Changes in Intraocular Pressure After Intravitreal Injection

Intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections introduce additional fluid volume into the eye, which can cause an acute, transient elevation in intraocular pressure (IOP). The purpose of this prospective observational study is to evaluate the immediate and early changes in intraocular pressure following intravitreal anti-VEGF injections and to determine how rapidly pressure recovers toward baseline levels. Adult participants scheduled to receive routine intravitreal anti-VEGF therapy for established clinical indications, such as diabetic macular edema, neovascular age-related macular degeneration, or retinal vein occlusion, will be enrolled. Intraocular pressure will be measured using an Icare rebound tonometer with single-use disposable probes before injection (baseline) and at 1 minute, 5 minutes, and 20 minutes post-injection. The study will also analyze whether factors such as refractive error, the number of prior injections, or the type of anti-VEGF drug administered affect the severity of post-injection pressure spikes and subsequent recovery.

Inclusion Criteria: * Age 18 years or older. * Scheduled to receive an intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection for an established clinical indication (e.g., diabetic macular edema, neovascular age-related macular degeneration, or retinal vein occlusion). * Provision of written informed consent prior to enrollment. Exclusion Criteria: * Known history of glaucoma or ocular hypertension. * History of previous glaucoma surgery. * Corneal diseases or ocular conditions that significantly interfere with accurate intraocular pressure measurement. * Inability to cooperate adequately during intraocular pressure measurement. * Refusal to participate or failure to provide informed consent. * Development of marked intraocular pressure elevation immediately after injection (IOP ≥ 40 mmHg) requiring anterior chamber paracentesis.