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Updated: Feb 22, 2026
A Magnetic Microbead Occlusion Model to Induce Ocular Hypertension-Dependent Glaucoma in Mice
Published on: March 23, 2016
Establishment of an experimental glaucoma animal model: A comparison of microbead injection with or without
1Department of Ophthalmology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, P.R. China.
Abstract:
The present study aimed to compare microbead injection with and without hydroxypropyl methylcellulose (HPM) in order to establish an experimental animal model of glaucoma. This model was established in C57BL/6 mice and transgenic mice expressing cyan fluorescent protein (CFP) under the control of the Thy1 promoter in retinal ganglion cells (RGCs). C57BL/6 mice aged between 12 and 20 weeks old were randomly separated into three groups, which received different injections into the anterior chamber of the eye. Group A (microbead) received 2 µl microbeads (10×106 beads/ml) and 1 µl air. Group B (microbeads + HPM) received 2 µl microbeads and 1 µl HPM. Group C (control group) received 2 µl PBS and 1 µl air. The intraocular pressure (IOP) was measured with a tonometer under topical anesthesia daily for 1 month. A single injection of microbeads, with or without HPM, induced consistent IOP elevation when compared with the control group. Thy1-CFP mice received an injection of 2 µl microbeads and 1 µl HPM into the anterior chamber of the eyes, and the number of CFP+ RGCs was subsequently assessed in vivo by confocal scanning laser microscopy in the same area of the retina weekly for 6 weeks. The results from in vivo imaging of Thy1-CFP mice were comparable with the immunohistochemical staining results from the C57BL/6 mice. The combined injection of microbeads and HPM induced longer and higher peaks of IOP elevation when compared with the microbeads alone. The rate of RGC loss following the administration of microbeads alone was 25.0±1.3% 6 weeks after the initial IOP elevation, while it was 33.2±1.9% following the administration of microbeads + HPM. These results indicate that the injection of microbeads + HPM is a more effective method of establishing a mouse model with chronic elevation of IOP. In addition, the in vivo imaging that can be used with this technique provides an effective and noninvasive approach for monitoring the progress of RGC loss.
Insights
Hydroxypropyl methylcellulose (HPM) combined with microbead injections effectively models glaucoma in mice by causing sustained intraocular pressure (IOP) elevation and retinal ganglion cell (RGC) loss.
Area of Science:
- Ophthalmology
- Animal Models
- Glaucoma Research
Background:
- Glaucoma is a leading cause of irreversible blindness.
- Accurate animal models are crucial for understanding glaucoma pathogenesis and testing therapies.
- Current models may not fully replicate chronic intraocular pressure (IOP) elevation seen in human glaucoma.
Purpose of the Study:
- To compare microbead injection with and without hydroxypropyl methylcellulose (HPM) for establishing a glaucoma animal model.
- To evaluate the efficacy of HPM in enhancing microbead-induced intraocular pressure (IOP) elevation and retinal ganglion cell (RGC) loss.
- To assess the utility of in vivo imaging for monitoring RGC changes in this model.
Main Methods:
- Established a glaucoma model in C57BL/6 and Thy1-CFP mice via anterior chamber injection of microbeads with or without HPM.
- Measured intraocular pressure (IOP) daily for one month using tonometry.
- Assessed retinal ganglion cell (RGC) loss in vivo using confocal scanning laser microscopy in Thy1-CFP mice over six weeks.
Main Results:
- Microbead injection, with or without HPM, consistently elevated IOP compared to controls.
- The combination of microbeads and HPM induced higher and more prolonged IOP elevation than microbeads alone.
- RGC loss was greater with the microbead + HPM method (33.2%) compared to microbeads alone (25.0%) at six weeks.
Conclusions:
- Microbead injection combined with HPM is a more effective method for creating a mouse model of chronic IOP elevation.
- This model allows for noninvasive, in vivo monitoring of RGC loss, aiding glaucoma research.
- The HPM-enhanced model provides a valuable tool for studying glaucoma progression and therapeutic interventions.
