Disclosed herein is a composition comprising at least 0.1% w/v 2-amino-9-[[(1S,2R)-1,2-bis(hydroxymethyl)cyclopropyl]methyl]-1,9-dihydro-6H-Purin-6-one (A-5021) as depicted in formula I and at least 20% w/v of a cyclodextrin. Also disclosed is the use thereof as an ophthalmic solution for the diagnosis and treatment of herpetic eye infections in companion animals.