >5 mmHg from baseline (OR 10.45–11.75, p < 0.001) at T2; aflibercept formulation was not associated with either outcome. No injection required paracentesis. Conclusion Aflibercept 8 mg demonstrates comparable IOP dynamics to aflibercept 2 mg. Glaucoma/OHT represents the strongest predictor of early pressure elevation, warranting enhanced monitoring.