Comparative Study On The Preservation Of Rabbit Cornea By Glycerol And Silicone Oil

Keratopathy is one of the main blinding Ophthalmopathies in the world,corneal scars and turbidity can affect visual acuity for a variety of reasons,corneal transplantation is an important method for the treatment of this kind of keratopathy.The key to the success of corneal transplantation is to provide high quality corneal graft at any time,there are two methods of preservation of corneal graft,respectively active and inactive,inactive preservation is to remove the moisture of corneal and inhibit the activity of enzymes and autolysis.Common conservative agent are glycerol and molecular sieves.But the corneal graft is hard after dehydration and severely edema after rehydration,which make it difficult and time-consuming to dissection during operation.Poor corneal transparency and astigmatism caused by uneven interlayer scar and implant sectioning restrict the application.Silicone oil is a common filler for posterior segment surgery.It has the advantages of stable nature and low toxicity.It is insoluble in water and not hydrophilia.As a preservative agent of corneal graft,it can play a role in isolating the external environment.Now we are wondering about whether the corneal graft preserved by silicone oil conforms to the requirements for lamellar transplantation or not and trying to figure out advantages and disadvantages of these two methods.ObjectiveIn order to explore the feasibility of preserving rabbit cornea by silicone oil and compare the advantages and disadvantages between the glycerol and silicone oil preservative methods.Method30 healthy rabbits are executed by air embolism in auricular vein and extracted eyes balls immediately to make corneal grafts.30 corneal grafts conserved in silicone oil are experimental group,while 30 corneal grafts conserved in glycerol are control group.Observe the transparency of the rabbit corneas preserved by two methods.Observe routine HE staining sections of corneal grafts in 1 week?1month and 3months respectively.Detect bacterial growth in two kinds of preservative agents and measure central corneal thickness of grafts.Result1.In 1 week,both the glycerol group and the silicone oil group(30 each)were transparent,without cracks or rupture.In 1month,the glycerol group(30)were all transparent,2 of the silicone oil group were translucent,and the remaining(28)were transparent,without crack or rupture.In 3 month,the glycerol group(30)were all transparent,5 of the silicone oil group were translucent,and the remaining(25)were transparent,without crack or rupture.2.The routine HE staining sections showed that,the collagen fiber bundles in the glycerol group and silicone oil group were arranged in layers,and the diameter was homogeneous in 1 week.There were parenchymal cells in the parenchyma,and no shrinkage was found in the cells.In 1 month,a small amount of corneal parenchymal cells in the parenchymal layer,and some cells were crumpled.In 3 month,the glycerol group were mild swelling,there were no corneal parenchyma cells in the parenchymal layer.The collagenous fiber bundles in the silicone oil group are closely arranged.3.No bacterial growth was found in 1 weeks,1month,and 3 month by bacteriological tests.Objective4.The difference of central corneal thickness before and after cleaning in glycerol group and silicone oil group was statistically analyzed.The change of central corneal thickness in glycerol group and silicone oil group was different between 1 week and 1 month.The change of glycerol group was more than that of silicone oil group.Conclusion1.Rabbit corneal grafts preserved in silicone oil meet the basic requirements of lamellar keratoplasty.2.In short term(within 1month),the corneal grafts preserved in silicone oil are lighter edema than these preserved in glycerol after rehydration,and the thickness is closer to the fresh graft.