Efficacy of Polytetrafluoroethylene/Polylactide-co-glycolide (PTFE/PLGA) Laminate and PTFE/PLGA Laminate Containing Slow-Releasing Thalidomide in Delayed Adjustable Strabismus Surgery in a Rabbit Model

Observation of Cyclosporin A: Sustained Release Intraocular Lens Implantation in Rabbit Eyes

PURPOSE

To observe the performance of cyclosporine A (CsA)-loaded intraocular lens (IOLs) implanted into rabbit eyes.

METHODS

To prepare a PLGA-based CsA-sustained release IOLs and study the in vitro drug release. Forty-two New Zealand white rabbits were randomly and equally divided into three groups, and all right eyes underwent phacoemulsification. In group A, a common polymethylmethacrylate (PMMA) IOLs was implanted, while polylactide-glycoli acid (PLGA-loaded)-PMMA-IOLs was implanted in group B, and CsA-PLGA-PMMA-IOLs was implanted in group C. All experimental eyes were examined by slit-lamp microscopy. In addition, fundoscopy and the number of corneal endothelial cells, anterior chamber flare grading, and the number of aqueous humor cells were assessed at different time points post-surgery. The wet lens capsule was weighed and histological examination was performed 6 months post-operation.

RESULTS

In the early post-operative period, the inflammatory reaction of anterior chamber in groups A and B were more severe than group C. The initial appearance of PCO in group C was much later than the other two groups (F = 68.91; p = 0.000), and PCO grade in group C was much lower than the other two groups (χ² = 36.07; p = 0.000). The mean weights of wet lens capsules in groups A and B were significantly heavier than group C (F = 134.88; p = 0.00). Histological observation showed no obvious toxic reaction in the intraocular tissues of the CsA-PLGA-PMMA-IOLs group, and the proliferation and accumulation of lens epithelial cells in groups A and B were greater than in group C.

CONCLUSION

CsA-sustained release IOLs can effectively prevent PCO in rabbit eyes without defined intraocular toxicity.

Histologic and Immunohistochemical Evaluation of Radiosurgery in Strabismus Surgery in a Rabbit Model

PURPOSE

The aim of this study was to evaluate the use of monopolar radiosurgery (MRS) assisted strabismus surgery and to compare its histologic and immunohistochemical wound healing outcomes with conventional surgery.

MATERIALS AND METHODS

Superior rectus muscle resection was performed on 30 white rabbits with three different surgical muscle cutting techniques: monopolar radiosurgery (MRS group), conventional scissors preceded by bipolar electrocautery (BEC group), and conventional scissors with no cauterization (control group). Degree of tissue injury, bleeding, inflammation, and fibrosis, as well as wound healing rate (CD68+ cell number), were evaluated.

RESULTS

In CS group, hemorrhage scores were significantly higher than those in the other groups (MRS group: Z = 5.182; p < 0.001 and BEC group: Z = 4.463; p < 0.001) and MRS group had lower scores than BEC group; however, the difference was not significant (Z = 1.423; p = 0.211). The tissue injury score in BEC group was higher when compared with MRS, and the difference was statistically significant (p = 0.028). Median inflammation scores at days 1 and 21 were lowest in MRS group, but the difference was not statistically significant among groups (day 1; p = 0.115, day 21; p = 0.095). The median fibrosis score was higher in the control group, when compared with MRS, and the difference was statistically significant (muscle-sclera; p = 0.011 and muscle-conjunctiva: p = 0.003). The macrophage score (number of CD68+ cells) was lowest in CS group; however, the difference was not significant (p = 0.657).

CONCLUSIONS

Monopolar radiosurgery is a novel method for strabismus surgery and provides equivalent hemostasis effects and wound healing properties, compared with conventional methods, and enhances surgeon comfort, as muscle incisions are made in one step with clean surgical area.