An Experimental Study Of Absorbable Scleral Buckling Materials

Retinal detachment (RD) is one of the important causes of blindness. Surgery is the necessary treatment of retinal detachment. Conventional buckling surgery is an effective surgical approach, especially for rhegmatogenous retinal detachments (RRD). Commercially available implants used for scleral buckling in the treatment of retinal detachment are mainly made of nonabsorbable materials, such as silicon rubber, silicon sponge. However, when nonabsorbable materials are used, there is always a risk of long-term complications, such as extrusion, infection or extraocular muscle imbalance causing diplopia. So people have focused on the absorbable scleral buckling materials.The polycaprolactone (PCL) used for scleral buckling in the study is a kind of absorbable material with good biological compatibility. The melting point is 59°C～64°C. PCL is flexible and easy to process. PCL has been studying as implant materials. In the current experiment we evaluated the feasibility of PCL as scleral buckling materials.PurposeTo evaluate the feasibility of PCL used for scleral buckling implants.Materials and methods Twenty-four healthy pigmented rabbits(1.5～2.0 kg) were chosen and divided into 4 groups at random, group A, group B, group C and group D. Each group had 6 rabbits. The left eye of each group had PCL implants, the right eye had silicon sponge as control. The implants were sutured episclerally. The sutures were fastened to moderate tightness. Group A, group B, group C and group D examined 4 weeks, 8 weeks, 12 weeks, 16 weeks after surgery respectively. The buckle heights created by absorbable implants were measured with B-scan and the eyeballs were enucleated for macroscopic and histopathological examinations to evaluate the tissue reactions at the same time. After 4 weeks, 8 weeks, 12 weeks, 16 weeks, weight lose, molecular weight were measured to observe the biodegradation of PCL.ResultsThere were no complications, such as infection, extrusion during the study. B-scan demonstrated the amount of buckle height postoperation was almost not changed during the study. The amounts of lymphocytes had no statistical differences between experimental eyes and controlled eyes in 4 groups(P>0. 05). There were no differences between group A and group B(P>0. 05). The weight lose of PCL had no obvious changes 16 weeks after surgery. The molecular weight was decreased by 16.49%.ConclusionsThe buckle height created by PCL buckling implants lasted for the whole follow-up period of 16 weeks. The sufficient buckle height is useful to reattachment of the retina. PCL showed good biocompatibility in rabbits. Compared with silicon sponge, tissue reactions of PCL implants were mild, the reaction had not increased in the study. The weight lose of PCL had no obvious changes, the molecular weight had decreased during the study.