Abstract: Objective To compare the safety and early biological responses between xenogeneic sclera and a titanium-silicone composite plastic scleral reinforcement graft in posterior scleral reinforcement (PSR) surgery in New Zealand white rabbits. Design Experimental study. Participants Twenty-four clean-grade healthy adult rabbits (weight: 2.0~3.5 kg). Methods The rabbits were randomly assigned to two groups with sex matching Group A received xenogeneic sclera, and Group B received a moldable plastic graft; all underwent PSR in the right eye. External ocular inflammation was assessed using a modified Efron grading scale, intraocular pressure (IOP) and tear secretion (Schirmer’s test) were measured at postoperative day 3, week 4 and 12. Flash electroretinography (ERG) and graft-sclera integration were evaluated at week 12. Main Outcome Measures Total ocular inflammation score, IOP, Schirmer test results, ERG a- and b-wave amplitudes, and graft integration status. Results On day 3, Group A showed significantly higher inflammation scores than Group B [median (IQR): 9.0 (9.0-10.0) vs. 4.0 (4.0-5.0), P=0.002], with greater reduction in schirmer test [（-7.83±1.11）mm vs. （-5.25±0.89）mm at day 3; （-5.25±0.87）mm vs. （-3.13±0.83）mm at week 4 ] (all P<0.05). At week 4 and 12, inflammation resolved in both groups, and tear production returned to baseline (all P>0.05). No significant differences were observed in IOP at any time point or ERG a-/b-wave at week 12 amplitudes between groups (all P>0.05). At week 12, grafts in Group A exhibited blurred margins and tight fusion with the host sclera, whereas those in Group B remained clearly demarcated and slightly mobile; both were encapsulated by dense fibrous tissue. Conclusion The plastic reinforcement graft demonstrated comparable safety to xenogeneic sclera. It induced milder early inflammation due to minimally invasive surgery, while xenogeneic sclera promoted better biological integration, potentially offering superior posterior pole perfusion benefits. The two materials are complementary, and selection should be individualized based on therapeutic goals.

Key words: Posterior scleral reinforcement, Plastic scleral reinforcement graft, Xenogeneic sclera