Clinical Observation Of A Different Mode Of Administration Of Vitamin C And Dexamethasone On Corneal Alkali Burns

Objective:To compare self-made vitamin C or Dexamethasone medicine cotton placed in conjunctival sac with normal eye-drops,and to observe the effect of different administrations of same drug and same administration of different drugs for corneal alkali burn in rabbits .Methods:Thirty-two adult rabbits were choosen to establish alkali burn models of right eyes,and were randomly divided into four experimental groups: groupA,groupB, groupC and groupD,every group had eight rabbits.Group A using vitamin C eye-drops combining subconjunctival Dexamethasone ,in group B, vitamin C eye-drops replacing with cotton placed in conjunctival sac; group C using Dexamethasone eye-drops combining subconjunctival vitamin C ,in group D,Dexamethasone eye-drops replacing with cotton placed in conjunctival sac. Corneal surface were stained by Fluorescein Natrici at hours 0,24,48 after alkali burn. Repair rates of corneal epithelium were determined. Pathological specimens were made to observe the differences under light and electron microscopes at different stages.Results:1.The repair rates of corneal epithelium :The corneal epithelium gradually repaired with time process. The repair rates of corneal epithelium at hour 24 in group B (0.4575±0.03284)was better than group A(0.4313±0.03643), group D (0.3313±0.03643)was higher than group C(0.2900±0.01852), and group A was superior to group D. The differences of all group have significant meaning (P<0.05). At hour 48 , the corneal epithelium repair rate of group B(0.9863±0.01768)was the best of all, while group C(0.8363±0.03204)was the worst,group A(0.9163±0.02264) or group D(0.9125±0.02816)lay between the above two groups,and group A and D have no statistical difference(P>0.05).2. Observation by light microscope :At 1 week after corneal alkali burn ,the corneal epithelial cells of group B were repaired well with 2-3 layers, While in group C corneal epithelium cells were about 1-2 layers,and lots of epithelium cells deletion. The changes of group A or D lay between the above two groups.At 3 weeks, the stromal collagen fiber of group B was regular ,comparing with that of group A and group D,while group C was disorder.Group B had the least inflammatory cells, while group C had the most of all.3.Observation by transmissing electron micoscope:At 3 weeks after alkali burn,group B had more desmosomes, and was rich in mitochondria, endoplasmic reticulum and ribosome. Group C had no desmosome and had more vacuolization of mitochondria and fat droplet.Group A and D had less desmosomes and minor amount of vacuolization of mitochondria and fat droplet.Conclusions:1.Effect of self-made vitamin C or dexamethasone medicine cotton placed in conjunctival sac in corneal alkali burns of rabbits is superior to eye-drops,and the method is convenient and feasible. 2.In group B, vitamin C medicine cotton placed in conjunctival sac combining subconjunctival Dexamethasone was the best means for corneal alkali burn,while Dexamethasone eye-drops combining subconjunctival vitamin C was the worst, the changes in Group A and D lay between the above two groups.3.Medicine cotton as carrier placed in conjunctival sac was efficient for the treatment of corneal alkali burn, it could be recommended for the treatment of other ocular surface diseases.