Injection of New PMMA* Loaded Microspheres into Anterior Chamber to Establish a Rabbit Glaucoma Model

Abstract

Objective: To develop a novel PMMA material microsphere and characterize it. Named it PMMA*.The microsphere was loaded with drugs, and the intraocular pressure of rabbits was increased by anterior chamber injection, so as to establish a new animal model of ocular hypertension. Methods: PMMA* microspheres with a diameter of 50-80μm were prepared, and the drug loading, release and biosafety of PMMA* microspheres were analyzed. PMMA* microsphere suspension was prepared at 1% dosage of atropine sulfate. Eighteen healthy male New Zealand white rabbits were selected, with the right eye as the experimental eye and the left eye as the control eye. They were randomly divided into blank microsphere group, atropine sulfate group and atropine sulfate loaded microsphere group with 6 rabbits in each group. The chronic ocular hypertension model of the right eye was established. Intraocular pressure was monitored postoperatively and Micro-CT was used to determine the position of the microsphere at the anterior chamber Angle. The pathological changes of chronic glaucoma were studied. Results: PMMA* microspheres have the characteristics of micropore structure, adjustable size, slow release, in situ residence and good biosafety. There was no significant difference in preoperative intraocular pressure in rabbits (P>0.05), which was comparable. At 15 days after surgery, the intraocular pressure in experimental eyes was significantly higher than that in control eyes, with statistical significance (P<0.05), and the increase of intraocular pressure caused by drug-loaded PMMA* microspheres was more significant. Micro-CT determined the position of the microsphere in the anterior chamber Angle of rabbit. The atropine sulfate loaded microspheres showed more obvious ganglion cell - retinal nerve fiber layer damage. Conclusions:The PMMA* microspheres synthesized in this study have good drug loading performance and slow release performance. Intraventral injection of drug-loaded PMMA* microspheres can block the outflow of aqueous solution to establish a better chronic glaucoma model.