Application of sustained delivery microsphere of cyclosporine A for preventing posterior capsular opacification in rabbits

AIM: To explore the inhibitory effect of a sustained cyclosporin A (CsA) delivery microsphere (CsA-MS) on posterior capsular opacification (PCO) in rabbit eyes after cataract extraction. METHODS: Twenty New Zealand white rabbits accepted cataract extraction plus intraocularlens implantation and their left eyes were intraoperatively injected CsA-MS prepared using polymer polylactiogly colic acid (PLGA) as a carrier and their right eyes were injected with empty MS. The changes in cornea, anterior cham ber reaction, intraocular pressure, PCO and CsA concentration in aqueous hum or were exam ined postoperatively and all the eyes were enucleated 3 months after surgery for histopathological and morphological exam ination with light microscopy and electron microscopy. RESULTS: Conjunctival hyperemia, corneal edema, intraocular pressure and anterior chamber response of experim ental and control eyes were similar, while PCO in CsA-MS injected eyes was greatly improved compared with that in control eyes. Posterior capsules in CsA-MS injected eyes were smooth and lens epithelial cells (LEC) did not proliferate significantly (P>0.05), while LEC in posterior capsule of control eyes had different degrees of proliferation and cortical regeneration. LEC in CsA-MS injected eyes were not functionally active and underwent apoptosis, whereas LEC in control eyes were functionally active (F-test, P = 0.025). In addition, the corneal ultrastructure showed no differences between CsA-MS and MS injected ey es. CONCLUSION: CsA-MS has high bioavailability in rabbit eyes and could inhibit postoperative PCO occurrence and development during the study period, suggesting that CsA-MS may be a promising, effective and safe adm inistration route to prevent PCO in clinic. Copyright International Journal of Ophthalmology Press.