RETINAL BLOOD VELOCITY AFTER INTRAVITREAL INJECTION FOR NEOVASCULAR AGE-RELATED MACULAR DEGENERATION WITH OPTICAL...

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Vascular Biology

Background:

• Intravitreal injections can cause transient intraocular pressure (IOP) spikes.
• Assessing the impact of IOP on retinal blood flow is crucial for patient outcomes.
• Optical coherence tomography (OCT) offers potential for in vivo hemodynamic assessment.

Purpose of the Study:

• To quantify the effect of transient IOP elevation post-intravitreal injection on retinal blood flow.
• To utilize a validated speckle-based OCT method for in vivo hemodynamic assessment.
• To investigate the relationship between IOP, age, and retinal blood flow changes.

Main Methods:

• Nineteen eyes with neovascular age-related macular degeneration underwent OCT and IOP measurements.
• Measurements were taken before, immediately after, and 15 minutes post-anti-VEGF injection.
• Speckle-derived flow index, proportional to erythrocyte velocity, quantified retinal blood flow.

Main Results:

• Mean IOP increased from 14.1 mm Hg to 54.4 mm Hg immediately post-injection, then decreased to 24.1 mm Hg.
• Retinal blood flow remained stable up to IOPs of 40 mm Hg.
• Flow declined by 3.6% per mm Hg above 40 mm Hg (P < 0.001); older patients showed less arterial flow reduction.

Conclusions:

• Speckle-based OCT provides quantitative in vivo assessment of retinal blood flow.
• Retinal perfusion is autoregulated up to approximately 40 mm Hg IOP.
• Higher IOPs reduce retinal blood flow, with potential age-related differences possibly due to vascular rigidity.