Experimental Study Of Intraocular Injection Of Terbinafine In The Treatment Of Exogenous Fungal Endophthalmitis

Exogenous fungal endophthalmitis is a severe complication of penetrating wounds of the eye and ocular surgery, it rapidly damaged precise histology of eye . If we didn't apply the effective treatment, it often defered to the poor prognosis and enucleation is eventually required because of severe inflammation. And to overcome the blood-retinal barrier ,which prevents diffusion of drug into the vitreous. Therefore, the treatment of Exogenous fungal endophthalmitis is a knotty problem from begin to end. Intravitreal injection and Pars plana vitrectomy is the most effective treatment. Pars plana vitrectomy in the globe eye led to the severe complication of retinal detachment and introcular hemorrhage. According to the shortage of Pars plana vitrectomy ,we want to study if intravitreal injection of terbinafine by the animal experiment can treat Exogenous fungal endophthalmitis modle. To investigate feasibility of intravitreal injection of terbinafine, it is not reported before.Purpose: This study was to inject terbinafine intravitreously into the rabbit eye and observe the retinal toxicity andinvestigate the safe dose of intravitreal injection. Retinal toxicity was examined by electroretinogram, transmission electron microscopy, light mictoscope. And to evaluate the effect treatment intraocular injection of terbinafine in the exogenous fungal endophthalmitis.Methods: After twenty New Zealand white rabbits, Five rabbits each were randomly assigned to one of four groups and one eye of each rabbit was experimental eye, the other is contrast eye .1-4 groups received intravitreal injection of a single dose of terbinafine rangingfrom 10 to 250ug respectively ; the contrast eyes were injected with sterile water (0.1ml) at the position .The rabbits were all followed from 3 days to 14 days, and in this period all eyes were examined with slit-lampbiomicroscopy,indirectophthalmoscope ,electroretinography .After two weeks , the animals were killed and the eyes enucleated transmission electron microscopy and light mictoscope were performed. The other sixteen New Zealand white rabbits were divided at random into 4 groups :a normal control group and 3 groups were the experimental group that were made. Aspergillus fungal endophthalmitis; the contral group wasn't any treat. After treatment , all eyes were examinedwithslit-lampbiomicroscopy, indirectophthalmoscope , B-scan . After two weeks , the animals were killed and the eyes enucleated .Light mictoscope were performed.Results: Terbinafine concentration of 10～25ug didn'tproduce inflammatory response and retinal toxicity in the eyes. 50ug terbinafine caused mild inflammatory response in the vitreous without retinal histological changes , while the concentration caused a reversible decrease in the ERG b-wave. 250ug of terbinafine caused severe inflammatory response with retinal histological and elecoretingraphic changes. In safty dosage early application of intravitreal injection of 25ug terbinafine in the treatment of exogenous fungal endophthalmitis had some the effect treatment .Conclusion : 1. 10～25ug of terbinafine are safe to retina and others structures in the eyes without any toxicity .2. Early application of intravitreal injection of 25ug terbinafine in the treatment of exogenous fungal endophthalmitis had some the effect treatment .