Different Frequency Of Vitamin C And Efficacy Of Additional Subconjunctival Vitamin C Injections At Night On Early Alkali-Burned Rabbit Cornea

Objective:This study is to evaluate the efficacy of conventional frequency vitamin C point eyejoint night with high fre and additional subconjunctival injection of vitamin C at night on earlystage of corneal alkali burn in rabbits.Methods:Twenty-four adult rabbits were randomlydivided into four experimental groups: groupA,groupB, groupC and groupD.Every group had sixrabbits.They were choosen to establish alkali burn models with their right eyes. The rabbitsingroup A were frequency eye joint by injection group forged at night; Group B, were Highfrequency in the day with additional subconjunctival injection of vitamin C at night; Group Cwere drug in the day only; group D were conventional frequency vitamin C point eye joint nightwith high frequency forged injected vitamin C point eye joint night. Corneal fluorescein stainingwas performed at different stages after alkali burn 30min, 1, 3, 5, 7 and 14 days, and the recoveryof corneal epithelium were evaluated and its pH measured. Samples collected at each time pointswere analysed by microscopy. Pathological specimens were observed by light and electronmicroscopes at different stages.Results:1.The repair rates of corneal epithelium:After corneal alkali burn,the corneal epithelium wasgradually repairing as time went by.The repair rates of corneal epithelium on the 1st day in groupD(0.5635±0.02462)was better than groupB(0.4054±0.01424), group Bwas higher than groupC(0.3965±0.02506), and group C was superior to groupA(0.3055±0.02066). All groups hadstatistical differences(P<0.05). On the 3rd day , the corneal epithelium repair rate of groupD(0.8881±0.03664)was the best, while group A(0.7035±0.02522)was the worst. Group B(0.8485±0.01444)or group C(0.8443±0.03255)laid between the above two groups,and theyhad no statistical differences(P>0.05).On the 7th day, except group Band C,statistical differencesexisted between two of other groups. The corneal of the 3rd day and the 7th day epitheliumrepair rate of groupDwas higher than group B andC.But group Band group Cwere superior togroup A.2.PH value of corneal:After Alkali burn the recovery of corneal organization pH after first fastslower,from the data of group B and C to see,PH recovery are almost parallel,The analysis ofvariance and q inspection,and they had no statistical differences(P>0.05),Group D werecompared with A, B and C group in 14d results after burns,the result were compared withgroupD,A,B,and the group C in 14d after burns. All groups had statistical differences(P<0.01). 3.Observation by light microscope:On the 7th day after corneal alkali burn ,the cornealepithelial cells of groupD were well repaired with 3-4 layers,and cell morphology was regular,Aligned,the stromal layer collagen fibres were rules,less inflammatory cells infiltrating；While in groupA corneal epithelium cells were about 2-3 layers.And cell morphology wasabnormal, with cells arrangement disorder.Corneal epithelium cells were about 2-4 layers ingroup Bor C ,and part of the cells arrangement was irregular.On the 21th day, compared withgroup A,B,Cand D,the stromal collagen fiber of group D was regular .However, group Acompared with B and C, inflammatory cells within the matrix of group A,it was disorder ingroupA . more Lymphocytes,PMN,Group D had the least inflammatory cells, while group Ahad the most of all. The morphological changes of group B or group Cwere between the abovetwo groups.4.Observati4.Observation by transmissing electron micoscope:On the 7th day after alkali burn,group Dhad normal cells in morphology by large,And with more desmosomes between cells, and wasrich in mitochondria,rough endoplasmic reticulum. The stromal collagen fiber in group D wasregular.However in group A, corneal epithelial cell morphology was irregular, cell gap wasbigger than normol.and without desmosome.These cells had more condensation or vacuolizationof mitochondria and fat droplet.Stroma collagen fibers in group A were irregularly arranged.group B, C were between A and D which have healed, less inflammatory cell ,corneal epitheliumbasic morphological rules epithelial cells, orderly rows, the stromal layer collagen fibres wererules. On the 21th day after alkali burn , group D had normal cells in morphology by large,Andwith more desmosomes between cells, and was rich in mitochondria,rough endoplasmicreticulum,Golgi complexes and chromatin. The stromal collagen fiber in group D was regular.Group A of vcorneal epithelium uneven, Epithelium has more fractures. These cells had morecondensation or vacuolization of mitochondria and fat droplet. The corneal epithelial cells ofgroupB,Cwere collagen fibres were relatively tidy, inflammatory cells in a point eye group wereobviously reduced. The former stromal layer inflammatory cell than the latter light, collagenfibres were relatively tidy.They had less desmosomes and fat droplet.Conclusions:1. Day treatment with additional subconjunctival vitamin C injection at night has exertedbetter efficacy on alkali-burned rabbit cornea.2. High frequency in the day with additional subconjunctival injection of vitamin C at nighthas a better therapeutic effect to rabbit cornea alkali burns.