One hundred seventy-three patients ( 173 eyes involved ) who were diagnosed as recurrent HSK definitely , including stromal keratitis and corneal endotheliitis , were divided into three groups randomly : negative control ( placebo ) group was topically administered with 0.15 % GCV ophthalmic gel , 4 times per day and 0.1 % fluorometholone eye drops , 3 times per day until resolution of HSK ; positive control acyclovir ( ACV ) group was topically adopted the same ophthalmic gel and eye drops and additionally received oral ACV 400 mg 5 times a day for 10 weeks and followed by 400 mg 2 times per day for 6 months ; test GCV group was topically adopted the same treatment as negative control group and additionally received oral GCV 1000 mg 3 times per day for 8 weeks .